Food Technology
Mahshad Lavarsetagh; Nafiseh Zamindar; Yasaman Esmaeili
Abstract
Color is the most important indicator of the quality of food that affects consumer acceptance. In order to replace the color lost during the process, increasing the existing color and minimizing variation during processing; natural colors, synthetic and inorganic colorants are added to the food. Red ...
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Color is the most important indicator of the quality of food that affects consumer acceptance. In order to replace the color lost during the process, increasing the existing color and minimizing variation during processing; natural colors, synthetic and inorganic colorants are added to the food. Red beet is one of the most important natural sources of color; In this study, the overall results showed that increase in the extraction pH and time, increased the extraction of betacyanine and betaxanthine. It would be better to extract betacyanine at temperatures below 25 ° C since this pigment is sensitive to high temperatures and at the temperature above, 25 °C will be destroyed. The maximum yield was observed when pH value, temperature and time were 5, 21 °C and 20 min, respectively. Comparison of experimental and predicted values of the proposed responses at the proposed optimal point by t-test showed no significant difference (p< 0.05). Quadratic model was suggested for the responses and lack of fit was not significant (p<0.05). The extraction of betaline from red beet using ultrasonic method causes the reduction of time, temperature, energy and solvent consumption. The maximum yield was observed when pH value, temperature and time were 5, 21 °C and 20 min, respectively. Comparison of experimental and predicted values of the optimal points showed no significant difference by t-test (p< 0.05).
Bahman Saedpanah; Nasser Behroozi-Khazaei; Jalal khorshidi
Abstract
Introduction: Microwave-assisted extraction (MAE) is one of the newest techniques for extracting essential oils from medicinal plants. Microwave waves penetrate into plant cells and affect the polar molecules, causing heat to build up inside the plant tissue, destroying the cells and releasing the active ...
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Introduction: Microwave-assisted extraction (MAE) is one of the newest techniques for extracting essential oils from medicinal plants. Microwave waves penetrate into plant cells and affect the polar molecules, causing heat to build up inside the plant tissue, destroying the cells and releasing the active ingredients. Although in terms of essential oil extraction efficiency, MAE method is slightly higher than Clevenger, but in terms of energy consumption, process time and amount of solvent consumed has an inherent advantage over the Clevenger method. In this study, the aim is to evaluate the quantity and quality of rosemary essential oil in the developed microwave extraction system and process optimization in this system.
Materials and Methods: Rosemary plant (Rosmarinus officinalis L.) with 200 g used for each experiment. In this study, a microwave-assisted essential oil extraction system was developed. The system consisted of a home microwave, a distillation condenser, a cold-water source and a pump. In this study, the response surface methodology (RSM) used in the form of a central composite design with 13 treatments. The effect of two independent variables including power in the range of 300 to 900 watts and time in the range of 5 to 35 minutes on the efficiency of essential oil as dependent variables was investigated. To evaluate the quality of the extracted essential oil and compare it with Clevenger treatment, GC-Mass analysis was done using an Agilent technology apparatus (Agilent 7990B, USA).
