Food Technology
Samira Farizad; Hajar Abbasi
Abstract
Introduction
Hydrocolloid is a term refers to all polysaccharides extracted from plants, seeds, and microbial sources that regardless of their biological and nutritional role has various functional properties in food products such as concentration and gel production of aqueous solutions, stabilization ...
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Introduction
Hydrocolloid is a term refers to all polysaccharides extracted from plants, seeds, and microbial sources that regardless of their biological and nutritional role has various functional properties in food products such as concentration and gel production of aqueous solutions, stabilization of foam, emulsions and dispersed systems, prevention of ice and sugar crystals, control of the release of flavor compounds and consequently control and improve food quality. Ultrasound has been widely used in the food industry due to its numerous physical and chemical effects. The effect of ultrasound is due to cavitation, heating, dynamic mobility and shear stresses to the sample. Today, ultrasound is used as a green new technology with unique effects on food storage and processing. One of the newest applications of ultrasound is altering the structure of polymers such as polysaccharides. Changes in the structure of hydrocolloids lead to modification in their functional properties.
Materials and Methods
In this study, effect of ultrasonic waves, time (0-90 min) and processing temperature (25-75 °C) on physicochemical, rheological and functional properties of locust bean gum was investigated. In this regards, different parameters including changes in pH, solubility, minimum gelatinization concentration, viscosity and emulsifying properties (Emulsifying capacity, emulsion stability and particle dimensions) of treated locust bean gum were determined. Response surface methodology in central composite design was used to evaluate the effect of independent variables on qualitative properties of locust bean gum and model their changes. The best treatment condition was determined and the optimum treated samples were evaluated and compared in microstructure using scanning electron microscopy, rheological properties (rotational and oscillatory test) and Fourier transform infra-red.
Results and Discussion
The results showed that with increasing the time of ultrasound treatment, pH, and viscosity of the hydrocolloid decreased and its solubility and minimum gel concentration increased. However, with increasing temperature, pH, minimum gelatinization concentration and hydrocolloid viscosity increased and its solubility decreased. Optimization of treatment conditions was performed by considering the achievement of the best hydrocolloid performance characteristics. Two different temperature and time conditions were proposed for the desirable treatment of the hydrocolloid using ultrasound. In the first case, the selection criteria were to achieve the best solubility and emulsifying properties of the hydrocolloid, and in the second case, the selection criteria were solubility and emulsifying properties improvement while maintaining the gelatinization properties of the hydrocolloid. Based on the desired quality factors, optimization was performed and the results showed that in the first optimal sample (treated at 40 ° C and 48.9 minutes), solubility and emulsifying properties and in the second optimal sample (treated at 66.67 ° C and 15 Min) by maintaining the gelation properties of hydrocolloid, the solubility of the hydrocolloid increased significantly. The performance of treated samples validated developed models. SEM results showed that the ultrasound increased three-dimensional structure of gum. The smaller microscopic structure was observed in untreated sample and the larger one was in treated with ultrasonic waves for 40.9 minutes at 40 ° C. Therefore, ultrasound caused agglomeration of treated freeze dried gum. It is noteworthy that several holes observed in the structure of treated gum with ultrasonic, which can increase solubility of the gum. The flow behavior of the sonicated and control samples showed that the viscosity of all samples decreased with increasing shear rate, which indicates their pseudoplastic behavior. At low shear rates (about 0.01 per second), the viscosity of the control sample was higher than that of the sonicated samples. However, at high shear rates (about 40 per second), viscosity of the three samples were almost the same. Therefore, the control sample was more affective to shear rate compared to the treated samples. The modulus of elasticity (G ') and viscosity (G' ') of the treated specimens were lower compared to the control. Also, the frequency sweep of samples shown that in the frequency range under study, G 'and G'' were frequency dependent and with increasing frequency, the amount of these two parameters increased. This observation indicates the influence of rheological properties of the samples on the frequency changes that are commonly observed in suspensions. At low frequencies, the predominance of viscous behavior over elastic was observed in all three control and ultrasonic samples (G ''> G ') and this feature was higher in the treated samples than the control. The modulus of elasticity and viscosity of the treated sample for 49 minutes was lower than other treated samples for 15 minutes, which shows the effect of ultrasound on the rheological properties of the hydrocolloid.
Conclusion
The results of this study showed that ultrasonic waves provide a good opportunity to change the physical and functional properties of carob seed gum. It is possible to significantly improve the solubility and emulsifying activity of this hydrocolloid using ultrasound. It is necessary to determine the treatment conditions of the sample according to the intended application.
Food Technology
Somayeh Ghandehari alavijeh; Mehran Alami; Yahya Maghsoudlou; Alireza Sadeghi Mahoonak
Abstract
Introduction: Porous starch granules are becoming of great interest such as non-toxic absorbents, owing to their great absorption capacity derived from the major specific surface area. Pores can protect sensitive elements as oils, minerals, vitamins, bioactive lipids, food pigments such as beta-carotene ...
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Introduction: Porous starch granules are becoming of great interest such as non-toxic absorbents, owing to their great absorption capacity derived from the major specific surface area. Pores can protect sensitive elements as oils, minerals, vitamins, bioactive lipids, food pigments such as beta-carotene and lycopene that are sensitive to light, oxidation or high temperature. Alpha-amylases from Bacillus and glucoamylases from Aspergillus niger have the strongest hydrolytic ability toward starch. Ultrasonic treatments have been reported to produce modified starch. In the last years, the effects of sonication on the starch microstructures and properties have been studied. It was shown that the C–C bonds of starch granules were destroyed, and hollows or pores were formed on the surface and inside the granules. Therefore, the main objective of this study was to identify a suitable starch (corn or wheat) to carry and protect iron ions. The enzyme having a fixed concentration of 0.1% within a fixed period of 36 hour, was added to the starch solutions in three different steps - after, simultaneously and before - the ultrasound processes. The power of the ultrasound was 350 watt for 10 minutes. Iron ions (Iron Ammonium Sulfate (II)) were added to the porous corn and wheat starches in concentrations of 40, 60 and 80 ppm. Materials and methods: The ability of water and oil adsorptions were measured in the produced corn and wheat porous starches. The microstructures of porous starches were revealed by using Scanning Electron microscopy (SEM). After adding iron ammonium sulfate (II) to the porous starches of corn and wheat, the amount of iron ions absorbed and the type of bonds formed between starch and iron ions were determined by inductively coupled plasma (ICP) and infrared spectroscopy (FTIR), respectively. Statistical analysis was performed by using SPSS software and the mean comparison test at 5% probability level and in the form of factorial test. Results & Discussion: The hydration capacity in processed wheat starch was lower than corn starch due to the differences in granular structure of wheat and corn starch. The hydration capacity in native wheat and corn starches was significantly (p < 0.05) lower than the processed forms. No significant difference (P>0.05) was observed between the three steps of adding enzyme (e after, simultaneously and before the ultrasound processes). According to the results, the oil adsorption capacity in the processed starches was more than that of the native forms. Scanning Electron Microscopy (SEM) shows that the native corn and wheat starch granules appeared without any clear of fissures, fractures and pores. The corn and wheat starches which were treated by the enzyme after (step 1), simultaneously (step 2) and before (step 3) the ultrasound change and lose their smooth surfaces and become uneven. The surface of corn granules in group 2 and 3 have less pores and porosities with more laminated. In simultaneously processes (phase 2) the ultrasound causes the enzyme to be inactivated. In phase 1, it can be concluded that the ultrasound helps the enzyme performance in creating the porosities and cavities. The wheat granules in step 1, 2 and 3 have a lot of damage on the surface and it is likely that the surface of the wheat granule is more resistant to enzyme penetration than the corn. The results of the ICP test show that processed corn starch has significantly (P <0.05) greater ability to absorb iron ions than processed wheat starch. Also, corn starch had a significant difference in iron uptake in the step 1 than steps 2 and 3 (P <0.05), but the data of the second and third steps did not differ significantly (P> 0.05). Hydroxyl groups of D-glucose units in starch granules bond with iron ions and FTIR spectrums give drop at 575 (cm-1) wavelengths. This study showed that enzymatic treatment and ultrasound led to the native corn starches convert to porous starches. The corn starch is more suitable than the wheat because the wheat is more resistant and the cavities were rarely formed. The corn porous starch is a suitable carrier for iron ions.
