Introduction: Plenty of plastic material is used as food packaging. It can be released in food and consequently it affects human and animal health. Nowadays, plastic material and microplastics pollution represent one of the major issues on planet Earth. An alternative to plastic packaging are the so called edible coatings for foods, which are biodegradable, edible and composed of renewable sources e.g. from proteins, lipids and polysaccharides or/and their combinations. Chitosan, a derivative of chitin, is one of the polysaccharides that can be used as edible coating. Due to its poor antioxidant and antimicrobial efficacy, various additives are added to the chitosan coating, which have the characteristics of improvement, like apple extracts. Purpose: The aim of this study is the determination of antioxidant and antimicrobial potential of an apple extract, made from home-grown apples without any pesticide treatment. Methods: Firstly, we reviewed the existing literature on the basis of which we continued with the laboratory work. From various varieties of apples, we prepared an apple extract with the highest possible chlorogenic acid (a model compound coming from naturally present apple antioxidants) content through experimentation. The antioxidant activity of apple extract, standard chlorogenic acid solution and chitosan solution was tested by the Folin–Ciocalteu method. The antimicrobial activity of apple extract, reference chlorogenic acid solution and chitosan solution were checked by determining the susceptibility of ten strains of microorganisms to their presence. Results: The optimal method of antioxidants extraction from apples was determined by experimental analysis. Among the five samples extracts of home-grown apple varieties and one sample of purchased apples, the highest content of chlorogenic acid showed the domestic variety Jabolka 2, which had 10 times better antioxidant activity than other apple extracts and also had better antioxidant efficiency than standard chlorogenic acid solution. Chitosan solution did not show antioxidant efficacy. The solution of chitosan and higher concentrations of apple extract had the best antimicrobial properties against the investigated microorganisms, while the standard solution of chlorogenic acid did not have an inhibitory effect on any of the analyzed microorganisms. Discussion and conclusion: Compared to other authors, our apple extract had higher concentrations of chlorogenic acid. The antioxidant efficacy of our apple extract was comparable to the results of studies by other authors. Apple extract had inhibitory properties on 40% of the microorganisms tested. Based on our results, we can claim that apple extract has the potential to improve chitosan based edible coating. However, the antimicrobial and antioxidant properties of chitosan could be further improved with the addition of other additives, which would offer an overall protection of food.
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