Process Optimization, Structural Characterization, and Calcium Release Rate Evaluation of Mung Bean Peptides-Calcium Chelate

Abstract

To reduce grievous ecological environment pollution and protein resource waste during mung bean starch production, mung bean peptides-calcium chelate (MBP-Ca) was synthesized as a novel and efficient calcium supplement. Under the optimal conditions (pH = 6, temperature = 45 °C, mass ratio of mung bean peptides (MBP)/CaCl2 = 4:1, MBP concentration = 20 mg/mL, time = 60 min), the obtained MBP-Ca achieved a calcium chelating rate of 86.26%. MBP-Ca, different from MBP, was a new compound rich in glutamic acid (32.74%) and aspartic acid (15.10%). Calcium ions could bind to MBP mainly through carboxyl oxygen, carbonyl oxygen, and amino nitrogen atoms to form MBP-Ca. Calcium ions-induced intra- and intermolecular interactions caused the folding and aggregation of MBP. After the chelation reaction between calcium ions and MBP, the percentage of β-sheet in the secondary structure of MBP increased by 1.90%, the size of the peptides increased by 124.42 nm, and the dense and smooth surface structure of MBP was transformed into fragmented and coarse blocks. Under different temperatures, pH, and gastrointestinal simulated digestion conditions, MBP-Ca exhibited an increased calcium release rate compared with the conventional calcium supplement CaCl2. Overall, MBP-Ca showed promise as an alternative dietary calcium supplement with good calcium absorption and bioavailability.

Structural characterisation of deer sinew peptides as calcium carriers, their promotion of MC3T3-E1 cell proliferation and their effect on bone deposition in mice

“…The absorption peaks of deer sinew peptide amide bands II and III (N–H and C–N) were shifted from 1550.51 cm −1 and 1340.31 cm −1 to 1560.16 cm −1 and 1334.52 cm −1 , which may be due to the difference in the coupling between δ NH and ν C–N affected by binding with calcium, and the peptide bond was speculated to be involved in the chelating reaction of the deer sinew peptides with Ca 2+ . 43 In addition, the absorption peaks of the –COOH and –COO − stretching vibrations of the deer sinew peptides were shifted from 1450.23 cm −1 and 1405.88 cm −1 to 1457.95 cm −1 and 1403.95 cm −1 , which may be caused by binding with Ca. The chelation mode is mainly being due to the unbound free electrons on the carbonyl oxygen.…”

Lactobacillus helveticus-Derived Whey-Calcium Chelate Promotes Calcium Absorption and Bone Health of Rats Fed a Low-Calcium Diet

“…The absorption peak of LHW at 2170 cm −1 corresponding to the phosphate group O=P-O-H disappeared after chelation, indicating that H in the phosphate group was replaced by calcium ions. The absorption peak of LHWCC weakened at 1600 cm −1 and 1400 cm −1 , indicating that -COOH participated in the formation of chelates in the form of covalent bonds [ 25 ] with calcium ions to form -COO-Ca. The absorption peak of LHWCC shifted at 1072 cm −1 , which might be due to the formation of C-O-Ca by the combination of -CO bond and calcium [ 26 ].…”

Structural characterization and calcium absorption‐promoting effect of sucrose‐calcium chelate in Caco‐2 monolayer cells and mice

“…Besides, intake of inorganic calcium often results in adverse side effects such as constipation and flatulence (Naciu et al, 2022). Although organic calcium helps increase the bioavailability of calcium, it can hinder the absorption of other essential nutrients (Zhai et al, 2023). Amino acid calcium is known to be more effective than inorganic and organic calcium in increasing the release and absorption of calcium ions in the intestine (Tang & Skibsted, 2016).…”

“…Amino acid calcium is known to be more effective than inorganic and organic calcium in increasing the release and absorption of calcium ions in the intestine (Tang & Skibsted, 2016). However, high cost, pro-oxidation, and undesirable color reaction limit its use as a calcium supplement (Zhai et al, 2023). Chelated calcium has been proposed as a solution to two major issues associated with ionized calcium: low absorption and bioavailability at low concentrations and biological toxicity at high levels (Bronner & Pansu, 1999).…”