EFFECT OF COMPOSITION AND PROPERTIES OF CHITOSAN-BASED EDIBLE COATINGS ON MICROFLORA OF MEAT AND MEAT PRODUCTS

ABSTRACT Background. Analysis of the properties of various chitosan grades has resulted in a working hypothesis that chitosan can be used as part of protective fi lm-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 chitosan with food gelatin, or distarch glycerol, or wheat fi ber, 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 fl ow and pH of mixtures of fl uids 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:fi ber are two-phase colloidal systems. Coatings did not alter the samples inherent fl avour characteristics. 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 provided the strongest suppressing effect on microfl ora in all samples. Conclusions. The chitosan-based edible coatings developed can be used to increase the shelf life and improve the microbial safety parameters of meat and meat products. The results of this study indicate that coatings have bigger stabilising effect on samples with the least amount of basic hurdle factors, in other words on most shelf unstable products

Changes in the fatty acid composition of avocado fruit treated with preparations during storage

This article presents data on the fatty acid composition of avocado fruit and the dynamics of the free fatty acid content during storage of fruit treated with preparations “Agrohit”, “KHAN-8”, and “Extrasol-90”, which have antimicrobial properties. Avocado fruit treated with preparations by spraying and without treatment were placed in polymer containers and stored at a temperature of (4±1)°C and relative humidity of 90–95% for 45 days. During the storage of avocado fruit, the fat content was determined by the Soxhlet method and free fatty acids were determined on a Shimadzu 20-AD chromatograph. It has been established that palmitic, palmitoleic, oleic, and linolenic acids predominate in Fuerto avocado fruit. It has been shown that during storage of avocado fruit treated with preparations, the hydrolysis of fats (triacylglycerides) is slowed down, which reduces the accumulation of free fatty acids. It was determined that treatment of fruit with the preparation “KHAN-8” slows down the oxidation of arachidonic acid, which is a resistance inducer of the fruit to phytopathogens