採收、處理及儲藏以防止棕變、污染與洋菇原料之保鮮

Prevention of Browning and Blemish by Postharvest Treatments and Storage Conditions for Keeping Better Quality of Fresh Mushrooms

直接切柄採收較現行之整業採收堆積後再切柄，可減少洋菇表面自菇床上帶去之泥土量約2/3，因而洋菇之色澤可獲改善，同時可省略送廠前檢收時之水洗。採用密寶包裝可減少運輸途中機械之擦傷。洋菇採收後應立即加工或冷藏，採收後若放置於室溫（16℃）達2.5小時以上，其色澤有顯著之暗化及組織有失去彈性之現象。改變大氣組成分及濃度之亞硫酸氫鈉（0.1%）處理原料洋菇無改善儲藏保鮮之效果。低溫（0~5℃）高溫（95% RH）配合PE袋包裝，可延長洋菇之儲藏壽命及防止失重。為了增加罐頭洋菇固形量之收量起見，原料洋菇先浸於冷水中半小時，則可達到減少因加工收縮及失重之發生，由統計分析可知本試驗所採用之洋菇色澤之目視評仨值與漢特色差計之”L”值間呈正相關（r=0.922）。組織之手壓評估值與果實硬度計之測定值亦呈正相關。

The object of this experiment is to find out some postharvest treatments and storage conditions suitable for prolonging the storage life and keeping better quality of fresh mushrooms. The results are summarized as follows: It found that less soil was put on the surface of the mushrooms just harvested by the direct stem-cut picking method than that by the present picking method (picking mushrooms togather then cut down their batts), and the ratio was 1:3. The former picking method would be established in a time save system to transport mushrooms from harvest to canneries and omit washing at mushroom collection station. On the way the mechanical damage and bruised loss for the fresh mushrooms could be minimized by tight-fill packing during transportation. In order to prevent darkening and de-elasticity of texture, mushrooms could be kept at room temperature (16℃ in winter season) not more than 2,8 hours after harvest. It showed that fresh mushrooms soaked in cold water for half-hour and stored in cold storage for several hours, a higher drained weight of canned product would be obtained. There are no significant difference between the treatments of samples by changing atmosphere composition and chemical treatment. A better way for prolonging the storage life and control weight-loss of the fresh mushrooms packed in pg bags at low temperature (5℃) and high humidity (95 %R. H.) was found in this experiment. A positive correlation of mushroom color was existed between the visual evaluation scores and Hunter's color-difference meter readings, and a same correlation of mushroom texture was existed between. the finger-touch evaluation score and fruit pressure-tester readings as shown by this report.