Characterization and physicochemical properties of dietary fiber concentrates as potential prebiotic ingredients for use in fish nutrition

Abstract

Dietary fibers are formed by non-starch polysaccharides as cellulose, hemicellulose, pectins, gums, mucilages, β-glucans, among others. These constituents have prebiotic properties and are therefore not digested in the gut, reaching intact in the colon and altering the microflora of the colon. In developing, beneficial microflora produces physiological effects capable of improving the life of the host. Thus, the knowledge of the biological and functional properties of dietary fibers has led to the development of methods of obtaining these compounds for possible use in animal nutrition. Then, this study aimed to obtain dietary fiber concentrates (DFC) from different agro-industrial sources and evaluate their respective chemical composition and physicochemical properties. The DFC - mucilage, pectin, and βglucan + mannan (βG+M) were obtained from linseed, citrus pulp, and brewer’s yeast (Saccharomyces cerevisiae), respectively, through different physicochemical processes. The chemical composition revealed that the predominant component in all DFC were dietary fiber and the insoluble fraction. The DFC that obtained most extraction yield was βG+M (19.81% ± 8.54), followed by pectin (14.54% ± 2.72), and mucilage (7.18% ± 1.54). The mucilage and pectin composition have greater monosaccharide diversity since the βG+M consisted primarily of mannose (74.5%) and glucose (24.3%). The pectin showed numerically lower hydration capacity than the other DFC. For the oil binding ability, all DFC had similar values. In this study, the DFC presented nutritional and technological characteristics that indicate potential application of the agro-industrial sources as a prebiotic for fish supplementation.