The protein composition is different in bovine and human milk. Infant formulae made with bovine milk (BM) has been modified by a substitution of whey proteins by purified bovine α-lactalbumin and lactoferrin (BM+) with the aim to better mimic the protein composition of human milk. We compared the protein structures in these 2 model formulas before and after their heat treatment and during their in vitro digestion.

The 2 Infant formulas, were heat treated between 67.5 °C and 80 °C. It has been shown that the protein composition and the heat treatment impacted:

• ­ the kinetics of denaturation of the whey proteins,
• ­ the structure of the heat-induced aggregates,
• ­ the structure of the aggregates in the stomach conditions, as studied during an in vitro digestion.

For identical heat treatments, proteins in the infant formulae BM+ (the closest to human mik protein composition) was less denatured than in the BM formulae.

	BM			BM+
	Infant formulae	80 min in gastric conditions	120 min in gastric conditions	Infant formulae	80 min in gastric conditions	120 min in gastric conditions
Before heat treatment
After heat treatment
Figure: Larger aggregates are seen in stomach conditions for the unheated BM formulae than for the unheated BM+, and after heat treatment as compared to before heat treatment. Auteur de la photo : Agnès Burel – Plateforme MRic BIOSIT, Rennes

These results could help understanding the protein hydrolyses and peptide release in these 2 formulas. Modulating the protein composition and structures, could be a lever for improving the nutritional quality of infant formula, including their physiologic impact (microbiota, intestinal epithelium development, …).

Collaborations

This work was conducted by Amira Halabi during her PhD, which was funded by INRAE and the Brittany Region. Her PhD defence took place on the 20th of October 2020 in Rennes, Agrocampus Ouest.

Read more

Halabi, A., Croguennec, T., Bouhallab, S., Dupont, D., & Deglaire, A. (2020). Modification of protein structures by altering the whey protein profile and heat treatment affects in vitro static digestion of model infant milk formulas. Food & Function, 11(8), 6933–6945. DOI: 10.1039/D0FO01362E

Halabi, A., Deglaire, A., Hamon, P., Bouhallab, S., Dupont, D., & Croguennec, T. (2020). Kinetics of heat-induced denaturation of proteins in model infant milk formulas as a function of whey protein composition. Food Chemistry, 302, 125296. DOI:10.1016/j.foodchem.2019.125296

Halabi, A., Deglaire, A., Hennetier, M., Violleau, F., Burel, A., Bouhallab, S., Dupont, D., & Croguennec, T. (2020). Structural characterization of heat-induced protein aggregates in model infant milk formulas. Food Hydrocolloids, 107, 105928. DOI: 10.1016/j.foodhyd.2020.105928

Leite, B., Croguennec, T., Halabi, A., & Costa Junior, E. F. da. (2021). Comparing different methods for estimating kinetic parameters of whey protein heat-induced denaturation in infant milk formulas. Journal of Food Engineering, 292, 110272. DOI: 10.1016/j.jfoodeng.2020.110272

Contacts

Thomas Croguennec • Scientist UMR STLO

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