Soy Peptides as Functional Food Material
Peptides are unique components of living organisms and appear in many biological capacities, nutritional activities, and fermentation processes. Many types of biologically active peptides in the body, such as peptide hormones, participate in inter- and intracellular communication and activities. Partially fermented foods contain various peptides and amino acids due to microbial activity and result in specific tastes in traditional foods. Much attention has been paid to food-derived peptides because of their good absorbability compared to amino acids. Many processing methods using enzymes, acids, and heating are used for protein hydrolysis to produce peptides. Industrialized soy peptide production by enzyme hydrolysis started in the early 1980s in Japan with the growth of soy protein manufacturing. Food manufacturers are interested in the solubility, low viscosity, and good absorbability of peptides. Practical commercial soy peptide production consists of the following processes. The soybean protein curd from whole soybean first undergoes delipidation, water extraction, and isoelectric point precipitation.