Song Dong-Heon, Gu Tae-Wan, Kim Hyun-Wook
Department of Animal Science & Biotechnology, Gyeongsang National University, Jinju 52725, Korea.
Foods. 2021 Dec 10;10(12):3074. doi: 10.3390/foods10123074.
The objectives of this study were to evaluate antioxidant capacity of hot water extract from red maple leaf with different extraction times (experiment I) and to determine their impacts on color, free anthocyanin content, and hardness of gelatin gels (experiment II). In experiment I, hot water extraction time (30, 60, 120, 180, and 360 min at 60 °C) was fixed as a main effect. The different extraction times had no impacts on total polyphenol content and DPPH radical scavenging activity ( > 0.05). However, extraction time for 360 min could decrease anthocyanin content as well as ferric reducing antioxidant power ( < 0.05). In experiment II, 6%, 18%, and 30% gelatin gels were prepared without/with red maple leaf extract (1000 mg/L). The red maple leaf extract significantly increased redness, yellowness, and hardness, but decreased free anthocyanin content. Such impacts were obviously observed at high gelatin concentration. Thus, red maple leaf extract could be a novel anthocyanin source for improving antioxidant capacity and reddish color of gelatin gels. However, the addition amount of red maple leaf extract may be limited in the development of senior-friendly jelly food for soft texture in that it could increase the hardness of the gelatin gel.
本研究的目的是评估不同提取时间下红枫叶热水提取物的抗氧化能力（实验I），并确定其对明胶凝胶的颜色、游离花青素含量和硬度的影响（实验II）。在实验I中，将热水提取时间（60℃下30、60、120、180和360分钟）设定为主要影响因素。不同提取时间对总多酚含量和DPPH自由基清除活性没有影响（P＞0.05）。然而，360分钟的提取时间会降低花青素含量以及铁还原抗氧化能力（P＜0.05）。在实验II中，制备了6%、18%和30%的明胶凝胶，分别添加/不添加红枫叶提取物（1000mg/L）。红枫叶提取物显著增加了红色度、黄色度和硬度，但降低了游离花青素含量。在高浓度明胶中这种影响明显可见。因此，红枫叶提取物可能是一种新型花青素来源，可用于提高明胶凝胶的抗氧化能力和红色度。然而，在开发质地柔软的老年友好型果冻食品时，红枫叶提取物的添加量可能受到限制，因为它会增加明胶凝胶的硬度。
