Showing 8 results for Karazhiyan
Volume 13, Issue 57 (0-0)
Abstract
In this research different methods of DNA extraction from Aspergillus niger in tomato paste have been optimized and compared with each other. For this purpose classical optimization techniques and commercial Kit base methods were used. Mold spores of Aspergillus niger at different levels (101, 103 and 105 CFU/g) were added to the tomato paste. After mycelium growth DNA extraction was perfomed by five methods. Different methods employed by use the Liquid nitrogen, ultrasonic and lysis solution in the cell wall. These methods in terms of quality and quantity of DNA extracted were studied using spectrophotometer with NanoDrop. The absence of smear, protein contamination and no presecnce of PCR inhibitors determined with PCR that performed forward and reverse primers. Result of gel electrophoresis and PCR assay showed that Method 1 is the most appropriate method for DNA extraction is the mold of tomato paste.
Volume 16, Issue 91 (September 2019)
Abstract
Berry is expanded in different regions of Iran. Due to short time of harvesting season and sensitiveness to storage drying is a method for its preservation. Due to high wastages of this fruit in the country, importance of processing industry and evidences about high disadvantages of using sugar in foods, the aim of current research is based on achievement to a kind of concentrate from dried berry with profit properties for further usages in food formulations as a sugar or invert syrup substitute in different foods. After cleaning and maceration of dried berry, the obtained extract was evaporated using a rotary evaporator at a constant rate and temperature and 0, 30, 60, 90 and 120 minutes. Rheological properties, pH, density, brix and colour indices were evaluated. Results demonstrated that pH, b*, L* indices and flow index behavior decreased and brix, density, a* index and consistency coefficient increased during evaporation time. Flow behavior showed an intensified in pesudoplastic behavior.
Volume 18, Issue 6 (11-2016)
Abstract
Microbial detoxification is considered as one of the most common methods used for the elimination of aflatoxins. Reports indicate that S. cerevisiae can be effective in removing aflatoxins through the adsorption of aflatoxins to their cell wall. In the current research, the ability of S. cerevisiae (viable, acid-, heat- and ultrasound-treated yeasts) to bind aflatoxin M1 was assessed in yoghurt. To this end, firstly, recombinant milk containing 12% solids, non-fat skimmed milk powder was prepared. Next, the samples were spiked by aflatoxin M1 using different concentrations (100, 500 and 750 pg mL-1). When the starter bacteria were added to the milk, the treated yeasts were added as well. The concentration of aflatoxin M1 residue in the supernatant of the yoghurt samples after different storage times (1, 7, 14 and 21 days) was measured using the ELISA method. The results showed that all treatments containing viable, acid-, heat-, ultrasound-treated yeast and starter bacteria were able to adsorb aflatoxin M1, and the ability of the treated yeast was significant as compared with the control (P< 0.05). Among the treated yeasts, the ability of the acid-treated yeasts was higher in toxin binding. Overall, it can be concluded that using S. cerevisiae for the biological adsorption of aflatoxin M1 is effective in fermented dairy products.
Volume 19, Issue 123 (May 2022)
Abstract
Dairy desserts are milk-based products that play an important role in maintaining the mankind diet because of their nutritional value. The aim of this study is to investigate the effect of adding millet flour on quality characteristics of dairy desserts based on rice flour. Desserts were produced using millet flour at different contents (0, 10, 20, 40 and 50%) and their physicochemical, textural and sensory properties were investigated. The results showed that desserts with millet flour had less moisture content and sugar, but more ash and fat content (p˂0.05). The acidity and pH of the dairy dessert samples were affected by the storage time and the amount of millet flour. With increasing time, the acidity of the product increased and pH decrease due to the prebiotic properties of millet flour, which provides the conditions for better growth and development of lactic acid bacteria. Millet flour decreased L * value, but indices a * and b * values increased significantly (p˂0.05). The results of texture tests showed that with increasing the concentration of millet flour, the texture properties (hardness, adhesion and resilience) of dairy desserts improve. Evaluation of sensory characteristics of the samples indicates that desserts with low and medium amounts of millet flour had the highest sensory acceptability amount.
