Reza Farahmandfar; Seyed Ali Mortazavi; Farideh Tabatabaei Yazdi; Arash Koocheki
Abstract
In this study, variations of the pasting properties, swelling power and solubility of two rice starches, low amylose (8.7%) and high amylose (26%) at two citric acid concentrations (0 and 0.01 M) was investigated. The results showed that the peak viscosity and breakdown viscosity of rice starch decreased ...
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In this study, variations of the pasting properties, swelling power and solubility of two rice starches, low amylose (8.7%) and high amylose (26%) at two citric acid concentrations (0 and 0.01 M) was investigated. The results showed that the peak viscosity and breakdown viscosity of rice starch decreased significantly (P<0.05) with increased the proportion of amylose while hot past viscosity and cold past viscosity increased significantly (P<0.05). As the concentration of citric acid increased, pasting properties decreased but did not change (P>0.05).The swelling power and solubility of both starch pastes with and without citric acid increased with the increase of the temperature. As the concentration of citric acid increased, swelling power of low and high amylose starch decreased and this event was clearer in low amylose samples. On the other hand, citric acid induced solubility of samples particularly in high amylose rice starches. Furthermore, the swelling power and solubility of treatments decreased and increased with increasing amylose content of rice starch, respectively.
Hadi Bagheri; Mohebbat Mohebbi; Arash Koocheki
Abstract
The effect of wheat-sorghum flour ratio (0, 25, 50, 75 and 100%) on viscoelastic and farinographic behaviour of dough was investigated. Constants of Peleg - Normand model and the stress relaxation (% SR) was calculated for the variables and the correlation between farinograph characteristics and stress ...
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The effect of wheat-sorghum flour ratio (0, 25, 50, 75 and 100%) on viscoelastic and farinographic behaviour of dough was investigated. Constants of Peleg - Normand model and the stress relaxation (% SR) was calculated for the variables and the correlation between farinograph characteristics and stress relaxation test parameters were evaluated. The results showed that with increasing the ratio of sorghum in flour, the amount of initial force (F0), mixing tolerance index and the stress relaxation (% SR) increased. However, the rate of water absorption, dough stability and Peleg - Normand model parameters (K1 and K2) decreased with increasing substitution of sorghum flour. Survey results showed that the correlation between the parameters of water absorption, dough stability and K1 and K2 was a highly positive. The stress relaxation (% SR), mixing tolerance index and the initial force (F0) had also positive correlations. With increasing substitution of sorghum flour, dough indicated the liquid-like viscoelastic behavior. Fitting the experimental data with the model showed the efficiency of Peleg - Normand model at high strain (10%).
Sepideh Amirabadi; Arash Koocheki; Mohebbat Mohebbi
Abstract
In this research, different concentrations of xanthan and Lepidium perfoliatum seed gums (0.1, 0.2 and 0.3%) were used to improve the quality and shelf-life of chiffon cake. For this purpose, specific gravity and apparent viscosity of batter, and the volume, specific volume, moisture, sensory and texture ...
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In this research, different concentrations of xanthan and Lepidium perfoliatum seed gums (0.1, 0.2 and 0.3%) were used to improve the quality and shelf-life of chiffon cake. For this purpose, specific gravity and apparent viscosity of batter, and the volume, specific volume, moisture, sensory and texture properties, crumb and crust color were examined. To investigate the effect of gums on the shelf-life, all cakes were stored for sixth days. Results showed that there were a positive correlation between viscosity of batter and cake volume. Both gums improved chiffon cake properties after removing from the oven and during storage. It was found that using 0.1% xanthan gum increased the cake volume, cohesiveness and sensory scores, decreasing firmness and moisture loss during storage of cake.
Rassoul Kadkhodaee; Arash Koocheki; Seyed Mohammad Ali Razavi
Abstract
The effect of addition of Qodumeh shahri (Lepidium perfoliatum) seed gum on the emulsion properties were investigated in this study. L. perfoliatum seed gum with 0-0.6% (w/w) concentration was used together with 2% (w/w) WPC to emulsify 20% (w/w) corn oil. The emulsion was analyzed for emulsion stability, ...
