Submitted to: American Peanut Research and Education Society Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 7/10/1998
Publication Date: N/A
Technical Abstract: Low density lipoprotein (LDL) oxidation is suspected to be a triggering factor for hardening of the arteries in humans. Polyunsaturated fatty acids attached to the lipoproteins are much more susceptible to oxidation than monounsaturated fatty acids (MUFA). Studies suggest that changes in diet can increase MUFA content and decrease PUFA content in lipoproteins and thereby decrease LDL oxidation. This may explain the reduction in atherosclerosis seen as a result of changes in dietary fat. Peanuts have oil contents near 50%, whereas partially defatted peanuts have been reduced to oil contents near 30% by means of mechanical presses. The O/L ratio of peanut oil is highly correlated with the shelf-life potential of peanuts. Peanut breeders have produced peanuts with O/L ratios near 30, whereas the O/L ratio of regular peanuts is usually ca. 1.5. The use of high oleic peanut oil to roast regular O/L peanuts has been shown to improve the shelf-life of regular O/L peanuts. High oleic peanut oil was used to roas both regular and partially defatted peanuts with a regular peanut oil roast used as a control. Post-roast treatments were used to vary oil uptake into the peanuts. Peanuts were roasted at 177 C to a Hunter L value of 49 plus or minus 1. Roasted samples were stored at 30 C in glass jars and aerated 3 times per week for 8 weeks. Samples were taken at regular intervals and analyzed for peroxide value (PV), oxidative stability index (OSI), moisture content, total fat, oil uptake and O/L ratios. The goal of this experiment was to produce peanuts with lower total oil content (35-40%) and higher O/L ratios. Lower total fat content and an increase in monounsaturated fats relative to polyunsaturated fats should result in both improved peanut product shelf and improved health benefits to consumers.