Calcium peptide chelates are developed as efficient supplements for preventing calcium deficiency. Spent hen meat (SHM) contains a high percentage of proteins but is generally wasted due to the disadvantages such as hard texture. We chose the underutilized SHM to produce peptides to bind calcium by proteolysis and aimed to investigate chelation between calcium and peptides in hydrolysate for a sustainable purpose. The optimized proteolysis conditions calculated from the result of response surface methodology for two-step hydrolysis were 0.30% (w_enzyme/w_meat) for papain with a hydrolysis time of 3.5 h and 0.18% (w_enzyme/w_meat) for flavourzyme with a hydrolysis time of 2.8 h. The enzymatic hydrolysate (EH) showed a binding capacity of 63.8 ± 1.8 mg calcium/g protein. Ethanol separation for EH improved the capacity up to a higher value of 68.6 ± 0.6 mg calcium/g protein with a high association constant of 420 M⁻¹ (25°C) indicating high stability. The separated fraction with a higher amount of Glu, Asp, Lys, and Arg had higher calcium-binding capacity, which was related to the number of ─COOH and ─NH₂ groups in peptide side chains according to the result from amino acid analysis and Fourier transform infrared spectroscopy. Two-step enzymatic hydrolysis and ethanol separation were an efficient combination to produce peptide mixtures derived from SHM with high calcium-binding capacity. The high percentage of hydrophilic amino acids in the separated fraction was concluded to increase calcium-binding capacity. This work provides foundations for increasing spent hen utilization and developing calcium peptide chelates based on underutilized meat.

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废母鸡水解液中具有钙螯合能力的肽的研究

钙肽螯合物被开发为预防钙缺乏的有效补充剂。废母鸡肉 (SHM) 含有高比例的蛋白质，但由于质地坚硬等缺点，通常被浪费。我们选择未充分利用的 SHM 来生产通过蛋白水解结合钙的肽，旨在研究水解产物中钙和肽之间的螯合，以实现可持续的目的。根据两步水解的响应面法结果计算出的最佳蛋白水解条件为：木瓜蛋白酶为 0.30%（w_酶/ w_{肉），水解时间为 3.5 h；风味酶为 0.18%（} w_酶/ w_肉），水解时间为 3.5 小时。水解时间2.8小时。酶水解产物 (EH) 显示出 63.8 ± 1.8 mg 钙/g 蛋白质的结合能力。 EH 的乙醇分离将容量提高至 68.6 ± 0.6 mg 钙/g 蛋白质的更高值，具有 420 M ^-1 (25°C) 的高缔合常数，表明高稳定性。氨基酸分析结果表明，Glu、Asp、Lys、Arg含量较高的分离级分具有较高的钙结合能力，这与肽侧链中的─COOH和─NH ₂基团的数量有关。傅里叶变换红外光谱。两步酶水解和乙醇分离是生产具有高钙结合能力的 SHM 衍生肽混合物的有效组合。结论是分离的级分中亲水性氨基酸的高百分比增加了钙结合能力。这项工作为提高废母鸡利用率和开发基于未充分利用的肉类的钙肽螯合物奠定了基础。