Abstract
The effect of the trimming which cut back the stipe end as a conventional preparation for market on freshness and composition of name-ko during storage at 20°C was studied. The trimming showed a favorable effect to prevent the elongation of stipe and the opening of cap, but resulted in higher respiration rate and accelerated browning as well as softening and squashing of the sporophore during storage at 20°C. Therefore name-ko with stipe end had some advantages for prolonging the shelf life, exhibiting suppression of browning and activation of polyphenol oxidase and protease in sporophore after harvest. Titratable acidity increased and pH declined in the sporophores stored at 20°C, but little difference was found between name-ko with and without stipe end. Trehalose was found to be predominant in name-ko at harvest and rapidly decreased during storage. On the other hand, mannitol and glucose contents increased sharply regardless of presence of stipe end. In sporophores with stipe end, trace of fructose was detected at harvest and increased reaching a maxium accumulation after 2 days of storage and then decreased, while no accumulation was found in ones without stipe end. Total free amino acid contents increased and almost doubled during storage at 20°C for 5 days, and the increase was more notable in materials without stipe end. Among the free amino acid components, remarkable increase in contents of alanine, valine, leuicine, isoleuicine, and γ-aminobutylic acid was observed during storage.
