Healthy Mushroom Sugar
Richard Chen, Rain Huang
St George's School, Collingwood School
Floor Location : M 034 H

The goal of this project is to evaluate antioxidant benefits of polysaccharides from common low-cost mushrooms. White button mushroom, brown crimini button mushroom, black oyster mushroom, and shiitake were purchased from a local grocery store. Polysaccharides from these four mushrooms were extracted by distilled water. Aqueous phase containing polysaccharides was recovered by centrifuge, followed by precipitation and 2-step wash by ethanol. The purified mushroom polysaccharides pellets were re-dissolved in water for High Performance Liquid Chromatography to accurately quantitate polysaccharides contents. Polysaccharides were found and detected in all four mushroom extracts. Among the four mushrooms, shiitake had the highest polysaccharides level of 1.78 g/L, followed by black oyster mushroom with 1.14 g/L. White button mushroom and brown crimini button mushroom contained the least amount of polysaccharides at around 0.45 – 0.52 g/L. Furthermore, the antioxidant activity of the above mushroom polysaccharides was determined by DPPH assay to evaluate its free radical scavenging activity. Shiitake was shown to possess the highest antioxidant activity which was likely due to the highest amount of polysaccharides. White button mushroom and brown crimini button mushroom had very comparable antioxidant activity, which was similar to their polysaccharides contents. Surprisingly, black oyster mushroom showed the lowest antioxidant activity among all, regardless of its relatively high polysaccharides content. The last part of this project is to investigate the interactions among the four mushroom polysaccharides on antioxidant activity. White button mushroom and black oyster mushroom, brown crimini button mushroom and black oyster mushroom are the two combinations which are observed to possess significant enhancement effect, indicating synergistic interactions. White button mushroom and shiitake, brown crimini button mushroom and shiitake showed slight antagonistic interactions. Rest of other combinations had simple additive effect, elucidating no interactions among each other. Therefore, it is recommended to combine either white button mushroom or brown crimini button mushroom with black oyster mushroom to boost the antioxidant benefits.