An efficient method for maintaining clarity and forming tight and low amount of sediment in pomegranate juice during storage: Enzymatic hydrolysis with “tannase + lactonase + papain”

Abstract

Turbidity and sediment formation in pomegranate juice (PJ) is a consequence of the interaction between tannins and proteins. The aim of this study was to disrupt this interaction by enzymatic hydrolysis of tannins [“tannase,” “lactonase (R-PON-1)”] and proteins (papain). The effect of enzymatic treatments on sediment/turbidity was studied throughout storage (20 °C). Low and tight sediment formation was only possible when protein and tannins were hydrolysed together. In “tannase + R-PON-1 + papain” treated PJ, turbidity decreased after storage and the lowest and tightest sediment was also detected (p < 0.05). The strongest correlations were found between the “prolamin/punicalagin-2” ratio and turbidity (r = 0.997) and tight sediment formation (r = −0.964). This ratio should be 4.38 ± 0.07 to completely eliminate sediment formation in PJ. To achieve this ratio, punicalagin-2 should be added to PJ. This study is the first to show that punicalagin-2 should be added to PJ to produce a clear and sediment-free PJ, contrary to previous clarification methods.