COMPARISON OF FATTY-ACID COMPOSITION AND OXIDATIVE STABILITY OF PEANUT OILS PREPARED FROM SPRING AND FALL CROPS OF PEANUTS

Spring and fall crops of peanut are grown each year in Taiwan. Fatty acid composition of oils prepared from peanuts of spring and fall crops of Tainan 9 and 11 cultivars planted consecutively from 1991 to 1993 were analyzed. For both cultivars, the oleic/linoleic (O/L) ratio was higher in oils prepared from spring crops than that from fall crops. When the harvested in-shell peanuts were stored at ambient and refrigeration temperatures for 5 months, conjugated diene hydroperoxide (CDHP) contents were significantly higher in spring crops than in fall crops. CDHP and free fatty acid contents increased more rapidly with time at ambient temperature than they did at refrigeration temperature. Growing season and storage time were the prime causes to result in significant changes of fatty acid composition. When the oils were subjected to an oven test at 75 degrees C, oils prepared from in-shell peanuts of spring crops of both cultivars after 3 months of storage at both temperatures were comparatively more stable against peroxidation than other test oils.