Coconut Flour From Residue : A Good Source Of Dietary Fiber
The composition and fermentability of coconut flour made from residue, a by-product of the coconut milk industry was determined. Total dietary fiber, insoluble and soluble fiber of coconut flour was analyzed and compared with other local sources such as banana, cassava, wheat and rice flours using AOAC methods. The fermentability characteristics of the above test foods were determined by in vitro fermentation using human fecal inoculum. Results showed that the dietary fiber content of coconut flour was 60.9±1.0 g/100 g sample, 56% insoluble and 4% soluble and was significantly greater than the other local fiber sources. Fiber isolates from coconut flour, banana and cassava flour produced short chain fatty acid, e.g. acetic, propionic and butyric acid, after fermentation. Butyric acid fl. 73±0.07 mmol'gfiber isolate) producedfrom coconutflour was significantly greater than propionic f0.47±0.0J fi 0.05) and acetic acid (1.40±0.12: (P 0.05) and was significantly different from the short chain fatty acid pattern of other local dietaryfiber sources. This may have some important role in the prevention of colon cancer. The effect of dietary fiber ffom coconut flour on mineral availability was also determined. Increasing concentrations of dietary fiber from coconut flour was added to ten bakery products and was used as the test foods in the study. Total iron, zinc and calcium were determined as well as the total dietary fiber, phytic and tannic acids content of the test foods. Mineral availability was determined in vitro simulating conditions that prevails in the small intestine and colon. Dialyzable minerals were used as a measure of mineral availability. Dialyzable iron and zinc were highest for carrot cake (Fe, 33.3±0.7 %>; Zn, 12.6±0.1 %) supplemented with 20% dietary fiber while multigrain loaf supplemented with 10% dietary fiber and macaroons with 25% dietary fiber were highest for dialyzable calcium (63.4+8.0 % and 38.7±1.1%, respectively) among the test foods. It is concluded that coconut flour is a good source ofdietary fiber and that increasing amount of dietary fiber from coconut flour has little or no effect on mineral availability. Differences in mineral availability may be attributed to the interaction of minerals and the presence of phytic acid, tannic acid and other nutrients in the test foods. Studies to support other physiological effects and health benefits of dietary fiber present in coconut flour needs to be fiirther investigated e.g. prevention of cancer, cardiovascular disease and in the proper control and management of diabetes melUtus and obesity.