Improvement of Hydrophobicity and Gas Permeability of the Polyvinyl Alcohol Film Utilizing Monoglyceride Coating and Diatomaceous Earth Filling and Its Application to Fresh-Cut Mango
Fengsong Liu, Chenghao Li, Caiwei Liu, Jialin Zheng, Kaiyue Bian, Hong Bai, Yan Zhang, Yifang Cao, Yijia Xie, Xiangxing Xiao
Abstract
The widespread utilization of the polyvinyl alcohol (PVA) film is significantly hindered by two prominent limitations: water sensitivity and low gas permeability. In this work, a novel PVA film coated with monoglyceride (MG) and filled with diatomaceous earth (DS) was fabricated to address these issues. Scanning electron microscopy and 3D morphology revealed that the R a value improved from 3.72 to 7.21 μm. Also, the successful coating of MG was confirmed by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Pull-off adhesion tests proved that the film containing 0.5 g of MG exhibited the highest adhesive properties. The PVA/MG/DS film had the highest contact angle of 122.32°, the lowest water vapor permeability of 7.19 g/m 2 /day, and the lowest oxygen permeability of 55.35 (cm 3 × cm × cm 2 × s × Pa) −1 . Moreover, this type of film exhibited higher light transmittance, better thermal stability, and greater mechanical properties than pure PVA film. Consequently, the PVA/MG/DS film displayed superior performance in preserving the freshness and quality of fresh-cut mango, with a lowest weight loss of 4.48%, a lowest total soluble solids of 7.98%, a greatest titratable acidity of 0.88%, a highest ascorbic acid of 76.67 mg/100 g, and best sensory quality.