Rheological study of galactomannan depolymerisation at elevated temperatures: Effect of varying pH and addition of antioxidants
Yükleniyor...
Dosyalar
Tarih
2010
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Sci Ltd
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Guar gum (GC) and locust bean gum (LBG) are neutral and should not be expected to change viscosity at different pH values. However, heat treatment at 100 degrees C within the range of pH values 5.0-9.0 did show significant differences in viscosity. Lowest viscosity and therefore probable maximum degradation was found at pH 7.0 which is indicative of free radical attack being optimum at this pH. Antioxidants, sodium sulphite (SS) and propyl gallate (PG), added at 1000 and 500 ppm, respectively, provide both gums with stability when subjected to temperature treatments up to 121 degrees C. This also supports the proposal that it is the action of free radicals at higher temperatures that causes thermal degradation. LBG shows a better conservation of viscosity than CC, on addition of antioxidants, suggesting that the protective effect of its intermolecular associations is further enhanced by the antioxidants. (C) 2010 Elsevier Ltd. All rights reserved.
Açıklama
Anahtar Kelimeler
Galactomannans, Depolymerisation, Thermal Degradation, pH, Antioxidant, Intermolecular Associations
Kaynak
Carbohydrate Polymers
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
81
Sayı
3