Volume 19, Issue 123 (May 2022)
Abstract
Hydrocolloid stabilizers have the potential to produce high viscosity products at low concentrations. Due to their unique functionalities these products are widely used in food process industry. In current research the effects of different concentrations of Glucomannan Konjac (different levels of 0.2, 0.4, 0.6%) were evaluated on physical properties including pH, acidity, fat, total solids and melting resistance, sensorial characteristics and rheological properties of ice cream including flow behaviour and fitting with famous rheological models. The results revealed that viscosity, total solids and melting properties had direct relation with konjac substitution level. All substitution levels lead in significant increase in viscosity. The lowest resistance to melting and the highest total solid contents was related to the highest konjac concentration. Consistency coefficient increased and flow index behaviour decreased, With increasing konjac level up to 0.6%. Power law and Herschel-Bulkley models were successfully fitted with the rheological parameters. Yield stress significantly increased with increasing level of stabilizer. These improvement in rheological behaviour is attributed to the presence of high molecular weight components that have the potential to maintain water. Control sample gained the lowest score in sensorial evaluations.
Volume 20, Issue 138 (August 2023)
Abstract
Although millet flour lacks gluten, however it is a rich source of protein, amino acids, energy, vitamins and nutritional ingredients in comparing with other cereal grains. In addition, it is overfilled of dietary fibers, phytochemical materials and micronutrients as well. In current research the effect of millet and wheat flour combinations in bread making was evaluated at different percentages of substitutions (10, 30 and 50 %). Baking properties of different bread samples were evaluated and related parameters with bread quality including volume, height, textural attributes (hardness, adhesiveness and cohesiveness), bread color and sensorial characteristic analyzed and compared with control bread. Results revealed that height and volume decreased but bread hardness increased with increase in substitution level. Color indices decreased for crust; however similar behavior was not observed for crumb. Interesting results observed by sensorial analysis. Total acceptance was higher in comparison with control bread due to different texture and taste. But this total acceptance decreased with substitution. The results of current research revealed high potential of millet flour for further usage in different food formulation.
Volume 21, Issue 149 (July 2024)
Abstract
In current study, whey powder, guar and tragacanth gums were used at the different levels of 0.1, 0.3 and 0.5%, and in a mixed forms of 0.25% whey powder and 0.25%. Guar gum, 0.25% of whey powder and 0.25% of tragacanth gum in the formulation of Sangak bread to improve farinographic and extensograph properties of dough and physicochemical and sensory properties of bread. The results showed that the highest water absorption and dough development time and the lowest weight loss and firmness were observed in the sample containing 0.5% tragacanth gum. The samples containing guar gum and tragacanth and the sample containing 0.25% whey powder and 0.25% guar gum had the longest dough stability time. Tragacanth gum had the greatest role in reducing the degree of softening and increasing the farinograph quality number. Guar gum was more effective than other ingredients in improving dough extensibility. The effect of tragacanth gum and guar on dough resistance was increasing and decreasing, respectively. The highest energy was observed in the sample containing 0.25% whey powder and 0.25% tragacanth gum. The additives used improved the odor, color and chewability of Sangak bread. Thus, the sample containing 0.5% tragacanth gum (1 priority) and the sample containing 0.25% whey powder and 0.25% tragacanth gum (2 priority) has been introduced as the best samples.
Volume 22, Issue 159 (May 2025)
Abstract
The viability of probiotics in sensitive environments, particularly gastrointestinal conditions, is of significant importance. In this study, the microencapsulation technique was used to increase the viability of probiotics (Lactobacillus acidophilus La5) under simulated gastrointestinal conditions. These bacteria were microencapsulated using the emulsification method in a matrix of Sodium alginate and Sodium caseinate at five concentration levels, individually and in combination. Then it was examined for viable cell count, encapsulation yield, survival against bile salts, and viability against gastric acid and intestinal fluid with and without bile salts. Our results showed significant differences between the treatments in all tests when comparing the average data (p<0.05). The survival of free cells in digestive conditions decreased sharply; however, microencapsulation acted as a protective role, and the survival of microencapsulated strains was higher than that of free cells. The results showed that microencapsulation acts as a protective mechanism for improving the viability of microencapsulated strains compared to free cells. On the other hand, the combination of Sodium alginate and Sodium caseinate as an encapsulant can significantly increase the bacteria's resistance to digestive conditions (p<0.05). Among the treatments, the free cells (L-FC) treatment showed the lowest survival against the simulated digestive environment. In the viability test in the intestinal environment with bile salt, no live cells were present after 300 minutes. However, in contrast, the treatment 75% Sodium alginate + 25% Sodium caseinate (L-SA3SC1), had the highest encapsulation yield and exhibited the best protective effect against bile salts, gastric acid, and intestinal fluid. In conclusion, microencapsulation using the emulsification method with a combination of Sodium alginate and Sodium caseinate effectively enhances the survival of Lactobacillus acidophilus. It thus can significantly benefit human health, particularly in improving gastrointestinal diseases.