Unconventional method for preparation of soluble fibres from starch
New starch preparations were produced by thermolysis of potato starch acidified with hydrochloric and citric acids in a microwave oven. Effect of microwave heating with different exposure times and various radiation level on physical, chemical properties and total dietary fibre (TDF) content in starch preparations was studied. Physico-chemical characteristics of dextrins including water solubility, water binding capacity, acidity, dextrose equivalent, intrinsic viscosity, HPSEC chromatograms were done. TDF content was determined by AOAC Official Method 991.43. Moreover, the stability of dextrins in in vitro model simulating the stomach and small intestine was tested. Studies showed that starch dextrins were characterized by increased dietary fibre content and increased resistance to digestion and absorption in the upper part of digestive tract.
Dietary fibre (DF) offers many health benefits. It protects against cardiovascular disease, lowers the risk of coronary heart disease. There is a strong inverse relationship between DF consumption and development of type II diabetes (1). DF is important for normal laxation. Studies report that people who consume higher amounts of fibre weigh less than people who consume smaller amounts (2). Some fibres may also play a role in improving immune function via production of short-chain fatty acids (SCFAs) (3). Currently, recommended daily intake of DF is of 14.1 g/1000 kcal energy intake for adults. In practice this means an advised daily intake of about 35 g for a man and 28 g for a woman (4). Unfortunately, in many countries the levels of fibre intake are significantly below recommended levels (1). Therefore, scientists look for new sources of fibre, design a food with fibre added and seek to improve methods for the determination of this component in food. The concept of DF has continuously evolved. It expanded from the first Hipsley’s definition (1953) including lignin, cellulose, and hemicellulose to a much wider range of compounds, not onl ...