EFFECT OF CHITOSAN PRETREATMENT ON THE QUALITY OF STRAWBERRIES DURING COLD STORAGE

The paper is focused on improving the technology of storing strawberries. It has been investigated how pretreatment of berries with aqueous solutions of low-molecular-weight chitosan of three concentrations (0.1%, 0.3%, 0.5%) affects the quality parameters of strawberries during refrigeration. The treated berries and the reference (untreated sample) were stored in 500 g perforated plastic containers at 0±2°C for 14 days. It has been found that strawberries treated with chitosan solutions had significantly smaller weight loss than the reference. At the end of storage, this parameter was 9.7% in the reference and 7.0–8.6% in the treated berries. It has been established that the respiration rate of the strawberries decreased sharply on the first day, which was caused by refrigerated storage, and continued to decline until the end of storage. Finally, this parameter attained the value 3.3 mg CO2/kg-1h-1in the reference and 2.2–3.0 mg CO2/kg-1h-1 in the treated berries. The hardness of the strawberries at the end of storage was 0.10–0.14 kg/cm2. The change in the lustre level of the berries has been observed. It has been established that on the 14th day of storage, the surface of the untreated berries was dull. The best characteristics have been observed for treatment at the chitosan concentration 0.5%. The effect of chitosan films on the sensory characteristics of berries has been investigated. It has been found that the pretreatment did not impair the taste of the berries. The results of the tasting evaluation indicate that the taste, aroma, and colour were better in the variants with the treatment concentrations 0.3 and 0.5%. However, as for the appearance and consistency, the experts preferred the berries treated at the concentration 0.5%. After two weeks’ storage, the strawberries have been found to be damaged by four fungal diseases. The infections found in the samples were Botrytis cinerea (grey mould), Rhizopus stolonifer (black mould), Whetzelinia sclerotiorum (white mould), and Penicillium spp. It has been established that pretreatment of strawberries with chitosan solutions reduces the development of phytopathogenic diseases. It has been shown that chitosan-based edible coatings have a positive effect on strawberries, increasing their shelf life and improving their quality. A conclusion has been drawn about the technology of application of chitosan solutions and about their concentrations.

TECHNOLOGICAL FEATURES OF CAMEMBERT CHEESE MADE FROM COW’S AND GOAT’S MILK

For the production of elite cheeses with mould, the basic raw material is cow’s milk, but goat’s milk is also of increasing interest. Goat milk has a high protein and fat content, is rich in vitamins, macro- and microelements. Therefore, the object of the study was represented by cow’s milk obtained from the Jersey cows and goat’s milk obtained from goats of the Saanen breed. According to physical and chemical parameters, the milk of cows and goats of these breeds was characterized by a high content of fat and protein, which affect the yield and quality of cheese. The goat milk cheese clot had a more delicate structure during the formation of the cheese layer and a sharp taste due to the different composition of medium-chain fatty acids. In the process of cheese ripening, changes in a number of physicochemical parameters such as cheese acidity, mass fraction of moisture, and amino acid composition of the protein are observed. On the 7–19th day of ripening, a cheese head gets covered with white mold, the cheese consistency becomes softer, and it starts smelling with a “mushroom” hue. Starting from the 15–22nd day, the cheese is completely covered with white mould and gets a smearing texture under the crust. Cheese made from goat’s milk have a more delicate consistency and structure of the cheese layer than those made from cow’s milk, which is most likely due to biochemical processes that occur when cheese is ripened.