Results and Discussion: A quadratic model was proposed for modelling of extraction efficiency and it was able to model with the values of R2, Adj R2 and Pred R2, which were 0.9521, 0.9180 and 0.574, respectively. The "Pred R2" of 0.547 is not as close to the "Adj R2" of 0.9180 as one might normally expect. The difference is more than 0.2. This may indicate a large block effect or a possible problem with the proposed model and/or data. Things to be considered for model modification are model reduction and response transformation. Results of ANOVA showed that only the linear terms of time, power and quadratic power of time are significant. The normal probability plot showed the normal distribution of errors observed in the experimental design space. The actual measured values R2 of the extracting efficiency from the experiments versus the values R2 predicted by the model indicated that this model could estimate the extracting efficiency with a correlation coefficient of 0.746. Box-Cox plot demonstrated for obtaining better results, the data of the amount of essential oil efficiency should be transferred to the power of 0.68 by the power function and the new model should be fitted to the data. Therefore, based on the Box-Cox diagram and the transfer of response data to the power space, as well as the use of a step-by-step method to remove meaningless terms from the model, the proposed model is as shown in equation 6. The results of the new model shows that the Pred R2 increased from 0.5574 to 0.8644, which indicates an
improvement in the performance of the new model. Alpha-pinene, camphene, borneol, camphor, cineole, and caryophyllene were the predominant compounds of the essential oil. In 300 and 600-watt treatments with a time of 35 minutes, the amount of dominant compounds of essential oil is slightly higher than Clevenger. However, in the power of 900 watts, due to the increase in temperature, some compounds have been destroyed and the extraction level of some compounds has decreased drastically, and in contrast, the level of caryophyllene was increased to 23.595 %, which indicates a sharp increase in its value at 900 watts. On the other hand, the components of alphapenine, camphor and cineole have the highest medicinal value, which according to Table 8, the highest values for these compounds have been extracted in 300 watt treatment. At the higher microwave power, due to the decomposition of the compounds, the amount of extraction of these compounds was significantly reduced. Also, at 300 watts, the extraction efficiency of these compounds was higher than that of Clevenger, which shows the ability of the MAE method in extracting essential oils from medicinal plants.
The results showed that the amount and quality of essential oil in the MAE with power of 300 and 600 watts was almost the same as Clevenger in most compounds. Essential oil compounds are degraded at 900 watts, so it is recommended not to use maximum power in the experiments. However, if the goal is to extract the highest amount of cariophylene, verbenone and cariophylene oxide in the extracted essential oil, higher power can be used.
Mitra Mansouri Bani; Vahid Samavati; Marzieh Bolandi
Abstract
Introduction: The Cholesterol in our diet is a risk factor for the prevalence of cardiovascular diseases. One of the effective ways to reduce the incidence of such diseases is to remove cholesterol, including animal fats, from our food sources. In this research, attempts were made to investigate the ...
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Introduction: The Cholesterol in our diet is a risk factor for the prevalence of cardiovascular diseases. One of the effective ways to reduce the incidence of such diseases is to remove cholesterol, including animal fats, from our food sources. In this research, attempts were made to investigate the effect of operational factors on reducing cholesterol in cream by beta-cyclodextrin using RSM and to examine its physicochemical properties. The variables in this study were beta-cyclodextrin concentration, mixing temperature and mixing time. Materials and Methods: The 3.5% fat raw milk was pasteurized at 72°C for 16 s, and then it was cooled to 55°C. The milk cream was separated by a separator and adjusted to 36% fat. Beta-cyclodextrin was added in 0.5, 1, 1.5% concentration in water bath at three levels of 10, 30, 50 ° C. It was mixed at three time intervals of 5, 15, 25, min. Cream containing beta-cyclodextrin was centrifuged to eliminate the complex formed in different periods and the beta-cyclodextrin and cholesterol complex was isolated. Beta-cyclodextrin of 99.2% purity was purchased from Sigma-Aldrich and all chemical agents from Merk, Germany. To measure cholesterol content in the preparation phase, hexane and ethanolic solution of potassium hydroxide (Merk) and the standard solution of cholesterol (Merk) were used. To determine the level of cholesterol in the samples, Lee et al. (1999) method was used after a few modifications. Firstly, cholesterol was extracted from the specimens and the cholesterol levels in the samples were determined with a chromatography apparatus equipped with flame ionization. The quantitative measurement of cholesterol was conducted by comparing the peak areas with a response from the internal standard. The experiments were designed, using the response surface method and the Box-Behnken Design (BBD), to achieve a high-efficiency