Physicochemical properties of a fibrous fraction from chia (Salvia hispanica L.)

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Abstract

An evaluation was done of some physicochemical properties of a fiber-rich fraction (FRF) obtained by dry processing of defatted chia (Salvia hispanica) flour. The fiber-rich fraction (FRF) had 29.56 g/100 g crude fiber content and 56.46 g/100 g total dietary fiber (TDF) content, of which 53.45 g/100 g was insoluble dietary fiber (IDF) and 3.01 g/100 g was soluble dietary fiber (SDF). The FRF water-holding capacity was 15.41 g/g, its water absorption capacity 11.73 g/g, and its organic molecule absorption capacity 1.09 g/g. The FRF also had low oil-holding (2.02 g/g) and water adsorption (0.3 g/g) capacities. Emulsifying activity in this fraction was 53.26% and emulsion stability was 94.84%. Its evaluated antioxidant activity was 488.8 μmol/L Trolox equivalents/g FRF, which is higher than for many cereals and similar to drinks such as wine, tea, coffee and orange juice. The chia FRF values for the evaluated properties, particularly for water-holding, oil-holding and organic molecule absorption capacity, suggest it could be a useful ingredient in dietetic products such as baked and fried foods, among others.

Introduction

The beneficial aspects of dietary fiber depend on its physicochemical properties, which group into four categories: (1) hydration properties (solubility, swelling, water-holding and absorption capacity, viscosity and gelling); (2) cationic exchange capacity; (3) particle size, density and surface characteristics (porosity and oil-holding capacity); and (4) organic molecule adsorption capacity (López et al., 1997). The principal physiological effect of fiber is its ability to swell when absorbing water, which occurs due to the presence of carbohydrates with free polar groups, interaction with hydrophilic links or retention within the matrix (López et al., 1997). These lead to formation of gel and a consequent increase in feces volume, which provokes more frequent peristaltic movements of the intestine. This in turn facilitates transit of the fecal bolus and intestinal distention, and thus aids in reducing the probability of intestinal tract disorders and constipation (Oliveira, Reyes, Sgarbieri, Areas, & Ramalho, 1991).

Fiber extracted from some grains and seeds exhibits physiological and functional properties that make it promising for use in food industry and health applications. This promise has led researcher to search for novel raw materials that meet needs in these areas, with a particular focus on the co-products of protein extraction or other components from raw materials such as legumes (Betancur-Ancona et al., 2004, Goff et al., 2001). There is a parallel interest in new sources of dietary fiber that contain concentrations comparable to those in cereal and legume subproducts such as wheat, rice and oat bran, lupine, etc. (Villarroel, Acevedo, Yánez, & Biolley, 2003).

Fiber source research has focused on tubers, cereals, vegetables, fruit and algae, all of which are characterized by high dietary fiber content with low digestibility and low caloric content. The fiber fraction from chia (Salvia hispanica L.) seed has similar characteristics. A native of southern Mexico, chia has been under cultivation in the region for thousands of years. Chia (Salvia hispanica, L.) was among the principal crops grown by ancient Mesoamerican cultures. Recent evaluation of chia's properties and possible uses has shown that it has a high content of oil (32%) and 60% of this, is linolenic acid, a fatty acid denominate omega-3 associated with various benefits to consumer health (Rosamond, 2002). However, after extracting the oil to the seeds, defatted chia has fiber (22 g/100 g) and protein (17 g/100 g) contents similar to those of other oilseeds currently used in the food industry (Ayerza & Coates, 1999). This product has not been object of great interest in the investigation. Also, they have been carried out a good number of investigations on the composition in fatty acids of the oil (Bushway, Wilson, Houston, & Bushway, 1984), the benefits that it contributes their consumption to the health and the inclusion of seeds in animal feeding (Ayerza & Coates, 1999).

