Food Chemistry
Mozhgan Akbari; Reza Farhoosh; M. Moeenfard
Abstract
IntroductionToday, many edible oils such as palms, corn, soybeans and sunflowers are used in food preparation. Essential oleic, linoleic and linolenic fatty acids, found abundantly in olive, sunflower and soybean oils, respectively, play an important role in maintaining health. Antioxidant compounds ...
Read More
IntroductionToday, many edible oils such as palms, corn, soybeans and sunflowers are used in food preparation. Essential oleic, linoleic and linolenic fatty acids, found abundantly in olive, sunflower and soybean oils, respectively, play an important role in maintaining health. Antioxidant compounds are used to increase the shelf life of oils, which are classified into two groups of natural and synthetic antioxidants based on the source of production. Phenolic acids are a subset of a large group of phenolic compounds that are used as natural antioxidants in industry. Gallic acid is much stronger than protocatchuic acid due to its three hydroxyl groups. However, the presence of more than three hydroxyl groups does not seem to increase the antioxidant effect in oily systems. The position of the hydroxyl group on the aromatic ring also affects the antioxidant activity, so that the replacement of the hydroxyl group in the ortho and para position increases the antioxidant activity of phenolic acids. Methyl gallate, which is widely found in plants and polyphenolic secondary metabolites, is a natural antioxidant. Despite efforts to date, no suitable natural antioxidant has been proposed to control the thermal oxidation of oils at high temperatures. Therefore, due to the widespread use of oils in food, the thermal stability of natural antioxidants gallic acid and methyl-gallate compared to the powerful but synthetic antioxidant TBHQ, depending on the degree of satiety of the lipid system (sunflower oil and olive oil) and 80 degrees Celsius will be evaluated in this study. Material and MethodsSamples of sunflower and olive oil were purchased from local stores. All chemicals and solvents were provided by Merck and Charlot. Sunflower and olive oil were purified by column chromatography to remove natural antioxidants. Oxidation of purified sunflower oil (1 g per oil) in the presence of a concentration level of gallic acid, methyl gallate and TBHQ (1.2 μmol/g) in glass bottles. The rate of progression of oxidative reactions and the evaluation of oil quality during temperature application is possible by measuring the peroxide number. The carbonyl number is determined using 2-propanol as solvent and 2,4 decodenal as standard and absorbance at 420 nm. The effect of antioxidants (InH) on the oxidation of the test samples can be measured based on the kinetic parameters. These parameters are stability factor F, ORR oxidation rate ratio, activity A and average consumption of WInH antioxidants. Results and DiscussionThe minimum and maximum induction times are related to the control sample and the sample containing the synthetic antioxidant TBHQ, respectively, which, considering the position of the two hydroxyl groups in the para position relative to each other in the TBHQ molecule, make this antioxidant stronger. Justifies. At 80 °C and in sunflower oil, the antioxidant methyl gallate shows a more effective stability factor (F) and antioxidant activity (A), indicating greater antioxidant power than gallic acid. Similarly, F-ORR-A values in methylgalate treatment have a significant effectiveness compared to other treatments. The higher oxidative stability of olive oil against sunflower oils can be attributed to the small amounts of oleic acid and especially the small amounts of linolenic acid in olives. Stability factor (F), is significantly higher for the TBHQ antioxidant than the values obtained for the other two. This factor is affected by the induction period of antioxidants and can be expected due to the effectiveness of antioxidants in increasing the duration of the induction period. The highest value obtained for the ORR oxidation rate parameter, is related to the antioxidant gallic acid. The parameter of antioxidant activity A, in TBHQ is higher than the other two antioxidants. Measurement of carbonyl compounds resulting from the decomposition of hydroperoxides is a good measure of the rate of development of oxidative reactions. In the treatment of gallic acid and TBHQ, the changes in the carbonyl number decrease at the end of the annealing, which is probably due to the decomposition of carbonyl compounds and the production of polymer compounds. Which cannot be measured by carbonyl number test. ConclusionBetter efficacy of gallic acid compared to methyl gallate in olive oil and better efficacy of methyl gallate compared to gallic acid in sunflower oil at 80 °C show the composition of fatty acids, the nature of lipid systems and the position of antioxidants in the reaction medium. Have a great effect on improving the performance of antioxidants. Determination of oxidative stability based on carbonyl number shows similar results to peroxide number .
Food Chemistry
Maedeh Hosseinkhani Abadchi; Reza Farhoosh
Abstract
Introduction
Thermal process is the most prominent option for treating foods. During the heat treatment, food nutrients response simultaneously but adversely under pH, temperature, moisture, and other provided conditions. It might result in an irreversible transformation of composition and structure ...
Read More
Introduction
Thermal process is the most prominent option for treating foods. During the heat treatment, food nutrients response simultaneously but adversely under pH, temperature, moisture, and other provided conditions. It might result in an irreversible transformation of composition and structure that influences oxidative stability and sensory properties. The use of antioxidants is one of the most common methods to prevent edible oils oxidation. Safety concerns of synthetic antioxidants including tert-butylhydroquinone (TBHQ) as food additives have led to increasing demands for natural ones. Phenolic compounds such as Gallic Acid (GA) and Methyl Gallate (MG) represent to possess markedly high activity to scavenge free radicals which are among the most powerful natural sources of oxidative inhibitors in foods. Apart from their antioxidant activity, GA and MG also exhibit multiple biological characteristics such as anti-atherogenic, anti-spasmodic, and anti-microbial activities. This study aimed to investigate the oxidative stability of the in-use sunflower (S) and palm (P) oils as affected by the GA, MG, (GA+MG), and TBHQ to clarify their antioxidant behavior.
Materials and Methods
Antioxidants Gallic acid, Methyl gallate and TBHQ (Purity>98%) were purchased from Sigma Aldrich, USA. All solvents and chemicals were provided from Merck, Germany and Sigma Aldrich, USA with analytical grade. Antioxidant-free sunflower and palm oil were prepared from Three Goals factory, Neyshabur, and potatoes (Agria variety) from Fariman region, Khorasan Razavi.
Results and Discussion
Chemical changes, oxidative stability and quality indices of the in-use sunflower oil (S) and palm (P) (65:35 w.t. %) were evaluated during 8-hour heat treatment at 180 °C through GA, MG, GA/MG (25:75, 50:50 and 25:75) and TBHQ. All experiments were carried out in quadruplicate, and data were subjected to analysis of variance (One-way-ANOVA). Mean data were compared based on Duncan's multiple range test at 5% level (p<0.05). Observations of the chemical properties showed that sample S mainly contained Linoleic fatty acid (61.53%) and Oleic acid (25.50%) and for sample P, Oleic acid (41.90%) and the saturated long-chain fatty acid of Palmitic acid (38.9%). Also, the total phenolic content (TPC) and tocopherol (TTC) of sample P were 53.12 and 185)µg.g-1(, respectively, and sample S were 36.01 and 490 )µg.g-1(. The results of oxidation stability test were analyzed based on Carbonyl value (CV), Conjugated diene value (CDV) and acidity (FFA) parameters. According to our findings, all parameters increased significantly at different speeds during the heat treatment (p<0.05). Moreover, the oxidative stability of the in-use oil was significantly promoted by the antioxidants added, meaning that the control treatment and the treatment containing synthetic antioxidant TBHQ had the highest and lowest FFA%, respectively. The CDV of the antioxidant-free treatment was reduced by 68.6% in the presence of GA75+MG25.In addition, the CV change rate of the antioxidant-free sample in the presence of TBHQ was reduced by 70.2%. It was concluded that the natural antioxidants were capable of being competed with TBHQ antioxidants.
Conclusion
The results of this study showed that the heat treatment affected the nutritional value, quality indexes and chemical structure of the treatments, decreasing the quality and stability of the oil. As observed, all FFA, CDV and CV parameters increased significantly at different speeds during 8-hour frying process. The analysis also indicated that the oxidative stability of the treatments increased at the presence of antioxidants during the heat treatment at 180 °C. Thus, the control treatment and the treatment containing synthetic antioxidant TBHQ had the highest and lowest acidity, respectively. Also, the CDV of the antioxidant-free treatment decreased by 68.6% in the presence of GA75+ MG25. In addition, the rate of CV changes was declined by 70.2% through the TBHQ. The results indicated the key role of this synthetic antioxidant in preventing the formation of secondary compounds in the advanced stages of oxidation.
