Program of Agroindustrial Engineering, Faculty of Agricultural Engineering, Universidad del Tolima, Ibagué-Tolima 730006299, Colombia.
Packaging Laboratory, Department of Food Technology, Universidade Federal de Viçosa, Viçosa-MG 36570-900, Brazil.
Biosensors (Basel). 2020 May 31;10(6):59. doi: 10.3390/bios10060059.
Global growth of the food industry and the demand for new products with natural characteristics, safe conditions and traceability have driven researches for the development of technologies such as intelligent packaging, capable to fulfil those needs. Polydiacetylene (PDA) is a synthetic material that has been highlighted in research field as a sensor substance, which can be used to produce intelligent packaging capable to detect chemical or biochemical changes in foods and in their environment due to PDA's color transition from blue to red. This work focused on the development and optimization of an intelligent packaging constituted of a polymeric matrix of cellulose acetate-based incorporated with PDA as the substance sensor. Cellulose acetate films (3% wt.) were developed by a casting method and the amounts of triethyl citrate plasticizer (TEC) (0-25% wt. of cellulose-acetate) and PDA (0-60 mg) were analyzed to optimize the conditions for the best color transitioning at this study range. The compound amounts incorporated into polymeric matrices were established according to Central Composite Designs (CCD). Three more design variables were analyzed, such as the polymerization time of PDA under UV light exposition (0-60 min), pH values (4-11) and temperature exposure on the film (0-100 °C), important factors on the behavior of PDA's color changing. In this study, film thickness and film color coordinates were measured in order to study the homogeneity and the color transitioning of PDA films under different pH and temperature conditions, with the purpose of maximizing the color changes through the optimization of PDA and TEC concentrations into the cellulose acetate matrix and the polymerization degree trigged by UV light irradiation. The optimal film conditions were obtained by adding 50.48 g of PDA and 10% of TEC, polymerization time of 18 min under UV light, at 100 °C ± 2 °C of temperature exposure. The changes in pH alone did not statistically influence the color coordinates measured at the analyzed ratio; however, variations in pH associated with other factors had a significant effect on visual color changes, and observations were described. PDA films were optimized to maximize color change in order to obtain a cheap and simple technology to produce intelligent packaging capable to monitor food products along the distribution chain in real time, improving the food quality control and consumer safety.
全球食品工业的增长以及对具有天然特性、安全条件和可追溯性的新产品的需求，推动了智能包装技术的发展研究，以满足这些需求。聚二乙炔（PDA）是一种合成材料，在研究领域中作为传感器物质得到了突出的重视，它可以用于生产智能包装，能够检测食品及其环境中的化学或生物化学变化，因为 PDA 的颜色从蓝色转变为红色。本工作重点开发和优化一种由基于醋酸纤维素的聚合物基质组成的智能包装，其中包含 PDA 作为物质传感器。通过浇铸法制备醋酸纤维素薄膜（3%wt.），并分析三乙基柠檬酸酯增塑剂（TEC）（0-25%wt. 醋酸纤维素）和 PDA（0-60mg）的用量，以优化在本研究范围内获得最佳颜色转变的条件。根据中心组合设计（CCD）确定掺入聚合物基质中的化合物量。还分析了三个更多的设计变量，例如在紫外线照射下 PDA 的聚合时间（0-60min）、pH 值（4-11）和薄膜暴露温度（0-100°C），这些因素对 PDA 颜色变化的行为很重要。在这项研究中，测量了薄膜厚度和薄膜颜色坐标，以研究不同 pH 值和温度条件下 PDA 薄膜的均匀性和颜色转变，目的是通过优化 PDA 和 TEC 浓度进入醋酸纤维素基质以及通过紫外线照射引发的聚合度来最大化颜色变化。通过添加 50.48g 的 PDA 和 10%的 TEC、在紫外线照射下聚合 18 分钟以及在 100°C±2°C 的温度暴露下，获得了最佳薄膜条件。单独改变 pH 值并没有在统计学上影响所分析比例的颜色坐标；然而，与其他因素相关的 pH 值变化对视觉颜色变化有显著影响，并进行了描述。优化了 PDA 薄膜以最大程度地改变颜色，以获得一种廉价且简单的技术来生产智能包装，能够实时监测食品产品在分销链中的情况，提高食品质量控制和消费者安全。
