Food Technology
Fatemeh Shokrollahi; Fakhri Shahidi; Mohammad Javad Varidi; Arash Koocheki; Farshad Sohbatzadeh
Abstract
IntroductionSorghum is a valuable source of starch for human use, being a drought-tolerant cereal grain that contains a large amount of starch (approximately 70%). However, native sorghum starch has limited application in the food industry due to its poor functional properties. Modification of sorghum ...
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IntroductionSorghum is a valuable source of starch for human use, being a drought-tolerant cereal grain that contains a large amount of starch (approximately 70%). However, native sorghum starch has limited application in the food industry due to its poor functional properties. Modification of sorghum starch would overcome its shortcomings and tailor it to the targeted application. Among physical methods, non-thermal plasma is a novel method for starch modifications. Plasma is an ionized gas including electrons, atoms, ions, radicals, and quanta of electromagnetic radiation that affects the functional properties of starch. The effect of plasma on starch is influenced by apparatus type, treatment conditions (feed gas, time, and power), and the source of starch. Two main mechanisms of starch modification are known as cross-linking and oxidation together with depolymerization. Although the effect of plasma on many types of starch has been investigated, no research has yet been found on sorghum starch modification by non-thermal plasma. So, this investigation determines the effects of non-thermal plasma on sorghum starch to overcome the deficiency of the native form and to explore wider applications for sorghum starch. Materials and Methods Sorghum starch was extracted by alkaline steeping and purified using toluene-salt-water treatment. Dielectric Barrier Discharge (DBD) plasma was performed to modify sorghum starch. The applied DBD plasma setup consisted of two flat rectangular aluminum electrodes with the dimension of 6.5×45 cm and 7×18 cm and an electrode distance of 3 and 6 mm for air and argon plasma, respectively. Each of the electrodes was covered with a mica sheet as a dielectric barrier. DBD reactor was supplied with alternating current (AC). The frequency was adjusted to 375 Hz. Starch samples were treated for 1, 10, and 20 min at 23 kV at atmospheric pressure. The amylose content of sorghum starch was determined by iodine binding colorimetry. Evaluation of other chemical parameters including protein, lipid, ash, and moisture was carried out according to AAC methods. The clarity was determined using a spectrophotometer at 650 nm. The swelling and solubility of 1.5% sorghum starch suspension (at 55, 65, 75, and 85 °C) were measured using the centrifuge method. The centrifuge-filtration method was performed to evaluate freeze-thaw stability of sorghum starches up to 4 cycles. Results and Discussion Chemical parameters showed that the extracted sorghum starch was purified. The amount of protein, lipid, ash, and amylose was 0.39, 0.15, 0.59, and 29.23%, respectively. Plasma caused significant altering in sorghum starch properties. Compared to the argon plasma, the air plasma was more effective at increasing the clarity, solubility, and freeze-thaw stability. Increasing the time of treatment also improved the above-mentioned functional properties. The clarity of native starch (14.02%) was increased to 56.10% for the sample treated with air plasma for 20 min, probably due to intense oxidation and depolymerization of starch molecules. While the lowest clarity (13.07%) belonged to the 1-min argon plasma treated sample, this value was improved with increasing time of treatment. Probably cross-linked bonds were predominantly formed during the first minute of argon plasma treatment, resulting in a reduction of paste clarity, while a competitive depolymerization and oxidation reaction could be a reason for the increase of paste clarity. Solubility was increased for all treatments (except for argon-1 min). The highest solubility in each of the temperatures was found for 20 min air plasma treated sample. Depolymerization of starch molecules under plasma treatment produces low molecular weight fragments which leach out easily and increase solubility. The swelling power of 20 min air plasma treated starch was lower than that of native starch, probably due to the structural disintegration. Other samples had higher swelling power. The lower freeze-thaw stability of 1 and 10 min argon plasma treated samples may be due to cross-linking which increase retrogradation. The 20 min air-plasma treated sample had higher stability than other samples in 3 and 4th cycles of freeze-thawing. The freeze-thawing stability of other samples was similar to that of the native starch. Conclusion Non-thermal plasma treatment improved the functional properties of sorghum starch. The best results were detected for the sample treated with air plasma for 20 min. Cross-linking may be the main reaction in the first minute of argon-plasma treatment. However, this mechanism was suppressed in a longer treatment time. It may also be stated that the effect of oxidation along with depolymerization was predominant in air-plasma treatment.
Food Engineering
Fatemeh Heydari; Mohebbat Mohebbi; Mohammad Javad Varidi; Mehdi Varidi
Abstract
The effect of various levels (5, 10 and 15%) of fish protein concentrate (FPC) in batter formulation was investigated. The physicochemical properties of chicken nugget were evaluated in order to find the optimium level of FPC in batter formulation. Flow behavior showed that the control batter and a treatment ...
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The effect of various levels (5, 10 and 15%) of fish protein concentrate (FPC) in batter formulation was investigated. The physicochemical properties of chicken nugget were evaluated in order to find the optimium level of FPC in batter formulation. Flow behavior showed that the control batter and a treatment contains of 7.5% FPC had higher viscosity. Moisture loss and fat uptake in control sample was higher than all treatments contain FPC in both deep fat and air fryer. Thicker crust resulted by higher level of FPC in batter leads less oil uptake during frying. Moreover, the samples contain FPC had the highest score in terms of texture and overall acceptability. In spite the fact that nuggets contain FPC had the high rate of our research priorities, however, the level around 15% considered as a limitation. Using desirability optimization, the range between 7.5- 8% of PFC in batter formulation was selected as the best level.
