| Summary: | 碩士 === 國立嘉義大學 === 生化科技學系研究所 === 106 === Inoculation of probiotics is amongst the ways to maintain and increase nutrition and bioactivity of fruits and vegetables. This study was aimed to develop the fruit and vegetable ferments with higher bioactivity for promoting product market competition. Firstly, acid-fast yeasts were selected from the aging broths, which contain various fruit and vegetable ferments in Taiwan Enzyme Village Co, Ltd., by plating on pH 4.8 YM agars containing chloramphenicol and inoculation in pineapple or papaya ferments at 30°C incubation. After 26S rDNA sequencing, physiological and biochemical analyses, one of the best performed isolates was identified and renamed EVY01. In acid tolerance test, EVY01 showed the best growth in pH 4.2 YPD broth after 24 and 72 hours incubation (OD600 1.5 and 2.0) than Yeast a (Ya; OD600 0.2 and 1.4), the similar species of EVY01, and non-survival Rhodosporidium toruloides (Rt). In ethanol tolerance test, EVY01 showed the best growth in YM broth containing 8% ethanol after 72 hr incubation (OD600 1.2), whereas no yeast were found in those inoculated with Ya or Rt. We further inoculated EVY01, Ya and Rt in papaya ferments without or with yuan zhi at 30°C to obtain referments P or PZ. The 7-day referments were inoculated into the corresponding papaya ferments without or with yuan zhi for another 14 days refermentation to obtain referments P2 and PZ2. Only the EVY01-inoculated P, P2, PZ and PZ2 referments showed the fermented effects on continuous growth (9.0 × 104, 9.0 × 104, 5.0 × 107 and 1.5 × 107 CFU/mL, respectively), continuous decrease of reducing sugars (39%, 36%, 73% and 51%, respectively), increased total flavonoids content (53%, 54%, 231% and 151%, respectively) and decreased triterpene content (80%, 75%, 76% and 74%, respectively). Finally, in the anti-inflammatory test on NO inhibition in LPS-induced RAW264.7 macrophages, EVY01-inoculated P referment showed 31% and 28% increases as compared with referments without any inoculation and Ya inoculation. The 7-day referment PZ2 inoculated with EVY01 also showed a 38% increase as compared with Ya inoculation. This study provides the acid-resistant yeast EVY01 with better acid- and ethanol-resistant abilities than the similar species. The increased live yeast, antioxidant and anti-inflammatory activity after EVY01 inoculation in pH 3-4 of vegetable and fruit ferments may be applied for the company to develop health benefit beverages in future.
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