Journal of Food and Nutrition Research, 2013, Vol. 1, No. 3, 13-23 Available online at http://pubs.sciepub.com/jfnr/1/3/1 © Science and Education Publishing DOI:10.12691/jfnr-1-3-1 The Application of Dietary Fibre in Food Industry: Structural Features, Effects on Health and Definition, Obtaining and Analysis of Dietary Fibre: A Review Filiz Yangilar * Department of Food Engineering, Faculty of Engineering, Ardahan University, Ardahan, Turkey *Corresponding author: filizyangilar@ardahan.edu.tr Received May 29, 2013; Revised June 19, 2013; Accepted June 20, 2013 Abstract It is important for food materials to be delicious as well as nutritious and natural. Rapidly increasing of human population of world, environmental pollution caused by consistently developing technology, insufficient education and problems caused by wrong nutrition are making supplying of natural food is more difficult. Healthy nutrition refers to efficient and balanced nutrition, that is, efficient intake of nutrient elements (lipids, carbohydrates, proteins, vitamins, minerals) for body cells to work smoothly. But, oil content present in the structure of some food materials is a problematic situation for consumers. In order to solve this problem, dietary fibre can be used, which can improve the textural and sensual qualities of products in addition to being functional. An excessive interest has been observed over the last years in fibrous nutrients in developed countries (e.g. USA and various parts of Europe). In the present review, it has been conducted on the food products in which dietary fibres are used, changes taking place in the structures of these nutrients, the importance of the use of dietary fibres. Keywords: dietary fibres, laxative, analtical methods, health 1. Introduction A nutraceutical food may provide expanded utility beyond its nutritional benefit. These benefits can be both physcial and mental and are commonly attributed to the active components of the food. Today’s functional foods and dietary supplements are typically marketed to large groups of the total population. Scientific evidence confirming the relationship between food and health has promoted the rapid development of a new food market in recent years: the functional food market (Siró, Kápolna, Kápolna and Lugasi, 2008; Viuda-Martos et al., 2010). Dietary fibre (DF) was originally defined in 1972 by Trowell as ‘that portion of food which is derived from cellular walls of plants which are digested very poorly by human beings’ (De Vries, 2010; EFSA, 2010; Westenbrink et al., 2012). DF has been known and investigated for a very long time (Asp, 2004), from being considered as waste to being described as a ‘universal remedy’ that improves any physiological problem within human organism (Rodríguez et al., 2006). Dietary fibre cannot be digested by the human digestive enzymes to absorbable components in the upper alimentary tract (Trowell et al., 1976; Ajila and Prasada Rao; 2013). Over the past two-hundred years diet has become increasingly processed, leading to greatly reduced fibre content (Burkitt & Trowell, 1975; Cleave, Campbell, & Painter, 1969; Kendall et al., 2010). Dietary supplements are typically marketed in the form of a capsule, pill, powder or gel and are not presented for use as a conventional food, meal or diet. Dietary supplements contain one or more dietary ingredients (e.g., vitamins, minerals, amino acids, herbs or other botanicals) and are intended to supplement the diet (U.S. Food and Drug Administration, 1994; van Kreijl et al., 2006; Eussen et al., 2011). 2. Structural Features of Dietary Fibres Dietary fibre as a class of compounds includes a mixture of plant carbohydrate polymers (Thebaudin, Harrington, & Bourgeois, 1997; Rodríguez et al., 2006; Mongeau, 2003; García Herrera et al., 2010), both oligosaccharides and polysaccharides, e.g., cellulose, hemicelluloses, pectic substances, gums, resistant starch, inulin, that may be associated with lignin and other non- carbohydrate components (e.g., polyphenols, waxes, saponins, cutin, phytates, and resistant protein). Dietary fibre is composed of nondigestible carbohydrate, lignin and other associated substances of plant origin, fibres of animal sources and modified or synthetic nondigestible carbohydrate polymers. Cereals are the principal source of cellulose, lignin and hemicelluloses, whereas fruits and vegetables are the primary sources of pectin, gums and mucilage (Normand, Ory, & Mod, 1987; Elleuch et al., 2011). Each polysaccharide is characterised by its sugar residues and by the nature of the bond between them (Table 1) (Elleuch et al., 2011). Resistant starch and resistant protein withstand digestion in the small intestine. Resistant starch is composed of four groups (RS1: physical inaccessible starch, RS2: ungelatinised starch granules, RS3: retrograded starch and RS4: chemically modified starch) (Fuentes- Zaragoza, Riquelme-Navarrete, Sánchez-Zapata, & Pérez-Álvarez, 2010).