Polysaccharide-Based Edible Coatings Containing Cellulase for Improved Preservation of Meat Quality during Storage

The objectives of this study were to optimize the composition of edible food coatings and to extend the shelf-life of pork meat. Initially, nine meat samples were coated with solutions containing chitosan and hydroxypropyl methylcellulose at various cellulase concentrations: 0%, 0.05%, and 0.1%, stored for 0, 7, and 14 days. Uncoated meat served as the controls. The samples were tested for pH, water activity (a_w), total number of microorganisms (TNM), psychrotrophs (P), number of yeast and molds (NYM), colour, and thiobarbituric acid-reactive substances (TBARS). The pH and a_w values varied from 5.42 to 5.54 and 0.919 to 0.926, respectively. The reductions in the TNM, P, and NYM after 14 days of storage were approximately 2.71 log cycles, 1.46 log cycles, and 0.78 log cycles, respectively. The enzyme addition improved the stability of the red colour. Significant reduction in TBARS was noted with the inclusion of cellulase in the coating material. Overall, this study provides a promising alternative method for the preservation of pork meat in industry.

Chitosan and Cystatin/Lysozyme Preparation as Protective Edible Films Components

This work characterizes biological, physical, and chemical properties of films formed from an aqueous solution of hydroxypropyl methylcellulose (HPMC), with different concentrations of chitosan (CH) and bioactive cystatin/lysozyme preparation (C/L). The properties of biocomposites were examined by Dynamic Mechanical Analysis (DMA), Fourier’s transfer infrared spectroscopy (FTIR), water vapour permeability (WVP), and tensile testing. Antimicrobial activity againstMicrococcus flavus,Bacillus cereus,Escherichia coli,Pseudomonas fluorescens, andCandida famatawas conducted. Films glass transition and storage modulus were dependent on the C/L and CH concentration. Modulus values decreased during the temperature scan and with higher reagents levels. An increase of CH and C/L concentrations in the films resulted in a decrease in tensile strength from 2.62 to 1.08 MPa. It suggests the hydrolyzing influence of C/L, also observed in smaller peak size ofαrelaxation. C/L addition caused shiftingTgto higher temperature. DMA and FTIR analysis proved that HPMC and CH are compatible polymers. Water resistance was improved with rising CH concentration from1.08E-09to7.71E−10 g/m∗s∗Pa. The highest inhibition zone inM. flavusandC. famatawas recorded at the highest concentration of CH and C/L.