Extraction and evaluation of antioxidant potential of the extracts obtained from tamarind seeds (Tamarindus indica), sweet variety

•Ethanol extracts of sweet variety tamarind seed showed natural antioxidant potential.•Condition of 250 bar and 50 °C process optimization point.•Supercritical extraction with ethanol increased yield and antioxidant quality.•Kinetics study indicated that the main mass transfer mechanism is convection.•The main component extracted by supercritical fluid (the 9,12-octadecadienoic acid).

The objective of this study was to evaluate the antioxidant activity of tamarind seed extracts, sweet variety. The extracts were obtained by sub and supercritical CO2 different concentrations of ethanol. The extractions with pure CO2 were performed in the range of 20–50 °C and 100–250 bar and with ethanol under the conditions of 50 °C and 250 bar as well at 40 °C and ambient pressure. The yields of extractions with pure CO2 of better quality and quantity of antioxidant were obtained under the conditions of 50 °C and 250 bar. However, the phenolic content of the tamarind seeds extract, sweet variety, obtained with pure ethanol at 50 °C and 250 bar was superior to all the others, including the synthetic antioxidant butyl hydroxytoluene (BHT). Therefore, the ethanolic extracts of tamarind seed, sweet variety, are potential sources of natural antioxidants for the food industry.