Preparation and characterisation of bioemulsifier from Saccharomyces cerevisiae and its application in food products

Abstract

Mannoprotein in the cell wall of Saccharomyces cerevisiae was extracted by autoclaving in citrate buffer (pH = 7), and purified. The purified product was spray-dried for further characterisation. The molecular weight of the bioemulsifier mannoprotein was estimated to be 14,000-15,800 by SDS-PAGE method. Physical and chemical stability analysis showed that emulsions of 60% oil-in-water, 8 g/L bioemulsifier and 5-50 g/L sodium chloride were stable for 3 months at 4 °C at pH 3-11. The yield of emulsifier extracted from commercial strain of S. cerevisiae (g/g wet cells) was 80-100 g/kg. The mannoprotein consisted of approximately 380-410g/kg protein and 210g/kg carbohydrate. Emulsification tests on mannoprotein revealed that its function is similar to that of sodium caseinate. Practical application of this bioemulsifier for mayonnaise production with several different formulations indicated that it can be used with carboxymethyl cellulose (CMC) (instead of xanthan) for production of mayonnaise. © 1996 Academic Press Limited.