Boonchu Thapakorn, Utama-Ang Niramon
Division of Product Development Technology, Faculty of Agro-Industry, Chiang Mai University, Chiang Mai, 50100 Thailand.
Sensory Evaluation and Consumer Testing Unit, Division of Product Development Technology, Faculty of Agro-Industry, Chiang Mai University, Chiang Mai, 50100 Thailand.
J Food Sci Technol. 2015 Feb;52(2):783-92. doi: 10.1007/s13197-013-1079-7. Epub 2013 Jul 4.
Grape (Vitis vinifera L.) pomace constitutes a promising source of phenolic compounds, gallic acid, flavan-3-ols, flavonoids, stilbene and anthocyanins that are beneficial for human health. The objectives of this study were to optimize the extraction and microencapsulation of red grape pomace. Central composite designs with two factors were conducted for optimization using response surface methodology. The temperature (45-85 °C), and the time (2-8 h) were designed for the extraction. The results indicated that the extraction temperature and time introduced the increasing the extraction yield, total phenolic content, anthocyanin and resveratrol, but the long extraction time reduced the tannin content. The results showed that the optimize condition was the extraction at 80 ± 1 °C for 2 h 53 min. This provided the highest content of polyphenolic compounds. The next experiment was microencapsulation of the extract which studied the amounts of maltodextrin (7-28 % w/v) and carboxymethylcellulose (CMC) (0-1.4 % w/v). The results showed that the optimized microencapsulation used 10.21 % w/v maltodextrin and 0.21 % w/v CMC to maximize all polyphenolic compounds, and also to minimize bitterness and astringency. This study illustrated that the optimal conditions for extraction and microencapsulation of the red grape extract have a high potential to produce functional ingredients.
葡萄（Vitis vinifera L.）果渣是酚类化合物、没食子酸、黄烷 - 3 - 醇、黄酮类化合物、芪类化合物和花青素的一个有前景的来源，这些成分对人体健康有益。本研究的目的是优化红葡萄果渣的提取和微胶囊化工艺。采用响应面法进行了双因素中心复合设计以进行优化。提取过程设定的温度为45 - 85°C，时间为2 - 8小时。结果表明，提取温度和时间会提高提取率、总酚含量、花青素和白藜芦醇含量，但较长的提取时间会降低单宁含量。结果显示，优化条件为在80±1°C下提取2小时53分钟，此条件下多酚类化合物含量最高。接下来的实验是对提取物进行微胶囊化，研究了麦芽糊精（7 - 28% w/v）和羧甲基纤维素（CMC）（0 - 1.4% w/v）的用量。结果表明，优化的微胶囊化工艺使用10.21% w/v的麦芽糊精和0.21% w/v的CMC，以使所有多酚类化合物含量最大化，同时使苦味和涩味最小化。本研究表明，红葡萄提取物提取和微胶囊化的最佳条件具有生产功能成分的巨大潜力。