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The effect of addition of Qodumeh shahri (Lepidium perfoliatum) seed gum on the emulsion properties were investigated in this study. L. perfoliatum seed gum with 0-0.6% (w/w) concentration was used together with 2% (w/w) WPC to emulsify 20% (w/w) corn oil. The emulsion was analyzed for emulsion stability, particle size, specific surface area, particle size distribution and rheological properties. The mean particle size of emulsion decreased by increase in Qodume shahri seed gum up to 0.2% (w/w). Further increase in gum concentration had no significant effect on mean particle size of emulsion. Moreover, increase in gum concentration had no significant effect on particle size distribution (span) and specific surface area (m²/ml) of the emulsions. The rheological data indicated that increase in gum concentration significantly affected the viscosity, consistency coefficient (k) and flow behavior index (n) of the emulsions. Viscosity and consistency coefficient increased by increasing gum concentration. However, the flow behavior index decreased by the increase in Qodume shahri gum concentration. The flow behaviors of emulsions containing gum were well predicted by Herschel–Bulkley model (R2 > 0.99). While, in absence of gum, emulsion Showed Newtonian behavior.
Arash Koocheki; Seyed Ali Mortazavi
Abstract
In order to prevent the turbidity during storage of kiwifruit juice, clarification is necessary. Through proper clarification, flavor and taste of the product is also improved. Therefore, the purpose of the present study was to present a method to determine the optimum amount of clarifying agents (Pectinase ...
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In order to prevent the turbidity during storage of kiwifruit juice, clarification is necessary. Through proper clarification, flavor and taste of the product is also improved. Therefore, the purpose of the present study was to present a method to determine the optimum amount of clarifying agents (Pectinase enzyme, Bentonite and polyvinyl poly pyrolidone) for producing kiwifruit juice with stable clarity. For this purpose, effect of Pectinase enzyme (2-8 g/kg), Bentonite (200-350 g/Ton) and polyvinyl poly pyrolidone (70-110 g/100 lit) on viscosity, turbidity, clarity and total phenolics compound of kiwifruit juice was investigated. For each response a second order polynomial model was developed using a multiple linear regression analysis. Results showed that R2 for viscosity, turbidity, clarity and the total amount of phenolics were more than 0.90. The statistical analysis indicates that viscosity, turbidity and clarity (P
Elnaz Milani; Hajar Naeemi; Seyed Ali Mortazavi; Arash Koocheki
Abstract
In this study, symbiotic yog-ice (rozen yogurt) was produced that was inoculated with different levels of inulin(0,2.5 amd 5%)as prebiotic compound and Lactobacillus Casei as probiotic bacteria in two types; free and encapsulated with Sodium Algint-Whey Protein Concentration for low fat yog-ice cream.The ...
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In this study, symbiotic yog-ice (rozen yogurt) was produced that was inoculated with different levels of inulin(0,2.5 amd 5%)as prebiotic compound and Lactobacillus Casei as probiotic bacteria in two types; free and encapsulated with Sodium Algint-Whey Protein Concentration for low fat yog-ice cream.The survivability of this probiotic bacteria was evaluated under simulated gastro-intestinal conditions ,during 30 days storage at -18oC. In the samples with free state of probiotic bacteria, the number of viable cells ,after 1h exposuring simulated gastric juice(pH=2,pepcine) decreased from 9.78-9.81 log cfu/ml to 6.97-7.26 log cfu/ml,at the end of 30 days storage at -18oC,while, the viable number of encapsulated state of probiotic bacteria, after 1h exposuring simulated gastric juice, decreased from 8.15-8.66 log cfu/ml to 6.80-7.09 log cfu/ml at the end of 30 days storage at -18oc.After exposuring simulated gastric juice, samples was ezposured 2.5h under simulated intestinal juice(pH=7.4,panceratin), and the results that was gained showed that, the samples containing free probiotic bacteria after 2.5h exposuring simulated intestinal juice decreased from 8.808-9.355 log cfu/ml to 5.159-5.9 log cfu/ml at the end of 30 days storage at -18oC.While, in the samples containing sodium alginate-whey protein concentration capsules, the viable number of cells decreased from 7.38-8.201 log cfu/ml to 6.151-6.672 log cfu/ml, at the end of 30 days storage at -18oC. The results indicate that there are significant differences (p
Eisa Jahed; Mohammad Hossein Hadad Khodaparast; Khalil Behzad; Mohammad Elahi; Arash Koocheki
Abstract
In this study, response surface methodology was used to determine the optimum raw sugar beet juice purification process conditions using bentonite to produce inverted liquid sugar. For this purpose, impact of factors on the purification process such as bentonite concentration (1-5 gr/li), pH (3.5-6) ...