Foroozan Jafari; Nafiseh Zamindar; Mohammad Goli; Zahra Ghorbani
Abstract
Introductıon: In developing countries, camel meat is used to provide nutrients, proteins, vitamins, and minerals but it usually has a tough texture. Marinating meat may improve its flavor and tenderness. It has been shown that plant enzymes such as papain, ginger, and Cucumis increase the meat's tenderness ...
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Introductıon: In developing countries, camel meat is used to provide nutrients, proteins, vitamins, and minerals but it usually has a tough texture. Marinating meat may improve its flavor and tenderness. It has been shown that plant enzymes such as papain, ginger, and Cucumis increase the meat's tenderness and improve the flavor and aroma of the products.Ginger extract (GE) could improve the tenderness of camel meat by “Zingibain”. Marination in acidic solutions has been used both traditionally and industrially for the tenderization and flavoring of meat (Abdeldaiem and Hoda., 2013; Tsai et al., 2012). The tenderization effect of marination on meat have been examined by using organic acids such as citric acid (Aktas et al., 2003; Berge et al., 2001; Ke et al., 2009; Kim et al., 2013; Ke, 2006; Ke et al. 2009).The objective of this study was to evaluate the effect of ultrasound and marination with different concentrations of citric acid and Ginger extract 30% on the physicochemical characteristics of camel meat. Materials and methods: Fresh ginger rhizome (Zingiber officinalis roscoe) purchased from a local market was washed, peeled, sliced and immediately homogenized with an equal quantity of chilled and distilled water (4ºC) for 2 min to extract the crude enzyme. The homogenate was filtered through Buchner funnel and the water to get the GE. Marinade solutions were prepared by the addition of 0.5, 1 and 1.5% citric acid to 30% GE, and distilled water was used as control. To prepare the required 30% GE, the crude fresh GE was diluted with distilled water (He et al., 2015).The portions from Biceps femoris muscles of aged male camel carcasses (4 years of age) were prepared according to the method described by Abdeldaiem et al (2013). Uniform sized (3×3×3 cm) of aged camel meat chunks were dipped in the curing solutions at the ratio of 3:1(meat: liquid) and immersed in the polyethylene bags and kept at 4±1°C for 24 and 48 h (Abdeldaeim et al., 2014; Garge et al., 2006).The pH values were measured directly using a probe-type electrode (Naveena et al., 2004). Uptake of the marinade (%) was measured according to the method described by Garg et al (2006) and Hosseini et al (2012).The color measurements; lightness (L*), redness (a*) and yellowness (b*) were performed at the surface of the marinated meat samples (Barbut, 2004).Cooking loss of meat samples was determined so that He et al (2015) and Kim et al (1995) described.Shear force values of cooked samples were determined using texture analyzer with Warner-Bratzler shear apparatus, while muscular fibers were almost parallel to the force as normally occurs during chewing. Six meat cores (1.27 cm diameter) parallel to muscle fiber were sheared once through the center by a warner-Bratzler shear attachment using 50 kg compression load cell and 200 mm/min cross-head speed (Karimi et al., 2008; Hosseini et al., 2012).After 24 and 48 h marination, samples were prepared for (SEM) as described by Naveena et al (2004).A completely randomized design in a factorial experiment with 3 replications was employed by using analysis of variance (ANOVA) to study the effect of ultra-sonication, and time on the physicochemical properties of camel meat. Least significant difference (LSD) test was used to determine differences between treatments means (P<0.05). Data were analyzed using the procedure of SAS version 8 (Burke et al., 2003). Results and discussion: Ultrasonication caused a decrease in pH while increasing marination time caused an increase in pH of all samples compared with control. Cooked samples showed higher pH compering with raw marinated samples. Ultration and increasing marination time caused a significant increase in marinade uptake due to structural changes. Application of ultrasound, the higher concentration of acid in marinade solution and longer marination period resulted in lower shear forces of meat samples.Marination by 30% GE in addition to 1.5% citric acid and ultration illustrated maximum tenderness, lower pH and L*-value but caused less water holding capacity and higher cooking loss.
Mohammad Noshad; Mohammad Amin Mehrnia; Nasim Dehghan
Abstract
Introduction: Pectin is a type of water-soluble hetero-polysaccharide that is present in the primary cell wall of plant and is used as a jellying, thickening and stabilizing agent in various food products. The degree of esterification is the most important determinant of the use of pectin in the food ...
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Introduction: Pectin is a type of water-soluble hetero-polysaccharide that is present in the primary cell wall of plant and is used as a jellying, thickening and stabilizing agent in various food products. The degree of esterification is the most important determinant of the use of pectin in the food products, according to pectin is divided into two groups: high-esterification pectin (50% degree of esterification) and pectin with degree low esterification (degree of esterification less than 50 %(. Considering the high use of pectin in the food products, researchers are now looking for new sources of pectin extraction, among which the use of food waste has been considered high, because the waste of food factories is a major challenge for food manufacturers. Eggplant (Solanum melongena) belongs to the Solanaceae family, which is used extensively in the world. The plan species is believed to have originated in India, where it continues to grow in southern and eastern Asia. The skin and warhead of this product, which is discarded as waste, can be used as a valuable source for pectin extraction. The most commonly used methods for pectin extracting are the use of hot water, along with acids, which is a time-consuming process and the waste discard of this method is environmentally problematic. Therefore, the use of new methods such as ultrasound has been considered by researcher to minimize the limitations of the traditional method of pectin extracting. The purpose of this study was to extract pectin from eggplant waste using ultrasound and evaluate its physicochemical properties. Material and methods: The waste of eggplant from restaurant of agricultural sciences and natural resources university of Khuzestan were prepared. The waste was dried in an oven at 60 ºC to reach constant weight. The dried waste was powdered using a grinder and passed through the sieve. The ultrasound was used to extract pectin from eggplant waste (skin and warhead). For this purpose, the effect of ultrasound time (40-80 min) and dry matter /solvent ratio (1:10 – 1:30 g/ml) on extraction efficiency degree of esterification of extracted pectin were investigated. The FTIR (wavelengths scanned 4000-400 cm−1) and rheological behavior were studied to evaluate the performance characteristics of the extracted pectin. Analysis of variance (ANOVA) procedure followed by Duncan’s test using SPSS 16 (SPSS Inc., Chicago, IL, USA) software was applied to determine the significant difference (P < 0.05) between treatment means. Result & discussion: Based on results, increasing the extraction time had a significant effect (P<0.05) on the pectin extraction, so that the increase in extraction time from 40 to 60 min increased the extraction efficiency from 14.05 ±0.21 to 29.35±0.21 (%), which is probably due to the fact that the cavitation causes the cell wall to break down and more solvent penetrates the cell matrix, which results in increased extraction of pectin. The highest efficiency of pectin was obtained in the dry matter /solvent ratio (1:10 g/ml) and 60 min. The highest degree of esterification (84.18 ± 0.1 %) was obtained in the dry matter /solvent ratio (1:20 g/ml) and 60 min. Also, the degree of esterification of the obtained pectin varied from 67.69 ± 0.02 to 84.14 ± 0.1 %), which indicated the high quality of pectin was extracted. Due to the fact that the steric bonds are more unstable than acidic hydrolysis in comparison with glycosidic bonds, the higher degree of esterification indicates less damage to the pectin structure during the extraction process. FTIR showed all of the pectin's specific spectra and abundance of methoxy groups in extracted pectin. The FT-IR spectra show the characteristic absorption of -CH at the ranges of 3000-2800 cm-1 and at 1421 cm-1, while the wide band at 3406 cm–1 was assigned to the -OH stretching vibration. The wide band at the ranges of 1700-1600 cm-1 can be due to the stretching vibrations of the C=O bonds in the backbone of crude polysaccharide because of presence of uronic acid. Existence of a peak at 1200-900 cm-1 indicates that pectin contained multiple vibrations of glycosidic (C–O-C) and pyranoid (C=O) linkages due to the characteristic of the pyranose form of glucosyl residues. The apparent viscosity of the extracted pectin solution decreased with increasing shear rate (0.5 to 10 s-1) while in the higher shear rate (10 to 100 s-1), the apparent viscosity of the pectin solution remained almost constant. This process shows that the produced pectin solution at low shear rate exhibits pseudo plastic behavior, while at highest shear rate exhibits Newtonian behavior. These results indicated that eggplant waste could be used as a good source of high-performance pectin.
