The aim of this study was to investigate the influence of membrane pore size and filtration temperature on six individual milk protein fractions (αS-CN, β- CN, κ-CN, α-LA, β-LG A, β-LG A) during the protein fractionation microfiltration process. Pasteurised skimmed milk was microfiltrated using two different pore sizes of spiral-wound membranes, with pore sizes of 0.2 μm and 0.5 μm, at temperatures of 15 °C and 45 °C respectively. The microfiltration process was carried out with a final volume reduction of 66% and a diafiltration volume of 120% (300 L) of the original feed (250 L). It was observed that neither the pore size nor the filtration temperature significantly (p < 0.05) affected the permeation of the α-LA fraction. However, the permeation of the β-LG A and β-LG B fractions can be influenced by membrane pore size and filtration temperature, and the behaviour of the three whey protein fractions, A and B genetic variants of the β-LG and α-LA fractions differs significantly during the microfiltration process. The results of this study could form the basis for the development of new, unique tailor-made milk protein ingredients.

The aim of the present study was to determine the antioxidant capacity and total polyphenol content of raw milk, dairy products (ricotta and cottage cheese), and by-products (sweet and acid whey) from different animal breeds (cow, goat). Overall, the total polyphenol content of raw milk ranged from 420.34 to 490.72 mg GAE/100 mL, while the total antioxidant content changed between 8.95 and 28.72 mg AAE/100 mL. These values in the case of cottage cheeses were 32.29–124.29 mg GAE/100 mL for polyphenols and 14.12–16.38 mg AAE/100 g for antioxidants. Significant differences were observed between the total polyphenol content and antioxidant properties of sweet- (10.85–197.55 mg AAE/100 g antioxidant; 32.29–124.29 mg GAE/100 g polyphenol) and acid whey (13.28–158.69 mg AAE/100 g antioxidant; 43.50–98.03 mg GAE/100 g polyphenol). In addition, slight differences in total polyphenol content (10.55–19.01 mg GAE/100 g) and antioxidant capacity (10.84–15.93 mg AAE/100 g) were observed for ricotta cheeses made from milk of different animal breeds. The results show that milk and dairy products are excellent sources of antioxidants and polyphenols.

The aim of this study was to monitor the aflatoxin M1(AFM1) contamination in raw milk and drinking milk in Hungary over a one-year period. A total of 474 milk samples of raw milk (n = 278) and commercial milk (n = 196) were collected and analysed between September 2021 and November 2022. Enzyme-Linked Immunosorbent Assay (ELISA) determined the concentration of AFM1. It was found that 68.7% (191/278) of the raw cow milk samples were contaminated by AFM1 in the range 5.0–173 ng/L, the mean of the positive samples was 30.7 ± 24.7 ng/L, and the median was 21.8 ng/L. The percentage of contamination in drinking milk was 79.1% (155/196). The mean, median, and range of the positive samples were 18.0 ± 10.9 ng/L, 16.18 ng/L, and 5.3–100 ng/L, respectively. Overall, 9.4% (26/278) of raw milk samples and only 1 commercial milk sample of 196 (0.5%) contained AFM1 exceeding the maximum residue level (MRL) of 50 ng/L set by the European Union. Our study suggests that based on calculated AFM1-related health risk indicators, the Hungarian adult population are not exposed to high levels of AFM1, but regular monitoring of aflatoxins is necessary not only for dairy farmers but also for the milk processing sectors.

The main objective of this study was to determine the beta-casein A1/A2 polymorphism status of animals in two Holstein Friesian dairy cow herds in Győr-Moson-Sopron County, Hungary. The A1/A2 status of cattle is determined by the beta-casein gene on the sixth chromosome. The analysed single nucleotide polymorphism is non-synonymous; A1 and A2 variants of bovine beta-casein differ at position 67 of the amino acid chain: A1 variant codes for histidine and A2 codes for proline, which may affect the milk protein degradation process. The analysed polymorphism leads to key conformational changes in the secondary protein structure of beta-casein. Beta-casomorphin (known as BCM7) is released only from A1-type milk and cannot be completely degraded by enzymes during digestion. DNA isolation was performed from whole blood, and a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method with agarose gel electrophoresis was applied in order to determine individual genotypes. The results from the two dairy farms demonstrate that a high proportion of cows (86.08 and 90.74 %) carry the A2 gene variant without targeted selection. At farm „A”, beta-casein polymorphisms were determined in 599 cows and 148 heifers. The genotype distribution of the cows was 47.25 % heterozygous, 38.83 % homozygous A2, whereas 14.02 % of the cows carried the A1A1 genotype. In heifers, A2A2 was already present in a remarkably high frequency (91.89 %), whereas the prevalence of heterozygotes was 7.43 %, and A1A1 animals made up only 0.67 % of the analysed heifer population. In Hungary, a growing number of dairy farms are using verified A2 homozygous breeding bull semen. The introduction of homozygous A2 sperm on the farm „A” remarkably increased A2 frequency in the heifer population. In total, 324 cows were genotyped on farm „B”, where the A2A2 genotype was observed in 30.55 % of the animals. The second most common genotype was A1A2, with a genotype frequency of 60.19 %, whereas A1A1 homozygotes occurred with a 9.26 % frequency. The growing popularity of A2 milk due to potential health benefits is driving Hungarian stakeholders towards the targeted selection of dairy populations; animal genotyping is an evident approach to facilitate this transition.

The aim was to develop a reliable rapid reversed-phase high-performance liquid chromatography (RP-HPLC) method to simultaneously determine the main bovine milk protein fractions, including their genetic variants. Compared to the previous studies, our method is able to separate the main protein fractions within 20 min of total run time. The method validation consisted of testing repeatability, reproducibility linearity, repeatability, and accuracy. The procedure was developed using raw individual, bulk, and commercially available heat-treated cow milk samples. The RSD of peak areas ranged from 1.43 to 3.16% within analytical day and from 3.29 to 6.70% across analytical days. The method can be applied to investigate both raw and heat-treated milk samples.