MANNOPROTEIN FROM SPENT YEAST OBTAINED FROM THAI TRADITIONAL LIQUOR DISTILLATION: EXTRACTION AND CHARACTERIZATION

Abstract

ABSTRACTMannoprotein from spent yeast obtained from Thai traditional liquor distillation was extracted by autoclaving in a neutral citrate buffer for 30 min. The yield of mannoprotein was 0.27 g/g wet cells. The mannoprotein obtained was evaluated for chemical and physical stability to establish its potential use as a natural emulsifier in processed foods. The extracted mannoprotein exhibited emulsion of 60.23% toward palm oil as oil‐in‐water and had a critical emulsifier concentration of 20 g/l. The composition of the mannoprotein was 96% carbohydrate and 4% protein. The emulsion activity of the mannoprotein was similar to those of commercial emulsifiers (lecithin and gum arabic). The emulsion activity of mannoprotein towards palm oil was stable over a broad range of pH (3–12), NaCl concentrations of 0–3% (w/v), CaCl2 and MgCl2 concentrations of 0–0.1% (w/v). Temperature did not affect the emulsion activity of mannoprotein. Mannoprotein from spent yeast could be developed as a source of bioemulsifier for use in the food industry.PRACTICAL APPLICATIONSMannoprotein from spent yeast obtained from Thai traditional liquor distillation is considered to have an activity similar to the commercial emulsifiers, lecithin and gum arabic. It could be developed as a source of bioemulsifier for use in the food industry. The production of the bioemulsifier would be economically advantageous as the process converts a low‐value waste into a high‐value product.