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In order to meet one of the greatest problems of food technology, i.e. unwanted food spoilage caused by the action of microorganisms, active or intelligent packaging is being created and used with increasing frequency. At the same time, substitutes for plastics are being sought in order to protect the environment. Biodegradable polymer composites seem to be an extremely promising material that could replace synthetic materials in the future. By encapsulating biologically active substances in a polymer matrix, directional action and controlled release of the substance are possible. The use of ozone, which has become more and more popular especially recently, allows to limit the growth of microorganisms, and the production of ozone derivatives of unsaturated fats allows to reduce the short time of its decomposition. The aim of this study was to analyse the physicochemical and bacteriostatic properties of innovative chitosan-based films containing encapsulated nanocapsules of ozonated olive oil in two concentrations. The morphology and size of the obtained nanocapsules were determined using Scanning Electron Microscopy and DLS. The largest particle size was observed for the film containing the lower ozone concentration – up to 4900 nm, in the control film 3500 nm, for the film with the highest ozone concentration, the particle size was the smallest, with the majority in the range of 100–1000 nm. Ozone content was determined by peroxidation number. The properties of the composites were characterised by infrared (IR) which proved that chitosan is a good matrix for the formation of capsules and ultraviolet (UV) which showed that the obtained composite absorbs light in the range of blue and near ultraviolet light, and the addition of nanocapsules of ozonated olive oil increased the degree of absorption and decreased the transparency. We also performed photoluminescence spectroscopy before and after storage of pork meat proving that films are sensitive to the physico-chemical and biochemical transformation products formed as a result of meat spoilage. The study of the microbiological properties included the analysis of the microbiological quality of pork meat stored under the obtained films as a function of time. The films have a bactericidal and bacteriostatic effect and the addition of ozonated olive oil capsules increases the bactericidal effect against Gram-negative bacteria. Contact angles, Water Vapour Transmission Rate and transparency were also determined and they were subjected to enzymatic hydrolysis. Water absorption, solubility and liquid absorption capacity were determined. All tested samples show high hydrophobicity and low solubility, and the ozone content directly influences these parameters. • Innovative, environmentally friendly chitosan-based films containing nano- and microcapsules of ozonized olive oil have been developed. • Addition of ozonated oils to the matrix reduced Water solubility, transparency and significantly enhanced the photoluminescence of the composite. • Composites have a bactericidal effect so they can prolong shelf life. • Films with potential for use as active biodegradable packaging materials. [ABSTRACT FROM AUTHOR]

Abstract: In this work the effect of ozonation on olive oil, soybean oil, oleic-, linoleic- and linolenic acid was studied. The effects of ozonation time on the oils and acids were analyzed by 1H, 13C NMR. Further, the peroxide- and acid values, the viscosity and the molar mass were determined for pure and ozonated oils. The fatty chains in both ozonated oils showed a gradual decrease of unsaturation with the gradual increase of ozonation time. Reaction products were identified according to Criegee mechanism. The major product in the early stage of the reaction was ozonide. The disappearance of unsaturation and formation of ozonide was almost equal. Ozonation increased the peroxide and acid values for both oils, the increase being higher for soybean oil. After long ozonation times higher molar mass species, as well as low molar mass species were observed. These are interpreted as oligomeric ozonides and cross-ozonides, respectively. [Copyright &y& Elsevier]