School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China; Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, China; Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, & Guangdong Province Engineering Laboratory for Intelligent Cold Chain Logistics Equipment for Agricultural Products, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China.
School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China; Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, China; Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, & Guangdong Province Engineering Laboratory for Intelligent Cold Chain Logistics Equipment for Agricultural Products, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China; Food Refrigeration and Computerized Food Technology (FRCFT), Agriculture and Food Science Centre, University College Dublin, National University of Ireland, Belfield, Dublin 4, Ireland.
Food Chem. 2024 Dec 15;461:140917. doi: 10.1016/j.foodchem.2024.140917. Epub 2024 Aug 18.
Natural deep eutectic solvents (NADESs) showing higher cryoprotective effects are attracting concerns, because during the storage, system browning always occurs in aldose/amino acid-based NADESs, which generated brown substances remarkably weaken the cryoprotective effects. In this study, proline/glucose-based (PG) and proline/sorbitol-based (PS) NADESs were prepared, of which storage stability, browning profile, brown substance, and cryoprotective effects were investigated. Results showed that PG at molar ratios of 1:1, 2:1, and 3:1, as well as PS at 1:1, and 2:1 can form NADESs, among which only the PG-based ones could get browning after storage. The predominant brown substance was identified as 1-deoxy-1-L-proline-d-fructose (CHON, 278 m/z), which was subsequently verified to show cytotoxicity and decrease Saccharomyces cerevisiae cells viability after cryopreservation, suggesting that the brown substance could take a negative effect on cryopreservation. This study may help to attract more concerns to the storage and cryopreservation stabilities of the NADESs in food-related applications.
天然深共晶溶剂 (NADESs) 因其具有更高的抗冻保护效果而备受关注，因为在储存过程中，醛糖/氨基酸基 NADESs 中总会发生体系褐变，生成的褐色物质会显著降低抗冻保护效果。在本研究中，制备了脯氨酸/葡萄糖基 (PG) 和脯氨酸/山梨醇基 (PS) NADESs，并研究了它们的储存稳定性、褐变特征、褐色物质和抗冻保护效果。结果表明，摩尔比为 1:1、2:1 和 3:1 的 PG 以及摩尔比为 1:1 和 2:1 的 PS 可以形成 NADESs，其中只有 PG 基 NADESs 在储存后会发生褐变。主要的褐色物质被鉴定为 1-脱氧-1-L-脯氨酸-D-果糖 (CHON，278 m/z)，随后的实验证实该物质具有细胞毒性，并降低了冷冻保存后的酿酒酵母细胞活力，表明褐色物质可能对冷冻保存产生负面影响。本研究可能有助于引起人们对食品相关应用中 NADESs 的储存和冷冻稳定性的更多关注。
