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Antioxidant activity and phenolic co...

Sun, Ting.

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Antioxidant activity and phenolic contents of asparagus juice affected by the treatment of pectolytic enzyme preparations.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Antioxidant activity and phenolic contents of asparagus juice affected by the treatment of pectolytic enzyme preparations./
作者:	Sun, Ting.
面頁冊數:	134 p.
附註:	Source: Dissertation Abstracts International, Volume: 66-07, Section: B, page: 3486.
Contained By:	Dissertation Abstracts International66-07B.
標題:	Agriculture, Food Science and Technology. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3184172
ISBN:	054225588X

Antioxidant activity and phenolic contents of asparagus juice affected by the treatment of pectolytic enzyme preparations.
Sun, Ting.

Antioxidant activity and phenolic contents of asparagus juice affected by the treatment of pectolytic enzyme preparations. - 134 p.

Source: Dissertation Abstracts International, Volume: 66-07, Section: B, page: 3486.

Thesis (Ph.D.)--Washington State University, 2005.

The antioxidant activity of asparagus (Asparagus officinalis L.) ranks high among the commonly consumed vegetables. Effects of commercial pectolytic enzyme preparations on the rutin content and antioxidant activity of asparagus juice were investigated. The antioxidant activity of asparagus juice was determined using the DPPH (2,2'-diphenyl-l-picrylhydrazyl) method. Seven of the eight commercial pectolytic enzyme preparations showed various rutinase activities and Viscozyme contained the greatest rutinase activity. Rutinase can hydrolyze the glycoside of rutin to form quercetin. Although quercetin has greater antioxidant activity than rutin as determined by DPPH method, the antioxidant activity of asparagus juice treated with Viscozyme was not significantly increased. A pectinase from Aspergillus niger (pectinase AN) decreased rutin content and antioxidant activity of asparagus juice markedly, which was probably due to peroxidase existing in pectinase AN. The pH of asparagus juice, incubation temperature and amount of pectinase AN added to asparagus juice affected the rate of rutin loss in asparagus juice. For pectinase AN, rutin loss in asparagus juice was greater at pH 5.8 and pH 4.5 than that at pH 3.2. Rhamnosidase was identified in pectinase AN. Rhamnosidase can hydrolyze the rhamnose in rutin to produce quercetin-3-glucoside. Quercetin-3-glucoside has greater antioxidant activity than rutin as determined by DPPH method. Heating of pectinase AN at 70°C for 1.5 min decreased peroxidase activity of pectinase AN to almost zero and small amount of rhamnosidase was still remained. When pectinase AN heated at 70°C for 1.5 min was incubated with asparagus juice, the antioxidant activity of asparagus juice was significantly increased. In conclusion, commercial pectolytic enzyme preparations contained small amount of enzymes such as rutinase, rhamnosidase and peroxidase. These side enzymes can decrease the rutin content and affect the antioxidant activity of asparagus juice.

ISBN: 054225588XSubjects--Topical Terms:

1017813
Agriculture, Food Science and Technology.

Antioxidant activity and phenolic contents of asparagus juice affected by the treatment of pectolytic enzyme preparations.
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