Submitted to: American Oil Chemists' Society Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 12, 1999
Publication Date: N/A
Technical Abstract: Lipid degradation is a critical factor in shelf life of roasted peanuts. High oleic acid peanut oils as roasting medium appear to hold potential for improved shelf life of oil roasted peanuts. When virginia, runner, and spanish market types of peanuts were roasted in high oleic acid/linoleic acid (O/L) ratio (ca. 23) or commercial (O/L ratio of ca. 1.5) peanut oil, shelf life was greater in the high O/L roasted peanuts. Increases in shelf life measure were correlated to the original O/L ratio of the peanuts used. Peanuts roasted in high O/L ratio oil had consistently lower peroxide values (PV) and higher oxidative stability index (OSI) values in storage. In additional research to examine the full potential for shelf life improvement, high O/L peanuts were roasted in high O/L and commercial oil. After 20 wks of storage at 30 C, PV of high O/L roasted was 5.3 compared to 10.8 for commercial oil roasted. OSI values were 88.5 and 52.4 immediately after roasting for high O/L roasted and commercial oil roasted peanuts, respectively. Studies with reduced fat (pressed) peanuts have also been conducted. To examine product characteristics and shelf life functionality, reduced fat peanuts (ca. 30% oil content) were oil roasted in high O/L and commercial peanut oil. After roasting, oil content increased from 30% to 40% and O/L ratio was unchanged at 1.7 in commercial oil roasted peanuts but increased to 3.5 in reduced fat, high O/L roasted peanuts. Peanuts roasted in high O/L oil had a PV of 13.6 compared to 34.9 for peanuts roasted in conventional oil after 8 wks of storage with similar positive effects in OSI values. Lower total fat and increased oleic acid content suggest improved nutritional character of this product.