process in reducing the highest cholesterol level and determining optimum conditions. The viscosity was determined using a Brookfield viscometer, and the over run and foam stability of the cholesterol cream samples were determined using a Graduated cylinder. Results and discussion: Due to the cavity in the central part of beta-cyclodextrin molecular arrangement, it can form a stable cholesterol-insoluble complex and help to isolate it from the product. The results showed that time, mixing temperature, and beta-cyclodextrin concentration all had a positive effect on reducing the level of cholesterol, and the effect of independent factors was almost the same, as the time factor had the highest effect, supported in Makoto et al. (1999). Concentration factor had the least effect on cholesterol reduction, contrary to studies by Aryafar et al. (2007) and Yen et al. (1995). Among the interactions of the investigated factors, the highest effect was due to the simultaneous effects of temperature and time (88.9%) and the least effect was due to the simultaneous effect of concentration and temperature (85.5%). Findings of this study showed that the use of beta-cyclodextrin resulted in a successful reduction of cholesterol from the product without affecting tissue properties, increasing viscosity and volume, or reducing stability of the foam. The absorption of cholesterol by beta-cyclosporine depends on its concentration. The mixing time and temperature also boosts the effect. After examining the effects of each independent variable, it can be concluded that all three investigated variables have an incremental effect on the level of cholesterol in the evaluated levels. Increasing mixing time has the highest effect on increasing cholesterol and increasing the concentration of beta-cyclodextrin has the lowest effect on cholesterol reduction. Investigating the interaction effects of variables also showed that the simultaneous effect of temperature and time with the proper concentration of beta-cyclodextrin could have a significant effect on cholesterol reduction. The response surface method and Box-Behnken Design as statistical optimization and modeling techniques enabled the researchers to predict the optimal conditions for maximal removal of cholesterol by beta-cyclodextrin at the decided levels. The optimal operating condition obtained by the model for 36% fat cream contains 42.1% beta-cyclodextrin concentration, 76.75 ° C temperature and 87.83 min of mixing time. The predicted cholesterol reduction in these conditions was 89.92%, which was very close to the experimental value obtained in predicted optimal conditions. It indicates the accuracy and predictive power of the intended model.
Erfan Danesh; Hossein Jooyandeh; Vahid Samavati; Mostafa Goudarzi
Abstract
Introduction: Scientific evidence has demonstrated that consumption of high-fat foods has direct connection with increasing incidences of various diseases such as obesity, diabetes, hardening of the artery walls and blood pressure. Thus, demand for low-fat foods has increasingly been promoted by health-conscious ...
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Introduction: Scientific evidence has demonstrated that consumption of high-fat foods has direct connection with increasing incidences of various diseases such as obesity, diabetes, hardening of the artery walls and blood pressure. Thus, demand for low-fat foods has increasingly been promoted by health-conscious consumers. However, development of low-fat foods is challenging as fat makes a major contribution to sensory attributes of many foods. Low-fat cheeses are usually characterized as having a flat taste, more translucency and a rubbery and gummy texture. A common strategy for improving the properties of low-fat cheeses is to increase its moisture content sufficiently to provide moisture to protein ratio which is greater than or equal to its full-fat counterpart. The addition of denatured whey proteins, which are known for their high water-holding capacity, to cheese milk is one method used to achieve this objective. Likewise, transglutaminase treatment of cheeses milk has been shown to increase the moisture content of the resultant cheese. Enzyme transglutaminase (MTGase; protein-glutamine gamma glutamyl transferase, EC 2.3.2.13) catalyzes acyl transfer reactions between protein intra- or inter- chain glutamine (acyl donor) and lysine (acyl acceptor) peptide residues. UF-Feta cheese has the highest per capita consumption amongst cheese varieties in Iran. However, UF-Feta cheese is also perceived as being high in fat, discouraging some consumers from including it in their diets. The objective of this study was enzymatic incorporation of whey proteins into the formulation of UF-Feta cheese by TGase in order to obtain a low-fat product with desirable textural and sensory properties.
Materials and methods: The experiments were designed according to a 5-level-3-factor central composite design using response surface methodology (RSM). The independent variable were formulation ingredients including TGase enzyme (0-2 units/g protein), whey protein concentrate (WPC) (0-16 % w/w) and fat (0-10 % w/w) and the responses of interest were the physicochemical (moisture content and lightness (L*)), textural (hardness, adhesiveness, cohesiveness and springiness) and sensory properties (flavor and odor, color and appearance, texture and total acceptability) of UF-Feta cheese.
