[Effects of blanching and hydrocolloid coating of potatoes with methyl cellulose and tragacanth on French-fries oil uptake and qualitative properties]

French fries are a food product with an upward consumptuion trend in Iran. Because of high oil uptake during frying, French fries are an energy-dense food item, providing a very large number of calories to the body. Therefore, efforts to reduce the rate of oil uptake by this popular food item would contribute to the public's health. The purpose of this study was to determine the effects of blanching and coating of potatoes with methyl cellulose and tragacanth on French-fries oil uptake and qualitative properties. Strips of potato [Agria variety] were prepared, blanched in water or a calcium chloride solution [0.5%], coated with a solution of methyl cellulose [0.5, 1.0 and 1.5%], tragacanth [0.5, 1.0 and 1.5%], methyl cellulose [0.5, 1.0 and 1.5%] and sorbitol [0.5%], or tragacanth [0.5, 1.0 and 1.5%] and sorbitol [0.5%] and deep-fried. Oil uptake, moisture content, and color of the French fries were measured and their sensory properties determined and compared with those of control samples. Blanching and hydrocolloid coatings of the samples brought about a decrease in oil uptake and increases in moisture content and texture tenderness of the potato strips [p<0.01]. Blanching in calcium chloride alone reduced oil uptake by 8.61%. In comparison with the control samples, coating with methylcellulose [1.5%] with sorbitol [0.5%] decreased oil uptake from 19.85% to 16.29%. Blanching in calcium chloride resulted in a significant 5%increase in moisture content. The hydrocolloid coatings caused significant increases in moisture content and resistance to cutting of the samples [P<0.01], such that the highest moisture content [44.60%] was obsereved in the samples coated with methyl cellulose [1.5%]. Tragacanth at aconcentartion of 1.5% with sorbitol at a concentartion of 0.5% brought about the highest resistance [211/13 Newton] to cutting. The findings also showed that hydrocolloid coatings resulted in significant incremets in the L [asterisk] b [asterisk], a [asterisk] factors of the French fries color as compared to the control samples. However, there were no significant differences among samples with regard to sensory characteristic

[Isolation of cinnamon extract and assessing its effect on the stability of sunflower oil]

An effective way to prevent oxidation of oils and fats is addition of antioxidants. However, the use of synthetic antioxidants for this purpose is gradually being discontinued due to their undesirable side effects. Therefore, extraction and production of natural antioxidants is a necessity. The objective of this study was to isolate cinnamon extract by the Soxhlet and cold solvent methods, employing acetone and methanol as solvents, and to investigate its effects on the stability of sunflower oil. Acetone and methanolic extracts of cinnamon were obtained by the Soxhlet and cold solvent methods. Extraction efficiency was determined and the total content of phenolic compounds in the extracts measured by the Folin Ciocalteau method. The extracts were added to refined sunflower oil samples at concentrations of 0.02%, 0.04%, 0.06%, 0.08% and 0.1%, followed by determination of stability of the samples [as assessed by delayed oxidation]. Peroxide value and induction period measurements were used to evaluate the antioxidant activity, the control being synthetic antioxidant TBHQ at a concentration of 0.01%. The extraction efficiency by the Soxhlet method was higher than that of the cold solvent method; however the phenolic compounds content of the extracts isolated by the cold solvent method was higher. In both the Soxhlet and cold solvent methods, the efficiency of exrtarction by methanol was higher than by acetone solvent, while the phenolic compounds content was higher when acetone solvent was used. The data also showed that the antioxidant activity of the extracts was concentration-dependent .The extract isolated with acetone acted better than that isolated with methanol, such that at a concentration of 0.1% it showed the highest activity, second only to synthetic antioxidant TBHQ at the same concentration. Cinnamon extract has antioxidant activity, which is related to its content of phenolic compounds and other antioxidants. Further research is required to get more information before it can be used routinely as a source of natural antioxidants