Effect of frying conditions on the physico-chemical properties of rice bran oil and its blended oil

Abstract

The changes occurring in rice bran oil and its blend with sunflower oil during repeated frying cycles of dried and moist potato chips were monitored. The parameters assessed were: Colour, Refractive Index, SpecificGravity, Oryzanol Value, Free fatty acid, Iodine Value, Peroxide value, anisidine value, Saponification Value, trans fats and fatty acid composition. No significant changes (p≤0.05) were observed in the refractive index and specific gravity of rice bran oil, sunflower oil and their model blend. The colour of blended oil was lesser than RBO and the intensity of color increased after each frying cycle during the deep fat frying of moistened and dried potato chips. The oryzanol content and iodine value decreased with the frying cycles. The decrease in oryzanol value during the frying operation was more prominent in rice bran oil as compared to the blended oils. The increase in p-anisidine value was more in rice bran oil as compared to blended oil. No significant changes (P<0.05) in the myristic, palmitic and stearic acid composition was observed during the repeated deep fat frying cycles in both the rice bran oil and blended oils samples. The amount of unsaturated fatty acid decreased gradually during repeated deep fat frying cycles in both the oils. The trans fat increased with repeated deep fat frying cycles in both the rice bran and blended oils, when used to fry moistened and dried potato chips. Both the oil samples showed greater formation of trans fatty acids when the moistened potato chips were used during frying.

Effects of oil-water mixed frying and pure-oil frying on the quality characteristics of soybean oil and chicken chop

“…Table 4 shows fat content of fried chicken chops as a function of frying method and time. In previously published studies (Koh et al, 2011;Debnath et al, 2012;Mishra & Sharma, 2014), it was noted that the frying time had remarkable influence on oil content of fried products. This was also observed in the present study, where oil content showed significant (p<0.05) increment in the last day and in the last three days in the case of DWF and PDF, respectively.…”

Rice Bran Oil’s Role in Health and Cooking

“…3,[44][45][46] Edible oils, including RBO, are characterized by their major and minor components. Crude RBO is composed of 4% unsaponifiable matter, such as tocopherols and tocotrienols; 2-4% free fatty acids (FFAs) at the time of milling; and 88-89% triacylglycerols (neutral lipids).…”

Effect of frying on the rheological and chemical properties of palm oil and its blends

“…This observation provides information of gradual cis to trans isomerization throughout this treatment process (Sanahuja et al 2009;Tena et al 2009). Moreover, Mishra and Sharma (2011) reported that repeated frying caused trans fatty acids to increase while the blended samples were within the acceptable range after few frying cycles. In this case, palm olein has the lowest absorption band (0.220) as well, where as Soybean oil shows the highest with 0.265 followed by sunflower and canola oil at (0.244 and 0.238, respectively) but candlenut oil does not give any band at this frequency.…”