Results and discussion: The results indicated that fat reduction caused significant increment in the moisture content of UF-Feta cheese. The whey protein addition showed the same effect on moisture content as fat reduction whereas transglutaminase treatment decreased the moisture of UF-Feta cheese. As expected, fat reduction was accompanied by an increase in hardness and elasticity of UF-Feta cheese. Fat and moisture act as fillers in the casein matrix of cheese texture. When the fat content is decreased, the moisture does not replace the fat on an equal basis, so the total filler volume is decreased, resulting in lower moisture to protein ratio. This in turn increases possibilities of cross-linking between protein chains, resulting in a more compact cheese matrix with harder and chewier texture. Similarly, the increasing effect of TGase treatment on hardness and elasticity may be attributed to formation of a more compact protein matrix because of cross-linking action of enzyme on milk proteins. The whey proteins, however, decreased the hardness and elasticity of UF-Feta cheese. It seems that the added whey proteins increased the moisture content of cheese as sufficiently as to offset the decrease in the total filler volume caused by fat reduction, preventing the protein matrix to be more compact and elastic. Promoted protein-protein interactions of the cheese matrix resulting from fat reduction or TGase treatment might also account for our observation on decreased adhesiveness and increased cohesiveness. As the protein matrix becomes more compact, the cheese loses its adhesiveness. Conversely, as the number or strength of protein interactions increases, the structural integrity of cheese matrix called cohesiveness increases. Apart from fat, water can also create more open conformation for protein molecules, resulting in increased adhesiveness and decreased cohesiveness. This may justify our observation on higher adhesiveness and lower cohesiveness of whey protein-fortified low-fat cheeses with high moisture content. Not surprisingly, all the sensory attributes of UF-Feta cheese were adversely influenced by fat reduction. On the other hand, whey proteins improved the flavor and texture of low-fat UF-Feta cheeses. They, however, showed no effect on appearance score of cheese samples in spite of the fact that they somewhat compensated for lost lightness (L*) of low-fat cheeses. Similarly, TGase treatment did not affect the appearance acceptability of UF-Feta cheeses despite having significant effect on their L* value. The sensory panel did not appreciate the flavor of TGase-treated samples; however, they scored the samples treated with enzyme concentration lower than 1 U/g protein as having desirable texture. RSM suggested that the optimum formulation of 5.95% (w/w) fat, 0.56 unit TGase per gram protein and 8.79% (w/w) WPC could produce a low-fat cheese sample with desired textural (hardness 0.342 kg; elasticity 8.58 mm; adhesiveness -0.070 kg.s; cohesiveness 0.474) and sensory (overall sensory score 88.73 out of 100) attributes.
Elham Nourmohammadi; Alireza Sadeghi Mahoonak; Mohammad Ghorbani; Mehran Alami; Masoumeh Sadeghi
Abstract
Introduction: Proteins are vital substances for health since they provide nitrogen, amino acids and the energy required for normal body performance. However, the applications of proteins are limited due to their certain properties, such as their low solubility. The enzymatic hydrolysis of proteins is ...