Its high unsaturated oil content has gained its attention as a dietary component (Ayerza, 1995). Oil extraction in chia, however, produces a subfraction with relatively high dietary fiber content (33.9 g/100 g) (Craig & Sons, 2004), which also contains polyphenols (Taga, Miller, & Pratt, 1984), possibly involved in high antioxidant activity, and compounds conferring functional characteristics with food system applications. As part of an effort to determine possible applications for this fraction, an evaluation was done of the physicochemical and physiological properties of a high dietary fiber content fraction produced by dry processing of defatted chia (S. hispanica) flour.

Section snippets

Seeds and chemicals

Chia (S. hispanica L.) seeds were obtained from the February 2000 harvest at Tapachula, Chiapas, Mexico (14°54′N, 92°56′W). All chemicals were reagent grade from J.T. Baker (Phillipsburg, NJ), and enzymes were from Sigma (Sigma Co., St. Louis, MO, USA).

Flours

The flours were produced with 10 kg seed. All impurities and damaged seeds were removed and the remaining sound seeds milled (Thomas-Wiley®, Model 4, Thomas Scientific, USA). Oil extraction from the milled seeds was done with hexane in a Friedrich

Proximate composition

Proximate composition analysis showed fiber content to increase from 26.5 g/100 g in the chia flour to 29.56 g/100 g in the chia fiber-rich fraction (FRF) (Table 1), an increase that could be reflected more in TDF than crude fiber content. This increase may not seem substantive, but the FRF fiber content is appropriate for a fibrous product. The FRF also had a higher fiber content than Canavalia ensiformis fibrous residue (22.68 g/100 g) extracted by wet milling (Betancur-Ancona et al., 2004),

Conclusion

The fiber-rich fraction of chia (S. hispanica) had a high proportion of TDF (56.46 g/100 g), composed mainly of IDF (53.45 g/100 g) with a low SDF content (3.01 g/100 g). Its water-holding capacity (15.41 g/g), water absorption capacity (11.73 g/g) and organic molecule absorption capacity (1.09 g/g) were all high. In contrast, its oil-holding capacity (2.02 g/g) and water adsorption capacity (0.3 g/g) were low. Its emulsifying activity was 53.26 mL/100 mL with high emulsion stability (94.84 mL/100 mL). The

References (40)

  • J. Awika et al.

    Screening methods to measure antioxidant activity of sorghum (Sorghum bicolor) and sorghum products

    Journal of Agricultural and Food Chemistry

    (2003)
  • R. Ayerza

    Oil content and fatty acid composition of chia (Salvia hispanica L.) from five Northwestern locations in Argentina

    Journal of the American Oil Chemist's Society

    (1995)
  • R. Ayerza et al.

    An omega-3 fatty acid enriched chia diet: its influence on egg fatty acid composition, cholesterol and oil content

    Canadian Journal of Animal Science

    (1999)
  • D. Belén et al.

    Evaluación de algunas propiedades funcionales y reológicas de harinas de coroba (Jessenia polycarpa Karst)

    Revista de la Facultad de Agronomía (Venezuela)

    (2004)
  • A.A. Bushway et al.

    Selected properties of the lipid and protein fractions from chia seed

    Journal of Food Science

    (1984)
  • C. Chau et al.

    Functional properties of protein concentrate from three Chinese indigenous legume seeds

    Journal of Agricultural and Food Chemistry

    (1997)
  • C. Chau et al.

    Comparison of the chemical composition and physicochemical properties of different fibers prepared from the peel of Citrus sinensis L. cv. Liucheng

    Journal of Agricultural and Food Chemistry

    (2003)
  • J. Chen et al.

    Evaluation of water binding capacity (WBC) of food fiber sources

    Journal of Food Science

    (1984)
  • R. Craig et al.

    Application for approval of whole chia (Salvia hispanica L.) seed and ground whole chia as novel food ingredients

    (2004)
  • Cruz-Salazar, M. (2002). Caracterización del residuo fibroso obtenido de la cáscara de maracuyá Passiflora edulis...
  • Cited by (0)

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