Mohammad Ebrahim Goharjoo; Mohammad Reza Edalatian Dovom; Fakhri Shahidi; Farideh Tabatabaei Yazdi; Mohammad Javad Varidi
Abstract
Introduction: Carrot products such as carrot juice and fermented carrot products possess high nutritional value and they are considered as a major source of β-carotene. Carotenoids because of containing conjugated double bonds, have antioxidant properties and provide the natural yellow, orange and red ...
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Introduction: Carrot products such as carrot juice and fermented carrot products possess high nutritional value and they are considered as a major source of β-carotene. Carotenoids because of containing conjugated double bonds, have antioxidant properties and provide the natural yellow, orange and red colors in fruits and vegetables. Due to the outbreak of some problems such as lactose-intolerance and high blood cholesterol especially in dairy products’ consumption, great attention has been drawn toward fermented vegetable products. Lactic acid bacteria (LAB) including important genera: leuconostocs, lactobacilli, streptococci and pediococci are wide-spread and have been divided according to morphological features and fermentation pathway, which utilize glucose. Current knowledge regarding involved microorganisms in vegetable fermentation is still dependent on biochemical and classical data. Nowadays, application of molecular methods in the field of microbial identification has been provided better understanding from fermented foods ecology. Since local starter cultures are considered as precious genetic resources in each country and also they play an important role in production and creation of organoleptic characteristics in fermented products, therefore, the objective of present study was the isolation and identification of lactic flora from fermented carrot with the help of conventional (biochemical) and molecular methods and determination of phylogenetic relationships.
Materials and methods: Following the production of fermented carrot samples, they were packed in plastic container and stored at ambient temperatures (25-27°C). In the next step, total LAB count was performed according to Iranian standard of 5484. Isolation and selection of LAB was done during 32 days with the intervals of 0, 4, 8, 16, 24 and 32. For initial identification of LAB, isolated were subjected to gram staining and catalase tests. Also biochemical tests including growth at 15 and 45C, at NaCl 6.5% and 18%, pH=4.4 and 9.6, were done in order to identify and classify at genus level. Carbohydrate fermentation profiles were obtained for isolates with the aid of 10 sugars. Molecular identification was done with DNA extraction followed by amplification of 16S gene with universal primers (27 F and 1492 R). For sequencing of resulted PCR-products, they were sent to Macrogen Company, South Korea. Phylogenetic tree was plotted with Clustal Omega and Fig. Tree soft wares.
Results and discussion: In the first step, 144 gram positive, catalase negative isolates were screened and selected as presumptive LAB according to gram staining and catalase test and morphological characteristics. Among them, 48 representative isolates were chosen and identified up to genus level according to biochemical tests. Five distinct genera were identified as Pediococci (4.08%), homofermentative lactobacilli (34.69%), hetero fermentative lactobacilli (36.74%), Leuoconostocs (20.41%) and enterococci (4.08%). Carbohydrate fermentation profiles revealed Lactobacilli constitute the highest percent among other genera and also some species like Lb. kimchi and Lb. parakefiri were detected. Growth of lactic acid bacteria experienced increasing trend up to day-16 but thereafter showed decline trend until the end of storage time (day-32). 26 out of 48 isolates were subjected to molecular analysis. Results of sequencing revealed following species: Lb.plantarum (9), Lb. brevis (8), Leu. mesenteroides (4), Lb. casei (1), Lb. paracasei (1), and Lb, pantheris (1). Changes and variation of lactic flora during fermentation stages revealed that at initial stages of fermentation (0- day-8) Leuconostocs sp. were predominant species but disappeared then. In the next stages of fermentation Leuconostocs sp. were replaced by homo-fermentative strains such as Lb. plantarum which was present from the first day up to day-24 but constituted the majority of species on day-16. In the final stage, Lb. brevis dominated the others due to better survival and resistance of this bacterium at the increased acidity level. Phylogenetic tree results revealed three clusters including cluster I (composed of three sub-clusters), cluster II (three sub-clusters) and cluster III (two sub-clusters). Cluster I included two genera: Leuconostocs sp. (mesenteroides) and Lactobacillus (pantheris, casei and paracasei). Cluster II included Lb. brevis and finally cluster III composed of Lb. plantarum.
Shakiba Kianiani; Mohammad Javad Varidi; Mehdi Varidi
Abstract
Introduction: Meat and meat products contribute about 20% to human fat consumption. Fat is the main source of energy and the base of fat soluble vitamins. Besides, it improves cooking yield and water holding capacity, conserves taste and flavor of products and affects the emulsion stability, juiciness, ...
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Introduction: Meat and meat products contribute about 20% to human fat consumption. Fat is the main source of energy and the base of fat soluble vitamins. Besides, it improves cooking yield and water holding capacity, conserves taste and flavor of products and affects the emulsion stability, juiciness, costumer acceptability and structural and rheological properties of meat products. But Animal fat contains a relatively high amount of saturated fatty acids and cholesterol, which can increase the risk of cardiovascular disease, diabetes, cancer types and obesity. Thus, the meat industry is interested in merchandising fat-reduced meat products without neglecting the positive effects of fat on flavor and texture.