It is evident that most synthetic antioxidants are volatile and heat sensitive. Furthermore, there are some limitations in applying TBHQ to promote oxidative stability of food products due to its toxic potential. Evidences have also been reported on the mutation caused by the synthetic antioxidant TBHQ in the living organism's body. Compared to synthetic antioxidants, natural polyphenolic antioxidants such as MG and GA which widely distribute in plants mainly have antioxidative properties. Compared to GA and MG, GA+MG antioxidants have a longer induction period and higher oxidative stability. Promoting oxidative stability with such an arrangement of antioxidants is a good option in taking advantage of this class of natural antioxidants. According to the results of this study, it can be inferred that with a slight increase in natural antioxidants levels, we might be able to obtain the oxidative stability level comparable to the behavior of synthetic antioxidant TBHQ. Of course, it is worth noting that the addition of natural antioxidants to food such as edible oils should also be done according to national and international standards.
Paniz Khaloo Kermani; Marzieh Moeenfard; Reza Farhoosh; Arminda Alves
Abstract
[1]Introduction: Date seed are considered as a valuable by-product from Phoenix dactylifera L. which played an important role in the economy and social life of the people of the Middle East and North Africa region. They consist mostly of carbohydrates, fatty acids and proteins as well as phenolic compounds. ...
Read More
[1]Introduction: Date seed are considered as a valuable by-product from Phoenix dactylifera L. which played an important role in the economy and social life of the people of the Middle East and North Africa region. They consist mostly of carbohydrates, fatty acids and proteins as well as phenolic compounds. Despite the presence of various beneficial bioactive compounds, they are usually discarded or are utilized as animal fodder. Therefore, explore the effective methods to incorporate date seeds in the human diet is a great of interest. Roasting provides a low cost and easy approach to add value to these wastes as roasted date seed powder is being used in the Arabian region to make “date seed coffee”. However, along with color and aroma changes, carcinogenic substance such as acrylamide may also formed during the roasting process. To date, no data have been published on the analysis of acrylamide in the roasted date seeds and respective brews. Therefore, the objective of the present study was development of an analytical method for determination of acrylamide in various date seeds varieties and their respective moka brews for the first time. Besides, other parameters related to the roasting process such as the color parameters and melanoidins content were also determined and compared with values obtained from Arabica coffee. Materials and methods: For this purpose 5 different varieties of roasted date seeds including Shahani, Zahedi, Kabkab, Mazafati and Estamaran as well as Arabica coffee were used for coffee brewing. For acrylamide determination in solid samples, they were firstly extracted using hot deionized water. Afterwards, 5 mL of sample (extract or coffee brew) was placed in a 15 mL falcon and extraction solvents including acetonitrile (10 mL), hexane (5 mL) along with 1 g of NaCl and 4 g of MgSO4 were added. After mixing on vortex for 1 min and centrifugation (5 min, 5000 rpm), 2 mL of the supernatant was cleaned using appropriate combination of sorbents (100 mg PSA, 50 mg C18 and 50 mg SAX) along with 0.30 g of MgSO4.The cleaned supernatant was filtered and analyzed using high-performance liquid chromatography coupled with a photodiode array detector (HPLC-PDA) at 202 nm. The injection volume was 20 μL. The chromatographic separations were performed on a Eurospher 100-5 C18 column (250× 4.6 mm). Optimization was performed according to the type of organic solvent (acetonitrile and methanol), the percentage of organic solvent in the mobile phase (10, 5, 3% v/v) and the flow rate (0.1, 0.7, 0.5 mL/min). The color parameters (using photography and help of ImageJ software) and melanoidin content (spectrophotometrically at 420 nm) were also determined. Results and discussion: The results indicated that the water/acetonitrile with a ratio of 97:3 and a flow rate of 0.7 mL/min permitted the acceptable separation of the acrylamide peak from the interfering compounds. The LOD and LOQ of optimized analytical method were 9.1 and 30.62 µg/kg, respectively. The suggested HPLC/PDA method is promising for analysis in order to guarantee the quality control of acrylamide. The presence of acrylamide in all roasted date seeds was observed. Accordingly, acrylamide content in Arabica coffee (1825.23± 17.44 µg/kg) was significantly higher than those obtained from date seeds varieties. The amount of acrylamide in different types of date seeds varied from 360.99± 4.15 to 129.43± 2.37 µg/kg, being Kabkab and Mazafati as the highest and lowest values, respectively. Moka brews prepared from roasted date seeds demonstrated the presence of acrylamide in the range of 25-68 µg/L. The highest level of melanoidin were observed in Arabica coffee followed by Shahani, Zahedi, Kabkab, Mazafati and Estamaran, respectively. In the most cases, an inverse relationship was observed between the acrylamide and melanoidin content in roasted date seeds. For example, Shahani had low acrylamide and high melanoidin content. The study of color parameters revealed that the parameters a* and b* largely follow the pattern of melanoidin, so with increasing the amount of a* and b*, the amount of melanoidin also increased in the samples.
Food Chemistry
Farideh Mojrian; Marzieh Moeenfard; Reza Farhoosh; Hadi Mahdavian Mehr
Abstract
Introduction: Date seeds (also known as pits and kernel) are among the most important wastes which are generated during direct consumption or from the date processing industries. Despite the presence of several nutrients and bioactive compounds and their subsequent beneficial health effects, these by-products ...
Read More
Introduction: Date seeds (also known as pits and kernel) are among the most important wastes which are generated during direct consumption or from the date processing industries. Despite the presence of several nutrients and bioactive compounds and their subsequent beneficial health effects, these by-products are frequently discarded to use as soil fertilizer or as feed for livestock. Roasting opens a cost-effective way to include date seed in the human diet. The aqueous extract of roasted date seed represented a coffee-like beverage. Date seed coffee has a relatively low acceptance among consumers and is usually supplemented with a variety of additives to improve the taste. Therefore, due to rising the global coffee price, in the present studywe aimed to substitute Arabica beans with roasted date seeds in order to make a coffee beverage similar to Coffea Arabica boiled coffee brew. Results and Discussion: Substitution with roasted date seed resulted in lower lipids, protein and caffeine of coffee brews as the values were decreased from 330.67, 956.75, 76.51 mg/100 mL in Coffea Arabica (100%) to 192.61, 149.00, 45.59 mg/100 in date seed coffee (100%), respectively. Higher amounts of date seed also resulted in lower pH and acrylamide content. Accordingly, pH was decreased from 5.7 in D100 to 4.4 in A100. Acrylamide content was attenuated from 5.06 µg/100 mL in A100 to 1.71 µg/100 mL in D100. Reduction in viscosity was also observed from 0.93 (A100) to 0.86 mPa.s (D100). The mean value of the color parameter including L*, a* and b* in the 100% Coffea Arabica brew was more than the 100% date seed coffee, which indicated that the coffees brewed from date seeds in different proportions were brighter and had higher red and yellow color parameters. Substitution with date seed had less effect on the total phenol content as TPC of coffees ranged from 28 to 42 mg/100 mL for 100% date seeds brew and Coffea Arabica brew, respectively. On the other hand, the flavonoid content (TFC) of coffees was significantly affected by the amount of date seeds (5 to75 mg/100 mL for 100% date seeds and Coffea Arabica brew, respectively). All brews have high antioxidant activity. For DPPH the highest results (88/9 %) were obtained in the coffee brewed from 100% date seeds, while the FRAP value it was vice versa. The results of sensory evaluation indicated a high similarity among A100 and D10 coffees as parameters such as aroma, color and texture (concentration) of coffee were evaluated appropriate. The results also showed that substituting Coffea Arabica up to 35% with roasted date seeds can improve the overall acceptance of the coffee brews by reducing bitterness.Conclusion: In general, the ability to replace Coffea Arabica with date seeds up to 10 and 35% was reported acceptable in terms of sensory characteristics, as the color and aroma were similar to 100% Coffea Arabica. Besides that due to reduced bitterness, the overall acceptance were almost high.
Mohammad Reza Toorani; Reza Farhoosh; Mohammad Taghi Golmakani; Ali Sharif
Abstract
Introduction: Lipid oxidation is one of the most important factors affecting the loss of quality or the deterioration of edible oils. This reaction is accompanied by the production of harmful compounds that may threaten consumer’s health. Several parameters affect the severity of the oxidation ...
