Pontificia Universidad Católica de Chile, Department of Chemical and Bioprocesses Engineering, Santiago, Chile.
J Agric Food Chem. 2013 Jul 17;61(28):6929-36. doi: 10.1021/jf4010143. Epub 2013 Jul 8.
Grape pomace was extracted with pressurized hot water at laboratory scale before and after fermentation to explore the effects of fermentation and extraction temperature (50-200 °C) and time (5 and 30 min) on total extracted antioxidant levels and activity and to determine the content and recovery efficiency of main grape polyphenols, anthocyanins, and tannins. Fermented pomace yielded more total antioxidants (TAs), antioxidant activity, and tannins, than unfermented pomace but fewer anthocyanins. Elevating the extraction temperature increased TA extraction and antioxidant activity. Maximum anthocyanin extraction yields were achieved at 100 °C and at 150 °C for tannins and tannin-anthocyanin adducts. Using higher temperatures and longer extraction times resulted in a sharp decrease of polyphenol extraction yield. Relevant proanthocyanidin amounts were extracted only at 50 and 100 °C. Finally, TA recovery and activity were not directly related to the main polyphenol content when performing pressurized hot water grape pomace extraction.
葡萄渣先用加压热水提取，然后在发酵前后进行实验室规模的提取，以探讨发酵和提取温度（50-200°C）和时间（5 和 30 分钟）对总提取抗氧化剂水平和活性的影响，并确定主要葡萄多酚、花青素和单宁的含量和回收率。与未发酵的葡萄渣相比，发酵的葡萄渣产生了更多的总抗氧化剂（TAs）、抗氧化活性和单宁，但花青素较少。提高提取温度可以增加 TA 的提取和抗氧化活性。花青素的最大提取率在 100°C 和 150°C 达到，单宁和单宁-花青素加合物的提取率在 150°C 达到。使用较高的温度和较长的提取时间会导致多酚提取率急剧下降。只有在 50°C 和 100°C 时才能提取到相关的原花青素。最后，在进行加压热水葡萄渣提取时，TA 的回收和活性与主要多酚含量没有直接关系。
