Structural characterization and emulsifier property of yeast mannoprotein enzymatically prepared with a β-1,6-glucanase

Yeast cell wall mannoprotein with diverse structures and functions are effective emulsifiers due to the amphiphilic structure comprising a protein backbone and mannan chains. In this study, a β-1,6-glucanase-based approach to produce mannoproteins from baker's yeast was established. Batch production of mannoprotein MP112 was realized with 11.1% yield, 90.7% purity, and a mannan to protein ratio of 14.5. The mannan-protein conjugate structure was confirmed by composition analysis, FT-IR and NMR spectrometry, as well as SEM observation, and the assembled mesoporous structure with filamentous fibers was deduced to determine the favorable emulsifying properties from rheological analysis. Application of mannoprotein-based emulsion in the preparation of porcine myofibrillar protein gels showed that MP112 improves the properties of myofibrillar protein composite gels by the formation of a fine-stranded gel network with enhanced protein-polysaccharide-water interactions, which reduce damage to the muscle tissue and increase product quality. This study is expected to broaden the applications of mannoproteins as value-added ingredients.