Green tea has been an important beverage for humans since ancient times, widely consumed and considered to have health benefits by traditional medicine in Asian countries. Green tea phenolic compounds are predominately composed of catechin derivatives, although other compounds such as flavonols and phenolic acids are also present in lower proportion. The bioactivity exerted by these compounds has been associated with reduced risk of severe illnesses such as cancer, cardiovascular and neurodegenerative diseases. Particularly, epigallocatechin gallate has been implicated in alteration mechanisms with protective effect in these diseases as indicated by several studies about the effect of green tea consumption and mechanistic explanation through in vitro and in vivo experiments. The biological activity of green tea phenolic compounds also promotes a protective effect by antioxidant mechanisms in biological and food systems, preventing the oxidative damage by acting over either precursors or reactive species. Extraction of phenolic compounds influences the antioxidant activity and promotes adequate separation from green tea leaves to enhance the yield and/or antioxidant activity. Application of green tea phenolic compounds is of great interest because the antioxidant status of the products is enhanced and provides the product with additional antioxidant activity or reduces the undesirable changes of oxidative reactions while processing or storing food. In this scenario, meat and meat products are greatly influenced by oxidative deterioration and microbial spoilage, leading to reduced shelf life. Green tea extracts rich in phenolic compounds have been applied to increase shelf life with comparable effect to synthetic compounds, commonly used by food industry. Green tea has great importance in general health in technological application, however more studies are necessary to elucidate the impact in pathways related to other diseases and food applications.

Objective To evaluate the phenolic profile and antioxidant activity in vitro of peanut skin extract (PSE) and effect of PSE on characteristics of sheep patties during storage. Methods PSE phenolic profile was evaluated in LC–MS analysis and by total phenolic content, 1,1-diphenyl-2-picrylhydrazyl radical scavenging capacity and ferric reducing/antioxidant power. Patties elaborated with sheep meat were packaged in modified atmosphere and storage at (2 ± 1) °C. The analyses were performed every 5 days for 20 days on microbial counts, physico-chemical properties, lipid oxidation, protein stability and sensory characteristics. Results The major group of phenolic compounds in PSE was the proanthocyanidins followed by other flavonoids, which are related to potential phenolic content and antioxidant activity. The addition of PSE and butyl hydroxytoluene (BHT) reduced the microbial counts during the storage time, caused reduction on the loss of redness and sensory properties over time. The lipid and protein oxidation in sheep patties was effectively inhibited by PSE and BHT. Conclusions The present results showed the potential application of PSE as a natural alternative to replace synthetic antioxidants (BHT) for increasing the quality and extending the shelf-life of sheep patties.