Thumbnail Image
Item

Physicochemical and simulated gastric digestion properties of A1/A1, A1/ A2 and A2/A2 yoghurts

Davor, Daniloski
; 
Todor, Vasiljevic
; 
Daniela, Freitas
; 
Talita, A. Comunian
; 
Andre, Brodkorb
; 
Noel, A. McCarthy
Citations
Altmetric:
Keywords
Yoghurt, Gelation properties, β-casein, Gastric digestion, Structure
Date
2024-07-18
Collections
Food Chemistry & Technology
Show all metadata
Files
Thumbnail Image
1-s2.0-S0268005X24007045-main.pdf
Adobe PDF, 3.14 MB
Research Projects
Organizational Units
Journal Issue
URI
https://t-stor.teagasc.ie/handle/11019/64059
Citation
3
Abstract
This study aimed to determine the physicochemical properties of yoghurts from skim milk containing either β-casein A1/A1, A1/A2 or A2/A2 and establish their behaviour during simulated gastric digestion. Yoghurts produced from milk containing β-casein A1/A1 and A1/A2 had significantly higher storage modulus, water holding capacity, and lower syneresis compared to yoghurt produced from A2/A2 milk. Microscopy images also showed a more porous microstructure and greater pore size in A2/A2 yoghurts. The main conformational variability between the yogurts was approximately 35 % lower levels of aggregated β-sheets in A2/A2 yoghurt, compared to the other yogurt systems. The A2/A2 sample was also characterised by larger casein micelles, lower levels of κ-casein, and higher levels of β-lactoglobulin in the yoghurt serum phase. During gastric digestion, coagulum formation in all three yoghurts occurred within the first 5 min between the pH ranges of 4.3 to 3.8. However, protein breakdown in A1/A1 and A1/A2 yoghurts occurred faster, with the final gastric clot characterised as a loose protein network, as opposed to that of the A2/A2 digesta. Overall, the use of A2/A2 milk in yoghurt production results in prolonged gelation times, with altered gastric digestion properties compared to yogurts containing β-casein A1.
Funder
Davor Daniloski is supported by both the VU International Postgraduate Research Scholarship (VUIPRS) and Teagasc - the Agriculture and Food Development Authority (Walsh Scholarship Programme, Ireland) that was registered with the Victoria University (Funding Agency ID: 2019039). The authors acknowledge the assistance of team at the Moorepark Dairy Farm in Teagasc Animal and Grassland Research and Innovation Centre in collecting milk samples. André Brodkorb is funded by Science Foundation Ireland (SFI) and the Department of Agriculture, Food, and the Marine on behalf of the Government of Ireland under Grant Number [16/RC/3835]. Daniela Freitas is funded by Science Foundation Ireland (SFI, grant number 21/PATH-S/9418) and she also received funding from the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No 898013. Talita Aline Comunian received funding from the Research Leaders 2025 programme cofounded by Teagasc and the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie (grant number 754380).
Grant Number
Embedded videos