Resistant starch and total dietary fiber content of oatrim muffins with different levels of amylose, amylopectin, and beta-glucan

Nine types of muffins made with three levels of P-glucan and three amylose- amylopectin ratios were prepared at the Beltsville Human Nutrition Research Center, United States Department of Agriculture. They were fed to human su bjects to study effects of starch composition and dietary fiber content on the carbohydrate and lipid metabolism in normal and overweight women. The m ain objective of this study was to determine resistant starch (RS) and tota l dietary fiber (TDF) content of the muffins 1) using AACC Approved Method 32-07 and AOAC method 991.43, incorporating a pretreatment step with dimeth yl sulfoxide (DMSO) before enzyme incubation, 2) with pretreatment at 100 a nd 121 degreesC before incubation with amyloglucosidase, and 3) using sampl es chewed by human subjects before incubation with pancreatin and amylogluc osidase. For method 1, on an as-eaten basis, TDF content was 2.81 to 9.64 g /100 g for samples without DMSO pretreatment and 1.66 to 4.06 g/100 g with DMSO pretreatment. RS content was 0.30 to 11.18 g/100 g for methods 1 and 2 , respectively. Methods 2 and 3 had the best correlation for all muffins te sted (r(2) = 0.97).