Lipoxygenase lsoenzymes in Soybeans: Effects on Crude Oil Quality

Crude oils prepared from tempered or untempered Amsoy, Calland, and lipoxygenase‐1 null soybeans were stored under accelerated conditions and examined for peroxide value and sensory characteristics. Activity of three lipoxygenase isoenzymes was reduced by two of three tempering methods; steaming under pressure was most effective. However, with the exception of pressure steam‐tempered Calland beans, lipoxygenase was not completely inactivated. Peroxide values of stored oils were significantly higher than those of oils that were not stored. Cultivar differences were observed. Flavor scores for crude oils from tempered beans were not markedly different. Grassy/hay and roasted flavors were more predominant in oils from tempered than untempered beans. Tempering procedures had more effect on quality of crude soybean oils than cultivar.