Effect of Conventional and Microwave Heating on Protein and Odor Profile in Soymilk Powder

Soymilk contained serine protease enzymes with inhibitory activity against trypsin, causing a negative effect on nutritional absorption. This project aimed to investigate the effects of conventional heating (100 °C/20 min) and microwave heating (360–900 W/1–6 min) on trypsin inhibitor, protein digestibility, and odor profiles. Soymilk contained 46–47% protein, regardless of heating conditions. Using scanning electron microscopy, it can be seen that the conventionally heated sample had a smooth surface and a porous structure, whereas microwave-heated samples contained a protein matrix in clusters with rough surfaces. The molecular weight of proteins in SDS-PAGE was reduced to 19 kDa and