Various researches have shown that the substitution of fat on a polysaccharides base such as fibers, starch, gums, and gels have improved and modified the texture, residual moisture and freeze stability, and decreased the price of the products.
Aloe vera leaf gel contains about 99 – 99.5 % water and 1 - 0.5 % of the total solid content. On dry matter basis aloe vera gel consists of 55% polysaccharides, 17 % sugar, 16 % mineral, 7% protein, 4% lipids and 1% phenolic compounds (Lawless et al., 2014). The most important carbohydrates of aloe vera gel are the long chain polysaccharides, comprising glucose and mannose, known as the glucomannans [β (1, 4) – linked acetylated mannan]. All the solid content of aloe vera gel are surrounded by polysaccharide mucilage layer.
Literature review pointed out there have been little investigations into the functionality of aloe vera gel in the emulsion meat products. According to the importance of producing low - fat meat products from one hand as well as the nutritional values and health characteristics of aloe vera gel on the other hand, this study was designed to replace the fat with aloe vera gel in the production of low - fat German sausage.
Material and Methods: Sausage samples containing 40% of red meat (German sausage) were produced based on the conventional plants formula. animal fat and vegetable oil replaced by 0, 50 and 100% aloe vera gel in the German sausage formulation. All samples were cooked at 90°C temperature to achieve the core temperature of 70° C, followed by cooling, they were kept in the refrigerator (4°C) until the subsequent experiments. The AOAC (2000) methods were used for measuring the moisture content, the amount of fat, ash and protein. The amount of carbohydrate was calculated based on the calculation of the total weight difference from the sum of ash, protein, fat and moisture (according to the method FAO / WHO). The amount of energy was computed based on the total amount of energy from fats, proteins and carbohydrates. To measure the pH of samples by pH meter, method of choe et al (2013) was followed. The color analysis was done on the surface of sausage cuts by chromometer. The parameters of color include L* (lightness), a* (redness) and b* (yellowness) were measured. Texture parameters include hardness(N), cohesiveness, springiness (cm), gumminess (N), chewiness (N.cm), adhesiveness were determined by texture analyzer as described by Bourne (1978). The sensory attributes were evaluated by 10 trained panelists. A five-point hedonic scale rating (1= very bad, 2=bad, 3= neither bad nor good, 4= good, 5= very good) was carried out.
Results and Discussion: Physicochemical properties analysis indicated significant differences among meat products (p ≤.0.01). The addition of aloe vera gel resulted a decrease in fat percentage and amount of energy, an increase in moisture and carbohydrate, but the amount of pH, protein and ash content did not change. This study showed that reducing the fat content and replacing by aloe vera gel caused a significant difference in the amount of energy (p≤.0.01).With respect to the significant contribution of fat in the production of energy, the amount of energy was reduced as expected by reducing the fat of the formulation. The results indicated that the value of L * showed the negative and positive trends with animal fat and vegetable oil changes, respectively (p≤.0.01). b* decreased by reducing the amount of fat and oil (p≤0.01), but the value of a* always remained constant (p˃0.05). The presence of aloe vera gel in sausage caused a reduction in hardness, adhesiveness and gumminess (p<0.05), while it did not affect the amount of adhesiveness and cohesiveness of samples (p˃0.05).
The substitution of fat with aloe vera gel had a significant effect on the sensory characteristics of German sausage (p≤.0.01). By reducing fat and oil and adding aloe gel to the German sausage formulation, color acceptance score was decreased. In terms of panelists, the blank sample had the best color and the fifth sample color had the lowest score. Juiciness of the samples was increased by increasing the amount of gel. The results also showed that the fifth sample received the maximum score of juiciness. Sausages smell acceptance negatively changed by reducing the fat content and adding aloe vera gel. Third and fourth treatments got the highest texture score. Also, the third sample had the highest scores for taste and general acceptance. Chewiness analyzing showed that by increasing the amount of fat replacement the rate of this factor decreased. as well as the maximum rate of chewiness was related to the blank sample.
Mahsan Irajifar; Mohammad Javad Varidi; Mehdi Varidi; Younes Zahedi
Abstract
Introduction: Camel carcasses has lower fat content in comparison with cow, moreover, camel meat has relatively higher polyunsaturated fatty acids and lower cholesterol contents (Kadim et al., 2009a & 2006). However, calcium amount of camel meat is greater than that of cow, and its lower consumption ...
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Introduction: Camel carcasses has lower fat content in comparison with cow, moreover, camel meat has relatively higher polyunsaturated fatty acids and lower cholesterol contents (Kadim et al., 2009a & 2006). However, calcium amount of camel meat is greater than that of cow, and its lower consumption is partly related to this issue. With increasing demand of camel meat, more attention has been paid to the quality and chemical composition of it. Acid marinade can be used through the diffusion of the solution and its propagation over time as an extensive method to improve the meat tenderness (Yusop et al., 2010). Lactic acid is often used in the meat industry as an antimicrobial during carcass slaughter. In addition, lactic acid can improve meat tenderness (Hinkle et al., 2010). The aim of the present study was to determine the influence of lactic acid and sodium chloride on textural and sensory properties, also and proteolysis pattern of biceps femoris muscle of camel.
