Functional properties of guava seed glutelins

Five guava seed glutelin extracts were obtained with different buffer solutions: Na(2)B(4)O(7) alone (Glut.Bo) or containing SDS (Glut.BoSDS), 2-mercaptoethanol (Glut.Bo2-ME), or a combination of both (Glut.BoSDS2-ME) and NaOH (Glut.Na). All borate buffer solutions were at pH 10. The higher yield of glutelins corresponded to the Glut.BoSDS extract (81.9% dry basis) and the lower to Glut.Bo (6.8%). The functional properties of the five guava seed glutelin extracts were determined. Glut.BoSDS, Glut.BoSDS2-ME, and Glut.Na showed high values for several properties, including surface hydrophobicity (7.7, 10.8, and 0.6, respectively), solubility at pH 10 (91.1, 77.9, and 96.7, respectively), water-holding capacity at pH 3.6 (1.7, 2.5, and 2.8, respectively), emulsifying activity index (pH 10; 503.5, 238.2, and 838.0, respectively), and foaming properties (pH 10; V(0) = 0.14, 0.25, and 0.19, respectively; V(max) = 6.1, 5.59, and 4.51, respectively; t(1/2) = 266, 255.3, and 94 s, respectively). These results suggest that the denaturing reagent (SDS or NaOH) during extraction conferred on the proteins a structure that facilitated the development of their functional properties.     

Antiproliferative Effect of Amaranth Proteins and Peptides on HT-29 Human Colon Tumor Cell Line

Antiproliferative effect of Amaranthus mantegazzianus proteins and peptides released after simulated gastrointestinal digestion (DH% 37.8?±?3.8) was investigated on human colon cancer cell line HT-29. Inhibition of proliferation of HT-29 cells was exhibited after a 24 h treatment with different concentrations of amaranth protein isolate (API) and the peptides released after digestion (DGS), presenting IC₅₀ values of 1.35?±?0.12 and 0.30?±?0.07 mg soluble protein/mL, respectively. Lactate dehydrogenase assay indicated that both samples caused the loss of membrane integrity and cell lysis over HT-29 cells, and DAPI fluorescence microscopies evidenced typical apoptotic features. Moreover, Annexin V-FITC flow cytometry showed a significant increase of early apoptotic and late apoptotic/necrotic HT-29 cells compared to untreated ones, and caspase-3 assay confirmed the apoptosis induction with a 43.0?±?10.3 and 65.8?±?12.7% increase of caspase-3 activity produced by a 2 mg/mL treatment of API and DGS, respectively. In conclusion, amaranth peptides successfully released after simulated gastrointestinal digestion would exert a potential antiproliferative activity over HT-29 tumor cells. This effect was linked to the induction of cell necrosis and apoptosis, supporting the idea of using amaranth proteins as a potential food alternative ingredient for functional foods.

     

Amaranth Lemon Sorbet,Elaboration of a Potential Functional Food

Plant Foods for Human Nutrition - In the present work, amaranth proteins were used as a functional ingredient of formulated food. An amaranth lemon sorbet, a healthy alternative dessert for celiac,...