摘要
火龍果 (Hylocereus polyrhizus)，又名紅龍果，英文名稱為pitaya或dragon fruit，屬於仙人掌科，生長的適應能力強，對土壤、氣候等環境生長要求少。近年來更因為種植技術的改良，產量大增，而導致市場售價崩盤而下跌，因此希望能夠開發具有附加價值的火龍果副產品，解決農民們的困境。本研究從火龍果園土壤及果實中分離出Lactobacillus plantarum與實驗室之啤酒酵母Saccharomyces cerevisiae和醋酸菌株Acetobacter pasteurianus進行階段式發酵，以製備火龍果發酵飲品。實驗結果顯示。從土壤分離出之A6菌株具有最佳之提升總酚含量能力473 mg/L，將此菌株經API 50 CHL及16S rRNA鑑定後，以基因序列99.92 %卻認為植物型乳酸桿菌 Lactobacillus plantarum。L. plantarum在耐胃酸、耐膽鹽與抑菌能力之試驗中顯示其對胃酸及膽鹽皆具有一定之耐受性，同時也具有一定之抑菌活性，可推測此菌株具有益生菌潛力。在階段式發酵之部分，S. cerevisiae的最適生長條件為接種2 % (v/v)之種菌於含有添加2 % (w/v)的葡萄糖、0.5 % (w/v)的酵母抽出物、pH值5~7、於30 ˚C下，培養24小時；A. pasteurianus的最適生長條件為接種10 % (v/v)之種菌於火龍果發酵液中培養72小時；L. plantarum接種3 % (v/v)之種菌於含有2 % (w/v)的酵母抽出物、pH值5~7之火龍果發酵液、於30 ˚C下，培養24小時，經調整口味及加熱滅菌後，即為可常溫儲藏之機能性火龍果發酵飲品，其pH值為4.02±0.01、可滴定酸為1.71±0.03 %、糖度為40.2±0.01 ˚Brix及總酚含量為867.73±20.55 mg/L，其可當作每日食用之機能性飲料。
並列摘要
Hylocereus polyrhizus, also known as pitaya or dragon fruit, belongs to the cactus family. It is highly adaptable to soil, climate, and other environmental factors. Its production has increased in recent years as cultivational technology has improved, so the market price has plummeted. Simultaneously, low-cost products from China and Vietnam have been imported into the Taiwan market, driving down the price of local dragon fruits. Therefore, it is hoped to develop dragon fruit products. In this study, Lactobacillus plantarum isolated from dragon fruit and soil, Saccharomyces cerevisiae and Acetobacter pasteurianus took from laboratory bacteria database. The result showed that the A6 strain had the best ability to increase the total phenol content. The A6 strain was identified as Lactobacillus plantarum by API 50 CHL and 16S rRNA. In the artificial gastrointestinal tract condition, L. plantarum was tolerant to gastric acid and bile salts, also demonstrated antimicrobial activity in the agar diffusion test. In the staged fermentation, the growth conditions for S. cerevisiae are 2% (v/v) inoculum size with 2% (w/v) glucose, 0.5% (w/v) yeast extract, pH value 5~7, cultured at 30 ˚C for 24 hours; the growth condition for A. pasteurianus are 10% (v/v) inoculum size in dragon fruit fermentated for 72 hours; L. plantarum are 3% (v/v) inoculum size with 2% (w/v) yeast extract, pH value 5~7, cultured at 30 ˚C for 24 hours. After adjusting the taste and sterilization, the dragon fruit functional beverage can be stored at room temperature. pH value 4.02±0.01, titratable acid 1.71±0.03%, sugar content 40.2±0.01 ˚Brix, and total phenol content 867.73±20.55 mg/L. The functional beverage of dragon fruit can drink for daily consumption.