Materials and Methods: Six 4 to 7 years old camels were transported to the slaughterhouse in Mashhad (Iran). Slaughtering and dressing of camels were carried out according to Islamic methods. All chemicals and reagents in the experiments were of analytical grade and purchased from Merck and Sigma-Aldrich companies. Biceps femoris muscle was used as an experimental material, cutting into 2×2×5 cm3 pieces, and laid in lactic acid solutions (0, 0.5, 1, and 1.5% v/v, all accompanied with 2% w/v NaCl) at a ratio of 1 to 4 (meat to marination solution) within plastic bags. Marination process was carried out for 0, 24, 48, 72 h at 4 °C. The meats were then removed from the marinade and dried lightly. After that, moisture, ash, protein and fat contents of the meat were specified by AOAC (2002). Shear force was measured by TA.XT plus texture analyzer (Stable Micro Systems, UK) provided with a Warner-Bratzler shear force blade method in order to evaluation of meat tenderness (Byrne et al., 2000). Myofibrillar fragmentation index (MFI) was determined as described by zahedi et al. (1393). Sarcomere length was measured with the method of Botha et al. (2007). One-dimensional gel electrophoresis was determined as described by zahedi et al. (1393). Collagen content was specified by AOAC (1993). Sensory properties including color, texture, flavor, juiciness and overall acceptance were performed using a 5-point structured hedonic scale (Hoffman et al., 2006 & 2008). One-way analysis of variance (ANOVA) was used to determine the significant differences between treatments using SPSS software (version 19). Duncan’s multiple range test was used to compare the means.
Results and discussion: Acid concentration and marination time had a significant effect (p <0.05) on sarcomere length. It was likely due to the fact that the addition of acid led to increase in pure positive charges on myofibrils and cytoskeletal proteins. As a result, more repulsive forces were generated between the protein molecules of myofibrils. Eventually, myofibrils swelling caused distancing Z lines from one another, and increasing the sarcomere length (Ke et al., 2008). The results of analysis of variance showed that the concentration of lactic acid had a significant effect on MFI (p<0.05), and MFI value was less than zero at 0% concentration, however, it was non-significant in relation to the time (p> 0.05). The higher MFI values of the marinated samples may be due to the proteolysis of myofibrile proteins using D-cathepsins which activated at acidic pH (range 3-6). Meat samples marinated in the highest concentration for 72 h showed the lowest WBSF (p<0.05). The tenderising mechanism of acid marinades was believed to be including weakening of structures due to swelling of meat, increasing proteolysis by cathepsins, and conversion of collagen to gelatin at low pH during cooking (Berge et al., 2001; Offer & Knight, 1988). The retention time and acid concentration did not have a significant effect (p> 0.05) on the collagen amount of lactic acid treated samples. It was likely that low acid concentration, although affecting some of the parameters, is not suitable for degradation of connective tissue (Hinkle et al., 2010). Sensory analysis showed that tenderness of the samples marinated at with 1.5% acid received the highest score (p<0.05), which was consistent with the instrumental results. Acid concentration significantly affected (p<0.05) total acceptance of the samples. Higher levels of acid can be used for marinating without adversely affecting the consumer acceptance. Results from SDS-PAGE showed that number of seven bands on gels, on average, were belonged to intact proteins, and other bands were considered as peptides which resulted from proteins proteolysis, especially heavy proteins. Also, time had non-significant effect on band area of myosin heavy chain (p>0.05), while, acid concentration had a significant effect on the area of this protein (p<0.05). The band area of proteins C, α-actinin and actin proteins enhanced as a function of acid concentration and marination time (p<0.05).
In conclusion, we can claim that lactic acid and sodium chloride can be used as an effective acidic marination to improve biceps femoris muscle of camel meat. This method can be advice as a trick for tenderizing camel meat in household consumptions, restaurants and also meat industry, thereby increasing demand for camel meat in order to gain further healthy benefits of it.
Fatemeh Heydari; Mohammad Javad Varidi; Mehdi Varidi; Mohebbat Mohebbi
Abstract
In the present study the cow meat was replaced with camel meat (0, 25, 50, 75 and 100%) in burger formulation. Principal component analysis (PCA) was performed to understand quality variables differences and similarities of thirty-five sample burgers. Score plot, represents Principal component analysis ...
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In the present study the cow meat was replaced with camel meat (0, 25, 50, 75 and 100%) in burger formulation. Principal component analysis (PCA) was performed to understand quality variables differences and similarities of thirty-five sample burgers. Score plot, represents Principal component analysis of datasets derived from evaluated variables of thirty-five samples (samples contain of 0, 25, 50, 75 and 100% camel meat). Overall, six principal component was obtained which 65.8% of the total variance was concentrated into three first PCs. Cooked L*, cooked b* shrinkage, springiness, flavor, texture, juiciness, color and overall acceptability were the variables which separated by the first PC. The PC2 is characterized by the rest of instrumental texture parameters and the third by cooked a* and fat. The evaluation of score plot shows burgers contain higher amount of camel meat (50, 75 and 100%) had the higher moisture and fat content after cooking, higher scores in flavor, texture, juiciness and overall acceptability.
