Effect of dry process on antioxidantive and anti-inflammatory activities in methanolic extracts of kumquat peel and pulp

• Main Authors: Pi-Fang Hung, 洪璧芳
• Other Authors: Chih-Cheng Lin
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/u6v8w5

碩士 === 元培科學技術學院 === 生物技術研究所 === 95 === Abstract Flavonoids in fruit have been shown to act as strong antioxidants in various systems, exhibiting multiple biological actions. The effect of dry process (100℃, 55℃and freeze-dried) on the antioxidative and anti-inflammatory activities in methanolic extracts of kumquat peel and pulp (Fortunella margarita Swingle) was investigated in this study. The results showed dry process had significant effect in the total phenolic compounds and it in kumquat peel is twice as higher as pulp. Thermal treatment trend for total phenolic compounds and total flavonoids in kumquat peel are similar to pulp, higher temperature treatment will increase its contents. Flavonoids and phenolic acids were analyzed by HPLC, data showed the major flavonoids in peel or pulp is rutin and quercetin. Thermal dry process increase the rutin content, however, had no significantly effect in quercetin (P<0.05). In comparison with various temperature dry processes, heat treatment will increase Trolox equivalent antioxidant activity(TEAC), reducing power, DPPH free radical scavenging activity, DNA damage and protein nitration in methanolic extracts of kumquat peel. However, freeze dried pulp had highest activity in TEAC, reducing power, DPPH free radical scavenging activity, DNA damage and protein nitration (P<0.05). The suppressive effect of kumquat extracts on the anti-inflammation was investigated using a LPS-stimulated RAW 264.7 cell model. Peel (100℃) and pulp (freeze dried) exhibited higher activities compared to the others. Furthermore, methanolic extracts of kumquat peel and pulp can inhibit effectively pro-inflammatory cytokines (TNF-α, IL-6 and PGE2) production no matter what dry process. According to the results of this study, we suggested that kumquat peel after 100℃ dry process will significantly increase release of phenolic compounds like as flavonoids or rutin, and then enhance antioxidant and anti-inflammatory activities. In contrast, cooperate flavonoids with retainable ascorbic acid in freeze-dried pulp provide higher activities than in heat treatment pulp. Therefore, heat dried kumquat peel and freeze dried kumquat pulp were potential natural health food for antioxidant and anti-inflammation.