Oxidative stabilities of low‐linolenate, high‐stearate and common soybean oils

TLDR: In this paper, the oxidative stability of five SBO of various fatty acid (FA) compositions was compared by using peroxide values, conjugated dienoic acid values and sensory panel scores.

Abstract: It is generally agreed that the high linolenate (18:3) content of soybean oil (SBO) contributes to its flavor instability. In this study, the oxidative stability of five SBO of various fatty acid (FA) compositions was compared by using peroxide values, conjugated dienoic acid values and sensory panel scores. Three of the oils were from common commercial varieties representing the range of 18:3 content normally found in SBO. The other two oils were from seed developed in a mutation breeding program. One of these oils from the line A5 had an 18:3 content of 3.5%, and the other from the line A6 had a stearate (18:0) content of 24%. Seed from the five soybean varieties was cold pressed, refined and deodorized without additives under laboratory conditions. Two oxidation experiments were conducted. In the first, the oils were stored at 28 C for 67 days. In the second, the oils were stored at 60 C for eight days. Sensory comparisons were done by using the AOCS Flavor Intensity Scale. The A5 and A6 oils were more stable than the commercial varieties as measured by chemical tests, but the sensory data were inconclusive. Oils with similar 18:3 contents did not have similar rates of oxidation. The differences between the oils were not as distinct in the 60 C test as in the 28 C test.