Abstract
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.
Highlights
The growing interest and demand of producers as well as consumers for environmental friendly, biodegradable, biocompatible, and bioactive materials to produce edible films and coatings are observed
Lysozyme and cystatin are both proteins, but the brittleness was caused by the presence of lysozyme
Lysozyme is an enzyme with degraded properties towards β-(1 → 4) linkages of polysaccharides and could hydrolyze both chitosan and hydroxypropyl methylcellulose [33]
Summary
The growing interest and demand of producers as well as consumers for environmental friendly, biodegradable, biocompatible, and bioactive materials to produce edible films and coatings are observed. Most polymers and bioactive substances have very good film forming properties. These include polysaccharides: chitosan [1], cellulose [2], starch [3], and carrageenan [4], proteins: gelatin [5], collagen [6], and lipids [7]. Derivatives of cellulose are composed of the same β-(1 → 4)-glycosidic units with different substituents methyl, hydroxypropyl, or carboxyl. Hydroxypropyl methylcellulose is cellulose ether with hydrophilic groups, hydroxyl groups, which provide good interaction of HPMC with water [11]. The mechanical and thermal properties of HPMC are influenced by presence of these groups and water uptake [12]. HPMC exhibits thermogelation and has excellent filmmaking properties, high solubility, efficient oxygen, and lipid barrier properties [13, 14]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
