Pentapeptide-Zinc Chelate from Sweet Almond Expeller Amandin Hydrolysates: Structural and Physicochemical Characteristics, Stability and Zinc Transport Ability In Vitro

Dietary zinc supplements: beneficial health effects and application in food, medicine and animals

Zinc, a crucial trace element is vital for the growth and development of humans. It is frequently described as 'the flower of life' and 'the source of intelligence'. Zinc supplements play a pivotal role in addressing zinc deficiency by serving as a vital source of this essential micronutrients, effectively replenishing depleted zinc levels in the body. In this paper, we first described the biological behavior of zinc in the human body and briefly described the physiological phenomena associated with zinc levels. The benefits and drawbacks of various zinc supplement forms are then discussed, with emphasis on the most recent zinc supplement formulations. Finally, the application of zinc supplements in food, medicine, and animal husbandry is further summarized. © 2024 Society of Chemical Industry.

A critical review of a typical research system for food-derived metal-chelating peptides: Production, characterization, identification, digestion, and absorption

In the past decade, food-derived metal-chelating peptides (MCPs) have attracted significant attention from researchers working towards the prevention of metal (viz., iron, zinc, and calcium) deficiency phenomenon by primarily inhibiting the precipitation of metals caused by the gastrointestinal environment and exogenous substances (including phytic and oxalic acids). However, for the improvement of limits of current knowledge foundations and future investigation directions of MCP or their derivatives, several review categories should be improved and emphasized. The species' uniqueness and differences in MCP productions highly contribute to the different values of chelating ability with particular metal ions, whereas comprehensive reviews of chelation characterization determined by various kinds of technique support different horizons for explaining the chelation and offer options for the selection of characterization methods. The reviews of chelation mechanism clearly demonstrate the involvement of potential groups and atoms in chelating metal ions. The discussions of digestive stability and absorption in various kinds of absorption model in vitro and in vivo as well as the theory of involved cellular absorption channels and pathways are systematically reviewed and highlighted compared with previous reports as well. Meanwhile, the chelation mechanism on the molecular docking level, the binding mechanism in amino acid identification level, the utilizations of everted rat gut sac model for absorption, and the involvement of cellular absorption channels and pathway are strongly recommended as novelty in this review. This review makes a novel contribution to the literature by the comprehensive prospects for the research and development of food-derived mineral supplements.

Bitter Almond Albumin ACE-Inhibitory Peptides: Purification, Screening, and Characterization In Silico, Action Mechanisms, Antihypertensive Effect In Vivo, and Stability

Almond expeller is an undeveloped reservoir of bioactive peptides. In the current study, a zinc ion ligand Arg-Pro-Pro-Ser-Glu-Asp-Glu-Asp-Gln-Glu (RPPSEDEDQE) offering a noncompetitive inhibitory effect on ACE (IC50: 205.50 μmol·L-1) was identified from almond albumin hydrolysates via papain and thermolysin hydrolysis, subsequent chromatographic separation, and UPLC-Q-TOF-MS/MS analysis. Molecular docking simulated the binding modes of RPPSEDEDQE to ACE and showed the formation of hydrogen bonds between RPPSEDEDQE and seven active residues of ACE. Moreover, RPPSEDEDQE could bind to fifteen active sites of ACE by hydrophobic interactions, and link with the His387 and zinc ions of the zinc tetrahedral coordination. Ultraviolet wavelength scanning and Fourier-transformed infrared spectroscopy analysis revealed that RPPSEDEDQE can provide multiple binding sites for zinc ions. However, RPPSEDEDQE cannot bind with any central pocket of ACE, which was evidenced by an inhibition kinetics experiment. Additionally, the zinc-chelating capacity and inhibiting ability against ACE of RPPSEDEDQE were both not significantly reduced by the hydrolysis of gastrointestinal enzymes. A moderate to high dose of RPPSEDEDQE (100-150 mg·kg bw-1) significantly reduced the systolic and diastolic blood pressure of spontaneous hypertensive rats, but chelation with zinc ions decreased its antihypertensive efficiency. These results indicate that bitter almond albumin peptides may be used for lowering blood pressure.