Read More
Introduction: Lipid oxidation is one of the most important factors affecting the loss of quality or the deterioration of edible oils. This reaction is accompanied by the production of harmful compounds that may threaten consumer’s health. Several parameters affect the severity of the oxidation reaction, among them temperature is one of the most important parameter to consider. Lipid oxidation increase significantly with the increase of temperature, which drastically reduces the length of the shelf life of the oils. Numerous methods have been used to postpone the oxidation of oils that one of the most useful methods is the addition of antioxidants. Nowadays, natural antioxidants have been located in the hotspot of attention from safety and sensory characteristics point of view. Sesamol as a valuable natural antioxidant may help to provide healthy edible oils. The determination of thermal kinetic data and the evaluation of thermodynamic indices have long been used to the better identify the mechanisms and the events caused by temperature elevation. Examining the temperature and time variables together and merging these components could provide valuable information about the environmental effects of foodstuffs. These parameters are particularly important for edible oils. Hence, the kinetic-thermal information of the oils oxidation in the presence of sesamol may provide the valuable assistance in explaining the storage conditions of various edible oils in the presence of this antioxidant. Materials and methods: The sesamol's ability to quench free radicals was determined by DPPH test and at 517 nm. The oil purification process was performed by adsorption column chromatography in order to eliminate minor components that may be interfere with the oxidation reaction. The evaluation of the accelerated oxidation process in presence of sesamol was carried out in a dry oven and through monitoring the accumulation of hydroperoxides (peroxide value) over time at 60, 80 and 100 °C. The peroxide value was measured spectrophotometrically at 500 nm. The induction period of oils oxidation was determined through two lines fitted on initiation and propagation steps of the oxidation curve. The rate constants of the oils oxidation and sesamol consumption, the peroxide value corresponding to the length of induction period (PVIP), the minimum sesamol concentration to demonstrate the antioxidant activity and the oxidative stability time of lipid systems at ambient temperature were also determined by oxidation kinetic data. Results and discussions: The results of inhibitory test showed that the amount of sesamol required to inhibit 50 percent of the DPPH radicals is equal to 1 mM. The induction period of olive oil has reached to over 520 h in presence of 0.01% sesamol at 60 °C, whereas sesame and canola oils were placed in the subsequent positions with nearly 330 and 325 h, respectively. The average extent of PVIP (all sesamol concentrations) for two lipid systems i.e. sesame and canola oils was close to each other and drastically higher from olive oil. This delocalization of the numbers suggests that the PVIP is independent of the antioxidant concentration available and is affected by the fatty acids structure of oils. The effect of temperature elevation on the rate constant of oxidation for different oils did not follow the same pattern, so that the slope of increase of the rate constant for olive oil was very mild than to the other two oils. The results showed that the increase in temperature has markedly increased the rate of sesamol consumption, so that unsaturated lipid systems have undergone significant changes in this regard. Increasing the temperature increased the minimum concentration required for the antioxidant activity of sesamol. This pattern was linear for olive oil and hyperbolic for sesame and canola oils.
Seyed Hassan Jalili; Reza Farhoosh; Arash Koocheki; Abbas Ali Motallebi
Abstract
Introduction: Considerable amounts of essential fatty acids in fish oil makes it possible to use in the production of functional foods to meet nutritional needs and beneficial effects on health. One of the major problems is their high susceptibility to oxidative deterioration and consequent production ...
Read More
Introduction: Considerable amounts of essential fatty acids in fish oil makes it possible to use in the production of functional foods to meet nutritional needs and beneficial effects on health. One of the major problems is their high susceptibility to oxidative deterioration and consequent production of undesirable flavor. At present, some synthetic compounds are used as antioxidants in food and biological systems, but the use of synthetic antioxidants is of concern due to their potential health hazards. Therefore, the use of natural antioxidants in foods is the first choice. Enzymatic protein hydrolysis has been applied to food industry by-products to produce foods with enhanced functional properties. Antioxidant and antiradical activity of protein hydrolysates from meat, skin, bone, viscera and roes of various aquatic species has been reported. Silver carp (Hypophthalmichthys molitrix) skin (SCS), as low price by-product from minced products processing plants is available in I.R. Iran. Amino acids composition and sequencing determines the functional properties of peptides, which depends on the source of protein, the method and conditions of preparation and molecular weight distribution of resulting hydrolysate. The enzyme type and hydrolysis conditions, including enzyme/substrate ratio, temperature, time and pH, can affect the peptides length and functional properties of protein hydrolysates. The effects of hydrolysate from SCS hydrolyzed by alcalase on some quality features and oxidative stability of microencapsulated Kilka (Clupeonella spp.) oil at pH 6.8 and 3.4 were investigated. Materials and methods: SCS was pre-treated with NaOH and acetic acid, washed and freeze dried. Proteolysis with alcalase (1% w/w) at 50 ºC, without pH adjustment, was performed for 4 hours with gentle stirring. Enzyme inactivated by placing the sample in a boiling water bath for 15 minutes. After centrifugation at 13000 g for 20 minutes, supernatant was removed as silver carp skin hydrolysate (SCSH) and freez dried. Emulsions were prepared with 31.25% dry material. 25% of wall materials (equal proportions of maltodextrin and Hi-Cap®100), fish oil 25% and SCSH (for preparing 1, 2, 3, 4 and 5 mg/mL treatments) in two adjusted pH 3.4 and 6.8, was used. Fish oil was refined using multi-layered column chromatography (alumina-silica gel), and fatty acid composition was determined. The emulsion pre-homogenized by the IKA Ultra-turrax at 15,000 rpm for 2 minutes and finally by a HSTO homogenizer at 350 bar for 5 circle, to produce microemulsion. Effects of treatments on the characteristics and oxidative stability of microencapsulated Kilka oil for 28 days in the dark at 45 ºC were compared by determination of surface oil, microencapsulation efficiency, free oil, emulsion stability (%separation), droplet size, optical microscopic observation of morphology and peroxidation stability. Results & discussion: Results showed significant differences between proximate composition of silver carp skin, before and after pre-treatment and revealed that applied method and conditions reduced the amounts of oil and ash to an acceptable level. No aggregation and cluster formation was observed in optical microscopic images of prepared emulsions. The effects of pH on the droplet size and microencapsulation efficiency were insignificant (p> 0.05), but the amount of free oil and emulsion stability were significant at ≥2 mg/mL concentrations of hydrolysate (p<0.05). Peptides effectively retarded the preoxidation of Kilka oil in the model system. Hydrolysate antioxidant power was dose dependent. Peroxidation trends were nonlinear for control and 1-4 mg/mL treatments. These trends continued linearly, with mild slope for 5 mg/mL, and was similar for 2 pH during 28 days. Hydrolysate of SCS may be used as a natural antioxidant for the production of stable microencapsulated fish oil for the enrichment of various kinds of beverages with a wide range of pH.
Olga Azimi; Mohebbat Mohebbi; Reza Farhoosh; Mahdi Saadatmand-Tarzjan
Abstract
Discerning the expiration status (non-rejected and rejected) of edible vegetable oils is very significant because of the hazardous primary and secondary oxidation products. Therefore, it is of outmost importance to monitor the quality and safety of these oils. Based on previous literature, reports and ...
Read More
Discerning the expiration status (non-rejected and rejected) of edible vegetable oils is very significant because of the hazardous primary and secondary oxidation products. Therefore, it is of outmost importance to monitor the quality and safety of these oils. Based on previous literature, reports and experimental observation, the oil color changes during oxidation. Thus, the present study investigates the use of image processing and linear discriminant analysis (LDA) for the classification of non-rejected and rejected edible vegetable oils during oxidation process at 85°C, with respect to the induced period in both primary and secondary oxidation of four oil type (Olive, Sunflower, Palm and Soybean). The purpose of this study was to find less costly and quicker methods with environmental protection, by using the color spaces (RGB, HSI, L*a*b* with Grayscale) instead of chemical analyses to determine the expiration status of edible vegetable oils. Results of this study indicated that the best classification for expiration status of known oils according to induced period of peroxide value in each color space, was achieved with LDA model were for palm with 100% (HSI and Grayscale), olive with 84.61% (L*a*b* and RGB), soybean with 95% (Grayscale) and sunflower with 100% (RGB and HSI), also in induced period of carbonyl value test, the best classification performance was achieved in palm with 100% (L*a*b*), olive with 100% (L*a*b*), soybean with 89.47% and sunflower with 95% (HSI).
Fatemeh Habibi Nodeh; Reza Farhoosh; Ali Sharif
Abstract
Introduction: Frying is one of the oldest and popular preparation techniques broadly used at home and food industry. High temperatures plus the presence of air as well as the water from the food being fried cause many destructive reactions. Therefore, thermal stability and performance of oil during frying ...
Read More
Introduction: Frying is one of the oldest and popular preparation techniques broadly used at home and food industry. High temperatures plus the presence of air as well as the water from the food being fried cause many destructive reactions. Therefore, thermal stability and performance of oil during frying is considered as one of the important criteria in the selection of frying oil. In this regard, balanced chemical composition, presents it as a valuable option for frying purposes. Studies show lipid autoxidation considered as the most important deteriorative reaction in the olive oil. This reaction leads to the formation of a series of primary and secondary oxidation products. Hydroperoxides are the primary oxidation products of lipid oxidation. Carbonyl value (CV) does measure secondary decomposition products are more stable than peroxides and the CV seems to be a good index of oxidative changes in lipids. Therefore, the determination of carbonyl compounds in frying oils is very important for evaluating the quality of frying fats and oils. Several studies have been carried out on the oxidative stability of edible oil during frying. Rancimat test has also been considered among the accelerated methods of lipid oxidation measurement due to ease of use and reproducibility. However, although estimate of oxidative stability of edible oil according to accelerated methods, is used widely but there is always worries about accordance the results of such tests with the results found under real frying conditions and Presence of food. Therefore, necessity of simultaneous study oxidative stability is essential in order to justify and extension of result together during heating and frying.
