Oxidative-Enzymatic Depolymerization for Preparing Chito-Oligosaccharides and Cellodextrins

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Project title

Code/計畫編號

NSC89-2313-B019-067

Translated Name/計畫中文名

以氧化－酵素降解法製備幾丁寡醣與纖維糊精之探討

Project Coordinator/計畫主持人

Ke-Liang Chang

Funding Organization/主管機關

National Science and Technology Council

Department/Unit

Department of Food Science

Website

https://www.grb.gov.tw/search/planDetail?id=553172

Year

2000

Start date/計畫起

01-08-2000

Expected Completion/計畫迄

01-07-2001

Bugetid/研究經費

601千元

ResearchField/研究領域

食品科技(農)

低濃度的過氧化氫可以引發部份去乙醯化之幾丁質、幾丁聚醣及羧甲基纖維素(CMC)之隨意降解反應。多醣類之分子量依循一級反應之動力模式產生氧化降解，其速率與酵素水解之速率相當，但是遠比超音波降解為快。如果在高於80 °C 的溫度進行反應，經過較激烈反應之後則易於切斷分子鏈末端的鍵結而生成寡醣產物。若以低濃度臭氧進行反應，則在10 至30 °C的範圍，則多醣類亦會受到降解，但寡醣則不易產生。在不同反應條件之下，以商用酵素分解幾丁聚醣或CMC 可以得到11%到大約90%產率的單醣與寡醣。以膠體層析法分析多醣類分子量之變化，並配合高效能液相層析法分析寡醣類產物之分佈情況，可以對多醣類氧化降解和酵素水解之機制得到更進一步的了解。 Low concentrations of hydrogen peroxide induced random degradation of partially deacetylated chitin and chitosan and produced significant amounts of oligosaccharides at temperatures 3 80 °C. Average molecular weight decreased in accordance with the first-order kinetics. The degradation rate was much faster than that of the ultrasonic degradation and it was comparable to that of the or enzymatic hydrolysis degradation of chitosanpolymeric material. Chain-end scissions occurred after chitosan was degraded severely and produced significant amounts of oligosaccharides at temperatures 3 80 °C. Universal calibration moderated the change in molecular weight more tightly than that calculated by usual calibration using pullulan standards. Trace amounts of transition metal ions and the amino groups in chitosan were critical to the breakdown of the b-1, 4 glycosidic linkages. HPLC results of glucosamine and chito-oligosaccharides could be characterized by correlating the logarithmic values of retention time with the degrees of polymerization. The formation of glucosamine and chito-oligosaccharides depended on the concentration of H2O2, temperature, and the physico-chemical property of chitin/chitosan. Ozone or enzymatic degradation decreased the molecular weight of chitosan and CMC in a similar fashion, but at a much slower rate.

Keyword(s)

幾丁寡醣
纖維糊精
過氧化氫
酵素降解
氧化降解
臭氧
Chitooligosaccharide
Cellodextrin
Hydrogen peroxide
Enzymatic degradation
Oxidative degradation
Ozone

DSpace CRIS

Oxidative-Enzymatic Depolymerization for Preparing Chito-Oligosaccharides and Cellodextrins

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