Mohammad Farhadi Chitgar; Mehdi Varidi; Mohammad Javad Varidi; Ahmad Balandari
Abstract
Introduction: Extensive researches into native plants as a source of functional food have been conducted over the resent years. Meanwhile, barberry has been utilized as one of the main medicinal plants in Iran and many other countries, from the past decades. Currently, it has been known pharmaceutical ...
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Introduction: Extensive researches into native plants as a source of functional food have been conducted over the resent years. Meanwhile, barberry has been utilized as one of the main medicinal plants in Iran and many other countries, from the past decades. Currently, it has been known pharmaceutical active ingredients like berberin have wide application in pharmaceutical industry. The genus of Berberis includes about 450–500 species of deciduous or evergreen shrubs in which four species B.integerrima, B.crataegina, B.vulgaris and B.orthobotrys are found in Iran. Iran is the first largest producer of barberry (B.vulgaris) in the world. Apart from that, other species in different parts of Iran grow in wild conditions. B. Integerrima is a thorny shrub with fragile branches to a height of 1 to 3 meters. Its fruits are small and red with a mild sour taste. There are 1-4 small oblong seeds inside. The changes in this species are important and can produce hybrid with other species. B. Integerrima fruits are consumed fresh or used in the preparation of traditional foods. Barberry fruit, which contains large amount of anthocyanins, can be used as an alternative to synthetic colorants. In addition, aqueous extract of barberry has beneficial effects on both cardiovascular and neural system suggesting a potential use for treatment of hypertension, tachycardia and some neuronal disorders, such as epilepsy and convulsion. The physical properties of barberry genotype are important to design the equipment for sorting, transportation, separation, processing and packaging. Identification of the chemical characteristics of Berberis genotype can lead in using them in the pharmaceutical or food industries. Therefore, in order to introduce these native species, physicochemical characteristics of three wild barberries were evaluatedMaterials and method:Three native seed genotypes from Semnan province were manually collected from Research Institute of Food Science and Technology (Mashhad). The harvested fruits were instantly stored inside ice box to minimize damages and transported to the laboratory. Over ripened and damaged fruits were separated. Some physical properties (size, geometric mean diameter, sphericity, area, mass and the weight ratio of seeds to fruit) of fruits were determined using 100 repetitions at the natural moisture content of fruits. Chemical properties of samples were determined as follows: total anthocyanin content by the pH differential, total phenolic content by modified Folin–Ciocalteu method, mineral elements amounts such as Potassium(K), Sodium (Na) and Calcium (Ca) by Flame Photometer and microelements (Fe, Cu, Mg, and Zn) by Atomic Absorption Spectrophotometer, Moisture, crude oil, crude protein, ash, reducing sugar, water-soluble extract, pH and acidity were determined according to Indrayan et al,1989 and Iranian National Standard No. 2685. All experiments (except physical properties) were repeated at least three times and results were expressed as mean ± SD. The significant differences between mean values of juice samples were determined by analysis of variance (one way-ANOVA) using Duncan’s test at a significance level of p< 0.05. Data analysis was performed using the SPSS 19.0 software.Results and Discussion: Results showed that in physical properties such as, fruit length there was statistically difference between genotypes. The number of seeds in the three genotypes varied between 1 and 4 numbers. The weight ratio of seeds to fruit was 11.88%, 10.84% and 10.68 in Noshin, Negarin and Parchin genotypes, respectively. All three genotypes contained high amount of protein, total carbohydrate, fat and ash (3.82-5.255%, 21.68-23.97%, 2.04-2.70% and 0.94-1.27%). Noshin contained the highest reduced sugar (8.03±0.222). So, it is sweeter taste than others. In accordance with result, the amount of anthocyanins (950.17-3927.60mg/L) and total phenol (9.75-12.35gr/L) were higher than these fruits in comparison to the other fruits like mulberry and blueberry that represents the health benefits of these wild plants. All the three genotype emerged as good source of minerals, especially K, Ca, Mg and Zn.
Samira Feyzi; Mehdi Varidi; Fatemeh Zare; Mohammad Javad Varidi
Abstract
Introduction: Plant proteins play a significant role in the human diet, and among which legumes are excellent foods with several nutritional and functional advantages and low price. Among legumes, fenugreek (Trigonella foenum graecum) seed, belonging to the Fabaceae family, is a great source of plant ...
