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

Abstract

AbstractOil 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 °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 °C, 1 min) eliminated lipoxygenase of soybean and peanut OBs. Furthermore, oleosin exhibited a higher denaturation temperature (approximately 100 °C) than extrinsic proteins (approximately 50 °C). Pasteurization induced the conversion of the α‐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 °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.