Effect of Phenolic Acid on Antioxidant Activity of Wine and Inhibition of Pectin Methyl Esterase

Chien-Hao Chen^1,2, Ming-Chang Wu³, Chih-Yao Hou³, Chii-Ming Jiang⁴, Chi-Ming Huang³ and Yuh Tai Wang^5,6
¹ Department of Tropical Agriculture and International Cooperation, National Pingtung University of Science and Technology, Pingtung 912, Taiwan.
² Department of Food and Beverage Management, National Kaohsiung Hospitality College, Kaohsiung 812, Taiwan.
³ Department of Food Science, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan.
⁴ Department of Sea Food Science, National Kaohsiung Marine University, Kaohsiung 811, Taiwan.
⁵ Life Science Center, Hsing Wu College, No. 101, Sec.1, Fen-Liao Road, Lin-Kou, Taipei 244, Taiwan.
⁶ Corresponding author. Email: yuhtai@yahoo.com.

J. Inst. Brew. 115(4), 328–333, 2009 | VIEW ARTICLE

ABSTRACT
Antioxidant activity, malolactic fermentation and sensory evaluation of the grape must after fermentation in the presence of gallic acid and coumaric acid, as well as the inhibitory mechanism of gallic acid and coumaric acid on pectin methyl esterase (PME), were investigated. The content of malic acid and lactic acid increased 40.4% and 36.9% compared to the control when commercial pectic enzyme (CPE) was used. The increase in malic acid content was enhanced by 64.8% and 83.4%, compared to the control in the presence of CPE + Gallic acid and CPE + Coumaric acid respectively. Ferric reducing/antioxidant power (FRAP) increased in the samples with added CPE. In addition to an increase in the FRAP, antioxidant capacity was enhanced in the CPE + Gallic acid and CPE + Coumaric acid samples. No significant differences were found in the content of total anthocyanin and in the value of sensory characteristics. The content of total flavanols increased significantly in the samples with added CPE. Lineweaver-Burk plots of PME, with gallic acid or coumaric acid, indicated that gallic acid and coumaric acid were mixed inhibitors of PME.

Key words:
Commercial pectic enzyme, coumaric acid, gallic acid, pectin methyl esterase, wine.