Development of biobased-biodegradable packaging for button mushroom: Influence of pre-treatments and storage temperature on shelf-life extension

Abstract

The objective of this study was to develop biodegradable films using pure polylactic acid (PLA), PLA combined with 10% corn starch, and PLA with 10% corn starch and polyethylene glycerol (PEG) through a solvent casting method. The produced films were analyzed for their physical and morphological characteristics. The films thickness ranged from 0.043 to 0.064 mm, haze percentage from 16.37% to 89.67%, oxygen transmission rate (OTR) from 123.92 to 318.25 cc/m²/day, tensile strength (TS) from 31.58 to 56.49 MPa, and water vapor transmission rate (WVTR) from 134 to 217.49 g/m²/day. Scanning electron microscope (SEM) images of the pure PLA film showed a smooth surface texture without interfacial differences, indicating a single-phase structure and integrity. When comparing all prepared biodegradable films to PVC cling film, the pure PLA film exhibited superior performance. The developed pure PLA packaging films and biodegradable containers made from sugarcane bagasse were selected for packaging white button mushrooms (Agaricus bisporus). To extend the shelf life of the mushrooms, they were subjected to various washing treatments, including tap water, distilled water, and 1%, 2%, and 3% (w/v) citric acid solutions, before being packaged with the pure PLA film and stored at both ambient (25 °C) and low (5 °C) temperatures. The study found that washing treatments with different citric acid concentrations were effective at both temperatures in maintaining the quality of the stored mushrooms for extended periods. The shelf life of the mushrooms increased from 1 to 3 days at ambient temperature and from 5 to 12 days at low temperature compared to unwashed mushrooms. Among all treatments, washing mushrooms with a 2% citric acid solution and packaging them in biobased biodegradable packaging was the most effective. This method controlled physiological weight loss, pH, firmness, maturity index, microbial counts, total soluble solids (TSS), and color for up to 12 days at 5 °C. Therefore, biobased biodegradable packaging can be successfully used to increase the shelf life and maintain the quality of fresh mushrooms during storage.