Mahdi Zahedi; Zohreh Hamidi-Esfahani; Hassan Ahmadi Gavghili
Abstract
Introduction: Pectin is a structural heteropolysaccharide in the cell wall of plants and after extraction it is used as a gelling agent in food products. The main sources of pectin are apple and citrus peel, but pectin from various sources, may have unique properties. Therefore, research is ongoing to ...
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Introduction: Pectin is a structural heteropolysaccharide in the cell wall of plants and after extraction it is used as a gelling agent in food products. The main sources of pectin are apple and citrus peel, but pectin from various sources, may have unique properties. Therefore, research is ongoing to find new sources of pectin and study their properties. The conventional extracting method is performed using a solution of mineral acids, this process is time-consuming and has some disadvantages in terms of quantity and quality of extracted pectin. It is very important to look for new methods or modifications to produce pectin with high efficiency and quality. One of the new methods is ultrasonic extraction, which has been studied extensively. The aim of this study was to optimize and quantitative and qualitative evaluation of pectin extraction from tomato pomace as one of the major wastes of industries in Iran. Also Ultrasound was used as a new and effective method for extraction of pectin. Ultrasound assisted extraction (UAE) of pectin from waste tomato pomace was investigated and optimized using Box–Behnken response surface design. The individual and interactive effect of process variables (pH, temperature, extraction time and power density) on the pectin yield and purity was studied. Also, the degree of esterification, intrinsic viscosity and emulsifying properties were determined on optimized conditions.
Materials and methods: Tomato pomace was supplied from ATA Company located in Tehran, Iran. It was dried at 60 °C for 36 hours. Then was milled and sieved by 60 mesh size screen. Fatty acids and pigments were removed from tomato pomace and again dried. The obtained powder stored at ambient condition for further uses. Ultrasonic device (Ultrasonic Technology Development Company, IRAN and 400 w, 20 KHz) with 12 mm probe and double-shell tank was used to carry out the extraction. Response surface methodology (RSM) was carried out to study the effect of pH (1.5-2.5), temperature (60-90℃), extraction time (6-30 minutes), and power density (0.15-0.3 W/ml) as input variables on the yield and galacturonic acid (GalA) content as the output (responses). GalA content was determined by colorimetric method (titration), using the 3, 5- dimethylphenol as reagent and D-galacturonic acid as standard. To determine the degree of esterification, titration method was used. The intrinsic viscosity of pectin was determined by applying a capillary viscosimeter (Cannon Instruments Co., No. 150, Cannon-Fenske, Germany; k = 0.04137 mm2/s2). Emulsifying properties of pectin extracted at the optimal point were investigated at three levels of pectin concentration %0.25,% 0.5 and %1.
Results and discussion: The experimental data obtained were analyzed by analysis of variance (ANOVA) and second-order polynomial models were developed using multiple regression analysis both for pectin yield and GalA content. The models developed from the experimental design were predictive and good fit with the experimental data with high coefficient of determination (R2) value. Pectin yield and GalA content were more influenced by temperature. The highest extraction yield (10.5%) and galacturonic acid content (65%) was obtained at pH of 2, temperature of 86℃, time of 30 min, and power density of 0.3 W/ml, while in the conventional extraction method with the same extraction conditions, extraction yield of 4.5% and galactoronic acid content of 55% was obtained. According to results of this experiment, it can be concluded that main advantage of UAE is considerable shortening of extraction time with enhancement of pectin purity. Under optimal conditions, pectin with a degree of esterification 76% and intrinsic viscosity of 2.6 dl/g was obtained. The highest emulsifying activity (87.5%) was obtained at %1 concentration. By holding the emulsion at a temperature of 4°C and 23°C, the emulsion stability was significant (99%) at the concentration of %0.25 over a period of 30 days. These results showed that tomato pomace could be used as a good source of low cost pectin.
Mahsa Alikhani Faradonbeh; Reza Esmaeilzadeh kenari; Maryam Ghaderi
Abstract
Introduction: The peel of fruits, in particular, are an abundant source of natural compounds and contain the higher amount of phenolics compared to the edible portions. Ultrasound-assisted extraction (UAE) is an ideal extraction method capable of producing high quantities of bioactive compounds with ...