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Introduction: Plant proteins play a significant role in the human diet, and among which legumes are excellent foods with several nutritional and functional advantages and low price. Among legumes, fenugreek (Trigonella foenum graecum) seed, belonging to the Fabaceae family, is a great source of plant proteins, with a total protein content of about 25.00 – 38.60%. Functional properties are defined as physical and chemical properties, which could be altered due to the protein source and procedures used for flour preparation, protein concentrate and isolate extraction. Physiochemical parameters such as pH, temperature, salt and ionic strength can also highly affect proteins, functional properties.Therefore, in this study color parameters and functional properties of fenugreek protein isolate (FPI) were investigated. Also, the effect of pH changes on protein solubility, foaming capacity (FC) and stability (FS), emulsifying capacity (EC) and stability (ES) was studied. Materials and methods: Fenugreek seeds were obtained from a retail market in Isfahan, Iran. All chemicals were of analytical grade, and were purchased from Sigma Chemical Co. (St Louis, MO, USA), and Merck KGaA (Darmstadt, Germany). Protein Isolation: Protein from 10g defatted fenugreek flour (DFF) was extracted with 0.33M sodium chloride solution; the ratio of DFF to NaCl solution was set at 1:20 (w/v) and pH was adjusted to 9.25. The stirring period was 2 h, during which pH was also adjusted. Aliquots were then centrifuged and supernatants were adjusted to pH 4.5 (isoelectric pH of fenugreek protein). Again, the protein solution was centrifuged in order to precipitate the protein. Protein precipitate was washed twice with deionized water, followed by centrifugation and resolubiliztion by adjusting the pH to 7.2. The extraction process was carried out at room temperature (25°C). Color parameters: A digital colorimeter was used to measure the color of full fat and defatted fenugreek flours, and FPI samples. Color parameters were recorded in L*a*b* space. Protein solubility: Protein solubility of FPI at pH 2-10 was determined. A 1.5% (w/v) solution of sample was made in deionized water for each pH. The solutions were treated with either 0.5M HCl or 0.5M NaOH to obtain certain pH (2-10), while stirring. The slurry was centrifuged to separate the supernatant. Protein content was determined by the Biuret method using spectrophotometer at 540nm wavelength. Calibration was done using bovine serum albumin (BSA) as external standard. Viscosity: A suspension of 5% (w/v) FPI in distilled water was prepared. Viscosity of sample was determined using a programmable Brookfeildrheometer, using spindle ULA at room temperature. Coagulated protein: Percent of coagulated protein was measured by preparing 0.2g of FPI in 10mL of 0.025M citrate-phosphate buffer (pH 7.0). The solution was stirred, followed by centrifugation. The remaining supernatant was heated for 15min in a 100°C water bath, after cooling the same procedure was repeated. The absorbance of both samples, before heating (A1) and after heating (A2), was measured at 540nm according to Biuret method. The percent of coagulated protein was calculated by the following equation: Coagulated protein = (A1 – A2 / A1) × 100 (1) Foaming capacity and stability: FC and FS were determined using 2% (w/v) FPI solution in distilled water. For each sample solution, the pH was adjusted to desired level (2, 3, 4.5, 6, 8, and 10). The solution was stirred slightly for 5min and then was whipped vigorously by a disperser. The volume of solution before whipping, also the total volume of solution and foam after whipping were recorded as V0 and V1, respectively. The foam capacity percentage was calculated as: FC (%) = (V1- V0/V0) × 100 (2) Foam stability was determined as the total volume of solution and foam at 30, 60, 90 and 120 min at room temperature and it was recorded as V2. Foam stability (FS) was calculated as: FS (%) = (V2 - V0) × 100/ (V1 - V0) (3) Emulsifying capacity and stability:For EC and ES, a 1% (w/v) FPI solution in distilled water was prepared. The pH was adjusted to desirable level (2, 3, 4.5, 6, 8, and 10) followed by stirring for 5min, then sunflower oil was added. The mixture was homogenized to make emulsion, followed by centrifugation. Then the height of both emulsified layer after centrifugation (H1) and the total height of content before centrifugation (H0) were measured. Emulsion capacity was calculated as: EC (%) = (H1/H0) × 100 (4) The ES (%) was calculated at 0, 30, 60, 90 and 120 min by measuring height changes (H2). ES (%) = (H2/ H1) × 100 (5) Results and Discussion: FPI with 89.1% protein content had significantly (p < 0.05) lower L* than DFF, while its L* was higher than the full fat fenugreek flour. Also, FPI showed shear thinning behavior with viscosity equal to 1150, 922.5 and 787.5 cP at 15, 30 and 50 (1/s) shear rates, respectively. pH changes had noticeable effect (p
Mohammad Farhadi Chitgar; Mohammad Javad Varidi; Mehdi Varidi; Fakhri Shahidi
Abstract
Barberry is an agricultural product, which is cultivated in large amounts, only in Iran. Its popularity as an ingredient for many by-products has grown recently. It contains anthocyanins which can be used as natural food colorants. These compounds are useful for human health and have high economic value. ...
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Barberry is an agricultural product, which is cultivated in large amounts, only in Iran. Its popularity as an ingredient for many by-products has grown recently. It contains anthocyanins which can be used as natural food colorants. These compounds are useful for human health and have high economic value. Magnitude and duration of heating has a strong influence on anthocyanin stability. Temperature degrades the anthocyanins and the rates of degradation depend on the presence of oxygen, pH and their chemical structure. In this study the effect of temperature and solid content on degradation kinetic of anthocyanins in Berberis vulgaris var asperma were determined over a temperature range of 70-90◦C. Analysis of kinetic data suggested a first-order reaction for the degradation of barberry juice and concentrate anthocyanins. The half-life values were calculated 6.02, 3.32 and 1.06h for juice, 3.32, 1.84 and 0.76h for concentrate of 30 Brix and 3.19, 1.31 and 0.49h for concentrate of 50 Brix between 70 and 90◦C, respectively.The temperature-dependent degradation was modeled using Arrhenius equation. By increasing solid content, the activation energy value was increased but D-value and Z-values were reduced. The results shows that the degradation of anthocyanins in concentrates occurred at a faster rate than in juice. By increasing the temperature degradation rates were increased both in juice and concentate.
