Ahmad Ehtiati; Fakhri Shahidi; Arash Koocheki; Seyed Mohammad Ali Razavi; Mahsa Majzoobi
Abstract
Introduction: Sorghum (Sorghum bicolor) is a tropical plant and has the fifth ranking of world cereals production. One of the important aspects of sorghum is drought tolerance and little input need during growth which has made that suitable for cultivation in semiarid regions. Due to the presence of ...
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Introduction: Sorghum (Sorghum bicolor) is a tropical plant and has the fifth ranking of world cereals production. One of the important aspects of sorghum is drought tolerance and little input need during growth which has made that suitable for cultivation in semiarid regions. Due to the presence of tannin compounds in internal part of sorghum grains and low digestion of cooked protein, sorghum flour consumption is limited. Sorghum grain contains more than 70% starch which is an important tasteless ingredient in food formulas, as the main source of energy and thickening and gelling agent. Extraction of starch from sorghum in regarding to its nutritional problems is a good solution for extension of sorghum uses in food industry. Starch is a semi crystalline structure consisted on linear amylose and branched amylopectin molecules packed in granules. Ratio of these two molecules and their molecular short order and macrostructure and size and shape of granules determine functional properties of starch in the final product. Starch properties is depended on genetic residues so that starches from tubers have distinct differences with cereal starches even obvious differences exists between cereal starches and varieties. In this study we have investigated chemical, morphological, structural and thermal properties of starches four white sorghum line.
Material and methods: White sorghum grains were prepared from local farms with line numbers KDFGS1, KDFGS6, KDFGS9 and KDFGS20. Starches were extracted sorghum lines using alkaline steeping method and further purified using toluene-water-salt solution. Chemical parameters were determined including protein by Kjeldahl digestion method, lipid by soxhlet extractor, ash by burning in furnace, moisture by oven drying and amylose content by iodine binding colorimitry,. Light microscopy coupled with digital camera was used for granules shape and size determination moreover surface properties and morphology of granules was observed using scanning electron microscopy technique. Color of starches were determined with hunterlab colorimeter. To evaluate crystalline structure of sample i.e. type of crystals and degree of crystallinity, starches first were conditioned in desiccator containing saturated aqueous sodium chloride solution at 25°C for a week then X-ray diffraction of sample in diffraction angels from 4-40° was determined. Thermal properties of crystals melting or gelatinization were measured using differential scanning calorimetry of starch in deionized water in temperatures from 20-120°C with heating rate of 10°C/min .From heat flow changes over temperature, temperature of onset, peak and conclusion points of crystalline structure melting and its required enthalpy were calculated. Functional groups of starches were investigated using FTIR technique to observe.
Results & Discussion: Isolated starches had appropriate quality due to low amount of protein (
Hassan Afshari Jooybari; Asgar Farahnaki; Mahsa Majzoobi; Gholam Reza Mesbahi; Mehrdad Niakosari
Abstract
Mazafati date is a wet and semi-dried date fruit type with dark red to black color that has premier quality. Because of its high moisture content, date fruits of this variety are very perishable at room temperature and therefore must be refrigerated during storage. In this study, effect of air temperature ...
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Mazafati date is a wet and semi-dried date fruit type with dark red to black color that has premier quality. Because of its high moisture content, date fruits of this variety are very perishable at room temperature and therefore must be refrigerated during storage. In this study, effect of air temperature (50, 60, 70, 80 and 90 ˚C) and air flow rate (1, 1.5 and 2 m/s) in hot air drying of Mazafati date were investigated. The results showed that for all samples, drying occurred at the falling rate stage of drying and the main factor affecting the drying rate was air temperature. Air flow rate did not have significant effect on drying rate. Overall, it was concluded that moisture of Mazafati dates can be reduced by cabinet drying and therefore using drying process, the need for their cold storage can be eliminated.
Sara Hoseinpoor; Behnaz Layegh; Asgar Farahnaki; Gholam Reza Mesbahi; Mahsa Majzoobi; Nazanin Darabzadeh
Abstract
Pectin is used as a gelling, texturizing and emulsifying agent in many foods. Sugar beet pulp is a good source of pectin, however due to its low molecular weight and poor gelling characteristic its uses in food industry are limited. In this research, pectin extracted from sugar beet pulp was cross-linked ...
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Pectin is used as a gelling, texturizing and emulsifying agent in many foods. Sugar beet pulp is a good source of pectin, however due to its low molecular weight and poor gelling characteristic its uses in food industry are limited. In this research, pectin extracted from sugar beet pulp was cross-linked by phosphorus oxycholride at pH 11 to improve it functional properties. Rheological tests carried out revealed that modified pectin had a higher viscosity and greater intrinsic viscosity and molecular weight than native pectin confirming the cross-linking of pectin polymers. Ketchup sauces formulated using modified and native pectins were compared with the control sample without pectin. The results showed that the sample containing modified pectin had a higher consistency and a lower syneresis value compared to the native pectin.
Keywords: Pectin, Sugar beet pulp, Cross-linking, Viscosity, Functional properties
Mahsa Majzoobi; Gholam Reza Mesbahi; Farnaz Sariri; Asgar Farahnaki; Jalal Jamalian
Abstract
The main aim of this study was to improve the bread quality and to postpone its staling. Therefore, sugar beet pulp powder was added to Barbari bread dough formulation at five levels of 1, 3, 5 and 10% (w/w, flour basis). Then the properties of dough and the resulting bread were studied. The results ...
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The main aim of this study was to improve the bread quality and to postpone its staling. Therefore, sugar beet pulp powder was added to Barbari bread dough formulation at five levels of 1, 3, 5 and 10% (w/w, flour basis). Then the properties of dough and the resulting bread were studied. The results showed that with increasing the sugar beet pulp powder, the water absorption of the dough and the fiber content of the bread increased while, bread density and hardness decreased. The electro-micrographs of the bread crumb containing sugar beet pulp powder indicated the improved texture which can delay bread staling. Sensory evaluation of the samples revealed that the bread made with up to 5% sugar beet pulp powder had the highest general acceptability. However, higher levels of sugar beet pulp powder had diverse effects on bread color which would reduce general acceptability of the samples. It was concluded that sugar beet pulp powder can improve the quality of bread and delay its staling.
Keywords: Sugar beet pulp, Dietary fiber, Bread staling, Bread texture
Mahsa Majzoobi; Nazanin Darabzadeh
Abstract
Consumer’s demand for functional foods is increasing, however, production of such food is not an easy task, and sometimes the sensory aspects of food are affected adversely. To ensure the customers of the quality of food, it is necessary to label the product with accurate nutrition information ...
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Consumer’s demand for functional foods is increasing, however, production of such food is not an easy task, and sometimes the sensory aspects of food are affected adversely. To ensure the customers of the quality of food, it is necessary to label the product with accurate nutrition information in order to make people aware of the positive nutrition effects of such foods. The aim of this research was to study the effects of giving nutrition information to the customers on their perception of quality of a wheat germ cake. Therefore, some cakes containing 15% wheat germ were packed in two different packages, one with and the other without nutrition label. These cakes were evaluated by taste panel in terms of color, flavor, taste, texture, general acceptability and possibility of buying. The results showed that despite the similarity of the product, the cake with nutrition information received higher score in many sensory aspects, general acceptability and the possibility of buying than the other one. The results stressed the impacts of giving information and making the culture of the people on the marketing of healthy food products and the costumers' perception of the food quality. Keywords: Food culture, Nutrition information, Consumer perception, Healthy food, Wheat germ cake
