YUAN Chunlong

College of Enology, Northwest A&F University, Yangling, Shaanxi, China

Utilization of grape seeds and its nutrients to produce high quality nutritional ingredient is a better way to deal with the byproduct which generated by wine making, and the superfine milling technology is a good way to get more bioactive constituents. In order to understand the effects of comminution treatment on the particle size and polyphenol bioavailability and confirm the optimal comminution condition, we compared the particle size of powder, and the bioavailability of total phenolics and tannin from grape seeds milled at different temperatures and times by in vitro digestion. The results showed that the optimal milling condition was found at -20℃ for 45 min. The percentage of particles less than 100.00 μm was 88.43%, and the bioavailability of total phenolics and tannin reached the highest value 34.84% and 23.98% with this treatment condition. The milling time had significant effects on the size and the bioavailability of total phenolics and tannin when the time less than 45 min. Besides, the lower temperature could increase the percentage of particles less than 100.00 μm and the phenolics bioavailability, while the effects was not significantly. In all, this result indicated that the superfine milling technology could break down grape seeds to the powder with less than 100 µm of granular size as well as higher availability of phenolics.