Materials and methods: Six refined olive oil samples of different brands in 1 lit glass bottles were purchased from local shops and were stored at 4 ºC for further analysis. Fatty acid methyl ester (FAME) standards, and all chemicals and solvents used in this study were of analytical reagent grade and supplied by Merck and Sigma Chemical Companies. The ratio between monounsaturated and polyunsaturated fatty acids (M/P) was determined by gas–liquid chromatography. The spectrophotometric method was used to determine the PV. The AV was determined according to the AOCS. The TT content was determined according to the colorimetric method. The TP content was determined spectrophotometrically using Folin–Ciocalteau’s reagent. The CV of the oils was measured using 2-propanol and 2,4-decadienal as solvent and standard, respectively. A Metrohm Rancimat model 743 (Herisau, Switzerland) was used to measure the OSI and IPCV of olive oil samples. Frying process was performed in bench- top deep- fryer at 180ºC. ANOVA and regression analyses were performed according to the MATLAB and Excel software. Significant differences between means were determined by Duncan’s multiple range tests.
Results and discussion: There was good correlation between the OSI and induction period (IPcv) at the temperature range studied with a high determination coefficient (R2>0.99) in the Rancimat test. Generally, the results of the present study showed that the Rancimat method at 110 ºC correlated well with stability under frying condition and this correlation decreased as temperature increased in the Rancimat test. These observations can be explained by the fact that steps or pathway of chemical reactions that take place at low and high temperatures are different. Thus, choosing the right levels of operational parameters in the Rancimat method can produce the least possible difference between frying and the OSI test.
Azadeh Mardani Ghahfarokhi; Reza Farhoosh; Ali Sharif
Abstract
Introduction: Hydroxybenzoic acids are a large family of phenolic acids capable of inhibiting one of the most destructive reactions called lipid oxidation. Their antioxidant activities are markedly influenced by the number and position of phenolic OH groups. Increasing the number of electron-donating ...
Read More
Introduction: Hydroxybenzoic acids are a large family of phenolic acids capable of inhibiting one of the most destructive reactions called lipid oxidation. Their antioxidant activities are markedly influenced by the number and position of phenolic OH groups. Increasing the number of electron-donating groups in the molecule and their placement at the ortho and/or para positions of the phenolic ring, could lead to the increased ability of H atom abstraction or electron donating capacity. Gentisic (3,5-dihydroxybenzoic acid) and Alpha-resoecylic (2,5-dihydroxybenzoic acid) acids are dihydroxybenzoic acids wildly dispersed in the plant tissues with some valuable biological and pharmacological properties for human health. These compounds are different in structure and position of hydroxyl groups in phenolic ring, that may had a strong influence on their antioxidant properties. In addition of structural property, environmental interference can play an important role in the antioxidant potency. Antioxidants are found to behave differently when used in different media.
Materials and methods: Partition coefficient (log P) of Gentisic acid and Alpha-resorcylic acid was measured between 1-octanol and acetate buffers. Antiradical and antioxidant activity of compounds was investigated in different medium (solvent system, purified bulk olive and soybean oils and their O/W emulsions). DPPH radical scavenging activity of gentisic acid and alpha-resorcylic acid was measured in the methanolic solvent. Progress of lipid oxidation in olive oil and soybean oil containing 200 ppm of the antioxidants at 80 oC was followed by monitoring the changes in peroxide value (PV). PV was measured spectrophotometrically at 500 nm using a UV– Vis instrument. Oxygen depletion in emulsion systems in the absence and present of the antioxidant (200 ppm) was measured using a YSI Model 5300A biological oxygen monitor at 37oC. The effectiveness of the antioxidants in bulk oils and emulsions was estimated on the basis of the induction period (IP).
Results and discussion: The obtained results indicated that the effectiveness of the Gentisic and - resorcylic acids in free radicals scavenging, was greatly affected by molecular structure of these antioxidants and environmental conditions.
Ortho position of hydroxyl group with respect to the carboxyl group in Gentisic acid, caused higher antiradical potency of Gentisic acid than α-resorcylic acid, with meta-structure, in different used mediums.
In addition, it was found that the environment plays an important role in the free radical scavenging activity of phenolic compounds. Gentisic acid with more hydrophilic structure showed better antioxidant activity in bulk oil hydrophobic systems, than emulsion systems, while -resorcylic acid with less hydrophilic structure showed better activity in O/W emulsions. Both antioxidants showed low antioxidant performance in solvent system. The polar medium of the methanol used in DPPH assay, with enhanced intermolecular hydrogen bonds, decreased the radical scavenging potency of antioxidants.
Olga Azimi; Reza Farhoosh; Mohebbat Mohebbi; Mahdi Saadatmand
Abstract
Introduction: Discerning the expiration status (rancid and non-rancid) of edible vegetable oils is very significant because of hazardous primary and secondary oxidation products. Oils are a nutritious and valuable food source which play an important role not only in supplying energy but also in sustaining ...
Read More
Introduction: Discerning the expiration status (rancid and non-rancid) of edible vegetable oils is very significant because of hazardous primary and secondary oxidation products. Oils are a nutritious and valuable food source which play an important role not only in supplying energy but also in sustaining a health. Edible vegetable oils such as soya, sunflower, canola, sesame and olive, bring essential nutrient components for human being such as vitamins, fatty acids, and micronutrients, which are necessary for daily life. Lipid oxidation in vegetable oils is associated with unsaturation of the oils. This reaction leads to the formation of a series of intermediate compounds named hydroperoxides. Hydroperoxides are the primary oxidation products of lipid oxidation. Due to the unstable nature of these primary products which leads to their decomposition and turning into secondary oxidation products, such as carbonyl compounds occur soon.
The use of expired edible oils leads to a decrease in the nutrition value and an increase in potential hazards to people's health, so monitoring the quality and security of edible oils is important. Based on the reports and experimental observation the oil color changed during oxidation. Therefore, it is of utmost importance to find new and fast methods for detecting the quality of oils. Computer vision in food sciences is an affordable technology and is extensively used. The aim of this study was to introduce a simple and feasible method for classifying edible vegetable oils (soya, sunflower, canola, sesame and olive) and also for distinguishing their quality in terms of rancidity. In order to achieve this, multivariate statistical methods based on their rejection point of primary and secondary oxidation products was implemented.
Materials and methods: Digital camera and unsupervised multivariate statistical techniques such as linear discriminant analysis (LDA) and principal component analysis (PCA) were used for pattern recognition and classification. In this study, the physicochemical characterization of 77 oil samples includes their peroxide and carbonyl values were evaluated at 80 ◦C. The color indices L*a*b* were used for this classification. The space that was built for imaging was 120cm ×90cm ×90cm with dark walls to isolate the samples from external light. The compartment has a camera (Canon model, EOS 1000D), which was connected to computer by USB port. The illumination of the compartment was performed by using eight fluorescent lamps with 8 W (white color), the lamps were placed at a distance of 20 cm from the samples. The illustration was performed by Zoombrower EX 0.5, the other characteristics of the camera for imaging were as follow: flash (off), zoom (on), Iso speed (100), Aperture priority (F / 20) and Shutter speed (0.6 Sec). The illumination condition at compartment for each sample was the same. Image color analysis was performed using the Image j (Version: 1.4.3.67) software to convert images from R*G*B color space to L*a*b. The recorded images contained 24-bit (16.7 million colors) and 3888 pixels × 2592 pixels spatial resolution and were stored in JPEG format (jpg). A specific region at the center of each image was selected for converting R*G*B to L*a*b. In this study, three components of color space L*a*b* were extracted from 231 images samples ( 77 images of different types of oil before heating, 77 images at the rejection point based on peroxide value and 77 images on the rejection point based on carbonyl value). The extracted color values were used for linear discriminant analysis classification and principal component analysis. The classification was performed using MATLAB (R2013) software
Results & Discussion: The comparison of the results of the linear discriminant analysis showed that distinguishability between the two types of different oils was 100% and only the distinguishing of one oil type in rancid and non-rancid state resulted in a decrease in accuracy to 97%. Also the overall and simultaneous analysis of oil samples in both states (rancid and non-rancid) by the two classifiers of LDA and PCA showed that the classification of each oil individually has the highest accuracy (100%) and the results of the studying several different oils showed a decreased accuracy (98% and 96%). However, in practice, the result of this classification given the diverse colour range of vegetable oils, is acceptable in terms of accuracy and the linear discriminant analysis classifier acted more successfully compared to principal component analysis classifier by about 40%.