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Introduction: The peel of fruits, in particular, are an abundant source of natural compounds and contain the higher amount of phenolics compared to the edible portions. Ultrasound-assisted extraction (UAE) is an ideal extraction method capable of producing high quantities of bioactive compounds with a shorter extraction time. Probe and bath systems are the two most common ways of applying ultrasound waves to the sample. Probe sonicators are constantly in contact with the sample and make reproducibility and repeatability difficult. In addition, the risk of sample contamination and foam production is higher. Bath sonicators can act on a range of samples simultaneously and allow for higher reproducibility. Kiwifruit belongs to family Actinidiaceae and genus Actinidia. Kiwifruit is characterized by a high content of vitamin C and other useful compounds such as vitamin E, flavonoids, and minerals. Phenolic compounds present in Kiwifruit peel are catechin, epicatechin, chlorogenic acid, caffeic acid, coumaric acid, and rutin. Several studies have been done on the extraction of various plants with ultrasonic waves. Most of the research on the extraction of plant extracts by ultrasound-assisted under various conditions of parentage such as time, solvent, temperature, and intensity of the sound obtained matched with other traditional methods of extraction and different studies have shown that there was never study on the effects of ultrasound bath and probes under the same conditions (temperature, solvent, time and frequency) on obtained extract and comparison of both two methods has been done. The aim of this study was comparing the antioxidant activity of Kiwifruit peel extract (KPE) obtained by two extraction methods ultrasound bath and probe techniques in same conditions temperature, solvent, time and frequency. Materials and Methods: Hayward Kiwifruit variety was purchased from gardens in Tonekabon City. The peels were dried in the shadow at 25-27˚C, and then they were finely ground in a laboratory grinder. The dried peels were pulverized and sieved through a 40-mesh sieve to obtain the powdered samples. The dry plant material was then packed in the plastic bag and stored in a freezer at -18˚ C. 10 g of Kiwifruit peel powder was extracted with 100 mL of a mixture of ethanol–water 80% (v/v) at two methods Ultrasound Bath Extraction by using a 25 kHz ultrasonic system (model Elma Sonic S30H, Germany), temperature (45°C), time (20 min) and Ultrasound Probe Extraction by using a 25 kHz ultrasonic system (model VCX 250, Sonics & Materials, Inc., USA), temperature (45°C), time (20 min), amplitude of 45% with a probe of 1 cm in diameter was used. After obtaining extracts, an efficiency of extraction, total phenolic and flavonoid compounds, scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, and ferric reducing antioxidant power (FRAP) assay were measured and concentration of 0.1 mg/ml of synthetic antioxidant TBHQ was as the control sample. All data were reported as mean ± standard deviation of three replicates. The results were compared by analysis of variance (ANOVA) using SPSS for Windows [version 16]. Mean differences were significant for extraction efficiency, total phenolic and flavonoid compounds based on T-test (binary comparison) and other tests based on Duncan's test at 0.05. Charts were drawn with Microsoft Excel version 2016. Discussion & Results: These results showed that the highest amount of phenolic compounds, flavonoids, extraction efficiency, and antioxidant activity were obtained in UPAE-KP. In both extraction methods, with increasing KPE concentration, DPPH free radicals scavenging and ferric reducing antioxidant power also increased. The concentration of 2 mg/ml UPAE-KP extracted the highest percentage of inhibition (94.11%) in all of the concentrations of the extracts in two methods. UPAE-KP at concentrations of 1.5 and 2 mg/ml and UBAE-KP at a concentration of 2 mg/ml showed better performance in scavenging free radicals than TBHQ. Among the extracts, IC50 UPAE-KP was 0.2±0.06 mg/ml which was significantly different from UBAE-KP (P<0.05). TBHQ at a concentration of 0.1 mg/ml (with a percentage of inhibition of 88.04±0.5) showed a better radical inhibitory activity than the low concentrations of Kiwifruit Peel extracts. UPAE-KP with a lower IC50 (0.09±0.07) showed more reducing antioxidant power than UBAE-KP. TBHQ at a concentration of 0.1 mg/ml (with an absorption rate of 304/1) had greater reducing antioxidant power than the Kiwifruit Peel extracts at all concentrations except the concentration of 2 mg/ml UPAE-KP. In this study, the extraction of KPE with both ultrasound methods was acceptable in terms of efficiency and antioxidant activity, with the difference that the probe superior to the ultrasound bath. Therefore, according to the results, KPE was competitive with TBHQ activity. KPE can be used as a useful source to provide natural antioxidant, and the probe compared with the ultrasound bath is a better way of extracting the KPE phenolic compounds.
Mohammad Ganjeh; Seyed Mahdi Jafari; Mehrdad Niakosari; Ali-Mohammad Tamaddon; Yahya Maghsoudlou
Abstract
Introduction: In recent years, production of nutraceuticals by adding bioactive compounds and nutrients has been grown substantially. These compounds are generally sensitive to environmental or gastrointestinal conditions and their bioavailability is limited due to destructive reactions. One of the common ...
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Introduction: In recent years, production of nutraceuticals by adding bioactive compounds and nutrients has been grown substantially. These compounds are generally sensitive to environmental or gastrointestinal conditions and their bioavailability is limited due to destructive reactions. One of the common methods to reduce or prevent these kind of problems, is microencapsulation of valuable compounds in some materials which can protect them against environmental conditions, and enabling them to controlled release from trapped compounds at specific time and place. Orange peel oil, contains some important bioactive compounds such as limonene that is used in a variety of beverages, foods, cosmetics, pharmaceuticals and chemicals. D-limonene is the main constituent of orange peel oil, because it makes an 80-95% fraction of the orange peel oil volatile compounds, depending on fruit variety. In addition to its technological characteristics (flavor), D limonene can stop or delay the initiation of cancer. It can also be used as a safe alternative to antimicrobial compounds. Nevertheless, technological limitations (hydrophobic structure, high reactivity, sensitivity to oxidation and volatility) often avoid suitable use of this compound as a dietary supplement. Polysaccharides are among of the basic materials which are applied more in this field. Several factors such as cheap and easy access, having active groups interacting with hydrophobic and hydrophilic compounds, biodegradation, biocompatibility and relatively high thermal resistance, have turned them to be superior to lipid and protein carriers. One of the most important polysaccharide compounds existing in nature, is starch. It can be used as a carrier in encapsulation processes with different purposes, having advantages such as inexpensive, non-toxic, capable of recrystallization, the ability to form film and complex and resistant to various degrees of enzymatic hydrolysis. Spatial configuration of amylose is changed in the presence of ligands such as iodine and linear alcohols, resulting in a left-handed helix which can trap ligands within or between curvatures derived from glucose connections. One of the major structures which is created in the interaction of amylose and lipophilic substances, is known as V-amylose structure. V-amylose is a left-handed helix with an inner hole which ligands can be placed within it. The aim of this study was to determine the effectiveness of amylose in nanoencapsulation of limonene as a bioactive compound with desirable sensory characteristics using a thermo-mechanical stress.
Materials and methods: Based on the analysis of pure limonene samples (Sigma-Aldrich) as well as samples used in this study, more than 92% of examined sample comprised of D-limonene. In order to prepare amylose nanoparticles containing limonene, 0.1 molar solution of potassium hydroxide (Merck, Germany) was prepared in deionized water and then high amylose corn starch (HACS) (Sigma-Aldrich (St. Louis, MO, USA) with 70% amylose was added to it in the ratios of 2: 4% while stirring continuously for 30 minutes at 80°C. Limonene was then used in the ratios of 5: 10% of HACS was added to the suspension and stirring continued for 1 minute. Initial suspension has been processed by using ultrasound system (Model UP100- Hescheler Company, Germany) with 100 W power and frequency of 30 kHz for 9 and 18 minutes. The viscosity of amylose suspensions containing nanoparticles with different formulations was measured by using a capillary viscometer (Schott-Gerate-Capillary-Viscometer-525-00- Germany). Size and zeta potential was measured by using dynamic light scattering (DLS) and Nanotrac Flex In-situ Particle Size Analyzer devices and Microtrac ZETA-check determined. The morphology of nanoparticles was studied using a scanning electron microscopy (TESCAN-Vega3- Czech Republic). Microencapsulation efficiency and loading efficiency were determined by using spectrophotometry.
