Redhyang (Citrus hybrid ‘Kanpei’,CHK) is a subtropical citrus species introduced in Korea due to climate change. To enhance the nutritional value and usability of CHK as a processed food product, CHK extract was fermented with four types of commercial starters (YoFlex Harmony 1.0 (YFH), ABY-3 (ABY), YC-X11 (YXC), and YC-180 (YC)), and their antioxidant activities and changes in chemical properties during fermentation were investigated. The consumer acceptance of probiotic beverages containing fermented CHK extracts and their viability and antioxidant activity through in vitro digestion were also elucidated. The enumeration of lactic acid bacteria (LAB) in all samples after fermentation was above 7.60 log colony-forming units (CFU)/mL, with YC exhibiting the highest number after 24 h. Fermented CHK extracts containing higher levels of organic acids, total polyphenols, and flavonoids tended to exhibit higher antioxidant activities. YFH, ABY, and YC showed maximum antioxidant activity at 24 h, whereas YXC showed differences in the types of LAB at 12 h. After in vitro digestion, YXC showed higher antioxidant activity and LAB viability than the control. This result indicates that CHK extract fermented with YXC can increase antioxidant activity, bioactive ingredients, and sensory preference and positively impact the production of probiotic beverages.

中文翻译：

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使用益生菌开发柑橘类水果提取物发酵饮料：对抗氧化活性和体外消化率的影响

Redhyang（柑橘杂交种“Kanpei”，CHK）是由于气候变化而引入韩国的亚热带柑橘品种。为了提高 CHK 作为加工食品的营养价值和可用性，CHK 提取物与四种商业发酵剂（YoFlex Harmony 1.0 (YFH)、ABY-3 (ABY)、YC-X11 (YXC) 和 YC- 180（YC）），并研究了它们的抗氧化活性和发酵过程中化学性质的变化。还阐明了消费者对含有发酵 CHK 提取物的益生菌饮料的接受程度及其通过体外消化的活力和抗氧化活性。发酵后所有样品中乳酸菌（LAB）的计数均高于7.60对数菌落形成单位（CFU）/mL，其中YC在24小时后表现出最高数量。含有较高含量有机酸、总多酚和类黄酮的发酵 CHK 提取物往往表现出较高的抗氧化活性。YFH、ABY 和 YC 在 24 小时时显示出最大的抗氧化活性，而 YXC 在 12 小时时显示出 LAB 类型的差异。体外消化后，YXC 表现出比对照更高的抗氧化活性和 LAB 活力。这一结果表明，用 YXC 发酵的 CHK 提取物可以提高抗氧化活性、生物活性成分和感官偏好，并对益生菌饮料的生产产生积极影响。