Extraction Efficiency of β-D-glucan from Waste Part of Bottom Mushroom (Agaricus bisprous) and its Ability to Adsorb Aflatoxin B1

β-Glucans which are found in a variety of natural sources such as yeast, mushrooms, bacteria, algae, barley and oat show different biological effects. They are composed of D-glucose units linked by β-glycosidic bonds to each other. Adsorption of fungal toxins such as aflatoxin by β-glucan has been widely considered in recent years. Aflatoxins are a group of naturally-occurring carcinogens that are known to contaminate different human and animal foodstuffs. Aflatoxin B1 is the most genotoxic hepatocarcinogenic compound among all types of the aflatoxins. The efficiency of adsorption of fungal toxins is directly related to the molecular structure, extraction method and source of β-glucan. Fungal derived β-glucan consists of β (1-3) bonds in main and β (1-6) at lateral branching point, with the specification of short shoulder length, has high ability to adsorb fungal toxins.  In this study, for the first time, the efficiency of various extraction methods of β-glucan from stem cell wall of bottom mushroom (Agaricus bisprous) was measured and the ability to adsorb aflatoxin B1 was evaluated. The results showed that although the yield of β-glucan from acid based extraction was higher than other methods (20.5%), the hot alkaline extracted β-glucan could adsorb and discard 90.2% of aflatoxin B1 from contaminated samples based on HPLC analysis.