Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/25/2002
Publication Date: 10/1/2002
Citation: Baker, G.L., Sims, C.A., Gorbet, D.W., Sanders, T.H., O'Keefe, S.F. 2002. Storage water activity effect onoxidation and sensory properties of high-oleic peanuts. Journal of Food Science. Interpretive Summary: Peanuts containing high concentrations of the fatty acid, oleic acid, have longer shelf-life than peanuts with a normal concentration of oleic acid. This occurs because the oleic acid replaces linoleic acid in the oil in the peanuts and the rate of oxidation of oleic acid is less than that of linoleic acid. The value of this type peanut is that it should have better shelf-life in a variety of products. Many products contain some water and water can migrate into the peanuts. Water concentration is known to affect the rate of oxidation of oil and peanuts are about 50% oil. This study was conducted to evaluate the response of roasted, high oleic peanuts to different concentrations of water in the peanuts (water activity). The data indicated that best product quality is maintained when the peanuts (low oxidation, loss of crunchiness, and maintenance of desirable flavor) are stored at water activities between 0.33 and 0.44. Above this range, crunchiness decreased and oxidation increased, whereas below this range only oxidation increased.
Technical Abstract: Peanuts were stored under different water activities and maintained using saturated salt solutions, for 14 wks. Peroxide values, percent moisture, and sensory attributes were determined at 2 wk intervals. Peroxide values increased over time for all treatments. The highest oxidation values were observed in the peanuts held under 0.67 water activity, followed by 0.12, 0.52, 0.44 and 0.33, respectively. Moisture increased over time for all samples and correlated with the water activity of storage. Roast peanut flavor decreased with time and the decrease was greater at higher aw of storage.