The saponification value of fats and oils is one of the most common quality indices, reflecting the mean molecular weight of the constituting triacylglycerols. Proton nuclear magnetic resonance (¹H-NMR) spectra of fats and oils display specific resonances for the protons from the structural patterns of the triacylglycerols (i.e., the glycerol backbone), methylene (-CH₂-) groups, double bonds (-CH=CH-) and the terminal methyl (-CH₃) group from the three fatty acyl chains. Consequently, chemometric equations based on the integral values of the ¹H-NMR resonances allow for the calculation of the mean molecular weight of triacylglycerol species, leading to the determination of the number of moles of triacylglycerol species per 1 g of fat and eventually to the calculation of the saponification value (SV), expressed as mg KOH/g of fat. The algorithm was verified on a series of binary mixtures of tributyrin (TB) and vegetable oils (i.e., soybean and rapeseed oils) in various ratios, ensuring a wide range of SV. Compared to the conventional technique for SV determination (ISO 3657:2013) based on titration, the obtained ¹H-NMR-based saponification values differed by a mean percent deviation of 3%, suggesting the new method is a convenient and rapid alternate approach. Moreover, compared to other reported methods of determining the SV from spectroscopic data, this method is not based on regression equations and, consequently, does not require calibration from a database, as the SV is computed directly and independently from the ¹H-NMR spectrum of a given oil/fat sample.

In the present study, four Lactobacillus strains (Lacticaseibacillus casei ATCC 393, Lacticaseibacillus casei RC-1, Lactobacillus acidophilus RC-2 and Lacticaseibacillus rhamnosus RC-10) were investigated to determine their probiotic potential. The strains were evaluated based on their resistance to simulated upper gastrointestinal conditions, tolerance to bile salts, antimicrobial activity, antibiotic resistance and ability to adhere to intestinal cells. All the strains were resistant to simulated upper gastrointestinal conditions (pH 2.5 + pepsin and pH 7.4 + pancreatin) and exhibited cell recovery rates varying between 74.24 and 87.50% (pH 2.5 + pepsin) and between 93.95 and 98.15% (pH 7.4 + pancreatin) at the 24th h of cultivation. The strains demonstrated resistance to various concentrations of bile salts (0.25, 0.5, 0.75 and 1%) with survival rates > 50% (L. casei ATCC 393 and L. casei RC-1) and >60% (L. acidophilus RC-2 and L. rhamnosus RC-10) in bile salt concentration of 0.25% at the 24th h of incubation. The four Lactobacillus components—Lactobacillus culture (LC), cell biomass (CB) and cell-free supernatant (CFS) exhibited moderate to high antimicrobial activity against six Gram-positive and six Gram-negative bacteria; however, they failed to inhibit the growth of yeasts and fungi tested in the antimicrobial screening. In addition, the neutralized to pH = 7.0 cell-free supernatant (NCFS) of the four strains completely lost its antimicrobial effect. The results for antibiotic susceptibility of four Lactobacillus strains showed that L. casei ATCC 393 was resistant to 11, L. casei RC-1 was resistant to 9, L. acidophilus RC-2 was resistant to 8, and L. rhamnosus RC-10 was resistant to 11 of the total 23 antibiotics tested. The highest degree of adhesion of the studied isolates to the intestinal cell line IPEC-J2 was observed in L. casei RC-1 (39.45%), L. rhamnosus RC-10 (23.38%) and L. acidophilus RC-2 (19.25%) in comparison with the reference probiotic strain L. casei ATCC 393. Based on the results obtained, the strains studied can be considered as having probiotic potential.

Kashkaval is a hard cheese produced in Eastern Europe and consumed after ripening. The influence of ripening temperature (9±1°C, 11±1°C and 13±1°C) of cow's milk Kashkaval cheese on its physicochemical, microbiological and sensory characteristics was studied. For the ripening period no statistically significant differences (P>0.05) in the indicators dry matter, fat content, salt and protein were found. A slight decrease in active acidity was observed during the maturation process which tendency was more pronounced in the experimental samples ripened at higher temperatures (13.0±1.0°C). It was found that lowering the ripening temperature of Kashkaval cheese was accompanied by a prolongation of the lag phase in the development of lactic acid microflora. A significantly higher amount of lactic acid microorganisms (P0.05). The absence of unwanted side microflora in fresh cheese was established, which was an important prerequisite for the normal course of the maturing processes and the formation of a characteristic sensory profile of the cheese. Kashkaval cheese ripened at 13±1°C for 45 days was characterized by the highest overall sensory score comparable to Kashkaval cheese ripened at 9±1°C and 11±1°C for 60 days. The obtained results demonstrated that the higher ripening regime could be successfully used to reduce production costs without changing the specific physicochemical, microbiological and sensory characteristics of Kashkaval cheese from cow milk.

Sweet buttermilk, a by-product of butter production, remains highly underutilized despite containing some relevant components (i.e., phospholipids) that may have a high biological value and may exert some positive technological functions. The aim of this study was to investigate the possibility of using ultrafiltered (UF) sweet buttermilk at different volume reduction ratios (3 and 5) to replace emulsifiers and/or stabilizers in the production of a novel clean-label ice cream formulation made with sweet buttermilk-based mixtures. The functional, thermo-rheological, and sensory profile of four types of ice creams was investigated. Increasing the degree of sweet buttermilk concentration positively influenced the overrun values and at the same time improved the ice cream’s resistance to melting. Also, the thermo-rheological profile during melting was influenced by the presence of UF buttermilk. These differences in techno-functional properties were probably partly caused by the different total phospholipids content caused by UF buttermilk. Some sensory properties (i.e., structure, consistency) were positively related to the utilization of UF buttermilk, while aroma and taste were negatively influenced. This study demonstrated that UF buttermilk can be used as an additive replacer in ice cream production because it enhances the structural and rheological properties of the final product.

This work aimed to study the flux behavior, rejection and concentration factors, and energy demand to establish the optimal conditions during ultrafiltration of sweet buttermilk to produce ice cream. The experiments were conducted with a UF25-PAN membrane at a transmembrane pressure of 0.2, 0.35 and 0.5 MPa, and a volume reduction ratio (VRR) of 2, 3, 4, and 5. Total protein, fat, ash, and dry matter contents, phospholipid composition, and acidity of retentates and permeate were determined. The increase in the VRR led to a decrease in the permeate flux and an increase in the energy demand, rejection, and concentration factors of the main components of sweet buttermilk. The highest values of rejection and concentration factors established for fat were 98.65% and 4.93, respectively. The permeate flux and energy demand increased with the rise in the transmembrane pressure. The total phospholipids increased 2.8 times at VRR 5 compared to the initial buttermilk. The use of VRR 3 gave the best ratio between the permeate flux, the energy demand, and relatively high values of concentration and rejection factors. The use of VRR 5 will enrich the ice cream to the greatest extent to obtain a product with the highest level of biologically active substances (proteins, phospholipids, minerals).