Institute of Nanochemistry and Nanobiology, Shanghai University, Shanghai 200444, China.
Small. 2013 May 27;9(9-10):1765-74. doi: 10.1002/smll.201201506. Epub 2012 Oct 15.
Nanotechnology shows great potential for producing food with higher quality and better taste through including new additives, improving nutrient delivery, and using better packaging. However, lack of investigations on safety issues of nanofood has resulted in public fears. How to characterize engineered nanomaterials in food and assess the toxicity and health impact of nanofood remains a big challenge. Herein, a facile and highly reliable separation method of TiO2 particles from food products (focusing on sugar-coated chewing gum) is reported, and the first comprehensive characterization study on food nanoparticles by multiple qualitative and quantitative methods is provided. The detailed information on nanoparticles in gum includes chemical composition, morphology, size distribution, crystalline phase, particle and mass concentration, surface charge, and aggregation state. Surprisingly, the results show that the number of food products containing nano-TiO2 (<200 nm) is much larger than known, and consumers have already often been exposed to engineered nanoparticles in daily life. Over 93% of TiO2 in gum is nano-TiO2 , and it is unexpectedly easy to come out and be swallowed by a person who chews gum. Preliminary cytotoxicity assays show that the gum nano-TiO2 particles are relatively safe for gastrointestinal cells within 24 h even at a concentration of 200 μg mL(-1) . This comprehensive study demonstrates accurate physicochemical property, exposure, and cytotoxicity information on engineered nanoparticles in food, which is a prerequisite for the successful safety assessment of nanofood products.
纳米技术在提高食品质量和口感方面具有很大的潜力，例如添加新的添加剂、改善营养物质的传递以及使用更好的包装。然而，由于缺乏对纳米食品安全性问题的调查，公众对此感到担忧。如何对食品中的工程纳米材料进行特性描述，以及评估纳米食品的毒性和健康影响仍然是一个巨大的挑战。在此，我们报道了一种从食品产品（重点是糖衣口香糖）中简便且高度可靠地分离 TiO2 颗粒的方法，并提供了首次通过多种定性和定量方法对食品纳米颗粒进行的全面特性描述研究。有关口香糖中纳米颗粒的详细信息包括化学成分、形态、尺寸分布、晶体相、颗粒和质量浓度、表面电荷和聚集状态。令人惊讶的是，结果表明，含有纳米 TiO2（<200nm）的食品产品数量远远超过已知数量，消费者在日常生活中已经经常接触到工程纳米粒子。在口香糖中，超过 93%的 TiO2 是纳米 TiO2，而且咀嚼口香糖的人很容易将其取出并吞下。初步的细胞毒性试验表明，即使在 200μgmL（-1）的浓度下，口香糖纳米 TiO2 颗粒在 24 小时内对胃肠道细胞也相对安全。这项全面的研究提供了有关食品中工程纳米粒子的准确物理化学特性、暴露和细胞毒性信息，这是纳米食品产品成功安全评估的前提。
