Iodine deficiency remains a major nutritional concern worldwide, and fermented dairy products are considered promising vehicles for iodine fortification. However, the chemical form of iodine may influence the physicochemical and microbiological stability of fermented dairy systems. This study aimed to compare potassium iodide and iodocasein as iodine sources for the fortification of a fermented dairy product and to evaluate their effects on product quality and iodine retention during refrigerated storage. Three formulations were produced: a control sample without iodine fortification and samples fortified with potassium iodide or iodocasein at a level of 25 µg iodine per 100 g of product. Samples were stored at 4 ± 1 °C for 7 days. Changes in pH, titratable acidity, syneresis, viscosity, viable counts of starter lactic acid bacteria, iodine retention, and sensory properties were evaluated during storage. The results showed that the iodine source significantly affected product stability. The potassium iodide-fortified sample exhibited greater post-acidification, increased syneresis, lower viscosity, and a more pronounced reduction in viable lactic acid bacteria during storage. In contrast, the iodocasein-fortified sample maintained physicochemical and microbiological characteristics closer to the control and demonstrated higher iodine retention. Fortification at the studied level did not significantly affect the basic composition or amino acid profile of the product. The findings indicate that iodocasein can improve iodine stability while preserving the quality characteristics of fermented dairy products, supporting its potential application in the development of iodine-enriched functional dairy foods.

Meat from culled cows is characterized by increased toughness and limited processing suitability, yet the combined effects of microbial cultures and mechanical processing have not been sufficiently studied. The aim of this study was to evaluate the effect of Lactobacillus sakei (SafePro B-2, 10¹¹ CFU/g) in combination with vacuum massage on the physicochemical, structural, and functional–technological properties of culled cow meat, as well as to optimize the process using response surface methodology. It was found that the combined treatment led to a 25–35% reduction in shear force and a 12–18% increase in water-holding capacity compared to control samples. The pH value decreased from 6.2 to 5.6–5.8, indicating active lactic acid fermentation. Modeling using the response surface method demonstrated high predictive power of the models (R² = 0.91–0.96) and allowed for the determination of optimal process parameters (10⁷ CFU/g; 40 min of mixing), ensuring maximum softening and product stability. Analysis of the texture profile revealed a statistically significant (p < 0.05) decrease in hardness, stickiness, and chewiness, accompanied by an increase in cohesiveness, indicating a reorganization of the protein matrix at the microstructural level. Additionally, microstructural modifications and reorganization of the protein matrix were observed, accompanied by changes in amino acid composition, indicating a change in the state of proteins and their spatial distribution within the meat matrix. Overall, the combined use of Lactobacillus sakei and vacuum massaging effectively improves the functional, technological, and structural characteristics of low-grade beef raw materials. The proposed approach can be considered a scientifically sound strategy for optimizing processing parameters and increasing the efficiency of utilizing meat from culled cows.

Разработан ферментированный молочный напиток типа йогурта с добавлением цинка. Целью исследования являлась оценка содержания основных пищевых веществ и изменения pH в процессе ферментации контрольного и опытного образцов. Молоко нормализовали, пастеризовали при температуре 85–90 °C в течение 5–10 мин, охлаждали до 40–42 °C, после чего вносили закваску и цинксодержащий компонент. Расчетная доза составляла 10,0 мг элементарного Zn на 100 г продукта; контрольный образец готовили без добавления цинка. После завершения ферментации продукт охлаждали до 4±2 °C. В опытном образце содержание белка, жира и углеводов составляло соответственно 2,38±0,02%, 2,60±0,01% и 5,69±0,04%, тогда как в контрольном образце — 2,43±0,03%, 2,55±0,05% и 5,77±0,03%. Исходное значение pH обоих образцов составляло 6,64. Через 6 ч pH снизился до 4,55±0,03 в контрольном образце и до 4,43±0,04 в опытном образце. На 8-м часу по данным кинетической кривой значения pH составляли 4,36 и 4,27 соответственно. Различия по содержанию основных пищевых веществ не превышали 2,1%. Полученные результаты показали, что внесение цинксодержащего компонента в выбранной расчетной дозе не замедляло процесс ферментации. При этом содержание белка, жира и углеводов в опытном образце оставалось близким к контрольным значениям.