Solvent optimization for anthocyanin extraction from Syzygium cumini L. Skeels using response surface methodology

Abstract

Anthocyanins are plant pigments that are potential candidates for use as natural food colourant. In this study, Syzygium cumini fruit skin has been used as anthocyanin source. All the six major types of anthocyanins were identified in the sample by ultra performance liquid chromatography studies, and the antioxidant activity was found to be 4.34 ± 0.26 Fe²⁺g^{− 1} in the sample with highest anthocyanin content. Optimization of conditions for extracting high amounts of anthocyanin from the fruit peels was investigated by response surface methodology. The results suggested that highest anthocyanin yield (763.80 mg; 100 ml^{− 1}), highest chroma and hue angle in the red colour range could be obtained when 20% ethanol was used in combination with 1% acetic acid. Methanol was replaced with ethanol for the extraction of pigments due to its less toxicity and being safe for human consumption. The optimized solvent can be used to extract anthocyanins from the S. cumini fruits and used as natural colourants in the food industries.

Keywords::

• Plakett–Burman
• quadratic
• factorial
• colourant
• antioxidant
• pigment

Acknowledgements

The authors acknowledge Mr Ashwini Singh of Central Instrumentation Facility of BIT, Mesra, for operating the colorimeter.

Declaration of interest The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper. Bratati Chaudhary is thankful to BIT, Mesra, Ranchi, for providing fellowship and research facilities. The authors are highly thankful to the Ministry of Food Processing Industries (File No. 47/MFPI/R&D/2006/517) and University Grants Commission (F.No.34-275/2008-SR) for financial assistance.