College of Environmental Science and Engineering, Yangzhou University, Yangzhou 225127, PR China.
College of Resources and Environment, Key Laboratory of Agricultural Environment, Shandong Agricultural University, Tai'an 271018, PR China.
Sci Total Environ. 2023 Jul 20;883:163642. doi: 10.1016/j.scitotenv.2023.163642. Epub 2023 Apr 25.
Micro/nanoplastic (M/NP) contamination in food has become a global concern. Food-grade polypropylene (PP) nonwoven bags, which are widely used to filter food residues, are considered environmentally friendly and nontoxic. However, the emergence of M/NPs has forced us to re-examine the use of nonwoven bags in cooking as plastic contact with hot water leads to M/NP release. To evaluate the release characteristics of M/NPs, three food-grade PP nonwoven bags of different sizes were boiled in 500 mL water for 1 h. Micro-Fourier transform infrared spectroscopy and Raman spectrometer confirmed that the leachates were released from the nonwoven bags. After boiling once, a food-grade nonwoven bag can release 0.12-0.33 million MPs (>1 μm) and 17.6-30.6 billion NPs (<1 μm), equivalent to a mass of 2.25 - 6.47 mg. Number of M/NPs released is independent of nonwoven bag size; however, it decreases with increasing cooking times. M/NPs are primarily produced from easily breakable PP fibers, and they are not released into the water at once. Adult zebrafish (Danio rerio) were cultured in filtered distilled water without released M/NPs and in water containing 14.4 ± 0.8 mg L released M/NPs for 2 and 14 days, respectively. To evaluate the toxicity of the released M/NPs on the gills and liver of zebrafish, several oxidative stress biomarkers (i.e., reactive oxygen species, glutathione, superoxide dismutase, catalase, and malonaldehyde) were measured. The ingestion of the released M/NPs by zebrafish induces oxidative stress in the gills and liver, depending on the exposure time. Food-grade plastics, such as nonwoven bags, should be used with caution in daily cooking because they release large amounts of M/NPs when heated, which can threaten human health.
微/纳米塑料（M/NP）在食品中的污染已成为全球性关注的问题。食品级聚丙烯（PP）无纺布袋广泛用于过滤食物残渣，被认为是环保且无毒的。然而，M/NP 的出现迫使我们重新审视烹饪中无纺布袋的使用，因为塑料与热水接触会导致 M/NP 的释放。为了评估 M/NP 的释放特性，将三种不同尺寸的食品级 PP 无纺布袋在 500 mL 水中煮沸 1 小时。微傅里叶变换红外光谱和拉曼光谱证实浸出物是从无纺布袋中释放出来的。煮沸一次后，一个食品级无纺布袋可释放 0.12-0.33 百万个 MPs（>1 μm）和 17.6-30.6 亿个 NPs（<1 μm），相当于 2.25-6.47 mg 的质量。释放的 M/NP 数量与无纺布袋的尺寸无关，但随着烹饪时间的增加而减少。M/NP 主要由容易破碎的 PP 纤维产生，不会立即释放到水中。成年斑马鱼（Danio rerio）分别在未释放 M/NP 的过滤蒸馏水和含有 14.4±0.8 mg/L 释放 M/NP 的水中培养 2 天和 14 天。为了评估释放的 M/NP 对斑马鱼鳃和肝脏的毒性，测量了几种氧化应激生物标志物（即活性氧、谷胱甘肽、超氧化物歧化酶、过氧化氢酶和丙二醛）。斑马鱼摄入释放的 M/NP 会导致鳃和肝脏的氧化应激，这取决于暴露时间。在日常烹饪中，应谨慎使用食品级塑料，如无纺布袋，因为它们在加热时会释放大量的 M/NP，这可能会威胁到人类健康。
