Effect of pasteurization on membrane proteins and oxidative stability of oil bodies in various crops

Oil bodies (OBs) are natural pre-emulsion systems and an ideal green food additive. However, their proclivity to oxidation limits the applications of OBs. In this study, the effect of pasteurization (85 and 125 degrees C; 1 min) on membrane proteins and the oxidative stability of various OBs (soybean, sunflower, peanut, sesame, and walnut) were investigated. The membrane proteins are extracted from the OBs. The ultrahigh-temperature pasteurization (125 degrees C, 1 min) eliminated lipoxygenase of soybean and peanut OBs. Furthermore, oleosin exhibited a higher denaturation temperature (approximately 100 degrees C) than extrinsic proteins (approximately 50 degrees C). Pasteurization induced the conversion of the alpha-helix structure to a disordered structure by rearranging the hydrogen bonds. The pasteurized soybean and peanut OBs exhibited a high oxidative stability owing to their stable membrane structures and decreased lipoxygenase activity, while sunflower, sesame, and walnut OBs did not exhibit good oxidative stability because of their vulnerable membranes, a large number of unsaturated fatty acids, and severe aggregation of droplets. Simulated milk based on pasteurized soybean and peanut OBs (125 degrees C, 1 min) maintained outstanding storage stability. These results confirmed that pasteurized soybean and peanut OBs have the potential as a skim milk additive for the benefit of the consumer.