Soudabeh Einafshar; Hashem Pourazerang; Reza Farhoosh; Javad Asili
Abstract
Natural materials are complicated compositions; therefore, a rapid screening of the active antioxidants is being challenged in the literature. Different polarity solvents were applied to isolate four fractions (F1, F2, F3 and F4) of methanolic extract of Cuminum cyminum. Their anti-oxidative properties ...
Read More
Natural materials are complicated compositions; therefore, a rapid screening of the active antioxidants is being challenged in the literature. Different polarity solvents were applied to isolate four fractions (F1, F2, F3 and F4) of methanolic extract of Cuminum cyminum. Their anti-oxidative properties were tested using radical scavenging and FRAP assays. F3 (with IC50=0.006mg/mL and FRAP= 521.95 mmolFe2+/L) was significantly the most active fraction. Guided isolation through bio-autography on TLC using 1, 1- diphenyl- 2 – picryl- hydrazyl radical (DPPH) as a detection reagent led to the isolation of two antioxidant compounds from F3. F3 was injected to a preparative HPLC with the proper mobile phase (acetonitril: methanol/ water) and isolated two main compounds. These compounds were identified as Luteolin 7 glugoside and Apigenin 7 glucoside by means of 1HNMR and 13CNMR and compare them with references.
Najmeh Molaahmadibahraseman; Reza Farhoosh; Ali Sharif
Abstract
Introduction: Medical benefits of Omega 3 fatty acids have appealeda lot of research to be done on of fish oil. Among marine fish, kilka has the most industrial application. Kilka oil contains significant amount of omega-3 fatty acids. In this study, physiochemical properties, fatty acid composition ...
Read More
Introduction: Medical benefits of Omega 3 fatty acids have appealeda lot of research to be done on of fish oil. Among marine fish, kilka has the most industrial application. Kilka oil contains significant amount of omega-3 fatty acids. In this study, physiochemical properties, fatty acid composition and stabilization of kilka oil were investigated. p- hydroxy benzoic asid, its methyl ester and alpha-tocopherol as control were compared to each other.Materials and Methods: Crude Kilka fish oil was supplied by Khazarcompany (Babolsar, Iran). All chemicals and solvents used in this study were of analytical reagent grade and purchased from Merck (Darmstadt, Germany) and Sigma–Aldrich (St. Louis, MO). 200 ppm of the mentioned antioxidants was added to the purified oil and kinetic regime of oxidation at temperatures of 35, 45 and 55°C was prepared. After monitoring theoxidation over time using peroxide test, graph of peroxide changes over time was plotted and induction period and kinetic parameters (F, ORR and A) were calculated. In order to compare the performance of antioxidants in oil and water, 10% emulsion of Kilka oil-in-water was prepared and 200 ppm of antioxidant was added to it and its oxidation process was monitored at 55°C.Results and Discussion: Results showed that the fatty acid composition of this oil contains a variety of unsaturated fatty acids, saturated and polyunsaturated (mainly linoleic, eicosapentaenoic and docosahexaenoic acids). Temperature had significant effect on oxidation. p-hydroxymethylbenzoate, a little more than p-hydroxybenzoic asid, could increase oxidative stability of oil. Alpha-tocopherol had better performance as compared with other antioxidants. Performance of methylp-hydroxybenzoatewas better in emulsion than oil. In general, the emulsifier and emulsion preparation as compared with antioxidant had a more prominent role in the oxidative stability of Kilka oil.
Najmeh Molaahmadibahraseman; Reza Farhoosh; Saeid Johny; Ali Sharif
Abstract
Introduction: Medical benefits of omega-3 fatty acids have led to a lot of research on fish oil. Among marine fish, Kilka has the highest industrial applications. Kilka oil contains significant amounts of omega-3 fatty acids. In the present study, oxidative stability of Kilka fish oil based on the Schaal ...
Read More
Introduction: Medical benefits of omega-3 fatty acids have led to a lot of research on fish oil. Among marine fish, Kilka has the highest industrial applications. Kilka oil contains significant amounts of omega-3 fatty acids. In the present study, oxidative stability of Kilka fish oil based on the Schaal oven test and the use of two phenolic acid derivatives (syringic and vanillic acids) was investigated.Materials and methods: Crude Kilka fish oil was supplied by Khazar company (Babolsar, Iran). All chemicals and solvents used in this study were of analytical reagent grade and purchased from Merck (Darmstadt, Germany) and Sigma–Aldrich (St. Louis, MO). Free radical scavenging activities of phenolic compounds was measured by reading the absorbance of methanolic solutions of the antioxidants containing 1,1-diphenyl-2-picrylhdrazyl (DPPH)at 517 nm. The partition coefficient (log P) of the antioxidants was measured in terms of the maximal UV absorbance of aqueous (0.3 mM) and 50:50 aqueous/acetate buffer (0.1M, pH =5.5) solutions. In order to study the antioxidant activity in lipid systems, peroxide value of the chromatographically purified Kilka fish oil as well as its 10% oil-in-water emulsion containing 200 mg/kg of antioxidants was monitored at 55 °C. Results and discussion: Syringic acid with two methoxy groups showed higher scavenging activity (IC50) than vanillic acid with one methoxy group (54.2 vs. 418.2). Radical scavenging activity in phenolic acids had direct relationship with the type and number of electron donor groups on phenolic ring. Peroxide values changed exponentially. Despite the relatively high polarity (Log P = – 0.65) and high scavenging activity, the performance of syringic acid in Kilkafish oil was degraded as affected by inter-molecular interactions and was not in accordance with the "polar paradox" hypothesis. Antioxidant activity of syringic acid in emulsion increased significantly as compared with oil and it was similar to α-tocopherol. It was concluded that the type of emulsifier and also the way of emulsion preparation as compared with antioxidant had a more prominent role in the oxidative stability of Kilka fish oil.Introduction: Medical benefits of omega-3 fatty acids have led to a lot of research on fish oil. Among marine fish, Kilka has the highest industrial applications. Kilka oil contains significant amounts of omega-3 fatty acids. In the present study, oxidative stability of Kilka fish oil based on the Schaal oven test and the use of two phenolic acid derivatives (syringic and vanillic acids) was investigated.Materials and methods: Crude Kilka fish oil was supplied by Khazar company (Babolsar, Iran). All chemicals and solvents used in this study were of analytical reagent grade and purchased from Merck (Darmstadt, Germany) and Sigma–Aldrich (St. Louis, MO). Free radical scavenging activities of phenolic compounds was measured by reading the absorbance of methanolic solutions of the antioxidants containing 1,1-diphenyl-2-picrylhdrazyl (DPPH)at 517 nm. The partition coefficient (log P) of the antioxidants was measured in terms of the maximal UV absorbance of aqueous (0.3 mM) and 50:50 aqueous/acetate buffer (0.1M, pH =5.5) solutions. In order to study the antioxidant activity in lipid systems, peroxide value of the chromatographically purified Kilka fish oil as well as its 10% oil-in-water emulsion containing 200 mg/kg of antioxidants was monitored at 55 °C. Results and discussion: Syringic acid with two methoxy groups showed higher scavenging activity (IC50) than vanillic acid with one methoxy group (54.2 vs. 418.2). Radical scavenging activity in phenolic acids had direct relationship with the type and number of electron donor groups on phenolic ring. Peroxide values changed exponentially. Despite the relatively high polarity (Log P = – 0.65) and high scavenging activity, the performance of syringic acid in Kilkafish oil was degraded as affected by inter-molecular interactions and was not in accordance with the "polar paradox" hypothesis. Antioxidant activity of syringic acid in emulsion increased significantly as compared with oil and it was similar to α-tocopherol. It was concluded that the type of emulsifier and also the way of emulsion preparation as compared with antioxidant had a more prominent role in the oxidative stability of Kilka fish oil.
Samaneh Pazhouhanmehr; Reza Farhoosh; Reza Esmaeilzadeh kenari; Ali Sharif
Abstract
Introduction: Common Kilka (Clupeonella cultriventris caspia) is one of the most abundant and industrial fish in the Caspian Sea located in the north of Iran, and also the best source of long-chain polyunsaturated fatty acids, especially EPA and DHA [Fazli et al., 2009, Connor, 2000]. Due to high level ...
