Plastein reaction augments the metal chelating capabilities of silver carp (Hypophthalmichthys molitrix) hydrolysates: Unlocking the chemical modification mechanism

Plastein reaction mechanisms and the alteration of its product properties have been studied for decades. This study investigated the plastein-mediated modifications in silver carp protein hydrolysate (SCPH) from both mechanistic and functional perspectives. Unlike prior research, this investigation uncovered that hydrogen bonding supplemented the dominant hydrophobic interactions in plastein's mechanism for the first time, as supported by peptide concentrations, molecular weight, amino acids, chemical forces, and peptide sequence by LC-MS/MS. This innovative reaction mechanism cascaded into the enhancement of SCPH functional attributes. Plastein induced increased COOH in SCPH's side-chain groups significantly enhanced Fe2+ (from 4.49 to 14.12 %) and Zn2+ (from 53.53 to 64.47 %) chelation. Moreover, the elevated DPPH (17.56 %-23.97 %) and hydroxyl radical (68.49 %-79.32 %) scavenging power indicated a broader improvement in SCPH with plastein. In SCPH, plastein elucidated reaction intricacies and enhanced its utility, propelling SCPH into a realm of extended potential.

Phytochemical analysis, antioxidant and metal chelating capacity of Tetrapleura tetraptera

Tetrapleura tetraptera, claim to be beneficial for curing of human ailments. In this study, we determined phytochemicals, antioxidant and metal chelating capacity in the pulp, seeds and whole fruit (mixture of pulp and seeds) of T. tetraptera. Phytochemicals (flavonoids, alkaloids, terpenoids, tannins, steroids, saponins and phenols) were examined in aqueous and ethanolic extracts of the pulp, seeds and whole fruit. The recovery of all compounds was satisfactory, in the range of 90%-108%. The screening test revealed the presence of many phytochemicals in either one or both extracts. After the qualitative analysis, UV-Spectrophotometer was used to quantify phenols, flavonoids, saponins and alkaloids where higher phytochemical concentrations were recorded in the pulp followed by whole fruit and then the seeds. The metal chelating capacity was determined using EDTA standard, and was in the order of pulp>whole fruit>seeds. Also, the pulp was established to exhibit much antioxidant activity as compared to the whole fruit or seeds. This study therefore supports the use of T. tetraptera in traditional systems of medicine owing to its active chemical compounds, and has given many vital insights on which part of T. tetraptera fruit to consume as concentrations of these compounds varies in the pulp, seeds and whole fruit.