Garcinia mangostana Linn is known as the "queen of fruit" in Vietnam, which is grown in the provinces of the Mekong Delta and the South Eastern area. Many researches showed that the pericarp of this fruit has many active components, such as xanthones, anthocyanins, tannins, etc. Tannin content of Gacinia mangosteen Linn peel of four regions (Can Tho, Tra Vinh, Bình Duong and Vinh Long provinces) in Vietnam was investigated. It was 13.80% (Vinh Long), 13.91% (Can Tho), 14.15% (Binh Duong), 14.50 % (Tra Vinh). This study focused on the extraction of the tannins compound from the Garcinia mangostana Linn for applications in the food industry, especially in the wine-producing industry.The pericarp of mangosteen was treated with Termamyl SC and Pectinex Ultra SP-L enzymes, then mixed with 60% ethanol at the ratio of 1/20 (material /solvent) and heating for 120 minutes at 60°C. The extracts then were obtained after centrifugation at 5000 rpm for 10 minutes and vacuum filtered. The extraction efficiency was more than 90%, higher than without enzyme pretreatment (87.35%).

Mangosteen (Garcinia mangostana Linn) is one of the tropical plants grown in many countries, including Vietnam. This is a fruit of high nutrition value and its fruit peels have been used in many traditional remedies. Many scientific publications showed that mangosteen peel contains active ingredients such as xanthone, anthocynin and tannins in this study, we investigated extraction of anthocyanin from fresh mangosteens’ peel of Vietnam in organic solvent and then isolation by supramolecular method. Antioxidant activity was determined in vitro using DPPH reagent. Using 90% acetonitrile acidified with 1% HCl as a solvent, with a ratio of material to solvent of 3 (v/w) at 4°C for 3.5 hours. Anthocyanin content in the extract reached 0.41% dry matter, antioxidant activity DPPH was 51.28 nmol Trolox/mg. Next, anthocyanin was separated by liquid liquid extraction with a solvent mixture (1 water and 2 dichloromethane) and then isolated by supramolecular method with flavocomelin and aluminum chloride. The results of the anthocyanin isolation test by supersymmetry showed that anthocyanin complexes are formed with flavocomelin and aluminum chloride. That way could separate high purity anthocyanins without sophisticate instruments. The antioxidant activity of the super molar complex was 25.39 nmol Trolox/mg. Practical applications Anthocyanin extracted from peels of mangosteen, can be used afterward for additive in some food application as natural coloring substance and antioxidants for preservation.