Research on preserving red flesh dragon fruit by antimicrobial packaging containing polyguanidin

Abstract

The method of preserving dragon fruit with smart packaging films (improved in terms of water permeability and air permeability) to improve the microclimate in the packaging is evaluated as a suitable method for these condition facilities in Vietnam and gives the best efficiency. In this study, red flesh dragon fruit was packaged in antibacterial packaging film (LLDPE-G) made based on linear low-density polyethylene (LLDPE) combined with polyhexamethylene guanidine (PHMG). The objective of this study was to determine the effect of the ratio of LLDPE-G packaging film area/agricultural products’ mass (cm²/g), storage temperature (ºC) to oxygen and carbon dioxide balance in the package, and nutritional and sensory quality of red-flesh dragon fruit during storage. Experimental results showed that the packaging film area/fruit mass ratio is 2.00 cm²/g, and the appropriate storage temperature is 6ºC, corresponding to the equilibrium of the microclimate at 3.77% O2 gas concentration and 5.84% CO2 concentration. After 20 days of storage, the natural weight loss reached 7.86%, the fruit still retained its characteristics (with index a 50.55), total soluble solids (TSS) reached 14.56oBrix, vitamin C content reached 9.72 mg/100 g. These indicators met the food hygiene and safety standards on microbiology according to regulations of good agricultural practices (GAP).