title: Pectinesterase inhibitor from jelly-fig (Ficus awkeotsang Makino) achenes reduces methanol content in carambola wine.
abstract: Crude pectinesterase (PE) inhibitor (PEI) extracted from jelly-fig achenes (JFA) (Ficus awakeosang Makino) was added to carambola (Averrhoa carambola L.) puree to determine the change in methanol production during fermentation. Addition of pectin or microbial pectic enzyme to puree increased dose-dependently the methanol content in fermented products. Decreasing ratio (from 1:0 to 1:19, v:v) of pectic enzyme to diluted crude PEI solution in the puree-enzyme mixture decreased the PE activity remarkably. Except for transmittance (%T), addition of crude PEI to puree did not affect apparently the physical and chemical properties of wine; however, it reduced methanol content in the control from 256 to 58 ppm. The degree of esterification (DE) of pectin in starting puree was approximately 70%. It decreased to approximately 27% in the control group and reduced slightly to approximately 67% in fermented puree with crude PEI added after 14 days of fermentation. This reveals that crude PEI solution was potent in inhibiting intrinsic carambola PE activity and appeared to be a potential alternative for methanol reduction in wines.
authors.affiliation: Graduate Institute of Food Science and Technology, National Taiwan University, Taipei 106-17, Taiwan.
authors.forename: James Swi-Bea
authors.initials: JS
authors.lastname: Wu
authors.forename: Ming-Chang
authors.initials: MC
authors.lastname: Wu
authors.forename: Chii-Ming
authors.initials: CM
authors.lastname: Jiang
authors.forename: Ya-Ping
authors.initials: YP
authors.lastname: Hwang
authors.forename: Szu-Chuan
authors.initials: SC
authors.lastname: Shen
authors.forename: Hung-Min
authors.initials: HM
authors.lastname: Chang
mesh_terms: D002265:Carboxylic Ester Hydrolases / Q000037:antagonists & inhibitors*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005285:Fermentation; D030681:Ficus / Q000737:chemistry*; D005511:Food Handling / Q000379:methods; D005638:Fruit / Q000737:chemistry*; D019684:Magnoliopsida / Q000737:chemistry; D000432:Methanol / Q000032:analysis*; D014920:Wine / Q000032:analysis*
chemical_list: D004791:Enzyme Inhibitors; D002265:Carboxylic Ester Hydrolases; C022323:pectinesterase; D000432:Methanol