Determination of Soluble and Insoluble Dietary Fiber in Psyllium-Containing Cereal Products

Abstract

A method for soluble and insoluble dietary fiber determinations was developed for psyllium-containing food products, which are highly viscous in aqueous solutions. The assay is based on a modification of the AOAC soluble and insoluble dietary fiber method (991.43), which was recommended for nutrition labeling in the final U.S. food labeling regulations. We found that method 991.43 and other existing dietary fiber methods could not be applied to psyllium food products, which exhibit high viscosity in aqueous solutions, because highly viscous solutions could not be filtered easily. In this study, we modified AOAC method 991.43 to accommodate the filtration process of viscous sample solutions. Sonication followed by highspeed centrifugation was used before filtration. The principles of the method are similar to those for AOAC method 991.43, including the use of the same 3 enzymes (heat-stable α-amylase, protease, and amyloglucosidase) as well as similar enzyme incubation conditions. The modification using sonication and high-speed centrifugation did not alter the method performance for analytically normal products such as wheat bran, oat bran, and soy fiber. Yet, the modification allowed the separation of soluble dietary fiber fractions from insoluble fractions for psyllium products with satisfactory precision. This method for psyllium dietary fiber determinations may be applied to other food products that exhibit high viscosity in aqueous solutions.

Effects of β-glucan Rich Barley Flour on Glucose and Lipid Metabolism in the Ileum, Liver, and Adipose Tissues of High-Fat Diet Induced-Obesity Model Male Mice Analyzed by DNA Microarray

“…BF flour pearled to 70% yield was obtained from the National Agriculture and Food Research Organization (Tsukuba, Japan). Total dietary fiber was analyzed using the AOAC 991.43 method [ 23 ]. β-Glucan content was analyzed using the McCleary method (AOAC 995.16) [ 24 ].…”

Edible Brown Seaweed in Gluten-Free Pasta: Technological and Nutritional Evaluation

“…Soluble, insoluble, and total dietary fibre contents of Laminaria ochroleuca and all pasta samples (raw and cooked) were evaluated according to AOAC 991.43 [35] with the specific modifications for Psyllium fibre suggested by Lee et al [36].…”

Effects of barley β‐glucan with various molecular weights partially hydrolyzed by endogenous β‐glucanase on glucose tolerance and lipid metabolism in mice

“…Quantitative analysis of β‐glucan content in barley flour was determined by the McCleary method (AOAC 995.16) (McCleary & Codd, 1991). Total dietary fiber was analyzed by the AOAC 991.43 method (Lee, Rodriguez, Storey, Farmakalidis, & Prosky, 1995), proteins were analyzed by the Kjeldahl method, and lipids were analyzed using the acid hydrolysis method. Table 1 shows the nutrient properties of 70% pearled, PHEB‐2h, and PHEB‐8h barley flours.…”