Hydrolysis of chlorogenic acid in apple juice using a p ‐coumaryl esterase of Rhizoctonia solani

BACKGROUND Apple juice is rich in polyphenolic compounds, especially in chlorogenic acid. A sour and bitter taste has been attributed to the compound. Chlorogenic acid in coffee powder was quickly hydrolysed by a p ‐coumaryl esterase of Rhizoctonia solani (Rs p CAE) at its optimal pH of 6.0. It was unknown, however, if Rs p CAE would also degrade chlorogenic acid under the strongly acidic conditions (pH 3.3) present in apple juice. RESULTS Treatment of apple juice with Rs p CAE led to a chlorogenic acid degradation from 53.38 ± 0.94 mg L −1 to 21.02 ± 1.47 mg L −1 . Simultaneously, the caffeic acid content increased from 6.72 ± 0.69 mg L −1 to 19.33 ± 1.86 mg/L −1 . The aroma profile of the enzymatically treated sample and a control sample differed in only one volatile. Vitispirane had a higher flavour dilution factor in the treated juice. Sensory analysis showed no significant difference in the taste profile (  p < 0.05). CONCLUSION These results demonstrated a high stability and substrate specificity of Rs p CAE. An increase in caffeic acid and a concurrent decrease in chlorogenic acid concentration may exert a beneficial effect on human health. © 2019 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.