酸筍發酵過程中綠色斑點產生之探討與防治

Abstract

酸筍在發酵過程中，於筍節處發現有綠色斑點之產生，此綠色斑點經微生物分離、純化及接種，確認為黴菌污染所造成。此株黴菌經形態、生理與DNA之分析，鑑定結果為Aspergillus versicolor。分離株Aspergillus versicolor在好氣、微好氣環境下生長良好，但在嫌氣環境下則被抑制。而乳酸濃度在2.0％以上才具有顯著抑制效果“因此為了防止竹筍發酵時Aspergillus versicolor生長所造成的綠斑，發酵時應保持嫌氣狀態，並用重石加壓，以提供乳酸菌生長所需環境，並抑制黴菌生長，以利於特殊的乳酸發酵風味之產生，此外應將發酵用的竹籠容器改為塑膠桶，使發酵酸液容易保持於發酵槽內，更易造成嫌氣狀態。 The green spots of fermentated bamboo shoots was caused by contaminating fungus. The fungal species were isolated and identified to be Aspergillus versicolor by morphological, physiological and molecular biological method. Aspergillus versicolor can grow under aerobic and microaerobic conditions, whereas under anaerobic condition, the growth of the fungus is inhibited. In addition, lactic acid with concentrations higher than 2% can strongly inhibit the growth of the microorganism. For these reasons, bamboo shoot should be kept under anaerobic condition during fermentation by putting heavy stones on top of the basket; this would favor the growth of lactic acid bacteria to produce typical flavors and at the same time prevent the fungal growth. Furthermore, instead of bamboo baskets, plastic baskets are recommended as containers during the fermentation process to keep under the anaerobic condition.