Changes in the Contents of Carbohydrates and Organic Acids in Fruit-Bodies of Maitake-Mushroom [Grifola frondosa (Fr.) S. F. Gray] during Storage

Abstract

Changes in the contents of low molecular weight carbohydrates and organic acids in fruit-bodies of maitake-mushroom (Grifola frondosa) during non-packaging storage and hermetical storage (polyethylene film bags 100μm thickness) at five storage temperatures (0, 5, 10, 20 and 30°C) were investigated. (1) The shelf lives of non-packaging storage of maitake-mushrooms were 7 days at 0°C, 5-6 days at 5°C, 4-5 days at 10°C, 3-4 days at 20°C and 2-3 days at 30°C. The shelf lives of hermetical packaging storage of maitake-mushrooms were 7 days at 0°C, 6-7 days at 5°C, 5 days at 10°C, 3-4 days at 20°C and 2 days at 30°C, and hermetical packaging storage was not effective to extend the shelf lives. (2) In this mushroom, mannitol, arabitol, glycerol, trehalose and glucose were identified, and mannitol and trehalose were found to be major among them. During storage, the contents of each element except mannitol decreased. Especially the decrease in trehalose was marked, and trehalose may be functioning as the major respiratory substrate. (3) In this mushroom, formic, acetic, lactic, oxalic, succinic, fumaric, malic, pyroglutamic and citric acids were identified, and among them malic, pyroglutamic, fumaric, citric and acetic acids were found to be major. The contents of malic, oxalic and citric acids in fruit-bodies increased during storage at five storage temperatures with the elapse of storage days and the rise of storage temperatures.