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Introduction: Proteins are vital substances for health since they provide nitrogen, amino acids and the energy required for normal body performance. However, the applications of proteins are limited due to their certain properties, such as their low solubility. The enzymatic hydrolysis of proteins is an extensively used approach to produce bioactive peptides and promote the chemical, functional and nutritional properties of proteins. These compounds have interesting biological properties such as anti-oxidative, anti-hypertensive, anti-bacterial, anti-cancer and anti-thrombotic activities. Lipid peroxidation is one of the main reasons behind the deterioration of foodstuffs during processing and storage. In this case, the addition of anti-oxidative compounds is considered as an effective way to improve the shelf-life of lipid containing foods. Due to carcinogenic effect of synthetic anti-oxidative compounds, extensive efforts have been done to find natural anti-oxidative compounds with plant origin during recent years. Pumpkin (Cucurbitapepo) seeds are rich of proteins, unsaturated fatty acids, phytosterols and essential minerals like Zn, K, Ca, Mg, Fe, Cu and P. Oil content of pumpkin seeds is about 40-60%, and mostly consisted of oleic, palmitic and stearic acids. On the other hand, its protein content is about 45-46%, and this amount will reach to 55-56% after defatting. To date, pumpkin seeds have been mainly used for pumpkin oil production. After the oil extraction, a protein-rich by-product (pumpkin oil cake) remains, which is often used for animal feeding. In this study, the enzymatic hydrolysis of pumpkin oil cake protein isolate by a food-grade protease named trypsin was attempted and the optimum treatment was selected based on the DPPH radical scavenging and ferrous ion chelating activities Materials and Methods: In this study, the optimization of the hydrolysis of pumpkin (Cucurbitapepo) oil cake protein was investigated using response surface methodology (RSM) and central composite design (CCD) in order to achieve the maximum DPPH radicals scavenging and metal ion chelating activities. For this purpose, trypsin concentrations of 1-2% and hydrolysis temperatures and times of 35-45 ċ and 2-5 hours were examinedas independent variables. Preparations of pumpkin oil cake protein isolate (POCPI) Defatted pumpkin oil cake was dispersed in distilled water (1:10 w/v). The pH was adjusted to 10 with 1N NaOH, mixed for 1 hour at room temperature and centrifuged at 5000g for 20 minutes (Combi514R, South Korea). The supernatant was collected, pH was adjusted to 5 with 1N HCl and centrifugation was performed at the same condition. Supernatant was discarded and precipitate was collected as pumpkin oil cake protein isolate. Enzymatic hydrolysis Pumpkin oil cake protein isolate was dispersed in tris-HCl at pH= 8 for trypsin enzymatic treatment (5% w/v). After that, trypsin was added at 1%, 1.5% and 2% and hydrolysis was carried out for 2, 3.5 and 5h at 200 rpm in shaker incubator (8480-VS, South Korea). Hydrolysis temperatures were 35, 40 and 45˚C. At the end of hydrolysis, the enzyme was inactivated for 15 minutes at 85˚C; dispersion was centrifuged at 4000g for 30 minutes, the supernatant was collected and freeze dried. DPPH radical scavenging activity An aliquot of 1000 microliterpumpkin oil cake proteinhydrolysate was mixed with 1000 microliter of 0.1mM DPPH solution prepared in 96% ethanol. The mixture was allowed to stand for 60 minutes in the dark and the absorbance was read at 517 nm. The blank was prepared with the same manner except that 1000 microliter water was used instead of 1000 microliter pumpkin oil cake proteinhydrolysate. Ferrous ion chelating activity Pumpkin oil cake protein hydrolysate(4.7 ml) was mixed with 0.1 ml 2mM FeCl2 and 0.2 ml 5 mM ferrozine and was kept at room temperature for 20 min. The absorbance was read at 562 nm and the blank sample was prepared with the same manner except that 4.7 ml distilled water was used instead of sample. Results & Discussions: The results of this study, showed that the optimum conditions to reach the maximum DPPH radicals scavenging and metal ion chelating activities were 35 ċ, 5h, 1.1% enzyme concentration and 45 ċ, 2.05h and 2% enzyme concentration that showed DPPH radicals scavenging and metal ion chelating activities of 76.28% and 49.61% respectively. These results were to large extent similar to those suggested by Design Expert software (75.89% and 50.84%). The R2 was 0.9184% and 0.9761% for DPPH radicals scavenging and metal ion chelating activities respectively. Moreover the adjusted R2 was estimated to be 0.1333 and 0.1827 for DPPH radicals scavenging and metal ion chelating activities respectively, which suggested the suitability and fitness of proposed model for the considered responses. Conclusions: Based on the results, pumpkin oil cake protein hydrolysate demonstrated appropriate anti-oxidative and metal ion chelating abilities. The results of this study indicated that pumpkin oil cake protein hydrolysate had the ability to be used as an effective and natural anti-oxidative compound in lipid containing foods.