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In this study, response surface methodology was used to determine the optimum raw sugar beet juice purification process conditions using bentonite to produce inverted liquid sugar. For this purpose, impact of factors on the purification process such as bentonite concentration (1-5 gr/li), pH (3.5-6) and temperature (35-95 ˚C) was investigated. For each response, a second-order polynomial model was developed using multiple linear regression analysis. Correlation coefficients of fitted regression models of color, turbidity, ash, adjusted purity and invert sugar for juice purification process were determined as 0.95, 0.89, 0.90, 0.91 and 0.96 respectively. Results showed that while increasing the bentonite concentration increased the turbidity content but the adjusted purity decreased, and had no significant effect on other parameters. At lower pH levels, separation of color and turbidity causes by bentonite, but was in creased it decreased separation of ash and also increased invert sugar levels. With increasing temperature from 35˚C, to 95˚C, Separation of color and turbidity causes and invert sugar and adjusted purity content as well as increased, while this variable has no significant effect on syrup ash content. The optimum conditions of raw sugar beet juice purification process using bentonite was determined to obtain minimum color, turbidity and ash with maximum invert sugar and adjusted purity which were verified experimentals were found to be bentonite concentration of 1.70 gr/li, pH of 4.47 and temperature of 75˚C. At this optimum point, color, turbidity, ash, adjusted purity and invert sugar content were found to be 1664 ICU420, 6.3 NTU, 0.55 %, 93.9 % and 1.60 %, respectively.
Arash Koocheki; Fakhri Shahidi; Seyed Ali Mortazavi; Mahdi Karimi; Elnaz Milani
Abstract
The effect of xanthan and Qodume shirazi seed gum on fresh bread quality and its influence on dough rheology were studied. Incorporation of 0.3 to 1% of these two gums was investigated to evaluate its effect on the Mixing tolerance index (MTI), dough development time (DDT), gelatinization temperature ...
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The effect of xanthan and Qodume shirazi seed gum on fresh bread quality and its influence on dough rheology were studied. Incorporation of 0.3 to 1% of these two gums was investigated to evaluate its effect on the Mixing tolerance index (MTI), dough development time (DDT), gelatinization temperature (GT), viscosity, dough stability and quality of wheat flour. Addition of xanthan and Qodume shirazi seed gum increased the water absorption, viscosity and dough stability. In contrast, MTI and GT decreased with increase in gum concentration. DDT remained statistically unaffected by all the levels of gum. There was increase in softness of bread with increase in the level of these gums up to 1%. Hardness values indicated that the breads containing xanthan gum was softer than the one with Qodume shirazi seed gum. However, Qodume shirazi seed gum could also improve these qualities so that it could be used as a new source of hydrocolloid in bread.
Keywords: Bread, Gum, Alyssum homolocarpum seeds, Rheology, Hardness
Fatemeh Zabetian Hosseini; Seyed Ali Mortazavi; Bibi Sedigheh Fazli Bazaz; Arash Koocheki; Shadi Bolourian
Abstract
Thymus vulgaris is a plant from Lamiasceae family. The antimicrobial activities of T. vulgaris essential oil and extract depend on the phenolic compounds like carvacrol, thymol, γ-terpinene and p-cymene, which are reported to have antibacterial properties. In this research the antimicrobial effect of ...
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Thymus vulgaris is a plant from Lamiasceae family. The antimicrobial activities of T. vulgaris essential oil and extract depend on the phenolic compounds like carvacrol, thymol, γ-terpinene and p-cymene, which are reported to have antibacterial properties. In this research the antimicrobial effect of different concentration (0, 0.1, 0.2, 0.4%)of Thymus vulgaris extract was studied on Salmonella enteritidise PT4 presence mayonnaise at two different temperatures (4oC and 25oC) during storage time. This test was evaluated as a completely randomized factorial design with 3 replicates and the models were shown using RSM. The results showed that the antimicrobial effect of T.vulgaris extract was higher for the mayonnaise kept at 25oC. This effect increased with increase in concentration of extract. These concentrations of T.vulgaris extract didn’t have any unfavorable effect on the sensory parameters in mayonnaise.
Keywords: Mayonnaise, T. vulgaris extract, Salmonella enteritidise, Modeling