Results and Discussion: In all formulations, particle sizewere less than 50 nm. Starch granules were exposed to cavitation stress by applying the ultrasonic process .The constant formation of bubbles creates a mechanical impact with high energy on starch granules during bursting. Fast impingement of fluid to granule surfaces, hitting particles to each other as well as resistant of the granules against fluid stream cause breaking of starch particles into nanoparticle scales. The highest amount of zeta potential was related to the sample which had the highest starch and limonene concentration. Amylose concentration had the main effect on zeta potential changes. Electrostatic charges can be the main reasons for the higher zeta potential in samples with 4% amylose concentration. More increasing in surface active agents of amylose, namely ionized hydroxyl groups of glucose molecules leads to increasing in surface charge, and results in zeta potential. The most impact on solutions viscosity is related to amylose concentration. Generally, increasing the amylose concentration leads to increasing the solution viscosity, in other side, with ultrasound treatment, the amount of this index was reduced and the solution became more fluent. Microencapsulation and loading efficiency values ranged between 28-82% and 0.38-1.63% respectively. The limonene concentration had the most impact on the efficiency in various formulations. At similar treatments with %4 amylose concentration and 9 min sonication period, by increasing the amount of limonene from %5 to 10, microencapsulation and loading efficiency were increased from %31 to %82 (%62 growth) and from 0.52 to 1.41 (%63 growth) respectively.
Mohammad Hossein Naeli; Reza Esmaeilzadeh kenari
Abstract
Various mechanical, enzymatic and chemical techniques are used to improve the quality levels of meat. Such techniques have disadvantages such as being time-consuming and damaging to the meat quality indicators. Ultrasound is used as an effective method to modify technological properties and tenderize ...
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Various mechanical, enzymatic and chemical techniques are used to improve the quality levels of meat. Such techniques have disadvantages such as being time-consuming and damaging to the meat quality indicators. Ultrasound is used as an effective method to modify technological properties and tenderize the meat. The meat samples (Flank area) were put into brine solution or a mixture of the phosphate-brine solution under the ultrasound bath (at a frequency of 37 kHz) and probes (20 kHz) in 20, 25 and 30 minutes at 30, 40 and 50°C. The changes in the technological and textural properties of meat samples were then investigated. The results showed an increase in pH (from 5.55 for control up to 7.14), water-holding capacity (from 20.00 % for control up to 38.15 %), water-binding capacity (from 12.63 % for control up to 31.65 %) and a reduction in the drip loss (from 12.50 % for control up to 3.21 %), cooking loss (from 36.70 % for control up to 16.46 %), hardness and chewiness, whereas showed an increase in tenderness. In general, ultrasound treatment probe in a solution of mixed polyphosphate-brine was more efficient. It is concluded that ultrasound is an effective technique to improve the meat quality.
Elahe Maghsoudlou; Reza Esmaeilzadeh kenari; Zeynab Raftani Amiri
Abstract
Introduction: Lipid oxidation is a complex series of reactions that occurs during processing, storage and final preparation of foods containing lipids (Bera et al., 2006). Among the various methods of protection against oxidation, specific additives are used which are antioxidants (Pokorny et al., 2006).Polyphenols ...
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Introduction: Lipid oxidation is a complex series of reactions that occurs during processing, storage and final preparation of foods containing lipids (Bera et al., 2006). Among the various methods of protection against oxidation, specific additives are used which are antioxidants (Pokorny et al., 2006).Polyphenols are natural antioxidants that possess characteristic properties, such as free-radical scavenging and inhibition of oxidizing processes in the body. For using of phenolic compound, they must be extracted from plant material. Traditional methods of extraction are labor-intensive, time consuming, and require large volumes of solvent (Wang and Weller, 2006(. In recent years, ultrasound-assisted extraction (UAE) has become an effective method for edible oils and fats from natural product extraction. UAE is an inexpensive, simple and efficient alternative to conventional extraction techniques (Chen et al., 2010). The mechanism of UAE is attributed to mechanical and cavitation efficacies which can result in disruption of cell wall, particle size reduction, and enhanced mass transfer across cell membrane (Wang, Wu, Chen, Yue, Liang, & Wu, 2013). Figs are an excellent source of phenolic compounds and some studies have described the presence of several phenolic compounds in this species (Solomon et al., 2006; Teixeira et al., 2006; Vaya and Mahmood, 2006). However, according to our knowledge, there are no studies about the detailed investigation of different parts of the fig and evaluation of its oxidative stability. Therefore, the objective of this study was to evaluate antioxidant activity of pulp and skin of two varieties of fig (Siyah and Sabz) and its application as natural antioxidant in canola oil.
Material and methods: Fig fruit (F. carica L.) from two selected commercial varieties: Siyah and Sabz wwere collected from Gorgan, Iran in September 2014. Canola oil was purchased from Alia Golestan Company (Kordkooy, Iran). All other chemicals used in this study were of analytical grade and were purchased from chemical suppliers such as Merck and Sigma-Aldrich Chemical Companies.
The figs were weighed and immediately peeled. The pulp was cut and made into flat sheets. Thereafter, the pulp and skin of each fruit were shade-dried for 5 days followed by drying at 60 ℃ in an oven for 24 hours to ensure complete drying (Memmert 100-800, Germany). The samples were then milled and sieved. Samples obtained were kept in polyethylene bags.
Dried fig powders were mixed with ethanol (1:10), then placed in ultrasonic bath, and then sonicated at 37 kHz for 20 min at 40°C by Elma Transsonic ultrasonic bath model 690/H (Cottbus, Germany). The extract was filtered and subsequently evaporated at 40 ℃ in an oven. The concentrated extracts were stored at -18 C until further analyses (EsmaeilzadehKenari et al., 2014).Extracts were used in concentrations of 0.5, 1, 1.5, 2, 2.5 and 3 mg/ml.
Phenolic compounds and flavonoids were measured by Folincio-calteu and aluminum chloride, respectively. The antioxidant activity of the extracts was evaluated using DPPH and reducing power tests. Then we assessed the efficiency of extract of skin fig of Siyah variety at 1 mg/ml the oxidative stability using Peroxide, thiobarbituric acid, conjugate di en, acid value, Oxidativestabilityindexand colorindex in canola oil during thermal conditions (180 ℃, 24 hours) compared with Synthetic antioxidants of TBHQ.
Results and discussion: The fig extracts contained different antioxidative fractions which were able to inhibit lipid oxidation effectively, by different mechanisms of action. Antioxidant activity of Siyah variety extract was higher than that of Sabz variety extract; furthermore, skin extracts were found to render higher antioxidant activity than pulp extracts. The stabilization effect of Siyah fig skin extract on canola oil (using peroxide, thiobarbituric acid, conjugate di en, acid values, oxidative stability index and color index) was comparable with the synthetic antioxidant (TBHQ).Therefore, skin of Siyah fig can be used as a potent source of natural antioxidant in food system.
Forough Gillani; Zeynab Raftani Amiri; Reza Esmailzadeh Kenari
Abstract
Introduction: Cornelian cherry (Cornus mas L.), which belongs to the family Cornaceae, grows in Iran, in areas such as Qazvin and Arasbaran. The fruit possesses anti-inflammatory and antioxidant properties and it is used as an herbal remedy in medicine. Separation of natural antioxidant compounds from ...
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Introduction: Cornelian cherry (Cornus mas L.), which belongs to the family Cornaceae, grows in Iran, in areas such as Qazvin and Arasbaran. The fruit possesses anti-inflammatory and antioxidant properties and it is used as an herbal remedy in medicine. Separation of natural antioxidant compounds from plant sources requires an appropriate method of extraction, which is effective factor to achieve the higher efficiency of these valuable compounds. In this study, the effect of extraction methods (immersion and ultrasound) and different solvents (ethanol 100%, ethanol – water (50:50 V/V) and water) on amount of phenolic compounds and antioxidant properties of cornelian cherry fruit extract were investigated.