Arash Koocheki; Abdollah Hematian Sourki; Mohammad Elahi; Seyed Mohammad Ali Razavi
Abstract
Introduction: β-glucan is the most important water soluble fiber found in cell wall of some cereals such as barley, oat, wheat and rye, that are composed of β-D-glucoseunits with (1→4) (70%) and (1→3) (30%)anomericbonds(Benito-Román, Alonso, & Cocero, 2013).β-glucan ...
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Introduction: β-glucan is the most important water soluble fiber found in cell wall of some cereals such as barley, oat, wheat and rye, that are composed of β-D-glucoseunits with (1→4) (70%) and (1→3) (30%)anomericbonds(Benito-Román, Alonso, & Cocero, 2013).β-glucan is regarded as a dietary fiber in functional foods. It can act as a hydrocolloid due to its thickening characteristic in aqueous phase and can be used as a stabilizer in some foods such as sauces, salad dressing and ice cream (Dawkins & Nnanna, 1995; Kontogiorgos, Biliaderis, Kiosseoglou, & Doxastakis, 2004; Temelli, 1997; Wood & Webster, 1986). Hull-less barley is a barley variety that has no hard coat around its’ seeds. The content of soluble fiber e.g. β-glucan in hull-less barley is higher than of ordinary barley varieties. Hull-lessbarley cv. Lut is the first commercial hull-less barley in Iran registered in 2013 by SPII(Seed and Plant Improvement Institute). Lut is a kind of spring barley cultivar which is precocious and resistant to lodging. It’s average yield is 6.425 t/ha and it is suitable to cultivation in temperate regions of Iran (SPII, 2013).This type of barley contains about 6% β-glucan and thus is a good source for β-glucan extraction.To date no research has been conducted on properties of β-glucan from this cultivar of barley.Considering high technological properties of β-glucan, the present study was carried out to determine the optimal condition for extraction of β-glucan from hull-lessbarley using hot watermethod to achieve the highest qualitative and best functional properties.Materials and methods: Barley flour was obtained by grinding whole kernels of cv. Lut in a laboratory mill and sieved through a 0.50 mm screen. Prior to the extraction procedure, 50 g of barley flour was suspended in 200 ml of aqueous ethanol (80%, v/v) and stirred under reflux for 3 h to remove most of the lipids and inactivate the endogenous β-glucanases. The liquid phase was separated by vacuum filtration and dried at 40 °C for 12 h. 50 g of dried defatted barley flour was suspended in specified amounts of distilled water (solven:flour ratio = 6:1, 8:1 and 10:1) in a 1000 ml beaker. pH was adjusted to the designed levels (5, 7, and 9) by 0.1 N HCl and 0.1 N NaOH solutions. Extraction procedure carried out at 50±1°C for 30, 60 and 90 minutes. Total β-glucan content was determined by the specific enzymatic method of McClear and Glennie-Holmes (1985) using the mixed linkage β-glucan assay kit (K-BGLU 07/11) supplied by Megazyme International (Wicklow, Ireland). The colour of β-glucan gums was measuredusing a Hunter-Lab Colour Flex 45 spectrophotometer (Hunter Associates Laboratory, Inc., Reston, VA, USA). The L*a*b* (CIELAB space) colour space measurement was used for colour analysis of β-glucan samples. Emulsion stability (ES) against high temperature was determined by heating emulsions in a water bath at 80 °C for 30 min followed by centrifuging at 1200 g for 10 min. For foam stability, ovalbumin was dissolved in distilled water and added to β-glucan solution and then whipped vigorously with a laboratory rotor-stator homogenizer at room temperature. Flow behaviour measurements were done by a Brookfield viscometer. The flow behavior index (n) and consistency coefficient (k) values were obtained by fitting the power law model. All chemicals, reagents and solvents were of analytical grade and obtained either from Sigma-Aldrich Co (Deisenhofen, Germany) or from Merck (Darmstadt, Germany).Results &Discussion: Results showed that the extraction time, solvent: flour ratio and pH had significant effect on extraction yield, purity, foam and emulsion stability, consistency coefficient (k), flow behavior index (n) and colour. Increasing the extraction