TOMAS Mabel Cristina
capítulos de libros
Effect of Mucilage Extraction on the Functional Properties of chia meals
Food Industry
InTech Eds. I. Muzzalupo
Lugar: Rijeka; Año: 2013; p. 421 - 437
Chia (Salvia hispanica L.) is an annual herbaceous plant that belongs to the Lamiaceae family, which is native to southern Mexico and northern Guatemala. The Salvia hispanica fruit con‐ sists of four nutlets, similar to an indehiscent achene, which contain a single seed. These nut‐ lets are commonly called ?seeds? [1]. Chia seed, together with corn, beans, and amaranth were important crops for pre-Columbian civilizations in America, including the Mayan and Aztec populations [2, 3]. With time its use was abandoned, but by at the end of the last cen‐ tury there was a resurgence of interest in chia due to its nutritional value [4]. Chia is consid‐ ered an alternative crop to diversify and stabilize the economy of Northwestern Argentina [5]. The plant produces numerous small white and dark seeds that mature in autumn [6]. These seeds contain about 30% oil, and they mainly consist of unsaturated fatty acids [4, 7]. Chia seeds are a natural source of omega-3 fatty acids, antioxidants, proteins, vitamins, min‐ erals and dietary fiber [5, 7, 8]. Chia meal (residue of the seeds after oil extraction) is a good source of proteins (19-23%) [9], dietary fiber (33.9-39.9%) [10], and compounds with antioxidant activity [7]. It also ex‐ hibits some interesting functional properties for its use in the food industry [11]. Function‐ al properties are generally associated with the presence of proteins [12] and also of dietary fiber [13-16]. Dietary fiber (DF) consists of a heterogeneous mixture of compounds that are classified ac‐ cording to their physical properties and effects of their intake into: soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) [17], referring to the solubility of fibers in water. Plant secretions such as pectins and gums, components such as mucilage, and chelating agents such as phytates are sources of SDF; whereas cellulose, lignin, some fractions of hem‐ icellulose, phenolic compounds such as tannins and lipid structures such as waxes, suberins and cutins constitute IDF [18]. The functional properties of food components can be defined as any physicochemical property that affects and/or modifies some of its characteristics and that contributes to the quality of the final product. Knowledge about of functional properties such as color, parti‐ cle size, water holding, absorption and adsorption capacity, as well as those linked to the affinity for lipid components is very useful for the food industry, because during the proc‐ essing some modifications can occur that must be taken into account according to the us‐ age of the final product and its marketing conditions [19]. For example, water-holding capacity (WHC) is related to the freshness and softness effect present in bakery products, and the oil-holding capacity (OHC) is related to the un-fatty effect in fried food when it is low and to the juiciness and texture in meat products when it is high [18, 20, 21]. In addition to the characteristics mentioned above, it is important to consider the physio‐ logical effects of the DF intake. Given the capacity of SDF to form gels, it increases the viscosity of the bolus in the gastrointestinal tract, slowing the intestinal transit, making di‐ gestion and the absorption of nutrients more efficient, providing more of a feeling of sati‐ ety. Soluble fiber are fermentable fibers that can be microbiologically decomposed in the colon, producing gases such as carbon dioxide, hydrogen and methane, and short-chain fatty acids (acetic, propionic and butyric) which are absorbed and used as energy sources. Some of the most important beneficial effects of SDF is that it regulates blood sugar and lower cholesterol levels. On the other hand, IDF is responsible for adding bulk to the stool, speeding the passage of stool through the intestine by promoting peristalsis, allevi‐ ating constipation and other gastrointestinal disorders [22, 23]. Both types of fiber may al‐ so reduce the risk of obesity, hypertension, appendicitis, and other disorders [24]. The beneficial effects noted above show the important role that DF play in human intake, and that is why a daily intake of 25-30 g is recommended, with a good SDF/IDF balance (a minimum of 30% SDF and 70% IDF, optimum 50/50 ratio) in order to benefit from both fractions of fiber [25, 26]. Chia mucilage (SDF), a complex carbohydrate of high molecular weight, is an important component of the seed due to its physiological role. The mucilage is secreted when the seed comes into contact with water, generating high-viscosity solutions [27, 28]. Many studies have examined the functional properties of different types of gums (Linux usitatissimum, Opuntia Picus indica, Alyssum homolocarpum, Psyllium plantago) [29-32]. However, little infor‐ mation has been reported on the functionality of chia seed mucilage as a stabilizing or thick‐ ening agent of food products. The objective of the present work was to perform a comparative evaluation of the func‐ tional properties of chia meals (Salvia hispanica L.) obtained from seeds with and without mucilage.