Extraction of Polyphenols from Indian Grape Cultivars: A Review

This paper reviews the polyphenol-compound-extraction systems used to analysefruit (grape) samples over the last few years. Polyphenol compounds are naturally occurring antioxidants, usually found in some fruits. Sample preparation for analytical studies is necessary to determine the polyphenol composition in these matrices. The most widely used extraction system is liquid-liquid extraction (LLE), which is a inexpensive method since it involves the use of organic solvents, but it requires long extraction times, giving rise to possible extract degradation. Likewise, solid-phase extraction (SPE) can be used in liquid samples. Modern techniques, which have been replacing conventional ones, include supercritical fluid extraction (SFE), pulsed electrical field (PEP). These alternative techniques reduce considerably the use of solvents and accelerate the extraction process.