earticle

영어

An acidic polygalacturonase (PG) from Aspergillus kawachii was produced by solid state fermentation employinga polyurethane foam support. The conditions used for the production of acidic PG were particle size of support (0.6 or 500mm3) and fermentation time. From the factors studied, the particle size had important influence on enzyme production. Thebest conditions for acidic PG production were 0.6mm3 particle size, 18 hr at 30oC and initial pH of 5.0. In addition, pectinwas extracted from citrus pomaces (grapefruit, lime, and tangerine) by acidic PG at 50oC for 24 hr with citric acid solution.Infrared spectroscopy showed that lime pomace had more high-methoxylated (65%) endogenous pectin than was obtainedthan from grapefruit or tangerine pomaces. The enzymatically extracted pectin yield in dry basis (d.b.) for grapefruit and limepectins were 6.95 and 4.25%, respectively. The citric acid solution alone also contributed to pectin extraction from citruspomaces (7-9%, d.b.). Limited pectin extraction by acidic PG from tangerine pomace was most likely due to the presence oflow-methoxylated endogenous pectin. The enzymatic method for pectin extraction using acidic PG from A. kawachii is apromising technique for releasing highly polymerized pectic substances from high-methoxylated lime or grapefruit pomaces.