title: 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.
authors.affiliation: College of Bioscience and Biotechnology, Fuzhou University, Fuzhou, Fujian 350108, China. shywang@fzu.edu.cn.
authors.forename: Cai
authors.initials: C
authors.lastname: Xixi
authors.forename: Zhao
authors.initials: Z
authors.lastname: Lina
authors.forename: Wang
authors.initials: W
authors.lastname: Shaoyun
authors.forename: Rao
authors.initials: R
authors.lastname: Pingfan
mesh_terms: D065567:Absorption, Physiological; D001665:Binding Sites; D050071:Bone Density Conservation Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000737:chemistry* / Q000378:metabolism; D018938:Caco-2 Cells; D065096:Calcium Chelating Agents / Q000009:adverse effects / Q000737:chemistry; D002122:Calcium Chloride / Q000009:adverse effects / Q000378:metabolism; D002125:Calcium Gluconate / Q000009:adverse effects / Q000378:metabolism; D002136:Calcium, Dietary / Q000008:administration & dosage / Q000009:adverse effects / Q000032:analysis* / Q000378:metabolism; D002470:Cell Survival; D055598:Chemical Phenomena; D019587:Dietary Supplements / Q000009:adverse effects / Q000032:analysis*; D010450:Endopeptidases / Q000378:metabolism; D020895:Enterocytes / Q000378:metabolism; D006801:Humans; D007408:Intestinal Absorption; D053761:Nanocomposites / Q000009:adverse effects / Q000737:chemistry*; D010316:Particle Size; D017510:Protein Folding; D011492:Protein Hydrolysates / Q000009:adverse effects / Q000737:chemistry* / Q000378:metabolism; D059748:Proteolysis; D012995:Solubility; D000067816:Whey Proteins / Q000009:adverse effects / Q000737:chemistry* / Q000378:metabolism
chemical_list: D050071:Bone Density Conservation Agents; D065096:Calcium Chelating Agents; D002136:Calcium, Dietary; D011492:Protein Hydrolysates; D000067816:Whey Proteins; D010450:Endopeptidases; D002122:Calcium Chloride; D002125:Calcium Gluconate