COMPREHENSIVE QUALITY ASSESSMENT OF HARD CHEESE WITH FLAX SEEDS USING THE FACTOR AREA METHOD

The relevance of this study is determined by the need to improve the fatty acid composition of traditional food products and to develop methodological approaches that enable a comprehensive assessment of changes in their quality characteristics. The use of flaxseed as a source of polyunsaturated fatty acids represents a promising approach to modifying the lipid composition of hard cheeses. The study aimed to comprehensively assess the quality of hard rennet cheese containing flaxseed using the factor area method and to identify the most promising formulation based on the overall set of investigated parameters. A control sample and three experimental samples containing 1.5, 3.0, and 5.0% flaxseed were investigated. The dynamics of lactic acid microorganism growth and the contents of saturated and polyunsaturated fatty acids were determined. For integral assessment, the experimental parameters were normalized relative to the control sample and used to construct the corresponding factor spaces. Increasing the flaxseed content to 5.0% resulted in an increase in the maximum count of lactic acid microorganisms from 17.0 to 22.9 colony-forming units per gram and in their growth rate from 0.0708 to 0.0954 colony-forming units per gram per hour. At the same time, the proportion of saturated fatty acids decreased from 68.6 to 62.3%, whereas that of polyunsaturated fatty acids increased from 31.4 to 37.7%. For the sample containing 5.0% flaxseed, the normalized values of the maximum count and growth rate of lactic acid microorganisms exceeded the respective control values by 35.0 and 34.8%. In comparison, the polyunsaturated fatty acid content was 20.0% higher. The factor area of the control sample was 2.378 arbitrary units², whereas the corresponding values for the samples containing 1.5, 3.0, and 5.0% flaxseed were 2.68, 3.10, and 3.15 arbitrary units², respectively. The highest integral assessment was obtained for the sample containing 5.0% flaxseed, with its factor space reaching 132% of the control value. The practical significance of the results lies in substantiating the formulation containing 5.0% flaxseed as the most promising among the investigated variants and in demonstrating the applicability of the factor area method for quantitatively comparing multicomponent food systems based on a set of heterogeneous quality parameters.Received 30.06.2026, accepted 28.08.2026, published 22.09.2026