Effect of sulphite and propyl gallate or ferulic acid on the thermal depolymerisation of food polysaccharides

✍ Scribed by Hill, Sandra E; Gray, David A

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 110 KB
• Volume: 79
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/(sici)1097-0010(19990301)79:3<471::aid-jsfa269>3.0.co;2-0

✦ Synopsis

Thermal degradation of gums and starches can be an important factor in the texture of food products. This degradation can occur at neutral pH values and is thought to be due to oxidativereductive depolymerisation. It is thought that oxygen, a transition metal and a free radical mediate this reaction and thus it should be controllable by the addition of an antioxidant system. Previous studies have shown that the use of propyl gallate and sulphite, at a ratio of approximately 1 : 3, reduces the loss in viscosity which occurs on heating galactomannans. These additives can also be used to reduce starch conversion, which can be promoted by the inclusion of low levels of sulphite. Although propyl gallate is an allowed food additive, its use is limited and it would be of interest if other agents could be found to function in a similar manner. It has now been shown that ferulic acid can replace propyl gallate and the viscosity of heated guar gum samples can still be maintained at 70% of the pre-retorted values. At the concentrations of guar and additives used, an optimum of 1 :1.7 ferulic acid to sulphite was found. Preliminary work has shown that ferulic acid can also nullify the eþ ects of sulphite addition to cassava starches. It would therefore appear that ferulic acid does have the capacity to interfere with the mechanisms that can cause depolymerisation of polysaccharides. The relevance of this for food systems has yet to be determined.