Showing 3 results for Rheological Properties
A. Abdollah Zadeh, M. Shahedi,
Volume 11, Issue 40 (7-2007)
Abstract
Lots of investigation has been done in order to increase wheat yield per acre in Iran, but there is not enough study about quality of produced wheat. Bread quality in Iran has been deteriorated in recent years, mostly due to employing wheat flours of low quality. Thus the present study was conducted to find the chemical and rheological properties of four bread wheat cultivars (Omid, Rosshan, Golestani and “Kal”) produced in Sabzavar region. The results indicated that the quantity and quality of “Kal” wheat gluten are more desirable in comparison to the other varieties. The rheological experiment results indicated that the Omid wheat flour is the best regarding the dough resistance coefficient and alfa amylase activity. The alfa amylase activity of all flours was low. Appropriate time for fermentation of bread dough for all flours was 75 to 90 minutes. Mixture of one to ten ratio of Roshan and Omid flour produced bread with better quality. The results also indicated that the rheological properties of “Kal” flour dough such as mixing resistance, breaking point resistance and valorimeter value are acceptable. The bakery properties of “Kal” flour is better than Rosham flour. The “Kal” variety of wheat is the same as Roshan variety and the only difference between them is the region of production and farming conditions. It shows that farming condition is one of the important factors affecting bread wheat quality.
A Masoumi, A Shahriari,
Volume 13, Issue 47 (4-2009)
Abstract
To reduce storage space and transportation cost for alfalfa and straw bales, recompressing of the bales is recommended. In order to design different units and elements of double compressing device, some physical and rheological properties of desired products were determined. A factorial experiment with a randomized complete block design with three replications was used during the tests. Confined compression tests for three levels of axial strain (25, 35 and 45% of initial length) on alfalfa and straw bales were performed. In this study, the influence of the materials and strain on pressure, modulus of elasticity and required energy were investigated. The results showed that the effect of materials type and strain levels on the determined parameters were highly significant (P<0.01). The highest value of the measured parameter was obtained for straw bales at 45% strain. The Fabroad’s model (expressing the relationship between pressure and density) and two other models, namely, Sitki and Osbof which were used to describe the relationship between modulus of elasticity and density were fitted to the measured values, and then constants were determined for each model individually. The coefficients of friction for alfalfa and straw bales on steel and galvanized surfaces at three levels of perpendicular loads were determined. Effect of bales and surface types on frictional coefficient were not significant (P< 0.05), however, the effect of perpendicular load was highly significant (P<0.01). Tensile strength of hemp and nylon ropes, which are usually used to knot compressed bales, was measured. The results indicated that hemp ropes had more strength than nylon.
Gh Mesbahi, A Abasi, J Jalali, A Farahnaki,
Volume 13, Issue 47 (4-2009)
Abstract
In this research, tomato peel and waste seed obtained from tomato paste processing were dried and milled. The obtained powder was added to tomato ketchup sauce in different proportions (1, 2, 5, 7 and 10%). To study the effect of tomato peel and seed powder on physicochemical and nutritional properties of the tomato ketchup samples, the parameters including lycopen, total solid, brix, total sugars, reducing sugars, protein, fat, ash, fiber, vitamin C, pH, color (L, a/b) were evaluated. Rheological properties of the ketchup samples (consistency and viscosity) were determined and compared with control samples. Sensory evaluation of the ketchup samples was carried out after 1, 2 and 5 months of storage by a group of panelists. Addition of tomato peel and seed powder resulted in an increase in total solid, brix, ash, fiber, protein, fat, consistency and viscosity of the ketchup samples. Sensory evaluation tests did not show any significant difference between the color, flavor, texture and overall acceptability of the control and samples containing 1 or 2 % of tomato peel and seed powder. In addition, sensory evaluation tests did not show any significant changes in the ketchup samples during storage. Thus, it can be concluded that nutritional and rheological properties of tomato ketchup can be improved by addition of tomato peel and seed powder.
