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

• Published in: Journal of the science of food and agriculture Vol. 99; no. 14; pp. 6644 - 6648
• Main Authors: Siebert, Mareike, Berger, Ralf Günter, Pfeiffer, Franziska
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01-11-2019; John Wiley and Sons, Limited
• Subjects: Acids; apple juice; Apples; Aroma; Aroma compounds; Bitter taste; Caffeic acid; Chlorogenic acid; Chlorogenic Acid - chemistry; Coffee; Dilution; Esterase; Esterases - chemistry; Flavor; Flavoring Agents - chemistry; Flavors; Food processing industry; Fruit and Vegetable Juices - analysis; Fruit juices; Fungal Proteins - chemistry; Health risk assessment; Hydrogen-Ion Concentration; Hydrolysis; Juices; Malus - chemistry; Odorants - analysis; Organic chemistry; pH effects; Polyphenols; p‐coumaryl esterase; Rhizoctonia - enzymology; Rhizoctonia solani; Sensory evaluation; Sour taste; Substrate Specificity; Substrates; Taste; p-coumaryl esterase; Rhizoctonia solani; chlorogenic acid; apple juice
• ISSN: 0022-5142; 1097-0010
• DOI: 10.1002/jsfa.9940

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 (RspCAE) at its optimal pH of 6.0. It was unknown, however, if RspCAE would also degrade chlorogenic acid under the strongly acidic conditions (pH 3.3) present in apple juice.
RESULTS
Treatment of apple juice with RspCAE 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 RspCAE. 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.