Validation of a selenized chickpea flour as a potential ingredient for functional foods

Abstract

Germination of chickpea (Cicer arietinum L.) in presence of selenium (Se) is an alternative to increase the mineral and healthy-related properties of the sprouts. This study aimed to produce an Se-enriched chickpea sprouts flour as an ingredient for functional foods. Firstly, the Se-stored protein fraction was identified, and the protein hydrolysates cellular antioxidant activity (CAA) was evaluated. Secondly, the germination in presence of Se was scaled up to meet the criteria of saving and expanding production, obtaining high Se and isoflavones concentrations in the chickpea sprouts. In third place, the formulation and evaluation of a food containing germinated chickpea flour was carried out. Finally, the adjuvant capacity against colon cancer in xenografted mice model of a diet containing Se-enriched chickpea sprouts flour was evaluated. For the first step, chickpeas were germinated at laboratory conditions for 4 days soaking with sodium selenite (Na2SeO3) (0, 1, or 2 mg/100 g seeds). The protein fractions were digested, identified by Tricine-SDS-PAGE gels, passed through a 10kDa membrane, and evaluated by CAA. Se was accumulated in the order Glutelin (Glu) > Albumin (Alb) > Globulin (Glo). Glu hydrolysate of less than 10kDa from selenized chickpea sprouts (2 mg of Na2SeO3/100 g seeds) increased by 51.5% the CAA related to non-selenized chickpea sprouts. Besides, it was found that Glo digestibility increased with the selenization. For the second step, different doses of Na2SeO3 were used to soak the seeds (0, 24, 48, or 96 mg/L) at industrial level. Freeze- and convection-drying (FD, CD) were evaluated on the Se retention, isoflavones, and enzymatic activities (β-glucosidase, phenylalanine-ammonia-lyase, PAL). Increases of 65% and 19% were observed in PAL and phenolics, respectively when the lowest dose of Se was used. CD did not affect the Se content in the sprouts soaked with 0, 24, and 48 mg/L, and converted isoflavones glycosides into aglycones due to β-glucosidase activation. The highest dose of Na2SeO3 (96 mg/L) was found toxic. At the third objective, maize extrudates supplemented with germinated chickpea flour were formulated. Protein augmented with the chickpea supplementation and the interaction between fat, starch, and protein increased the RS in comparison to defatted samples. Germinated chickpea flour increased the water absorption index (WAI), but reduced water solubility index (WSI) when it was combined with maize grits to produce extrudates. The in vitro protein digestibility (IVPD) was higher in the germinates chickpea extrudates and with 20% of supplementation. The supplementation with 20 and 30% of germinated chickpea showed the highest acceptability. Finally, the tumor growing was evaluated with a Gompertz model and the lipid, liprotein and GPx and TrxR were evaluated. The Ti observed for NC group was significantly higher than the observed in the selenized C15Se and C30Se groups by 1.26-fold. HDL-C in serum showed that there were significant differences between the C30Se group and NC and C30 groups by 1.07- and 1.12-fold. C15NSe did not show inhibitory effect on the tumor growth and could be related to the observed in the LDL-C levels in contrast to observed in C60, C15Se, and C30Se. Triglycerides of basal group was significantly higher than those measured in C15, C30, C15NSe, and C30Se group; the reductions were in a range of 22 to 28% with the experimental groups. Almost an increase of 2-, 1.6-, and 1.9-fold were found in the GPx groups in selenized treatments in comparison to basal, NC, and C15 groups, respectively. As a result, C30Se showed the best significant outcomes in the in vivo study: lower Ti compared to NC, higher HDL-C compared to NC and C30; lower triglycerides compared to basal group; and higher GPx activity compared to basal, NC, C15, and C30 groups.