以Bacillus subtilis natto發酵黑豆及糙薏仁開發銀髮族食品

Abstract

台灣預估將於2026年成為超高齡社會，因此銀髮族群的疾病預防及營養健康的維持是十分重要的議題。攝食量減少的現象常伴隨老化發生，由於老年人咀嚼功能降低及消化酵素分泌減少等因素，往往會限制其進食種類與進食量。本研究利用篩選之納豆菌株 (Bacillus subtilis natto) 共同發酵黑豆及糙薏仁，透過納豆菌株發酵產生黏性物質聚麩胺酸 (γ- polyglutamic acid, γ-PGA ) 可包覆黑豆與糙薏仁，達到增加食品潤滑度而易於吞嚥，提高老年人食用意願而有助於補充其每日蛋白質、膳食纖維及熱量攝取之目的。實驗採用32因子設計，以溫度30℃、40℃及50℃和發酵時間12、24和36小時設計九種處理組合，再探討各組別的物化性質及活性物質，期望找出最適合台灣高齡長者的產品之發酵條件。實驗結果顯示，本研究使用之菌株YCL-L-039在三個溫度下發酵皆能產生γ-PGA，有助於改善產品可吞嚥性，其中又以於30℃發酵的條件樣品有較高之納豆激酶活性，且納豆激酶活性有隨著發酵時間增加而上升的趨勢。發酵產生之蛋白酶能有效水解黑豆及糙薏仁中的蛋白質使三氯醋酸可溶蛋白(trichloroacetic acid soluble protein) 含量增加，且在30℃及40℃發酵時蛋白質水解程度較高，有助於高齡長者食用後之消化吸收，同時在30℃及40℃發酵時間達24小時以上時，相較於未發酵樣品可顯著改善樣品之質地。本研究亦挑選五組樣品供應給30位中高齡受試者進行感官品評試驗之消費者接受性試驗，在整體喜歡程度方面，五組樣品之間無顯著差異。綜合上述，本研究認為30℃發酵36小時的樣品最具有開發為銀髮族食品之潛力。

Prevention of aging-associated disease and maintenance of nutritional status in elderly are urgent issues. Difficulties in chewing and swallowing are the major concerns for elderly. The aim of this study is to develop a high protein quality product with soft texture and easy-to-swallow characteristics. To achieve this goal, black soybeans and dehulled adlay are subjected to Bacillus subtilis natto fermentation. Experiments were conducted using a factorial design with nine treatment combinations at temperatures of 30, 40, 50℃ and times of 12, 24, 36 hours to obtain the optimal fermentation conditions. Texture, nattokinase activity and other chemical properties were tested. Results showed that YCL-L-039 B. subtilis strain can effectively produce γ-polyglutamic acid (γ-PGA) and provide the characteristic of lubrication in product at the tested condition. Nattokinase activity was significantly increased at 30℃ compared to those treated at other temperature. The content of soluble protein were marked elevated at 30, 40℃ fermentation, which indicated that protein in black soybeans and dehulled adlay is effectively hydrolyzed by fermentation. Regards to the texture, samples fermented at 30 and 40℃ for more than 24 hours significantly reduce the hardness. Five samples were selected for sensory evaluation. The results demonstrated no significant difference in acceptability among them. This result may imply that the optimized condition has the potential for future product development.