The mannoprotein of Saccharomyces cerevisiae is an effective bioemulsifier

Abstract

The mannoprotein which is a major component of the cell wall of Saccharomyces cerevisiae is an effective bioemulsifier. Mannoprotein emulsifier was extracted in a high yield from whole cells of fresh bakers' yeast by two methods, by autoclaving in neutral citrate buffer and by digestion with Zymolase (Miles Laboratories; Toronto, Ontario, Canada), a 0-1,3-glucanase. Heat-extracted emulsifier was purified by ultrafiltration and contained approximately 44% carbohydrate (mannose) and 17% protein. Treatment of the emulsifier with protease eliminated emulsification. Kerosene-in-water emulsions were stabilized over a broad range of conditions, from pH 2 to 11, with up to 5% sodium chloride or up to 50% ethanol in the aqueous phase. In the presence of a low concentration of various solutes, emulsions were stable to three cycles of freezing and thawing. An emulsifying agent was extracted from each species or strain of yeast tested, including 13 species of genera other than Saccharomyces. Spent yeast from the manufacture of beer and wine was demonstrated to be a possible source for the large-scale production of this bioemulsifier.

Acetylcholinesterase‐inhibitor hydrolysates obtained from ‘in vitro’ enzymatic hydrolysis of mannoproteins extracted from different strains of yeasts

“…The type of method used can have a great influence on the characteristics of the obtained mannoprotein fraction (N uñez et al, 2006). Cameron et al (1988) found similar results in the composition of the extracts obtained by both enzymatic treatment (with zymolase enzyme) and heat treatment. Dupin et al (2000a,b) evaluated different extraction methods and found that the most effective treatment for the release of mannoproteins was performed with zymolase enzyme.…”

“…The extraction of mannoproteins was performed according to the method of Peat et al (1961), modified by Cameron et al (1988). Each yeast strain was activated by three successive cultures in YM broth, incubating each culture at 30°C for 48 h. The final culture was obtained by seeding 4 mL of previous culture in 400 mL of YM broth and incubating at 30°C for 48 h with stirring.…”

Mannoprotein From Spent Yeast Obtained From Thai Traditional Liquor Distillation: Extraction and Characterization

“…Protein was estimated by the dye-binding assay (Bradford 1976) with bovine serum albumin used as the standard. Emulsification activity was measured according to the method of Cameron et al (1988), with a slight modification. To 1 mL of mannoprotein suspension, 1 mL of vegetable oil was added and vortexed at high speed for 3 min.…”

“…Saccharomyces cerevisiae is normally used for alcohol fermentation. Mannoprotein extracted from S. cerevisiae has been shown to be an effective bioemulsifier (Cameron et al 1988). The presence of hydrophilic mannose polymers covalently attached to the protein backbone provides the mannoprotein with the amphiphilic structure common to surface active agents and effective emulsifiers (Cooper and Goldenberg 1987).…”

“…It can make possible the producing of value-added by-products (Torabizadeh et al 1996). Because S. cerevisiae is edible and used in the manufacture of food and beverage products, it is assumed that a mannoprotein bioemulsifier would be nontoxic and generally recognized as safe (Cameron et al 1988).…”