Key Laboratory of Product Packaging and Logistics, Packaging Engineering Institute, College of Packaging Engineering, Jinan University, Qianshan Road 206, Zhuhai 519070, China.
School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2025 Jan 5;324:124997. doi: 10.1016/j.saa.2024.124997. Epub 2024 Aug 18.
Polylactic acid (PLA) straws hold eco-friendly potential; however, residual diisocyanates used to enhance the mechanical strength can generate carcinogenic primary aromatic amines (PAAs), posing health risks. Herein, we present a rapid, comprehensive strategy to detecting PAAs in 18 brands of food-grade PLA straws and assessing their migration into diverse food simulants. Surface-enhanced Raman spectroscopy was conducted to rapidly screen straws for PAAs. Subsequently, qualitative determination of migrating PAAs into various food simulants (4 % acetic acid, 10 % ethanol, 50 % ethanol) occurred at 70 °C for 2 h using liquid chromatography-mass spectrometry. Three PAAs including 4,4'-methylenedianiline, 2,4'-methylenedianiline, and 2,4-diaminotoluene were detected in all straws. Specifically, 2,4-diaminotoluene in 50 % ethanol exceeded specific migration limit of 2 μg/kg, raising safety concerns. Notably, PAAs migration to 10 % and 50 % ethanol surpassed that to 4 % acetic acid within a short 2-hour period. Moreover, PLA straws underwent varying degrees of shape changes before and after migration. Straws with poly(butylene succinate) resisted deformation compared to those without, indicating enhanced heat resistance, while poly(butyleneadipate-co-terephthalate) improved hydrolysis resistance. Importantly, swelling study unveiled swelling effect wasn't the primary factor contributing to the increased PAAs migration in ethanol food simulant, as there was no significant disparity in swelling degrees across different food simulants. FT-IR and DSC analysis revealed higher PAAs content in 50 % ethanol were due to highly concentrated polar ethanol disrupting hydrogen bonds and van der Waal forces holding PLA molecules together. Overall, minimizing contact between PLA straws and alcoholic foods is crucial to avoid potential safety risks posed by PAAs.
聚乳酸（PLA）吸管具有环保潜力；然而，用于增强机械强度的残留二异氰酸酯会产生致癌的芳香伯胺（PAA），对健康构成风险。在此，我们提出了一种快速、全面的策略，用于检测 18 个品牌的食品级 PLA 吸管中的 PAA，并评估其在各种食品模拟物中的迁移情况。表面增强拉曼光谱用于快速筛选吸管中的 PAA。随后，使用液相色谱-质谱法在 70°C 下将 2 小时内将迁移到各种食品模拟物（4%乙酸、10%乙醇、50%乙醇）中的迁移 PAA进行定性测定。在所有吸管中均检测到三种 PAA，包括 4,4'-亚甲基二苯胺、2,4'-亚甲基二苯胺和 2,4-二氨基甲苯。具体而言，50%乙醇中的 2,4-二氨基甲苯超过了 2μg/kg 的特定迁移限量，引起了安全担忧。值得注意的是，在短短 2 小时内，PAA 向 10%和 50%乙醇的迁移量超过了向 4%乙酸的迁移量。此外，在迁移前后，PLA 吸管的形状发生了不同程度的变化。与没有聚丁二酸丁二醇酯的吸管相比，具有聚丁二酸丁二醇酯的吸管不易变形，表明其耐热性增强，而聚丁二酸丁二醇酯-己二酸酯则提高了水解稳定性。重要的是，溶胀研究表明，溶胀效应不是导致乙醇食品模拟物中 PAA 迁移增加的主要因素，因为不同食品模拟物的溶胀程度没有显著差异。FT-IR 和 DSC 分析表明，50%乙醇中 PAA 含量较高是因为高度浓缩的极性乙醇破坏了聚乳酸分子之间的氢键和范德华力。总体而言，尽量减少 PLA 吸管与酒精类食品的接触对于避免 PAA 带来的潜在安全风险至关重要。
