Novel bioactive peptides sequences released by in vitro digestion of proteins isolated from Amaranthus hypochondriacus.

Amaranth is a protein-rich seed, highly consumed in Mexico and reported as a potential source of bio-peptides with physiological function. Therefore, the objective of this study was to evaluate and identify bioactive peptide sequences from amaranth protein fractions released by pepsin and pancreatin in vitro digestion. Multifunctional bioactivities of peptides were measured through antihypertensive, antithrombotic and antioxidant assays. Peptide sequences were identified by analysis with a Nano-LC-ESI-MS/MS. With these results, it was demonstrated that the in vitro enzymatic digestion mechanism allows the release of multifunctional bioactive peptide fractions from amaranth proteins.

Effect of Thermoultrasound on the Antioxidant Compounds and Fatty Acid Profile of Blackberry (Rubus fruticosus spp.) Juice.

Blackberry (Rubus fruticosus spp.) fruit has high antioxidant activity due to its significant content of anthocyanins and antioxidant compounds. Among emerging technologies for food preservation, thermoultrasound is a technique that reduces microbial loads and releases compounds with antioxidant properties. The objective of this study was to determine the antioxidant content and fatty acid profile of blackberry juice subjected to thermoultrasound treatment in comparison to pasteurized juice. Blackberry juice and n-hexane extracts from a control (untreated juice), pasteurized, and thermoultrasonicated samples were evaluated for antioxidant activity, fatty acid profile, and antioxidant content. The juice treated with thermoultrasound exhibited significantly (p < 0.05) higher levels of total phenols (1011 mg GAE/L), anthocyanins (118 mg Cy-3-GlE/L); antioxidant activity by ABTS (44 mg VCEAC/L) and DPPH (2665 µmol TE/L) in comparison to the control and pasteurized samples. Oil extract from thermoultrasound juice also had the highest antioxidant activity (177.5 mg VCEAC/L and 1802.6 µmol TE/L). The fatty acid profile of the n-hexane extracts showed the presence of myristic, linolenic, stearic, oleic, and linoleic acids and was not affected by the treatments except for stearic acid, whose amount was particularly higher in the control. Our results demonstrated that thermoultrasound can be an alternative technology to pasteurization that maintains and releases antioxidant compounds and preserves the fatty acids of fruit juice.