Materials and Methods: Qazvin cornelian cherry was purchased from the local market of Amol city, Mazandaran province, Iran. All solvents and chemicals used in this study were of analytical reagent grade and were prepared from Merck (Darmstadt, Germany) and Sigma–Aldrich (St. Louis, MO). Cornelian cherry was washed, core separated, dried in front of the sun for 5 days and then powdered with kitchen miller. Powdered cornelian cherry fruit was extracted using immersion extraction techniques, ultrasound and different solvents (ethanol 100%, ethanol –water (50:50 V/V) and water). In the immersion method, powdered cornelian cherry fruit were mixed with each solvent in the ratio of 1:10, individually. Then, the mixtures were shaken overnight at room temperature. After 24 hrs, the extracts were filtered through Whatman No. 42 filter paper and the solvents were evaporated in an oven at 55°C. In the ultrasound technique, the mixture of powdered samples with any solvent (1:10) was sonicated in an ultrasonic bath for 45 min at 35°C. The extracts were then filtered and the solvents were evaporated using an oven at 55°C. Finally, the extracts obtained from extraction methods were kept in a freezer for furthere experiments. The total phenolic content of the extracts was determined with the Folin-ciocalteau method, briefly, 0.5 mL of cornelian cherry fruit extracts with concentration of 1mg/mL were mixed with 2.5 mL of Folin–Ciocalteu reagent (previously diluted 10-fold with distilled water) and 2 mL of 7.5% sodium carbonate solution, then the samples were kept for 30 min at room temperature in the dark and at the end the absorbance of the solutions was read at 760 nm. The ability of the extracts to scavenge 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH) was determined. 0.3 mL of each extract with a different concentration (500-3000μg/mL) was mixed with 2.7 mL of methanolic solution of DPPH (6 × 10 -5 mole/L), then the mixture was shaken vigorously and was placed in the dark for 60 min. Absorbance was recorded at 517 nm. The percentage of the DPPH radical scavenging was calculated according to the following equation:
% inhibition of DPPH radical= [(ADPPH – AS) / ADPPH] ×100
AS and ADPPH are the absorbance of the solution the absorbance of the DPPH solution, respectively. Reducing power of extracts on iron ion was measured. 1mL of each extract with a different concentration (500-3000μg/mL) was mixed with 2.5 ml of phosphate buffer (0.2 M, pH= 6.6) and 2.5 ml potassium ferricyanide [K3Fe(CN)6] (1%), then the mixture was incubated at 50° C for 30 min. After that, 2.5 ml of 10% trichloroacetic acid were added to the mixture, then, was centrifuged at 1000g for 10 min. Subsequently, 2.5 ml of the upper layer solution was mixed with 2.5 ml of distilled water and 0.5 ml of 0.1% FeCl3. Finally, the absorbance values of the solutions were read at 700 nm.
Results and discussion: The result of this study showed that the type of solvent and extraction method has been effective on amount of phenolic compounds of extracts, and also concentration dependent of phenolic compounds with antioxidant activity was observed in all extracts. The highest amount of phenolic compounds with 142.72 mg/g (based on Galic acid) was observed in sample extract obtained from solvent of water- ethanol (50:50 V/V) employing ultrasound method. Also, this extract with the lowest IC50 value with the amount of 0.955 mg/ml in the DPPH free radical scavenging method and the highest absorption with the amount of 0.601 in the reducing power of Iron III test, the highest antioxidant performance is shown. A negative correlation was observed between the total phenolic content and the IC50 value in the methods of measuring the antioxidant activity (DPPH and reducing power), which revealed the higher total phenolic content will give the lower IC50, that means the higher antioxidant activity. The results of present research showed that cornelian cherry fruit is a natural source of phenolic compounds and have considerable antioxidant activity.
Mohammad Dolatabadi; Zeynab Raftani Amiri; Reza Esmaeilzadeh kenari
Abstract
Introduction: In recent years, much attention has been focused on agricultural wastes especially those containing phenolic compounds with natural antioxidant properties. One of these sources is the green husks of walnuts. The contents of phenolic compounds of plants are influenced under various factors ...
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Introduction: In recent years, much attention has been focused on agricultural wastes especially those containing phenolic compounds with natural antioxidant properties. One of these sources is the green husks of walnuts. The contents of phenolic compounds of plants are influenced under various factors including genetic factors, agricultural varieties and the species, climate and extraction procedures. Extraction is the first step for researchers who work on plants. Traditional extraction techniques with solvent such as water have disadvantages such as time consuming process, solvent consumption and high labor work. So the need to develop and use new extraction techniques, including combination of ultrasound bath and microwave devices, has provided valuable results. This method increases the mass transfer rate of the cell wall and intracellular compounds more rapidly transported out of the cell. In the ultrasound method to create cavitation in the extraction process and with collapse of bubbles and mechanical effects on the cell wall and most influential into the cell solvent improves the mass transfer. Extraction process performed by ultrasound process was used to facilitate the release of the intracellular content. These two methods can increase extraction efficiency within a shorter time and using less solvent, increasing the amount of extracted compounds are less damaging to the environment. Three different weather conditions for walnut production in northern Iran and different methods for extraction and measurement of phenolic compounds were adapted to find the best area and the most efficient extraction method.
Materials and methods: Three areas were selected from north parts of Iran including Bandar Gaz with mild climate, Shahrood with semi-arid climate and Hezarjerib region with mountainous climate located in the Alborz Mountain chains in which walnut is one of their major products. Walnuts randomly were picked by hand without any damage to their husks from a few walnut trees in a random garden in each region. The selected walnut trees were almost similar and were about 35 to 40 years old. In the selected areas, it is not conventional to use pesticides or chemicals and toppings for walnut trees. Walnuts collected were transported to the lab in cold conditions (8 to 10° C) and after cleaning the walnuts, green husks were separated and kept at -18 °C. Solvent extraction of phenolic compounds was carried out by choosing ethanol - water in a ratio of (1-1) by soaking, ultrasound and microwave methods at different times. The amount of phenolic compounds was measured using a spectrophotometer device with the aid of using the Folin Ciocalteau reagent, and antioxidant properties were measured using DPPH free radical scavenging and regenerative power of Iron III.
Results and discussion: This research was carried out on a factorial design (334) with three replications with Duncan's test for comparison of averages at the 95% confidence level. Comparing the extraction methods (soaking, microwave and ultrasound) showed that the most efficient method was ultrasound method at 30 minutes and the highest phenolic compounds in walnut green husk was for Hezarjerib area. In addition to the savings in time of extraction and safety in this method, the extraction of phenolic compounds is preferred to the other two methods. The results showed that the antioxidant properties were increased with increase in the amount of phenolic compounds. The results of this study also revealed that the walnuts green husks from Hezarjerib had the highest antioxidant properties followed by temperate region (Bandargaz) and semi-arid region (Shahrood).
Atefeh Farahmand; Mehdi Varidi; Arash Koocheki
Abstract
Introduction: Exploiting natural substances with dual or multiple functionalities is getting more attention in food industry due to the requirement from the health- conscious consumers and the trends for sustainable environment. Hydrocolloids are high molecular weight macromolecules that can be easily ...
