Acta Scientiarum Polonorum Technologia Alimentaria

Background. Analysis of the properties of various chitosan grades has resulted in a working hypothesis that chitosan can be used as part of protective film-forming coatings for meat and meat products. The aim of this study was the research of composition, properties and antibacterial activity of chitosan-based coatings used for cold storage of meat and meat products.
Material and methods. Protective coatings, developed by the authors, based on organic acids and chi- tosan with food gelatin, or distarch glycerol, or wheat fiber, or sodium alginate, or guar gum have been used as research material. The coatings were applied on the surfaces of retail cuts of veal and rabbit meat, boiled sausages, smoked sausages and smoked-boiled pork brisket. Antimicrobial activity of the solutions was evaluated in vitro. Microbial indicators of the mixtures were also determined by the zone of inhibition assay. Dynamic viscosity, the activation energy of viscous flow and pH of mixtures of fluids were measured. During the storage of meat and meat products total viable count of microorganisms was determined.
Results. Polymer solutions of chitosan:starch and chitosan:gelatin are technologicaly compatible, solutions of chitosan:fiber are two-phase colloidal systems. Coatings did not alter the samples inherent flavour char- acteristics. All coatings reduced total viable count of microorganisms compared to control samples without coating. Composition based on 2% solution of chitosan and organic acids and 2% gelatin solution in a ratio of 1:1 has the strongest bacteriostatic effect for meat and meat products. Including potassium sorbate and sodium benzoate in gelatin and chitosan solutions mixture for protective coating was not found reasonable, because of their lower bacteriostatic effect. Combined application of vacuum and protective coatings pro- vided the strongest suppressing effect on microflora in all samples.
Conclusions.The chitosan-based edible coatings developed can be used to increase the shelf life and im- prove the microbial safety parameters of meat and meat products. The results of this study indicate that coat- ings have bigger stabilising effect on samples with the least amount of basic hurdle factors, in other words on most shelf unstable products.