Bioproduct Research Unit, USDA-ARS, Western Regional Research Center, Albany, California, USA.
World Centric, Rohnert Park, California, USA.
Compr Rev Food Sci Food Saf. 2021 May;20(3):2596-2625. doi: 10.1111/1541-4337.12726. Epub 2021 Mar 7.
Per- and polyfluoroalkyl substances (PFAS) have been used in food contact paper and paperboard for decades due to their unique ability to provide both moisture and oil/grease resistance. Once thought to be innocuous, it is now clear that long chain PFAS bioaccumulate and are linked to reproductive and developmental abnormalities, suppressed immune response, and tumor formation. Second-generation PFAS have shorter biological half-lives but concerns about health risks from chronic exposure underscore the need for safe substitutes. Waxes and polymer film laminates of polyethylene, poly(ethylene-co-vinyl alcohol), and polyethylene terephthalate are commonly used alternatives. However, such laminates are neither compostable nor recyclable. Lamination with biodegradable polymers, including polyesters, such as polylactic acid (PLA), polybutylene adipate terephthalate, polybutylene succinate, and polyhydroxyalkanoates, are of growing research and commercial interest. PLA films are perhaps the most viable alternative, but performance and compostability are suboptimal. Surface sizings and coatings of starches, chitosan, alginates, micro- and nanofibrilated cellulose, and gelatins provide adequate oil barrier properties but have poor moisture resistance without chemical modification. Plant proteins, including soy, wheat gluten, and corn zein, have been tested as paper coatings with soy being the most commercially important. Internal sizing agents, such as alkyl ketene dimers, alkenyl succinic anhydride, and rosin, improve moisture resistance but are poor oil/grease barriers. The difficulty in finding a viable replacement for PFAS chemicals that is cost-effective, fully biodegradable, and environmentally sound underscores the need for more research to improve barrier properties and process economics in food packaging products.
全氟和多氟烷基物质（PFAS）因其独特的提供防潮和防油/油脂的能力，已在食品接触纸和纸板中使用了几十年。曾经被认为是无害的，但现在很明显，长链 PFAS 会生物累积，并与生殖和发育异常、免疫反应受抑制以及肿瘤形成有关。第二代 PFAS 的生物半衰期更短，但对慢性暴露健康风险的担忧突显了对安全替代品的需求。聚乙烯、聚乙烯醇共聚物和聚对苯二甲酸乙二醇酯的蜡和聚合物薄膜层压材料是常用的替代品。然而，这些层压板既不可生物降解也不可回收。与可生物降解聚合物的层压，包括聚酯，如聚乳酸（PLA）、聚丁二酸丁二醇酯、聚丁二酸、聚羟基烷酸酯，越来越受到研究和商业的关注。PLA 薄膜可能是最可行的替代品，但性能和可生物降解性都不理想。淀粉、壳聚糖、海藻酸盐、微纤维和纳米纤维素以及明胶的表面施胶和涂层提供了足够的油阻隔性能，但如果不进行化学改性，其防潮性能很差。植物蛋白，包括大豆、小麦面筋和玉米醇溶蛋白，已被测试用作纸张涂层，其中大豆是最重要的商业用途。内部施胶剂，如烷基酮二聚体、烯基琥珀酸酐和松香，可提高防潮性能，但油/油脂阻隔性差。寻找一种具有成本效益、完全可生物降解且对环境友好的 PFAS 化学物质替代品的困难，突显了需要更多的研究来改善食品包装产品的阻隔性能和工艺经济性。