Fatemeh Heydari; Mohammad Javad Varidi; Mehdi Varidi
Abstract
The objective of this study was the evaluation of pH, Color parameters [lightness (L*), redness (a*), yellowness (b*), chroma (C*), hue (H*), a*/b* ratio, and color differences (ΔE)], Mb, MetMb, OxyMb, DeoMb and WHC in minced meat. Three types of meat ( Beef, camel and ostrich) and four mincing ...
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The objective of this study was the evaluation of pH, Color parameters [lightness (L*), redness (a*), yellowness (b*), chroma (C*), hue (H*), a*/b* ratio, and color differences (ΔE)], Mb, MetMb, OxyMb, DeoMb and WHC in minced meat. Three types of meat ( Beef, camel and ostrich) and four mincing processes (three using a grinder with 7.5, 4 and 3 mm diameter holes in the plate, and a fourth in which a cutter was used to obtain a finely minced product) were studied. The intact meat was used as the control. Significant differences were observed in the pH, Color parameters [lightness (L*), redness (a*), yellowness (b*), chroma (C*), hue (H*), a*/b* ratio, Mb, MetMb, DeoMb and WHC of various types of meat (P 0.05). WHC and chroma showed statistically significant differences (P 0.05) for the mincing treatment. The ΔE and OxyMb showed no significant differences (p>. 0.05) for mincing and also in meat types. High correlation between pH and L* (R2=0.999), pH and WHC (R2=0.997) confirms the decrease in L* and increase in WHC along with increase in pH.
Homa Baghaei; Mohammad Javad Varidi; Mehdi Varidi
Abstract
Determination of the body composition weight due to the growing ostrich farms in Iran is a beneficial subject. It is so important for dependent industries to know the effects of sex and slaughter conditions on carcass quality. In present study, the mean value for hot yield (55.93%) was higher than cold ...
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Determination of the body composition weight due to the growing ostrich farms in Iran is a beneficial subject. It is so important for dependent industries to know the effects of sex and slaughter conditions on carcass quality. In present study, the mean value for hot yield (55.93%) was higher than cold yield (54.70%). Blood, feather and skin were evaluated as the maximum and the hide as the minimum body weight parts. Effect of sex on the body composition weight was insignificant (p>0.05). The mean value for cooling loss in carcasses was 2.2% that did not influence by sex significantly (p>0.05). The average values for drip loss in 1 and 7 days of postmortem were 1.52% and 1.68% respectively. The mean value for cooking loss in male and female ostriches were calculated 31.85% and 33.55% respectively while this parameter in stunned ostriches were evaluated 33.30% and in non-stunned one were 32.10% (p>0.05). Although drip and cooking losses increased during 14 days, there were no significant effects of ageing, sex and slaughter conditions (p>0.05).
Zahra Ahmadian; Mehdi Varidi; Mohammad Javad Varidi; Hashem Pourazerang
Abstract
High nutritional value and existence of bioactive components in sesame seeds converted it to a valuable food. One of the methods to increase per capita consumption is processing of sesame with different ways such as production of sesame milk. In this study, the effect of blanching time (0 as a control ...
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High nutritional value and existence of bioactive components in sesame seeds converted it to a valuable food. One of the methods to increase per capita consumption is processing of sesame with different ways such as production of sesame milk. In this study, the effect of blanching time (0 as a control sample, 15 and 30 min) at 95°C and roasting temperature (0 as a control sample and 145°C) for 20 minutes was evaluated on the physicochemical and sensory characteristics of sesame milk using completely randomized factorial design. Blanching of sesame before the milling, resulted in significant decrease of the fat content, viscosity and physical stability of sesame milk .Also, roasting of sesame seeds significantly reduced the total solid content, fat and physical stability of sesame milk, while the amount of ash and specific gravity significantly increased. The results of color analysis showed a significant increase in brightness (L *) of sesame milk from 83.864 in control sample to 88.941 with increase of blanching time to 30 minutes. Moreover the total color differences showed a significant decrease from 15.371 in control sample to 10.435 with increase of blanching time to 30 minutes. Finally, by optimization of processing, the best physicochemical and sensory properties of sesame milk achieved with blanching for 15 minutes at 95°C and roasting at 145°C for 20 minute.
Naeimeh Kazemi Taskooh; Mohammad Javad Varidi; Mohammad Hossein Hadad Khodaparast; Farideh Tabatabaei Yazdi
Abstract
In this study,The effect of Ozonated water(0.2, 0.5, and 1 ppm) with different exposure times (5,10, and 15 min) for control of Staphylococcus aureus , Escherichia coli and total counts in poultry Carcass, on Chiller water in slaughter house were investigated. For this purpose, Control samples passed ...
