G. Szafner

49061593100

Publications - 4

Effect of pore size and temperature on the behaviour of alpha-lactalbumin and the A and B genetic variants of beta-lactoglobulin during protein fractionation microfiltration

G. Szafner A. J. Kovács Henrietta Buzás Mónika Krassóy Aline Wiedmann

Publication Name: Food Hydrocolloids

Publication Date: 2025-03-01

Volume: 160

Issue: Unknown

Page Range: Unknown

Description:

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.

Open Access: Yes

DOI: 10.1016/j.foodhyd.2024.110759

Aflatoxin M1 detection in raw milk and drinking milk in Hungary by ELISA − A one-year survey

Attila Hucker Róbert Kocsis G. Szafner Solveig Bukovics Judit Süle A. J. Kovács Katalin Szabó Henrietta Buzás Sárvári Loretta Csilla Katalin Nagy-Kovács

Publication Name: Journal of Food Composition and Analysis

Publication Date: 2023-08-01

Volume: 121

Issue: Unknown

Page Range: Unknown

Description:

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.

Open Access: Yes

DOI: 10.1016/j.jfca.2023.105368

Developed rapid and simple RP-HPLC method for simultaneous separation and quantification of bovine milk protein fractions and their genetic variants

G. Szafner Solveig Bukovics Judit Süle A. J. Kovács Székelyhidi Rita Katalin Szabó Henrietta Buzás

Publication Name: Analytical Biochemistry

Publication Date: 2022-12-01

Volume: 658

Issue: Unknown

Page Range: Unknown

Description:

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.

Open Access: Yes

DOI: 10.1016/j.ab.2022.114939

Effect of protein content on the thermal effusivity of foods

G. Szafner Nóra Gombköto Ottó Dóka

Publication Name: Acta Alimentaria

Publication Date: 2021-12-31

Volume: 50

Issue: 4

Page Range: 475-483

Description:

The availability of thermophysical properties of both foods and their constituents is of considerable importance to the industry. The thermal effusivity is one of the less explored thermophysical parameters. It governs the penetration of heat into materials and is defined as the square root of the product of thermal conductivity of the material, volume-specific heat capacity, and density. This paper describes the application of a relatively new inverse photopyroelectric method (IPPE) to determine thermal effusivity of dehydrated whey protein isolate and egg white powder versus protein content. In both cases the effusivity values decreased linearly with increasing protein content. One percent increase in protein content of whey protein isolate and egg white lead to 6.5 and 7.2 Ws1/2 m-2 K-1 decrease in effusivity values, respectively.

Open Access: Yes

DOI: 10.1556/066.2021.00042