Assessment of in-vitro bioaccessibility and antioxidant capacity of phenolic compounds extracts recovered from grapevine bunch stem and cane by-products.

Grapevine woody by-products contain bioactive substances, mainly phenolic compounds (PCs), whose beneficial health effects initially depends on their levels of intake and bioavailability. Therefore, in-vitro simulated gastrointestinal digestion (GID; oral, gastric and intestinal phases) was performed to evaluate the bioaccessibility and antioxidant capacity (AC) of PCs extracts recovered from grapevine bunch stem and cane from Malbec grape cultivar. The total PCs in cane and bunch stem extracts were 74 and 20% bioaccessible, respectively. Syringic acid, cinnamic acid, ε-viniferin, naringenin and myricetin were highly bioaccessible, noticeably ε-viniferin in cane extract with 137%. The high bioaccessibility observed, particularly for compounds at high concentration such as ε-viniferin, will help to better understand the bioactive potential of these by-products. In this sense, bunch stems and canes can be considered as new and sustainable sources of bioactive substances for applications as functional ingredients or nutraceuticals in food and pharmaceutical industries.