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Introduction: Exploiting natural substances with dual or multiple functionalities is getting more attention in food industry due to the requirement from the health- conscious consumers and the trends for sustainable environment. Hydrocolloids are high molecular weight macromolecules that can be easily dissolved and dispersed in water under appropriate conditions. They can modulate rheological properties of foods, and are generally used as food thickeners, texture modifier, stabilizers and emulsifiers for various applications. Mucilage is a high molecular weight polyuronides consisting of sugar and uronic acid units. It is partially soluble in water and can form highly viscous solution. It exhibits hampering effect on the diffusion of glucose, help to postpone the absorption and digestion of carbohydrates. The mucilage extracted from the seeds of the quince fruit contained cellulose micro-fibrils strongly associated whit a glucuronoxylan possessing a very high proportion of glucuronic acid residues. Analysis of quince seed mucilage (QSM) has shown the presence of more cellulosic fraction and hydrolysable polysaccharide.Quince seed mucilage is one of the endemic hydrocolloids, which due to high viscosity, its extraction needs a method to reduce the extraction time, energy consumption and especially raise the extraction efficiency. The traditional extraction method of polysaccharide from plant tissues are maceration, mechanical rabbling and heat reflux. Theses extraction methods depend largely on energy input and agitation to improve the solubility and mass transfer efficiency of polysaccharides. Usually, the convention extraction method requires long extraction time and high extraction temperature with low extraction yield, but high energy consumption. Ultrasound in combination with conventional extraction is a potential technique, which is a fully reproducible food process, completed in shorter time with high reproducibility, reduced processing cost, simplified manipulation and work-up. To achieve this goal, in this study ultrasound- assisted extraction (UAE) as a novel extraction method was used.Materials andMethods:Quince seed used in this study was purchased from a local market (KhorasanRazavi, Mashhad). They were cleaned manually by removing the foreign matter such as stones, dirt and broken seeds. They were packed in hermetic plastic vessels and stored at 5ºC until further use. For mucilage extraction, first conventional extraction was optimized to select the best hydration conditions and after that UAE (24 KHz probe and 400 W power) was performed at three different levels of intensity (20, 60 and 100%) and times (5, 15 and 30 min).All chemicals used were analytical grades. Yield value of hydrocolloid was calculated by dividing the weight of dried hydrocolloid by the weight of initial dry seeds. Emulsion heat stability was determines by the method described in previous studies. In order to measuring the water absorption capacity (WAC), 0.05 g of mucilage was added to deionized water until QSM was completely wet (~ 10ml). The tubes were then centrifuged at 1600×g for 10 min. Excess water was discarded and residue was weighted. Apparent viscosity of QSM solution with 0.1% (w/v) concentration was measured using a rotational viscometer (Brookfield, DV- ІІІ, USA). Shear rate increased linearly from 2.5 - 35 s-1 at 25˚C.For measuring the foam stability and emulsion heat stability, the mucilage dispersions were prepared at 0.25 and 0.5 (w/v) respectively, and kept overnight at 4˚C. After complete hydration, 2% (w/v) egg white powder was added and then foamed by whipping at 8600 rpm for 2 min using adisperser.Results and Discussion: Optimized conditions of conventional extraction were 45 min, 47˚C and 32.5: 1 water to seed ratio. The results showed that extraction at 30 min with 100% intensity raised the extraction yield to 42.7% in comparison with control sample.Improvement in hydrocolloid extraction by ultrasound is attributed to ultrasound pressure wave diffusion which results in cavitation phenomenon.Amplitude level and exposure time had a significant (p
Elahe Maghsoudlou; Reza Esmaeilzadeh kenari; Zeynab Raftani Amiri
Abstract
Recently, Subcritical Water Extraction (SWE) has been well known as a green technology for extraction of bioactive compounds from plants. In this study, Subcritical water extraction, ultrasound assisted extraction (UAE) and shaker solvent extraction (SSE) were compared for extraction of phenolic compounds ...
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Recently, Subcritical Water Extraction (SWE) has been well known as a green technology for extraction of bioactive compounds from plants. In this study, Subcritical water extraction, ultrasound assisted extraction (UAE) and shaker solvent extraction (SSE) were compared for extraction of phenolic compounds from fig (Ficuscarica) pulp and skin. Antioxidant activity of the extracts was evaluated using DPPH radical scavenging, reducing power and rancimat tests. Subcritical waterhad the highest ability for extraction of total phenolic content (65.89±0.21 and 80.79±0.09 mg of gallic acid equivalents per gram of extract respectively) and flavonoid compounds (7.51±0.33 and 10.1±1.02 mg of quercetinequivalents per gram of extract, respectively)from both pulp and skin.The lowest IC50 in DPPH radical scavenging and reducing power tests were related to SWE of skin extract of fig. Furthermore, in extraction of total phenol and flavonoid compounds, subcritical water extraction showed to be a more suitable method than other solvent extraction methods, both in pulp and skin.
Fatemeh Roshani; Sara Movahhed; Hossein Ahmadi Chenarbon
Abstract
Introduction: Potato is raw food stuff with high popularity worldwide when deep fried. Deep frying is a fast budget process used for preparing savory food. In this process, oil is used both as a heating intermediate and as an ingredient producing calorific products. Nutrition has become a major health ...
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Introduction: Potato is raw food stuff with high popularity worldwide when deep fried. Deep frying is a fast budget process used for preparing savory food. In this process, oil is used both as a heating intermediate and as an ingredient producing calorific products. Nutrition has become a major health concern, particularly in developmental countries where obesity has turned into an ever-increasing problem, mostly among children. Deep frying is a widely-practiced method for cooking fast foods with desirable sensory properties. Frying is a process of simultaneous heat and mass transfer where heat is transferred by a combination of convection and conduction. At high temperatures, a great amount of moisture content is also lost as vapor, compensated by oil uptake in foods. Oil uptake of foods is an important concern associated with their moisture loss. Thus, it is important to examine moisture loss during frying. Today, the interest in production and consumption of low-fat French fries is on the rise. At the same time, the frying method has a great effect on quantitative and qualitative characteristics of foods. The final moisture content in French fries is about 38% of the product’s final weight. sufficient moisture content is therefore required in French fries to achieve both a soft moist core and a crunchy tasty crust. Numerous methods or pretreatments such as ultrasound and drying may improve these properties. Moreover, finding relationships between different variables during deep frying by modelling may provide an optimal control over process conditions thereby improving the quality of the final fried product. In the present study, effects of ultrasound and drying pretreatments on moisture content, oil uptake, activation energy and effective moisture diffusion coefficient in Satina potato slices during deep frying were investigated. Material and methods: 10kg of Satina potatoes were provided and stored at room temperature. Bahar vegetable frying oil containing cotton seed, sunflower and soybean oils was used for frying. For each experiment, potatoes were washed, peeled and sliced by a household French fry cutter with 1.2×1.2×4 cm dimensions. The cut samples were placed in a plate to avoid moisture loss and were washed with distilled water to remove surface starch before frying. The excess surface water was also removed by a hygroscopic paper. Then ultrasonic pretreatments at two frequencies of 20 and 40 kHz were applied for 15min, and the drying pretreatment was also conducted at 60°C for 15min. To fry the samples the fryer was filled with 1.5 lit of oil. The deep fryer was set to adjust temperature and frying time automatically. When the temperature reached the set value, 100-120g potato samples were placed in the frying basket, which was then submerged in oil automatically. The pretreated samples were fried at 170°C and 190°C for 5, 7 and 10 min. Oil uptake and moisture loss during frying were recorded at certain time intervals. Next, the fried samples were removed from the deep fryer and were placed on a mesh tray to remove the excess oil. The oil uptake and moisture content were analyzed. Oil content was measured by the Soxhlet method. It is based on extracting fat from foods using proper solvents. Moisture content was measured by drying in a convection oven at 105°C until reaching a constant weight. Moisture content and oil uptake of potatoes slices during deep frying were also modeled versus time. The factorial experiment was laid out in a completely randomized design with three replications, and means were compared using Duncan’s multiple-range test. SPSS 14 was used for statistical analyses. Results & Discussion: According to the results, samples pretreated with 20 kHz ultrasound at the same temperature and time conditions had higher moisture content than those treated with the 40 kHz frequency. The highest moisture content was found in samples pretreated with 20 kHz at 170°C for 5min. On the other hand, samples receiving 40 kHz ultrasound pretreatment showed higher effective moisture diffusion coefficient and activation energy than those receiving the 20 kHz pretreatment. The highest diffusion coefficient was achieved using 40 kHz at 190°C for 5min, whereas the highest activation energy was observed with 40 kHz at 170°C for 10 min. It should be mentioned that the effective diffusion coefficient was within the 6.95 × 10-8 – 8.80×10-8 m2/s (R2=0.99) range. Activation energy was also in the range of 13.161 – 16.307 kJ/mol (R2=0.99). Conclution: Samples pretreated with 40 kHz ultrasound showed the lowest oil uptake as compared with those pretreated with 20 kHz frequency. The highest oil uptake was observed for samples pretreated with 20 kHz at 170°C for 10 min. Through the multivariable regression analysis, it was found that the exponential model had the best fitting in predicting changes in moisture content and oil absorption.