Read More
Introduction: Common Kilka (Clupeonella cultriventris caspia) is one of the most abundant and industrial fish in the Caspian Sea located in the north of Iran, and also the best source of long-chain polyunsaturated fatty acids, especially EPA and DHA [Fazli et al., 2009, Connor, 2000]. Due to high level of the ω3 : ω6 ratio and polyene index, the common Kilka oil is expected to be highly susceptible to oxidation [Pirestani et al., 2010]. The interesting antioxidative characteristics of the oils and unsaponifiable matter (USM) extracted from the kernel and hull of bene fruit (Pistacia atlantica subsp. Mutica) attracted our attention to use them as natural alternatives for stabilizing the common Kilka oil and compare with BHT and α-tocopherol [Farhoosh et al., 2012]. Materials and method:The ripe bene fruits were collected from the fields of Islamabad in the Ilam province. After drying and also grounding to powder, the oils from the kernel (BKO) and the hull (BUO) of bene were extracted with n-hexane (1:4 w/v). Moreover, the USM content of the kernel (UKO) and hull (BHO) oils of bene were determined by the method described by Lozano et al, 1993. Chemical compositions of the bene oils’ unsaponifiable matter were determined by a thin-layer chromatography [Lercker and Rodriguez-Estrada, 2000]. Crude Kilka oil was purified by a multilayer column chromatography to eliminate the majority of pro-oxidant and antioxidant compounds normally present in it. The purified Kilka oil (PKO) was blended separately with 1 and 2% (w/w) of the antioxidative oils (BKO and BHO), 1 and 1.5% (w/w) of the oils’ unsaponifiable matter (UKO and UHO), and 100 mg/kg α-tocopherol and BHT and then exposed to the following stability test. Fatty acid composition of the oil samples was determined by gas-liquid chromatography [Sharina and Jumat, 2006]. The iodine value (IV) was measured according to the AOAC Official Method 920.158 [AOAC, 2005]. A colorimetric method was used to determine total tocopherols (TT) content [Wong et al., 1988]. Total phenolics (TP) content was spectrophotometrically determined using Folin–Ciocalteau’s reagent [Capannesi et al., 2000]. A Metrohm Rancimat model 743 (Herisau, Switzerland) was used for the oil/oxidative stability index (OSI) measurement in airflow rate of 20 L/h. The temperatures in measuring of the OSI were 60 °C for the PKO, OSI60, and 120 °C for the BHO and BKO, OSI120 [Farhoosh et al., 2008a; Mendez et al., 1996]. The analysis of variance (ANOVA) was carried out according to MStatC and SlideWrite software. Significant differences between means were determined by Duncan’s multiple range tests; p values less than 0.05 were considered statistically significant.Results and Discussion: The initial quality parameters of the PKO, BHO and BKO are shown in Table 1. The PKO was mainly constituted of MUFA, followed by the SFA and PUFA, and there was no measurable contents of TP, TT and USM fractions in it. The PKO showed a PUFA/SFA ratio higher than the minimum value recommended by the UK Department of Health (0.73 vs. 0.45) [HMSO. UK., 1994]. The ω3/ω6 ratio of the PKO was relatively similar to that of Indian mackerel (Rastrelliger kanagurta) (1.60 and 1.67, respectively) (Table 1) [Osman, Suriah, & Law, 2001]. The IV, as an indicator of the oil unsaturation and resistance to oxidation, for the PKO (114.99) was much lower than sardine (156.2) and salmon (165.8) oils [Frankel, 1998; Endo, Tagiri-Endo, & Kimura, 2005].As can be seen in Table 1, the BKO had higher contents of the USM, tocopherols and phenolic compounds than the BHO. The valuable effects of minor components especially polyphenols and tocopherols of the BHO and BKO on the oxidative stability of vegetable oils have been shown in the previous studies [Farhoosh et al., 2012]. The differences in the fatty acid composition and the amounts of minor components led to the greater OSI120 of the BKO than the BHO (9.46 vs. 7.91 h).The major constituents of the UHO and UKO were tocopherols and tocotrienols (Table 2). These compounds, which are particularly important functional constituents of the USM of vegetable oils, have nutritional importance for human health and render antioxidative properties [Lercker and Rodriguez-Estrada, 2000]. The OSI60 values of the PKO as affected by the antioxidative compounds are presented in Fig 1. As shown in Fig. 1, the OSI60 of the PKO (1.66 h) significantly increased in presence of the antioxidants added. Moreover, the highest significant stabilizing effect belonged to the UKO 1.5%, so that it was able to increase significantly the OSI60 up to 8.12 fold (OSI60, 13.48 h) (p < 0.05). Previous findings have demonstrated antioxidant activities of the constituents of the UKO and UHO in vegetable oils. In addition, it has been reported that the fraction of tocopherols and tocotrienols, and terpenoid compounds, particularly triterpenic dialcohols and 4,4'-dimethylsterols, possess antioxidative effects, in overall, better than those of other fractions examined [Farhoosh et al., 2008; Sharif et al., 2009]. Due to the higher amounts of these active fractions (Table 2), the UKO showed higher antioxidative effect on the PKO stability.
Mahmoud Yolmeh; Mohammad Bagher Habibi Najafi; Reza Farhoosh; Fereshteh Hosseini
Abstract
IntroductionFood consumers tend to use natural products without any synthetic additives. Therefore, many studies have been conducted to investigate the possibility of replacing synthetic additives with natural substances in various food products.Annatto dye is a natural carotenoid pigment extracted from ...
Read More
IntroductionFood consumers tend to use natural products without any synthetic additives. Therefore, many studies have been conducted to investigate the possibility of replacing synthetic additives with natural substances in various food products.Annatto dye is a natural carotenoid pigment extracted from the pericarp of BixaorellanaL. seeds. The major fraction of the annatto extract is 9´-cis-bixin that is soluble in oil and 9´-cis-norbixin is the major dye fraction of the alkaline extract that is soluble in water. Annatto dye creates orange to red color in food and to be used as a natural pigment in a variety of food materials including cheese, butter, margarine, confectionary and bakery products, different kinds of drinks, snacks and jams. In addition, annatto dye has antioxidant and antimicrobial activity.Nowadays, the extraction of natural dye from plant resources has become a common technology. However, complementary information using new methods and optimization of the extraction conditions seems to be necessary in order to accomplish the highest yield of extraction. Response surface method (RSM) is effective and efficient in optimizing color extraction conditions.In this study, the different conditions of extraction process were optimized through RSM in order to obtain maximum yield and best quality of annatto dye.Materials and methodsMaterialsAnnatto seeds were purchased from Hyderabad, India. All solvents were analytical grade, Merck, Germany.Extraction of annatto dyeA certain amount of annatto seeds was soaked in n-hexane for 6 hours in order to remove oils. After filtration, the defatted seeds were used for dye extraction. Since chloroform and acetone showed the highest yields of extraction during preliminary experiments, these two solvents and their mixtures were exploited for the final experiments assigning 0 for pure acetone and 100 for pure chloroform. The extracts were filtered through Whatman filter paper NO.1 and then vacuum-dried in the 1410D-2E vacuum oven (Shel Lab, USA) to produce dye powder. Low temperatures (40°C) were applied to prevent thermal dissociation of conjugated double bonds during drying. Dye measurementThe coloring strength was measured according to Vasu et al. method; model UV-160A spectrophotometer Shimadzu, Japan, at 502 nm in which bixin has the maximum absorbance value when it is dissolved in chloroform.Determination of extraction efficiencyThe obtained powder was weighed and the mass ratio of the powder to the weight of the seeds was taken into account as the extraction yield.Experimental designIn this study, Minitab® software version 16.1.1 (Minitab Inc. USA. 2010), was used and a five level four factor central composition design was created to investigate the effect of the independent variables such as temperature, extraction time, seed to solvent ratio and chloroform concentration on the dependent variables namely the extraction efficiency and absorbance values.Results and DiscussionThe values of R2, R2-adj and R2-pred revealed that the full quadratic models were the most adequate for the extraction efficiency and absorbance values.The all of the linear terms show a significant effect except the extraction time (P< 0.05). The quadric term of extraction time and the seed to solvent ratio also had a significant effect (P< 0.05) on the extraction efficiency, however, the effect of other two quadric terms was insignificant (P> 0.05). The interactive terms of extraction temperature* seed to solvent ratio(X1X3) and the seed to solvent ratio*Chloroform concentration (X3X4) had a significant effect on the extraction efficiency (P< 0.05); however, the other two interactive terms was insignificant (P> 0.05).For the absorbance values, the all of the linear terms show a significant effect (P < 0.05); the quadric term of extraction temperature (X12) and the seed to solvent ratio (X32) also had a significant effect (P< 0.05) on absorbance values, but, the effect of other two quadric terms (X22 and X42) did not show a significant effect (P> 0.05). The all of interactive terms was insignificant (P> 0.05).An increase in the extraction efficiency was observed with the increasing temperature. Banik and Pandey while extracting oleanolic acid from Lantana camararoots demonstrated that as temperature increases extraction efficiency improves too. However, at temperatures higher than 70 °C, the annatto seed pigments were degraded and the response was reduced so the quadratic effect of temperature was negative. The absorbance value was increased by increasing the temperature; however, the absorbance value decreased at higher temperature by thermal decomposition and damage of the conjugate double bond.The absorbance value increased by increasing the chloroform concentration and seed to solvent ratio initially, however, subsequently decreased due to the damage of the conjugate double bond in higher chloroform concentration and saturation of solvent in higher seed to solvent ratio.Temperature of 48.33 ˚C, extraction time of 2 hr, the ratio of seed to the solvent of 12.88 and chloroform concentration of 100% were found to be as the optimum conditions of the process. The extraction efficiency of 3.95 percent of annatto seed and absorbance value of 0.597 were acquired as the predicted results.
