Ultrasonic-assisted extraction and in vitro antioxidant activity of polysaccharides from Agaricus bisporus

To optimize ultrasonic-assisted extraction parameters of polysaccharides from Agaricus bisporus and evaluate antioxidant activities of A. bisporus polysaccharides.

Polysaccharides from A. bisporus was extracted by using methods of ultrasonic-assisted hot water lixiviation, ethanol precipitation, Sevag's deproteination and ethanol precipitation again. Extraction temperature, extraction time, ratio of water to raw material and ultrasonic power were selected in single-factor tests. Based on the single-factor tests, parameters combination for the ultrasonic-assisted extraction of A. bisporus polysaccharides was optimized by using four-factor-three-level orthogonal test. Antioxidant activities (reductive potential, superoxide anion scavenging activity and H2O2 scavenging activity) of A. bisporus polysaccharides were evaluated in vitro.

Optimum conditions for the extracting of A. bisporus polysaccharides were extracting temperature 65 degrees C, extracting time 40 min, ratio of water to raw material 30 mL/g and ultrasonic power 170 w. Practicing this optimal condition, extraction yield of polysaccharides from A. bisporus was 5.6 014%. In crude polysaccharides of A. bisporus, carbohydrates content, determined by applying the phenol-sulfuric acid method, was 75.48%. Polysaccharides of A. bisporus could reduce ferric ion, scavenge superoxide anion and hydrogen peroxide in a dose-dependent manner.

Utrasonic-assisted extraction could be used in the extracting of A. bisporus polysaccharides. Polysaccharides of A. bisporus, had direct and potent antioxidant activities, might be developed and utilized as natural antioxidant.