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In this study,The effect of Ozonated water(0.2, 0.5, and 1 ppm) with different exposure times (5,10, and 15 min) for control of Staphylococcus aureus , Escherichia coli and total counts in poultry Carcass, on Chiller water in slaughter house were investigated. For this purpose, Control samples passed chiller water(without Ozone) for (5,10, and 15 min) .Other examples also treated (5, 10 , and 15 min) with ozonated water(0.2, 0.5, and 1 ppm) in the laboratory, under the same temperature of chiller water(0 - 4 C) and immediately analyzed for microbiological tests. The results indicated that the use of ozonated water redused1.7 Log of Staphylococcusaureus , 2.3 Log of Escherichia coli and 1.16 Log of total counts. Results showed that Escherichia Coli (As a Gram- Negative Food Infection Bacteria) was more sensitive to Ozone treatment than Staphylococcus aureus(As a Gram-Positive Food Infection and Toxicogenic Bacteria),(2.3 Log reduction in Escherichia coli and 1.7 Logreduction in Staphylococcus aureus), At all levels observed significant differences (P
Adeleh Soleimani; Mohammad Javad Varidi; Alireza Sadeghi Mahoonak; Mehdi Nasiri mahalati
Abstract
This study was carried out to evaluate the chemical compoition of Alosa Caspia and results compared with Clupeonella engrauliformis which is a common fish catch among Clupeonella and Clupeidae spp in Caspian sea . Results showed that the amount of fat, protein, ash and dry matter in Alosa was higher ...
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This study was carried out to evaluate the chemical compoition of Alosa Caspia and results compared with Clupeonella engrauliformis which is a common fish catch among Clupeonella and Clupeidae spp in Caspian sea . Results showed that the amount of fat, protein, ash and dry matter in Alosa was higher than Clupeonella. The fatty acid composition showed that the EPA was very high in Alosa that show this fish is rich source of omega-3 fatty acid. Then the effect of salting method on moisture and salt content Alosa Caspia were evaluated. The salting methods including traditional (common in north reigon), brining with two salt concentration (saturated and 20% w/w brine) followed by two drying methods (sun and oven drying at 30°) were used. The texture changes during salting showed that salt absorption and water loss was different in different salting method and was higher in traditional salting method. These samples had the lowest moisture at the end of salting, but showed the highest moisture at the end of drying.
Bahareh Emadzadeh; Mohammad Javad Varidi; Mehdi Nasiri mahalati
Abstract
Sheep meat is one of the most important sources of red meat in middle-east countries and therefore having knowledge of its quality is necessary. The physicho-chemical characteristics of sheep meat were studied during 7 days of ageing period. Samples were taken from the top round section including Biceps ...
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Sheep meat is one of the most important sources of red meat in middle-east countries and therefore having knowledge of its quality is necessary. The physicho-chemical characteristics of sheep meat were studied during 7 days of ageing period. Samples were taken from the top round section including Biceps femoris and Semimembranosus muscles. Meat pH fell significantly during the first 24 h postmortem, reaching the mean value of 5.67±0.06. No significant changes (P
Bahareh Emadzadeh; Mohammad Javad Varidi; Mehdi Nasiri mahalati
Abstract
Carcass yield is important economical parameters for producers and contributors of meat science. In the present study, carcass yield and also the weight losses resulted post mortem until consumption were investigated. The mean values of cold carcass and hot carcass weight were 15.63 and 15.33, the mean ...
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Carcass yield is important economical parameters for producers and contributors of meat science. In the present study, carcass yield and also the weight losses resulted post mortem until consumption were investigated. The mean values of cold carcass and hot carcass weight were 15.63 and 15.33, the mean value of cooling loss was 1.87% and average value of hot and cold efficiency were 41.44% and 40.67%, respectively. The correlation between the weight of sheep and cold carcass weight was modeled using a power function with a high correlation coefficient. The mean value of drip loss and cooking loss were 2.10% and 24.51%, respectively. All parameters were evaluated for both sexes individually indicating that there was no statistically significant difference between sexes.
Keywords: Sheep meat; ageing; Hot and cold carcass yield; Cooling loss; drip loss; cooking loss
Aliakbar Gholamhosseinpour; Mohammad Elahi; Mohammad Javad Varidi; Fakhri Shahidi
Abstract
The rock candy is the grown sucrose crystal which has been produced in Iran and India for the first
time originally. In this process, the large sucrose crystals has been produced by cooling the
supersaturated solution. The traditional processing has not changed up to now. Recently, many efforts
were ...
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The rock candy is the grown sucrose crystal which has been produced in Iran and India for the first
time originally. In this process, the large sucrose crystals has been produced by cooling the
supersaturated solution. The traditional processing has not changed up to now. Recently, many efforts
were done to optimize it. The production of rock candy evaluated under cooled crystallization process.
To increase the yield and the growth of sucrose crystals, the supersaturation and crystallization
parameters should be optimized. Due to low efficacy in this procedure, sucrose crystals with
dimensions less than 3 mm are usually produced by evaporating crystallizers. In this research,
traditional production process of rock candy is studied by doing experiments at different phases in a
traditional plant. According to the results, it takes more than 90 min to reach the suitable
supersaturation, an temperature (112°C) and extra evaporation. So the invert sugar content, reach
from 0.015 % in original sugar to 0.571 % in effluent (mother syrup). The produced rock candy has
0.553 % invert sugar. The pH of solution decreases from 7.3 to 5.2, the color increased from 70 (in
primary sugar) to 1240 ICUMSA unit in the effluent and more than 250 Iu in produced rock candy
(measurement in λ = 420nm ). The high color rate and invert sugar cause the effluent can not be used
in production process.
Key words: sucrose, rock candy, crystallization, supersaturation.
