常見食用菇類之醣類成分

Abstract

食用菇類含有豐富之不易被消化的醣類和膳食纖維。本研究檢測21種食用菇類之醣類成分。受測菇類以乾基為基底其總膳食纖維含量介於25~83%，水溶性多醣主要構成水可溶膳食纖維，半乳糖、葡萄糖和甘露糖為水溶性多醣主要之糖組成，其比例分別為9.80 ~ 42.51%、11.85 ~ 54.87 % 和4.92 ~ 38.05%；部分菇類如黑木耳和白木耳，其半乳糖和葡萄糖比例低，木糖、甘露糖和醛醣酸則相對高。柳松菇則是半乳糖、葡萄糖和木糖比例高，甘露糖比例低。部分菇類例如鴻禧菇、雪白菇、香菇、白靈菇、柳松菇、金針菇和白木耳則含有高量之岩藻糖。許多菇類含有(1,3; 1,6)-β-D-葡聚醣，其為一被證實具有生理活性之多醣，其以乾重為基底，除了洋菇、巴西蘑菇、黑木耳及白木耳以外，其他食用菇含量介於29 ~ 211 mg/g，分支度則介於0.16~0.29之間。分析所選擇的食用菇含有高量之醣醇，例如阿拉伯糖醇、赤蘚糖醇、甘油、甘露糖醇和木糖醇，亦含有大量之游離醣，海藻醣。

Edible mushroom is a rich source of non-digestible carbohydrate and dietary fiber. This study examined carbohydrate profile in selected 21 edible mushrooms. The total dietary fiber contents of tested edible mushrooms were in the range of 25 ~ 83% on dry basis. Water-soluble polysaccharide was the major component of water-soluble dietary fiber. Galactose, glucose and mannose were the major sugar components of water-soluble polysaccharides from all of tested mushrooms. The molar ratio of galactose, glucose and mannose were in the range of 9.80 ~ 42.51%, 11.85 ~ 54.87 % and 4.92 ~ 38.05%, respectively. Some exceptions were those from Auricularia auricula-judae and Tremella fuciformis which were low in galactose and glucose but high in xylose and mannose with relative high amount of uronic acids. The one from Agrocybe cylindracea was high in galactose, glucose and xylose, but low in mannose. Some of samples also contained significant amount of fucose including Hypsizigus marmoreus, Lentinula edodes, Pleurotus nebrodensis, Agrocybe cylindracea, Flammulina velutipes and Tremella fuciformis. Many of mushrooms contained branched (1,3; 1,6)-β-D-glucans, the well-known bioactive glycan, in the range of 29 ~ 211 mg/g on dry basis, except Agaricus bisporus, A. blazei, Auricularia auricula-judae and Tremella fuciformis. The degree of branching of the (1,3; 1,6)-β-D-glucans were in the range of 0.16 ~ 0.29 for those mushrooms with significant amount of the glucan. Selected edible mushrooms also contained significant amount of sugar alcohols, arabitol, meso-erythritol, glycerol, mannitol, myo-Inositol and xylitol, and trehalose.