Abstract
Zinc-binding peptides from oyster (Crassostrea gigas) have potential effects on zinc supplementation. The aim of this study was to prepare efficient zinc-binding peptides from oyster-modified hydrolysates by adding exogenous glutamate according to the plastein reaction and to further explore the zinc absorption mechanism of the peptide-zinc complex (MZ). The optimum conditions for the plastein reaction were as follows: pH 5.0, 40 °C, substrate concentration of 40%, pepsin dosage of 500 U/g, reaction time of 3 h and l-[1-13C]glutamate concentration of 10 mg/mL. The results of 13C isotope labelling suggested that the addition of l-[1-13C]glutamate contributed to the increase in the zinc-binding capacity of the peptide. The hydrophobic interaction was the main mechanism of action of the plastein reaction. Ultraviolet spectra and scanning electronic microscopy (SEM) revealed that the zinc-binding peptide could bind with zinc and form MZ. Furthermore, MZ could significantly enhance zinc bioavailability in the presence of phytic acid, compared to the commonly used ZnSO4. Additionally, MZ significantly promoted the intestinal absorption of zinc mainly through two pathways, the zinc ion channel and the small peptide transport pathway. Our work attempted to increase the understanding of the zinc absorption mechanism of MZ and to support the potential application of MZ as a supplementary medicine.
Highlights
Zinc, as an essential micronutrient, is essential for human health and participates in numerous enzymatic and metabolic processes in human organisms [1]
The synthetic reaction dominated the plastein reaction and it inevitably led to a decrease in the free amino acids in the reaction system [17,19]
To improve the efficiency of the plastein reaction, the effects of hydrolysis pH, temperature, substrate concentration, pepsin dosage, reaction time, and glutamate concentration on the decrease in the free amino acid content of the plastein products were optimized in the present study
Summary
As an essential micronutrient, is essential for human health and participates in numerous enzymatic and metabolic processes in human organisms [1]. The human body mass contains 2–3 g of zinc [2]. Zinc deficiency usually leads to serious consequences, such as growth defects, hypogonadism, and neurological dysfunctions [3]. It is necessary to improve zinc bioavailability and absorption for optimum health. The efficacies of mineral supplements are strongly blocked by mineral absorption inhibitors (such as phytic acid) in daily diets [6]. Searching for both effective and safe components from seafood sources as alternatives to prevent zinc deficiency is a research area with urgent need worldwide
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
