Evaluation of Dietary Fiber in Potato Crisps: Influence of the Analytical Method Used

Abstract

Dietary fiber in ready salted potato crisps was determined by two methods, i.e., the official AOAC method, and the modified method of Englyst, recommended in the U.K. The ultimate aim was to compare the results and to evaluate the advantages and limitations of each method for the analysis of this food in order to obtain a figure to be included on the package. The AOAC method is an enzymatic-gravimetric procedure to determine the total dietary fiber (TLIF). The Englyst method consists of an enzymatic-chemical extraction and fractionation of the nonstarch polysaccharides (NSP) and their subsequent determination as neutral sugars by GLC. We modified the original chromatographic method. The AOAC method gave a value of 5.39 g/lOOg (dry matter) for IDF, and the Englyst method a value of 1.70 g/lOOg (dry matter) for NSP. It is assumed that the gravimetric method gives a higherfiber value than the Englyst method due to a contribution from retrograded starch. For this particular food, the AOAC method is faster and much easier to carry out and does not overestimate dietary fiber, if the resistant starch is regarded as part of it. 'To whom inquiries should be directed, Fax number: 34-1-5644853, Telephone number: 34-1 -5622900 ext.241. Journal of Food Quality IS (1995) 33-43. All Rights Reserved. Copyright I995 by Food & Nutrition Press, Inc. Trumbull, Connecticut. 33 34 M. GARCIMARTIN ETAL.

Dietary fibre in foods: a review

“…The process involves forming a slurry of 5-10% by weight of ground tapioca pulp in an aqueous media, enzymatically treating the slurry with a 1,4-α-Dglycosidase to depolymerise starch to yield a tapioca fibre comprising at least 70% total dietary fibre, of which at least 12% is soluble fibre. Garcimartin et al (1995) compared the results of the two methods: the official AOAC method and the modified method of Englyst for evaluation of dietary fibre in ready salted potato crisps. The AOAC method is an enzymaticgravimetric procedure to determine the total dietary fibre (TDF).…”