(266c) Preparation of pH-Responsive Latex Films from Glycerol Based Dendritic Precursors for Food Packaging

Abstract: Food safety is an important issue and a high priority globally placing human and animal health. Food spoilage causes approximately 50% waste of our food before and after it reaches to the customers due to the delay in food spoilage detection. It has been observed that the spoilage of food occurs in stages one indicator of which is a variation in pH as the food material undergoes changes in palatability. This study aims to encapsulate pH-sensitive and food-safety dye (e.g. alizarin S dye) in barrier biopolymers/films with natural and/or plant-based origins via miniemulsion polymerization. The glycerol-based acrylate dendrimer monomer is proposed to substitute synthetic butyl acrylate in the barrier film recipes to provide both pH-sensitivity and film physical properties. The achievement of nanoencapsulation provides the function of precise pH-sensitivity for barrier food packaging applications. At a varying pH, the nanoshell thickness and structure can be tuned to slowly release of food-safety dye for food spoilage detection. Transmission Electron Microscopy (TEM) images in combination with zetasizer analysis data indicate uniform size distribution of polymer particles, successful dye encapsulation in stable latex and dye release upon pH variation validated by fluorescence spectrometry. The properties of bionanocomposite films will be characterized via a variety of instruments such as Differential Scanning Calorimetry (DSC), tensile machine, and Gel Permeation Chromatography (GPC). We further evaluate the film visual color contrast due to different pH and its application on the pork sample.