Long term storage of soybean and cottonseed salad oils.

Commercially prepared and packaged soybean ::md cottonseed salad oils from several different processors were evaluated penodically during storage for 12 months. Panially hydrogenated and winterized soybean oils, as well as unhydrogenated soybean salad oils. were stored in bottles and cans at i8 and 100 F. Control samples of all oils were held at a F during the entire test. Some lots in bottles and cans were packaged under nitrogen to improve storage stability. Agreement was good between organoleptic and oxidative evaluation of aged oils. After 26 weeks of storage at 100 F, the flavor of panially hydrogenatedwinterized oils packaged under nitrogen showed a minimum loss. These same oils did not exhibit much, if any, reduction in their oxidative stability as indicated by storage peroxide values (active oxygen method). Soybean oil not protected with nitrogen demonstrated progressive flavor deterioration at 100 F. After 10 weeks of storage, the deterioration became marked and the f1avor score was below 5. From limited observations. bottled oils appear to have a better stability than oils packaged in screw-cap tin cans. Hydrogenated oils packaged under nitrogen in cans had good oxidative stability, but some lowering of the flavor score was observed. Nonhydrogenated soybean oils packaged in tin cans not under nitrogen exhibited the most rapid flavor deterioration of all lots of oil investigated.