Emulsifying properties of glucose-conjugated soybean 11S globulin with maximum antioxidant capacity, obtained under optimal preparatory conditions identified by random-centroid optimization

Abstract

The optimal preparatory conditions identified using random-centroid optimization revealed that the maximum hydroxyl radical antioxidant activity (63.4 ± 4.8 µmol of gallic acid equivalent/g of protein) was achieved at 70 °C; relative humidity, 45%; reaction time, 47.92 h; and glucose to soybean 11S globulin ratio, 10.66:1 (w/w). The average particle size of the oil-in-water emulsions prepared using optimally glycated, unreacted, and native soybean 11S globulin was 1.68 ± 0.11, 1.81 ± 0.18, and 2.36 ± 0.42 µm, respectively. The emulsion stability of the optimally glycated and unreacted soybean 11S globulin was superior to that of native soybean and did not exhibit complete separation after four weeks. When a sufficient amount of optimally glycated soybean 11S globulin was present in the emulsion, oil oxidation was significantly suppressed, suggesting the potential use of optimally glycated soybean 11S globulin as an antioxidant.