Phenolic fortification of yogurt using grape and callus extracts

In this study, acidified ethanol extracts of four different grape varieties (Cabernet sauvignon, Chardonnay, Shyrah, and Merlot) and grape callus were supplemented into yogurt as functional ingredients. The total phenolic substances, total anthocyanin content, and antioxidant activity of the yogurts were measured using chemical analyses. Yogurts inoculated with red grape and callus extracts displayed high phenolic anthocyanin content and thus exhibited higher antioxidant power compared to yogurts containing chardonnay extracts and control samples. The storage time significantly affected the free radical scavenging capacity of the yogurts. The yogurts supplied with grape callus extract displayed the greatest antioxidant power on the first day of storage compared to all the assayed samples. The Gas Chromatography (GC) analysis revealed the presence of at least 10 individual bioactive phenolic compounds in the callus yogurt. The results obtained from this investigation shows that grape callus culture has a potential to be used as a food supplement to play a role in reducing the risk of developing chronic diseases such as cancer and cardiovascular disease. (C) 2010 Elsevier Ltd. All rights reserved.