Fabrication and characterization of the nano-composite of whey protein hydrolysate chelated with calcium

Abstract

The nano-composites of whey protein hydrolysate (WPH) chelated with calcium were fabricated in aqueous solution at 30 °C for 20 min, with the ratio of hydrolysate to calcium 15 : 1 (w/w). UV scanning spectroscopy, fluorescent spectroscopy, Fourier transform infrared spectroscopy, dynamic light scattering and atomic force microscopy were applied to characterize the structure of the WPH-calcium chelate. The nano-composites showed the successful incorporation of calcium into the WPH, indicating the interaction between calcium and WPH. The chelation of calcium ions to WPH caused molecular folding and aggregation which led to the formation of a WPH-calcium chelate of nanoparticle size, and the principal sites of calcium-binding corresponded to the carboxyl groups and carbonyl groups of WPH. The WPH-calcium chelate demonstrated excellent stability and absorbability under both acidic and basic conditions, which was beneficial for calcium absorption in the gastrointestinal tract of the human body. Moreover, the calcium absorption of the WPH-calcium chelate on Caco-2 cells was significantly higher than those of calcium gluconate and CaCl₂ in vitro, suggesting the possible increase in calcium bioavailability. The findings suggest that the WPH-calcium chelate has the potential in making dietary supplements for improving bone health of the human body.

Effect of duck egg white peptide‐ferrous chelate on iron bioavailability in vivo and structure characterization

“…The particle size of the DPS‐Fe chelate (555.17 ± 10.37 nm) was significantly ( P < 0.05) increased compared to DPs (182.33 ± 6.37 nm), which indicated that the chelate reaction between Fe 2+ and DPs not only existed in intramolecular interactions, but also existed in intermolecular interactions . In addition, polydispersity index range of 0.24 to 0.26 was observed for the samples (DPs: 0.24 ± 0.02; DPS‐Fe: 0.26 ± 0.01), which indicated that DPs and DPs‐Fe had an acceptable homogeneity .…”

Characterization of sea cucumber (stichopus japonicus) ovum hydrolysates: calcium chelation, solubility and absorption into intestinal epithelial cells

“…However, when the calcium ion concentration increased, the absorption peak at approximately 260 nm gradually red‐shifted and finally disappeared. The UV spectra phenomenon was consistent with that of β ‐LG hydrolysate–iron complexes, which demonstrated that the spatial structure with the chirality of the chromospheres (C=O and −COOH) and auxochromes (−OH and −NH 2 ) of peptides changed after binding with the calcium ion . The interaction between SCOHs and calcium ions leads to the formation of a new chemical compound.…”

“…When excited at 295 nm, tryptophan exhibites an intrinsic fluorescence emission maximum at approximately 350 nm. Moreover, decreased florescence intensity is a classic indicator for peptide folding . Hence, interactions between metal ions and organic ligand groups in the proteins can be reflected as changes in emission peak wavelength and fluorescence intensity.…”

“…Moreover, decreased florescence intensity is a classic indicator for peptide folding. 39 Hence, interactions between metal ions and organic ligand groups in the proteins can be reflected as changes in emission peak wavelength and fluorescence intensity. As the concentration of CaCl 2 increased, the endogenous fluorescence decreased dramatically, and the absorption peak of the samples shifted from 344 to 352 nm (Fig.…”

Preparation and Characterization for Peptide-Chelated Calcium of Deer Bone

“…Until now, it has been demonstrated that the peptide-chelated calcium might be a typical calcium fortifier to improve bone health of human body. For example, several investigators had suggested that the peptides from whey protein (Xixi et al, 2015), fish scales (Guo et al, 2015, Chen et al, 2014 and soybean (Bao et al, 2008, Lv et al, 2013b could chelate with Ca 2+ and the reaction products were stable in the gastrointestinal tract to promote calcium absorption in vivo. Actually, the deer bone is rich in collagen which can be hydrolyzed into peptides, but there were little studies about the peptides from deer bone chelated with Ca 2+ as calcium fortifier.…”