Effect of proanthocyanidin-rich extracts from Chinese quince (Chaenomeles sinensis) fruit on the physical and oxidative stability of sunflower oil-in-water emulsions

To evaluate the effect of Chinese quince proanthocyanidins (PAs) on the physical and oxidative stability of sunflower oil-in-water (O/W) emulsions during storage, three proanthocyanidin (PA)-rich extracts, namely water extract (WE), ethanol extract (EE), and acetone extract (AE), were prepared. When added to O/W emulsions, all the three extracts inhibited the increase in droplet size and the absolute zeta-potential value during storage (55 degrees C, 24 days). All three extracts also exhibited superior antioxidative activity in the O/W emulsions. WE showed the highest efficacy in retarding lipid oxidation as proved by its lower conjugated dienes (8.18 +/- 0.49 mmol L-1) and thiobarbituric substances values (0.68 +/- 0.0025 mg MDA L-1), and such efficacy was similar to that of BHA at the same level. Lower molecular weight and degree of polymerisation have a positive effect on antioxidant activity of PA-rich extracts. According to these results, all three PA-rich extracts are potential natural antioxidants for improving the stability of food-grade emulsions.

Automated summary

Chinese quince proanthocyanidins show antioxidative and stabilizing effects on sunflower oil-in-water emulsions, with water extract exhibiting the highest efficacy in retarding lipid oxidation. Lower molecular weight and degree of polymerisation positively affect the antioxidant activity of proanthocyanidin-rich extracts, making them potential natural antioxidants for improving emulsion stability.