June 17/Food Weekly News -- "To determine effects of expeller oil pressing and decreased linolenic acid, intermittent batch frying tests were conducted with tortilla chips using soybean oil (SBO), expeller-pressed SBO (EPSBO), expeller-pressed low-linolenic SBO (EPLLSBO), high-oleic sunflower oil, corn oil and hydrogenated SBO for up to 35 hours of frying. Chips were aged at 25C and trained, experienced analytical sensory panelists evaluated their flavor," scientists writing in the Journal of Food Lipids report.
"Oxidative stability of the chips was determined by hexanal analyses, and oil fry life was measured by total polar compounds. The stability of tortilla chips fried in EPLLSBO was significantly better than chips fried in SBO or EPSBO as judged by rancid flavor intensity and hexanal formation after storage. This effect may be due, in part, to less linolenic acid in EPLLSBO and better tocopherol retention compared to EPSBO," wrote K. Warner and colleagues, Department of Agriculture.
The researchers concluded, "The combination of expeller pressing and low-linolenic acid (EPLLSBO) produced a significantly more stable fried product than expeller pressing (EPSBO) alone."
Warner and colleagues published their study in the Journal of Food Lipids ("OXIDATIVE AND FLAVOR STABILITY OF TORTILLA CHIPS FRIED IN EXPELLER PRESSED LOW LINOLENIC ACID SOYBEAN OIL." Journal of Food Lipids, 2009;16(2):133-147).
Additional information can be obtained by contacting K. Warner, ARS, National Center Agriculture Utilizat Research, Dept. of Agriculture, 1815 N University St., Peoria, IL 61604.
From the June 22, 2009, Prepared Foods E-dition