Mohsen Gavahian; Reza Farhoosh; Asgar Farahnaki; Katayoun Javidnia; Fakhri Shahidi
Abstract
As traditional extraction methods like Hydrodistillation (HD) and steamdistillation (SD) have long extraction times, some novel extraction methods like microwave-assisted hydrodistillation (MAHD) and ohmic-assisted hydrodistillation (OAHD) are recently introduced. In this study, essential oils of Mentha ...
Read More
As traditional extraction methods like Hydrodistillation (HD) and steamdistillation (SD) have long extraction times, some novel extraction methods like microwave-assisted hydrodistillation (MAHD) and ohmic-assisted hydrodistillation (OAHD) are recently introduced. In this study, essential oils of Mentha piperita were extracted by OAHD and MAHD and the results were compared with those of the SD and HD to clarify if these novel procedures have significant effect on antioxidant activities of extracted essential oils. The results showed that OAHD and MAHD are able to reduce extraction time (up to 72%) and also required electrical energy. Furthermore, all extracted essential oils were shown to have approximately same physical properties (relative density and visual color) and antioxidant activity using DPPH and β-carotene bleaching methods. The findings of this study revealed the applicability of using mint essential oil obtained by MAHD and OAHD as a natural antioxidant in food and pharmaceutical products.
Reza Farhoosh; Seyed Mohammad Ali Razavi
Abstract
Introduction: In this research, the effects of coating by Basil seed gum (BSG) (0.5 and 1%, w/w) compared to that by common gums such as xanthan and methylcellulose (MC) on the oil uptake, moisture removal, color, and texture in deep-fat fried potato strips were investigated. Today, numerous processed ...
Read More
Introduction: In this research, the effects of coating by Basil seed gum (BSG) (0.5 and 1%, w/w) compared to that by common gums such as xanthan and methylcellulose (MC) on the oil uptake, moisture removal, color, and texture in deep-fat fried potato strips were investigated. Today, numerous processed foods are prepared by deep-fat frying all over the world, since in addition to cooking, frying provides unique flavours and textures that improve the overall palatability. In fact, the desirable characteristics of most fried foods are derived from the formation of a composite structure: a crispy, porous, and oily outer layer or crust, and a moist cooked interior or core, whose microstructures have been formed during the process. In addition, the high oil content is costly to the processor and results in an oily and tasteless product . Also, Excess consumption of fat is considered as the key dietary contributor to coronary heart disease and perhaps cancer of the breast, colon, and prostate . The concern to develop healthier products that contain less fat, absorbed during industrial pre-frying and frying processes, is one of the prevailing factors in the latest research trends in this area, prompting studies of ways to lower the oil content of fried food. An edible coating (EC) is a thin layer of edible material formed as a coating on a food product, the EC are applied in liquid form on the food, usually by immersing the product in a solution generating substance formed by the structural matrix (carbohydrate, protein, lipid or multicomponent mixture), When frying coated food pieces, the film hinders absorption of the oil, improving its nutritional qualities and reducing the fat content and calories of the final product. Basil (Ocimum basilicum L.) is one of the domestic plants in Iran that is produced and used as a pharmaceutical plant in high quantity. When the seed of the O. basilicum L. is soaked in water, the outer pericarp swells into a gelatinous mass due to the presence of a polysaccharide layer. the present study aimed to expands the scope of previous works and focus on the effect of basil seed gum (as a novel hydrocolloid) on oil uptake and product quality (texture and color) during deep-fat frying of potato strips. In the first part of the study, investigate and compare the effects of endemic hydrocolloid, basil seed gum with xanthan(xan) gum and methyl cellulose(MC) for use as commercial hydrocolloids for coating edible.Materials and methods: Aqueous suspensions of 0.5 and 1% (w/w) were provided and used for coating formulations. blanched samples of potato were dipped in the coating suspensions for 2 min and rinsed to removal excessive gum then dipped samples dryed in oven 150 ºC for 3 minute. Frying was carried out in a controlled temperature deep fat fryer (Moulinex, Toucan Automatic). For each stage, nine samples were fried in 3 L of blended oil of canola: palm olein: olive oil (75:15:10, respectively). The uncoated and coated potato strips were fried 6 min at three temperatures (160 °C, 180 °C, and 190 °C).Rheological characterization of gum dispersions were measured using a rotational viscometer (Bohlin Model Visco 88; Bohlin Instruments, Worcestershire, UK) equipped with a heating circulator (Julabo, Model F12-MC; Julabo Labortechnik, GmbH D-77960, Seelbach, Germany). According to the viscosity of dispersions, appropriate measuring spindles (C25 and C30) were selected during viscosity measurements. Moisture and fat contents were determined according to the method of AOAC (1996). The color Color of crust models was measured using an image processing technique . Crispiness of potato strips was evaluated in term of hardness by a penetration test performed in a Texture Analyser (QTS25 CNS Farnell, UK). The Conical prob diameter and the cross-head speed was 3 mm and 60 mm/min, respectively. Statistical analysis was performed using factor completely randomized design in Mstat version 1.42 software. The level of statistical significance was determined at 95%. If significant difference was found, the treatments were compared by using Duncan’s multiple comparison test.Results and discussion: Solutions of BSG and XAN exhibited interesting pseudoplastic behavior with the viscosity decreasing with increasing shear rate( from 10 – 1001/s). No Newtonian region was detected at low shear rates suggesting that the zero-shear viscosity could exist at very low shear rates. The presence of high yield stress in BSG solution was comparable to xanthan gum. The apparent viscosity of Xanthan was markedly higher but methylcellose at both concentrations had Newtonian behaivear during shear rate. with regard to the controlling role of water in oil uptake, the oil content in all coated samples was less than that of the control (uncoated potato strips). The potato strips treated with BSG 1% and 0.5% had the lowest oil uptake (0.14 and 0.16 % d.b., respectively). The highest amounts of the oil uptake were found for the control and potatoes coated with methylcellulose 0.5%, respectively. The potatoes treated with the hydrocolloids experimented showed that the moisture content in all coated samples was higher than that of the control. The samples treated with the BSG 1% and 0.5% had the highest amounts of the reduced moisture loss. Also, the samples treated with xanthan and BSG 1% had the highest total color change (∆E) and hardness. Conclusion: Results of this study showed that basil seed gum (as a novel hydrocolloid) can be suggested for coating and usage in industrial French fries production.
Mohsen Gavahian; Reza Farhoosh; Asgar Farahnaki; Katayoun Javidnia; Fakhri Shahidi
Abstract
Ohmic-assisted hydrodistillation (OAHD) is an advanced hydrodistillation (HD) technique utilizing ohmic heating process and could be considered as a novel method for the extraction of essential oils. Long extraction time is one of the major problems with traditional methods. OAHD of essential oils from ...
Read More
Ohmic-assisted hydrodistillation (OAHD) is an advanced hydrodistillation (HD) technique utilizing ohmic heating process and could be considered as a novel method for the extraction of essential oils. Long extraction time is one of the major problems with traditional methods. OAHD of essential oils from the aerial parts of peppermint was studied and the results were compared with those of the conventional HD. The results showed that OAHD method had the extraction time of 19.71 min while this value was about 55.88 for HD. Scanning electron micrographs of mint leaves showed a sudden eruption of essential oil glands for OAHD samples. GC- MS analysis did not indicate any noticeable changes in the compounds of the essential oils obtained by OAHD in comparison with HD. The results introduced OAHD as a green technology.
Reza Farhoosh; Mohammad Shahedi; Ali Sharif
Abstract
The best PH for getting Millard reaction started and Acrylamide formation ranges 7 to 8. PH below the range slows the reaction speed down and the resultant Acrylamide formation delayed. This research assess how Acetic Acid in 0.05, 0.15, 0.25% concentrations together with sourdough may promote acidity ...
