We. Neff et al., OXIDATIVE STABILITY OF BLENDS AND INTERESTERIFIED BLENDS OF SOYBEAN OIL AND PALM OLEIN, Journal of the American Oil Chemists' Society, 71(10), 1994, pp. 1111-1116
Improvement of oxidative stability of soybean oil by blending with a m
ore stable oil was investigated. Autoxidation of blends and interester
ified blends (9:1, 8:2, 7:3 and 1:1, w/w) of soybean oil and palm olei
n was studied with respect to fatty acid composition, fatty acid locat
ion and triacylglycerol composition. Rates of formation of triacylglyc
erol hydroperoxides, peroxide value and volatiles were evaluated. The
fatty acid composition of soybean oil was changed by blending. Linolen
ic and linoleic acids decreased and oleic acid increased. The triacylg
lycerol composition of blends and interesterified blends was different
from that of soybean oil. Relative to soybean oil, LnLL, LLL, LLO, LL
P, LOO and LLS triacylglycerols were lowered and FOG, POP and PLP were
higher in blends and interesterified blends (where Ln, L, O, P and S
represent linolenic, linoleic, oleic, palmitic and stearic acids, resp
ectively). Interesterification of the blends leads to a decrease in PO
O and POP and an increase in LOP Linoleic acid concentration at triacy
lglycerol carbon-2 was decreased by blending and interesterification.
Rates of change for peroxide value and oxidation product formation con
firmed the improvement of soybean oil stability by blending and intere
sterification. But, blends were more stable than interesterified blend
s. Also, the formation of hexanal, the major volatile of linoleate hyd
roperoxides of soybean oil, was decreased by blending and interesterif
ication.