Characterization of chitosan edible coatings made with natural extracts of Solanum lycopersicum and Moringa oleifera for preserving fresh pork tenderloin

The purpose of this study was to develop edible films based on chitosan that also incorporate natural extracts of tomato (T) and moringa (M). The formulated films were evaluated for their physical, optical, mechanical, barrier, and bioactive properties. The incorporation of extracts into the biopolymeric matrix with 40% glycerol significantly decreased light transmission in the UV range (especially at 400 nm) from 30 to 0%, with respect uncoated films. Moreover, the antioxidant activity of the films was increased to 41.92 mg ET/100 g film (DPPH) and 34.67 mg ET/100 g film (ABTS). The formulation 60/40-TM was applied to the fresh pork loin, and the physical, microbiological, and sensory properties of coated and uncoated samples were evaluated during storage at 4 °C for 14 days. Compared with coated films (0.892 g), uncoated films showed higher water loss on day 14 (1.132 g). The results of microbiological analyses showed no changes in the coated samples that is, there was no microbial growth on the subsequent days of storage (days 5 and 10). However, the uncoated samples showed bacterial growth of fecal coliforms (11 MPN/g) and E. coli (3 log 10 CFU/g) on day 10. Sensory analysis of the samples with the treatments showed good overall acceptability with no significant difference ( p ≥ 0.05). The coatings formulated with both extracts and higher concentrations of glycerol presented good material properties, making them suitable for application in pork loin; these results are promising for food preservation. Graphical Abstract