Roksaneh Rouhani; Soudabeh Einafshar; Reihaneh Ahmadzadeh Ghavidel
Abstract
Sepals and petals are byproducts from saffron production process that waste without any use in Iran. These byproducts containing a lot of anthocyanin and natural antioxidants.The aim of this study is determine efficiency of extraction and measurement of antioxidant activity and anthocyanin pigments of ...
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Sepals and petals are byproducts from saffron production process that waste without any use in Iran. These byproducts containing a lot of anthocyanin and natural antioxidants.The aim of this study is determine efficiency of extraction and measurement of antioxidant activity and anthocyanin pigments of pollen and anther of saffron flower ,using mixed solvent of ethanol and hydrochloridic acid 1.5 N (85:15) by ultrasonic waves. Therefore, the time factors (5, 15, 25 minutes) and sound intensity (20, 60 and 100%) were usedThe results showed that the most efficient extraction of samples (54/48%) was extracted in 15 minute and 100% of sound intensity, and the maximum measure of anthocyanin compounds (48.83 mg/ml), total phenolic compounds (36.54 mg/ml), power of reviving the anti-radical DPPH activity of the extracts (335.7 mg/ml) and the power of scavenging Fe III (431.1µmol/lit Fe III), the best sample in all of the exams was extracted in 10 minutes and 100% of sound intensity. So, the optimized situation for extraction of anthocyanin compounds by ultrasound waves was time 15 min and 100% about sound intensity.
Mahdi Barmour; Jalal Dehghan nia; Babak Ghanbarzadeh
Abstract
The objective of this study was to evaluate the effect of process conditions and different pretreatments including ultrasound, microwave and osmotic dehydration on mass transfer and oil uptake during deep fat frying of potato slices. Ultrasound pretreatment was performed at frequency of 40 KHz for 10 ...
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The objective of this study was to evaluate the effect of process conditions and different pretreatments including ultrasound, microwave and osmotic dehydration on mass transfer and oil uptake during deep fat frying of potato slices. Ultrasound pretreatment was performed at frequency of 40 KHz for 10 and 30 minutes, microwave pretreatment was conducted at 5 W/g power and osmotic dehydration pretreatment was done in NaCl solutions with concentrations of 1 and 3 percent. Potato slices were then fried at 150, 170 and 190°C for 90, 180, 270 and 360 seconds. The results showed that ultrasound pretreatment for 10 minutes increases oil uptake of samples as compared with control sample, but when samples were exposed to ultrasound for 30 minutes, oil uptake was decreased. In addition, microwave pretreatment reduced oil uptake of potato slices insignificantly. Furthermore, osmotic dehydration pretreatment reduced oil uptake. In order to model oil uptake, experimental data were fitted with 6 models. The aforementioned models had the highest R2 and a minimum value of RMSE.
Elahe Eshraghi; Mahdi Kashani-Nejad; Yahya Maghsoudlou; Shahram Beiraghi-Toosi; Mehran Alami
Abstract
The aim of this research was to use Osmosis-Ultrasound Compound pre-treatment and studying the time of drying and the potentiality to rehydration in dried samples of kiwi fruit (Hayvard variety). The samples were drained in three timed phases, 10, 20 and 30 minutes in room temperature in 30, 50 and 70 ...
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The aim of this research was to use Osmosis-Ultrasound Compound pre-treatment and studying the time of drying and the potentiality to rehydration in dried samples of kiwi fruit (Hayvard variety). The samples were drained in three timed phases, 10, 20 and 30 minutes in room temperature in 30, 50 and 70 BX in Ultrasound bath osmosis solutions. The results of drying time showed that by decreasing the concentration of kiwi fruits samples from 8 to 6 mm and increasing the concentration of osmosis solution and ultrasound time, the time of gaining 20% moisture decreased for each treatment. The studies showed that the minimum time for getting 20% moisture in 6 and 8 mm kiwi fruits in pre-treated samples with 70 BX and 30 minutes ultrasound time is 263 and 313 minutes respectively. The results of rehydration in pre-treated compound samples showed that by increasing the concentration of osmosis solution, as well as the time for Ultrasound waving and increasing the kiwi fruits samples concentration from 6 to 8 mm, the rehydration decreased compared to control sample. The results of perceptive assessment in general acceptance of dried kiwi fruit showed that using pre-treated compound sample was more acceptable than the control sample.
Mahboubeh Ostadzadeh; Soleiman Abbasi; Mohammad Reza Ehsani
Abstract
Despite the potential of high intensity ultrasound treatment on homogenization of milk and dairy based products, this treatment, under certain conditions, may lead to produce off-odors which can influence its applicability in the food industry. Therefore, in this research, cacao flavored milk (chocolate ...
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Despite the potential of high intensity ultrasound treatment on homogenization of milk and dairy based products, this treatment, under certain conditions, may lead to produce off-odors which can influence its applicability in the food industry. Therefore, in this research, cacao flavored milk (chocolate milk) was treated using ultrasound at various levels of power intensity, exposure time, and treatment temperature. A light microscope equipped by high resolution digital camera was used to evaluate the size distribution of cocoa particles. Finally, the color, flow and viscosity, and sensory characteristics of stabilized samples were determined. According to the findings, increase of power intensity and exposure time led to a significant increase on the degree of homogenization, and subsequently a paramount decrease on the size of cocoa particles. The cocoa particle diameters of chocolate milk which sonicated at 65 ºC were significantly smaller than the other temperatures. Moreover, the stabilized samples showed Newtonian behavior where the viscosity of control was lower than those treated by ultrasonic. With increase of ultrasound power intensity and exposure time, the viscosity of treated samples decreased. In terms of color, the sonicated samples showed higher L* values and the increase of power intensity and exposure time led to a significant increase on L* value. These samples gained lower sensorial scores than control mostly due to their ‘rubbery’ aroma. But, overall acceptance of treated samples had no significant difference against control. The ultrasound is an effective, rapid, and novel technique which can reduce the size of cocoa particles in order to produce stabilized chocolate milk where its color, sensory and rheological properties was very similar to one treated by conventional heat treatment. These findings can open new approaches in terms of its applicability in dairy industry.
