Antioxidant activity and polyphenol content in extracts from various parts of fresh and frozen mangosteen

The search for new sources of natural antioxidants is very important because many diseases are caused by oxidative stress. Fruit which contain antioxidants are an important part of a healthy diet. The aim of this study was to evaluate the antioxidant activity of extracts of both the fresh and frozen peel and the flesh of Garcinia mangostana L.

The extracts from the fresh and frozen peel and the flesh of mangosteen were prepared by ultrasound-assisted extraction using 20%, 40%, 70% and 96% (v/v) ethanol for 15, 30 or 60 minutes. The antioxidant potential was evaluated by the DPPH, ABTS, CUPRAC, FRAP and FIC methods, whereas the total phenolic content was measured using the Folin-Ciocalteu (F-C) technique. The contents of anthocyanins and flavonoids in the peel extracts were also determined.

In most cases, the highest antioxidant activity was observed in the fresh peel samples. It was higher than the antioxidant potential of the frozen peels and the fresh and frozen flesh. The ultrasound-assisted extraction, in particular those lasting 30 or 60 minutes and using ethanol in concentrations higher than 20% (v/v), seemed to be an effective extraction process.

The obtained results suggest that G. mangostana, in particular its peels, could be a valuable source of antioxidants. The extraction parameters, such as the time or solvent concentration, as well as the type of plant material, had an impact on the tested properties of the extracts. However, more detailed studies on the antioxidant activity of the studied plants are required.