Solid Waste from Winery as a Value-Added Food Ingredient

• Main Author: Alik Maulidiyah
• Other Authors: Chien-Kuo Wang
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/97856240271221322614

碩士 === 亞洲大學 === 生物科技學系碩士班 === 97 === Grape seeds and peels contain high level total phenolic that can reduce oxidative stress and may prevent chronic diseases, such as cancer and cardiovascular disease. Tyrosinase also known as polyphenol oxidase (PPO), is responsible not only for melanization in animals but also browning in plants. The inhibitors of this enzyme are important in cosmetics for skin-whitening and should be clinically useful for the treatment of some dermatological disorder. The objective of our research is to identify, analyze polyphenolic content in grape seeds and peels of solid grape waste and their inhibitory effect on activity of mushroom tyrosinase. We propose that a valuable food and cosmetic ingredient could be obtained after drying and grounding to powder without large losses of phytochemicals. Total phenolic, flavonoid and anthocyanin content were measured by Folin-Ciocalteu method, colorimetric method and spectrophotometric method, respectively. The antioxidant capacity was determined as were expressed as Trolox equivalents antioxidant capacity (TEAC). Diphenolase activity of mushroom tyrosinase was assayed using 1 mg per ml of L-3,4-dihydroxyphenylalanine (L-DOPA) as substrate and 10 μl of mushroom tyrosinase has been used. Our current results revealed that post-fermentation solid grape waste contain higher level total phenolic, flavonoid and anthocyanin content than the pre-fermentation ones, significantly. Based on DMRT analysis, addition of 0.5 % ascorbic acid in the prefermentation peels could preserve total phenolic compounds, significantly. Likewise in the mixture of seeds and peels of post-fermentation, addition of 0.5 % ascorbic acid also could increase total phenolic compounds. The total phenolic compounds increase in post-fermentation seeds under treatment of 1 s steaming. The only treatment that can increase total phenolic compounds in the post-fermentation peels was addition of 0.5 % citric acid in the solution. The optimal processing condition for the post-fermentation seeds to preserve total phenolic content was 1 s steaming, then oven-dried at 60°C of 37.591±0.610 mg gallic acid equivalent per g of grape seeds powder. Whereas for the peels of post-fermentations, the best processing condition to preserve total phenolic content were dipped in 0.5 % citric acid then oven-dried at 80°C of9.062±0.682 mg gallic acid equivalent per g grape peels powder. For the mixture of seeds and peels of post-fermentations, total phenolic content could be retained by dipping in 0.5 % ascorbic acid solution then oven-dried at 60°C and 80°C of 25.729±0.113 and 22.229±0.225 mg gallic acid equivalent per g of grape seeds and peels powder, respectively. Addition of 0.5 % ascorbic acid then oven-dried at 80°C of 5.763±0.009 mg gallic acid equivalent per g of grape peels powder, were the best processing condition to increase total phenolic content in the prefermentation peels. Post-fermentation seeds steaming for 1 s also had higher antioxidant capacity of 1705.79 ± 4.99 μM trolox equivalents per g of solid grape waste powder, than peels or mixture seeds and peels. In this research, the inhibitory effects of grape solid waste on the activity of mushroom tyrosinase had been studied. Our result indicated that in 1 mg/ml of seeds of post-fermentation with 1 s steaming oven-dried at 60°C and air-dried had higher inhibitory effect of 88.03%±0.72 and 79.24 %±0.72 on the activity of mushroom tyrosinase. Based on these findings, grape seeds and peels powder could be utilized to obtain compounds with rich total phenolic compounds, which can be used as a valuable and attractive addition to healthy food products and cosmetic products.