Use of ultrasound treatment to extract mannan polysaccharide from Saccharomyces cerevisiae

The threat of food shortages has increased the demand for sustainable technology worldwide. We investigated the use of ultrasonic waves to extract polysaccharides from yeast for use as a feed source. Saccharomyces cerevisiae polysaccharides were extracted using ultrasound treatment (output: 400–1000 W, frequency: 20 kHz, operating hour: 2–8 h, and operating temperature: 70°C). To extract polysaccharides from the ultrasonic extract, the supernatant was recovered by treatment with .4% α‐amylase and 1% alcalase after ethanol precipitation. Monosaccharide composition, molecular weight, and structure of crude polysaccharide were analyzed using ion chromatography, rapid separation liquid chromatography, and H¹‐nuclear magnetic resonance analysis, respectively. Nitric oxide (NO) production was measured in RAW 264.7 cells using Griess reagent. The ultrasonicated extracts comprised mannose polysaccharides with an α‐(1→6) backbone and α‐(1→2) and α‐(1→3) side chain linkages with molecular weight of 31–34 kDa. This extract increased the nitric oxide content in RAW264.7 cells. Although the ultrasonic intensity did not significantly affect polysaccharide structure or NO production, extraction time did. Overall, our findings established a strategy to enable the eco‐friendly production of feed materials with immune enhancement effects. PRACTICAL APPLICATIONS: It is a well‐established fact that yeast polysaccharides exhibit immune‐enhancing effects. Chemical and physical extraction methods are used to extract these polysaccharides. In this study, we employed ultrasonic extraction technology to meet the demand for eco‐friendly technology development. Consequently, we were able to reduce the use of chemical solvents and obtain high polysaccharide yields. Notably, we discovered that polysaccharides of 31–34 kDa molecular weights had potent immune‐enhancing effects. Lastly, we developed functional polysaccharide materials as alternatives to antibiotics used in the animal feed industry.