ISSN:
1750-3841
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Sunflower pectins extracted from a 1:1 mixture of heads and stalks contained 98.5% galacturonic acid of molecular weight 122,200 with ester and acetyl contents of 29.4 and 1.4%, respectively. Gel firmness and strength were evaluated over the ranges of pH 3.0–4.7,15–30 mg Ca++/g pectin, 0.75–1.25% pectin and 10–50% sucrose in the gel formulation. Conditions of pH 4.3, 22.5 mg Ca++/g pectin, 1% pectin and 30% sucrose were optimal for gel firmness and strength. The sunflower pectin gel was particularly sensitive to pH and calcium concentration which had marked influences on pectin solubility, pregelation, brittleness and granularity. A high proportion of free carboxyl groups (69.1%), and possibly nonrandom distribution of demethoxylated groups on the pectin molecules, appeared responsible for the high sensitivity of sunflower pectins to ionic conditions in the gel formulation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2621.1978.tb02408.x