Read More
The best PH for getting Millard reaction started and Acrylamide formation ranges 7 to 8. PH below the range slows the reaction speed down and the resultant Acrylamide formation delayed. This research assess how Acetic Acid in 0.05, 0.15, 0.25% concentrations together with sourdough may promote acidity in bread dough and how they can cause a reduction of acrylamide content in Sangak bread [an Iranian traditional bread]. Here the acrylamide is assessed after it was derived and then transferring it to gaseous chromatography with ion indicator. The concentration of acrylamide in Sangak breads made of sourdough with 0.05, 0.15 and 0.25% of acid acetic showed a decrease of 73.47, 81.50 and 82.10% and also a 90.55, 92.80 and 95.96 % decrease when the bread has been made of the same compounds and yeast. The acidity of compounds with acidity rate of 0.05, 0.15 and 0.25% in Sangak bread made of yeast equates to 0.12, 0.14 and 0.17% (normal) respectively; while these values for Sangak breads made of sourdough stand at 0.16, 0.18 and 0.21% (normal). Therefore, decreased acrylamide can be attributed to increased acidity of dough.
Reza Farhoosh; Hashem Pourazerang; Mohammad Hossein Hadad Khodaparast
Abstract
Measuring the rate of changes in total polar compounds (TPC) content and polar fractions, the oxidative stability of canola oil during frying process as affected by bene kernel oil (BKO, 0.05 and 0.1%) and tert-butylhydroquinone (TBHQ, 100ppm) was investigated. It was observed that the TPC content increased ...
Read More
Measuring the rate of changes in total polar compounds (TPC) content and polar fractions, the oxidative stability of canola oil during frying process as affected by bene kernel oil (BKO, 0.05 and 0.1%) and tert-butylhydroquinone (TBHQ, 100ppm) was investigated. It was observed that the TPC content increased linearly with frying time (R2 > 0.98). The canola oil containing the BKO (especially 0.1%) was significantly capable of increasing oxidative stability. The TPC analysis by high-performance size-exclusion chromatography allowed the separation and quantification of triglyceride polymers (TGP), triglyceride dimers (TGD), oxidised triglyceride monomers (oxTGM), diglycerides (DG), and free fatty acids (FFA) during frying. The ability of the BKO to resist the TGP and oxTGM formations was near to that of the TBHQ, whereas the ability of the BKO to resist the DG and FFA formations was better than that of the TBHQ.
Azadeh Saadatmandi; Mohammad Elahi; Reza Farhoosh; Mahdi Karimi
Abstract
Corn tortiilas are flat breads made from corn dough (masa) which is prepared through the nixtamalization process (alkaline cooking). Corn, in nixtamalization, is cooked in a lime solution then the boiled maize is steeped in cooked liquor , following by washing out and milling to obtain wet masa flour. ...
Read More
Corn tortiilas are flat breads made from corn dough (masa) which is prepared through the nixtamalization process (alkaline cooking). Corn, in nixtamalization, is cooked in a lime solution then the boiled maize is steeped in cooked liquor , following by washing out and milling to obtain wet masa flour. Drying wet masa flour in air oven produce dry masa flour. Cooking temperature, cooking time , lime concentration ,and steeping time significantly affect the quality of masa flour and final product( tortilla). In this research the cross effects of these four factors , to determine the best treatment for production of masa flour, were studied. Effects of cooking temperature (75,85,95°C) , cooking time ( 0,30,60 min) , lime concentration(0, 0.5 , 1%) and steeping time ( 10,14,18 hr) by measuring pH, protein content , ash content , color parameters, water absorption index (WAI) and using central composite design were investigated. Statistical analysis revealed the best treatment for production of masa flour as: cooking temperature 85°C, cooking time 30 min, lime concentration 0.5%, and steeping time 14 hr.
Reza Farhoosh; Mohammad Hossein Hadad Khodaparast
Abstract
In the present study, the oxidative stability of nine Iranian commercial olive oils, including four virgin samples and five deodorized ones, was compared to that of two foreign virgin olive oils. In total, the foreign samples had the MUFA/PUFA ratios (av. 9.27) higher than those of domestic ones (av. ...
Read More
In the present study, the oxidative stability of nine Iranian commercial olive oils, including four virgin samples and five deodorized ones, was compared to that of two foreign virgin olive oils. In total, the foreign samples had the MUFA/PUFA ratios (av. 9.27) higher than those of domestic ones (av. 5.70). The peroxide and acid values of the olive oils studied ranged from 8.5 to 14.5 meq/kg and from 0.1 to 4.27 mg/g, respectively. Tocopherols content of the foreign olive oils (av. 436.7 ppm) was averagely higher than that of the domestic olive oils and even about two times that of domestic virgin ones (223.4 ppm). On average, the foreign virgin olive oils contained phenolic compounds (154.0 ppm) higher than that of the domestic ones (112.3 ppm) and especially deodorized olive oils (46.0 ppm). The oxidative stability of oil samples was suitably interpreted in terms of chemical composition data, so that the foreign virgin olive oils had more appropriate chemical composition in total, and therefore, indicated oxidative stabilities higher than those of the domestic virgin and deodorized olive oils.
Reza Farhoosh; Seyed Mohammad Ali Razavi; Seyed Mahmoud Mousavi
Abstract
In the present study, the growth of phospholipids' micelles in canola oil by chemical pretreatment and their separation by using membrane technology was investigated. Aqueous solutions of calcium chloride (1% w/w) and EDTA (150 mM) were added to canola oil miscella before ultrafiltration process. Ultrafiltration ...
Read More
In the present study, the growth of phospholipids' micelles in canola oil by chemical pretreatment and their separation by using membrane technology was investigated. Aqueous solutions of calcium chloride (1% w/w) and EDTA (150 mM) were added to canola oil miscella before ultrafiltration process. Ultrafiltration was conducted by a flat sheet PVDF membrane with two different MWCOs (50 KDa, M116, and 100 KDa, M183) at various temperatures and pressures (25 - 55 ̊C and 2 - 5 bar). Results showed that the permeate flux of M183 membrane was approximately half that of the M116 membrane. The EDTA pretreatment resulted to increase in the permeate flux obtained through M116 membrane. Increasing the operation temperature and pressure led to increase of the permeate flux. The phosphorus content of samples ultrafiltrated by the M116, especially those pretreated by EDTA, was more than that of other samples. Increasing temperature led to decrease of phosphorus rejection from permeates.
Keywords: Calcium chloride, Canola oil, Ethylenediaminetetraacetic acid, Phospholipids, Ultrafiltration
Amir Salari; Mohammad Bagher Habibi Najafi; Reza Farhoosh; Seyed Hassan Marashi
Abstract
The effect of different solvent systems on the extraction of antioxidant and anti radical agents of grape seed was studied. For this purpose 6 different solvent systems with similar polarity and different selectivity were used to prepare grape seed extract. Extraction efficiency, reducing activity, radical ...
Read More
The effect of different solvent systems on the extraction of antioxidant and anti radical agents of grape seed was studied. For this purpose 6 different solvent systems with similar polarity and different selectivity were used to prepare grape seed extract. Extraction efficiency, reducing activity, radical scavenging property and the effect of each extract on the increase of thermal resistance (oxidative stability index) of antioxidant free soybean oil were analyzed in the form of factorial test in a totally randomized design with triplicate repetition. Reducing activity test proved that grape seed extracts (GSE) had a higher reducing strength compared with BHT and α-Tocopherol except for ethylacetat treatment which had no significant difference between the extracts. Results of radical scavenging activity were similar to reducing activity results. The evaluation of oxidative stability index showed that acetone treatment has had the maximum Carry-through properties
Keywords: grape seed extract, antioxidant, antiradical, radical scavenging activity, solvent system, reducing power, oxidative stability index.
Amir Salari; Mohammad Bagher Habibi Najafi; Reza Farhoosh; Seyed Hassan Marashi
Abstract
This study has been done to survey of solvent system effect on extraction of grape seed extract and its antimicrobial properties. For this purpose, grape seed extracts were extracted with six different solvent systems. Minimum Bactericidal Concentration (MBC) of extract on six spoilage and Food-born ...
Read More
This study has been done to survey of solvent system effect on extraction of grape seed extract and its antimicrobial properties. For this purpose, grape seed extracts were extracted with six different solvent systems. Minimum Bactericidal Concentration (MBC) of extract on six spoilage and Food-born pathogens was determined. The results indicated that MBC of different extracts have no significant difference and its value for Salmonella enteritidis, Escherichia coli, Enterobacter aerogenes was 1000 ppm. This value for S.aureus and listeria monocitogenes was 500 ppm. Results showed that gram positive bacteria were more sensitive than gram negative ones.
