The link between polyphenol structure, anti-oxidative capacity and shelf-life stability in the presence of fructose and ascorbic acid

In recent years, the awareness of food effect on human health is rising and numerous studies indicated that polyphenol-rich diet has positive effect on many health aspects that may improve life quality by prevention of chronic diseases¹.Polyphenol stability in processed foods is a major, not fully understood, factor in both sensorial and health-promoting activities. In the current work we focused on the effect of polyphenols structure and formulationon their stability during shelf life and examined their total anti-oxidative capacity (TAC).

Polyphenol extract, used as the multi-components model system, was obtained from freeze-dried Nerina strawberry and 21 compounds were identified using HPLC-MS. The TAC and the first-order kinetics of degradation were obtained, linking polyphenol stability to its chemical structure, with and without the effect of fructose and ascorbic acid presence. The TAC was not affected dramatically by storage temperatures and formulation measured by oxygen radical absorption capacity (ORAC) and ferric reducing anti-oxidant potential (FRAP) assays, while polyphenol stability was strongly, and structure dependently, affected by temperature and the presence of ascorbic acid and fructose. Comparing most of the identified polyphenols stabilities, anthocyanins and phenolic acids were most unstable in the presence of ascorbic acid, while flavonols stability was enhanced by its presence. Purified polyphenols were significantly more stable than the same polyphenols in the strawberry extract when stored at 37℃ (presence of metals that catalyze oxidation, or activity of polyphenol oxidase/peroxidase in the strawberry extract was ruled out).

References:

1. Cory H, Passarelli S, Szeto J, Tamez M, Mattei J. The Role of Polyphenols in Human Health and Food Systems: A Mini-Review. Front Nutr. 2018, 5, 87.