Production of dietary fiber from sugar beet crops for application in food industry

Abstract

Chemical and nutritional composition of sugar beet crop and high content of dietary fiber, suggests the possibility of use its as raw material for dietary fiber production. Sugar beet fiber has improved nutritive value according to dietary fiber from other sources. The structure and composition of sugar beet fiber, a unique combination of naturally occuring soluble and insoluble fiber and calcium, result in many beneficial physiological and functional properties. Insoluble and soluble fiber prevents constipation, decrease the risk of cancer and coronary heart disease, prolong the feeling of being satiated by food, and limit the necessity for calories as noted by many authors. On the other hand, sugar beet fiber significantly lowers some quality characteristics of the final products, first of all colour, when it is included in white wheat flour composition for bread production. Sugar beet fibre addition to cookies results in dark crumb colour and in lower sensory acceptability and firmness. The present study estimated physicochemical (dry matter content, cellulose, lignin, hemicellulose and heavy metal content, fiber color, water-holding capacity and the solubility in water) and technological characteristics of sugar beet fiber obtained from sugar beet by extraction with sulphurous acid (nontreated sugar beet fiber), fiber treated with peroxide or sulfite ions (treated sugar beet fiber) and commercially available sugar beet fiber-Fibrex. The aims of these investigations were the confirmation of significance of dietary fiber production from sugar beet crop. The goal of the study was as well as to obtain additives with proper characteristics for bread and cookies production by applying treatment with peroxide and sulfite ions to sugar beet fiber. After the alkaline treatment with peroxide ions, sugar beet fiber has better characteristics for application in bread or cookies, because it becomes softer and more flexible, thus the degradation of gluten-starch matrix is not expected, nor the negative effect on the product softness. The fiber obtained after the treatment with peroxide ions (0.30 mol/dm3) of 15 min at pH 11.0 could be recommended for bread production, because of appropiate lightness and double higher water holding capacity (WHC), that guarantees technological and economical benefits, such as increased volume and better yield of product, as well as prolonged freshness. The fiber obtained after the treatment with peroxide ions (0.30 mol/dm3) at pH 8.5 which is longer than 15 min is recommended for the use as an additive in cookies production. This fiber has all the advantages of the fiber obtained at pH 11.0, except WHC, which is not changed in comparison to nontreated fiber, so that the water content of the cookies would not be increased. Bread enriched with sugar beet fibers of the highest volume and significantly improved crumb quality, even for 50% in comparison to conventional product, is attained if gluten, shortening and milk are included in dough formula at the level of 5, 5 and 2%, respectively. The optimal sensory quality, the colour and hardness of the biscuit cake are obtained by adding 7% of dietary fiber whose particle size ranges from 95 μm to 120 μm. The results presented in this chapter are the base for new methods for sugar beet characterization focused on chemical treatments and methods of dehydratation of dietary fiber. In addition, antioxidant properties of ethanolic extracts from above mentioned fibers were tested using: Folin-Ciocalteu, DPPH radical scavenging assay, antioxidant activity/β-carotene bleaching test, and chelating activity. The results are compared with commercially available product-Fibrex. © 2010 by Nova Science Publishers, Inc. All rights reserved.