Sung Jung-Min, Kim Young-Boong, Kum Jun-Seok, Choi Yun-Sang, Seo Dong-Ho, Choi Hyun-Wook, Park Jong-Dae
Food Processing Research Center, Korean Food Research Institute, Seongnam 13539, Korea.
Korean J Food Sci Anim Resour. 2015;35(6):807-14. doi: 10.5851/kosfa.2015.35.6.807. Epub 2015 Dec 31.
This study investigated the effect of added freeze-dried mulberry fruit juice (FDMJ) (1, 3 and 5%) on the antioxidant activity and fermented characteristic of yogurt during refrigerated storage. A decrease in pH of yogurt and increase in acidity was observed during fermentation. The yogurts with FDMJ exhibited faster rate of pH reduction than control. Initial lactic acid bacteria count of yogurt was 6.49-6.94 Log CFU/g and increased above 9 Log CFU/g in control and 1% in FDMJ yogurt for 24 h. The total polyphenol and anthocyanin content of FDMJ yogurt was higher than that of control due to the presence of phytochemical contents in mulberry. Moreover, antioxidant activity such as DPPH and reducing power was highest 5% FDMJ yogurt. During cold storage, pH decreased or remained constant in all yogurts with values ranging from 4.08 to 4.78 units. In sensory evaluation, the score of 1% FDMJ yogurt was ranked higher when compared with other yogurts. It is proposed that mulberry fruit juice powder can be used to improve sensory evaluation and enhance functionality of yogurt.
本研究调查了添加冻干桑果汁（FDMJ）（1%、3%和5%）对冷藏储存期间酸奶抗氧化活性和发酵特性的影响。发酵过程中观察到酸奶pH值下降，酸度增加。添加FDMJ的酸奶pH值降低速度比对照组更快。酸奶初始乳酸菌计数为6.49 - 6.94 Log CFU/g，对照组和添加1% FDMJ的酸奶在24小时内增加到9 Log CFU/g以上。由于桑椹中存在植物化学成分，添加FDMJ的酸奶总多酚和花青素含量高于对照组。此外，5% FDMJ酸奶的抗氧化活性如DPPH和还原能力最高。在冷藏期间，所有酸奶的pH值下降或保持恒定，范围为4.08至4.78个单位。在感官评价中，与其他酸奶相比，添加1% FDMJ的酸奶得分更高。建议桑果汁粉可用于改善酸奶的感官评价并增强其功能。