time had significant effects on β-glucan’s yield and purity and improved the emulsion and foam stabilizing effect of β-glucan. Increasing the pH from 5 to 9 significantly enhanced the purity, consistency coefficient (k), foam and emulsion stability. At higher pH levels, extraction yield, flow behavior index (n) and L* decreased. With increasing solvent:flour ratio, extraction yield, purity, consistency coefficient (k), foam and emulsion stability significantly increased. In contrast, the flow behavior index (n) decreased as a result of increase in solvent: flour ratio. However, solvent: flour ratio had no significant effect on L*, a* and b*. Models presented in this study were highly significant and the correlation coefficients could be used for optimization of ß-glucan extraction from hull-less barley. Considering the importance and desirability of the response variables, the best results were obtained when the extraction time, solvent: flour ratio and pH were 90 min, 10:1 and 7.33 respectively. At the optimal condition, extraction yield, purity, foam stability, emulsion stability, consistency coefficient (k), flow behavior index (n), L*, a* and b* were 4.12%, 69.11%, 86.95%, 88.77%, 1.51 Pa.sn, 0.62, 73.42, 0.81 and 8.72 respectively.
Sara Rrahbaran; Aazam Aarabi
Abstract
Introduction: The consumption of dietary fiber plays an important role in the prevention of illnesses such as diabetes type 2, hypercholesterolemia. Dietary fibers are not only desirable for their nutritional properties but also for their functional and technological properties. This study was undertaken ...
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Introduction: The consumption of dietary fiber plays an important role in the prevention of illnesses such as diabetes type 2, hypercholesterolemia. Dietary fibers are not only desirable for their nutritional properties but also for their functional and technological properties. This study was undertaken to investigate the possibility of alkaline hydrolysis to remove fiber from rice bran. Material and methods: In this study, the extraction of fiber from rice bran was carried out in the presence of sodium hydroxide as an alkaline media and under autoclave condition. The Response Surface methodology was evaluated by the central composite design (CCD) to build a model based on three variables including the time (X1), temperature (X2) and the concentration of Hydrogen Peroxide (X3) for the extraction of fiber, and water binding and fat binding capacity of produced fiber.Results and Discussion: Results showed that the optimum conditions for the maximum production of extracted fiber were 35min, 99.6 °C and 13.47% for time, temperature and the concentration of hydrogen peroxide, respectively. Results indicated that temperature was the most significant factor influencing considerably on fiber extraction and fiber fat binding capacity and none of the parameters had significant effect in the level of (0.05) on the water binding capacity of fiber
Simin Gholami-Avarashk; Javad Sargolzaei
Abstract
Black nightshade is a weed plant that grows abundantly in most parts of Iran. In this study, central composite response surface method to investigate the effect of temperature 35-55 °C and pressures 170-350 bar during the dynamic time of 120 min, the particle size of 150 microns and flow rate of ...
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Black nightshade is a weed plant that grows abundantly in most parts of Iran. In this study, central composite response surface method to investigate the effect of temperature 35-55 °C and pressures 170-350 bar during the dynamic time of 120 min, the particle size of 150 microns and flow rate of 3 liters per minute on the efficiency of oil extracted from the fruits of black nightshade and optimizing operation of the extraction process using supercritical carbon dioxide was used. Extraction with an organic solvent hexane was chosen as a comparison. Based on the results, operating parameters including both pressure and temperature and their quadratic effects as well as the interaction between two parameter significant effect on the rate of extraction of oil(P
