Micronization enhanced extractability of polyphenols and anthocyanins in tart cherry puree

Abstract

Tart cherries (Prunus cerasus L.) are the richest in phenolic compounds, among all the members of drupe family of fruits. To reduce the inherent sourness of the cherries, thermal processing or filtration steps are used. These processes lead to changes in pH, and exposure to temperature enhances oxidation leading to degradation of polyphenols. In the present study, Megatron® and high-pressure homogenization (HPH) were employed to produce micronized puree, which was analyzed for polyphenolic, flavonoid and anthocyanin contents using various assays. Both methods of micronization lead to breakage of cell wall structure facilitating enhanced release of bioactives from the cellular matrix and thus higher antioxidant release. The presence of functional groups was corroborated by FTIR spectrophotometric analysis, and reversed phase HPLC for the presence and relative amounts of various polyphenols and anthocyanins. There was a significant increase (p<0.05) of in the extractability of polyphenols with HPH (285.05 GAE μg/g) in comparison with the non-micronized samples (166.80 GAE μg/g). The changes in anthocyanins and flavonoids were also significant (p<0.05), thus confirming the impact of micronization on the antioxidant release in tart cherries.