Zhang Tong, Yang Zhihong, Zhang Yingcui, Yi Lunzhao, Duan Fengmin, Zhao Qiong, Gu Ying, Wang Shuo
Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.
Yunnan Institute of Measuring and Testing Technology, Kunming 650228, China.
Food Chem. 2025 Feb 15;465(Pt 1):141956. doi: 10.1016/j.foodchem.2024.141956. Epub 2024 Nov 7.
Tamarillo is widely grown in Yunnan Province, China, and has been found that it can be used in cheese-making with a distinctive fruity flavour. However, this primary component responsible for curdling milk remains unclear. This study aimed to identify the main component in tamarillo responsible for curdling milk using proteomics and ammonium sulfate (AS) precipitation. Herein, 3199 proteins were identified in tamarillo, of which 546 exhibited hydrolase activity. In particular, a novel serine protease with milk-clotting activity (MCA) and a molecular weight of 79.1 kDa, named "MCP746", was isolated from tamarillo. The milk-clotting proteases (MCPs) from tamarillo exhibited the highest MCA at 80 °C and stability under incubation temperatures below 70 °C, pH range of 5-8, and NaCl concentrations below 1 mol/L. This study revealed that serine protease is the primary MCPs of tamarillo along with a characterization of its milk-clotting characteristics, providing valuable insights into its potential application in cheese-making.
番茄树在中国云南省广泛种植，并且已发现它可用于制作具有独特果味的奶酪。然而，这种导致牛奶凝固的主要成分仍不清楚。本研究旨在使用蛋白质组学和硫酸铵（AS）沉淀法鉴定番茄树中导致牛奶凝固的主要成分。在此，在番茄树中鉴定出3199种蛋白质，其中546种具有水解酶活性。特别地，从番茄树中分离出一种具有凝乳活性（MCA）、分子量为79.1 kDa的新型丝氨酸蛋白酶，命名为“MCP746”。番茄树中的凝乳蛋白酶（MCPs）在80℃时表现出最高的MCA，并且在低于70℃的孵育温度、5-8的pH范围和低于1 mol/L的NaCl浓度下具有稳定性。本研究表明，丝氨酸蛋白酶是番茄树的主要MCPs，并对其凝乳特性进行了表征，为其在奶酪制作中的潜在应用提供了有价值的见解。
