How Heating Goat Milk Affects Protein Digestion and Bioactive Peptide Release in Infant Conditions | Research

The takeaway

Heating goat milk at different temperatures significantly changes how its proteins are digested and how many bioactive peptides are released, with mild heating (65°C) producing the most bioactive peptides under simulated infant digestion conditions.

65°C: optimal for bioactive peptides
Goat milk heated at 65°C released the highest abundance of bioactive peptides during simulated infant digestion, primarily from β-casein. Higher temperatures degraded these peptides into smaller, less active fragments.

What the researchers found

Heating goat milk at temperatures ≥80°C caused more extensive gastric clot formation with higher protein digestion rates, but also resulted in more undigested whey proteins due to severe aggregation.

β-Casein was the major source of bioactive peptides during digestion. Milk heated at 65°C produced the highest abundance of bioactive peptides, while temperatures above 75°C reduced bioactive peptide levels because the peptides were further cleaved into smaller, less bioactive fragments. The study demonstrated that different heating temperatures induce different degrees of whey protein denaturation, which directly affects digestion outcomes.

Why it matters

Goat milk-based infant formulas are a growing market, and processing conditions directly affect nutritional quality. This study shows that the temperature used during manufacturing can significantly impact how well infants digest the milk proteins and how many beneficial peptides are released. The findings could help optimize formula processing to maximize nutritional benefits.

How the study worked

Skimmed goat milk was heated at various temperatures (up to and above 80°C) and then subjected to simulated infant gastrointestinal digestion. Unlike most previous studies that only analyzed the liquid portion, this study examined both the supernatant and gastric clot. Researchers used peptidomic analysis to identify and quantify bioactive peptides released during digestion at each temperature.

What this study cannot tell us

The study used simulated infant digestion in the laboratory, not actual infant digestion, which may differ in important ways. Only skimmed goat milk was tested, so results may not apply to whole milk or formula products with added ingredients. The bioactive potential of the identified peptides was inferred from database matching rather than tested experimentally for biological activity. The study did not assess whether the differences would have meaningful nutritional impacts in real infants.

How to read the evidence

This is a laboratory study using simulated infant digestion conditions. While it provides useful mechanistic data about protein digestion and peptide release, the findings have not been validated in human infant feeding studies.

When this study was published

Published in 2023, this study reflects current understanding of how thermal processing affects goat milk protein digestion and bioactive peptide generation.

The bigger picture

Bioactive peptides from food proteins are an active area of research, with potential health benefits including immune modulation, blood pressure regulation, and antimicrobial activity. Understanding how food processing affects bioactive peptide release during digestion is essential for developing functional foods and optimized infant formulas. This study contributes to a growing body of evidence that processing conditions matter as much as raw ingredient quality.

Questions still open

Would these bioactive peptide differences translate to measurable health outcomes in infants?
Can goat milk formula manufacturing be optimized to use 65°C processing while maintaining safety and shelf stability?
How do these findings compare to cow milk-based formulas processed at similar temperatures?

Common questions

Does heating goat milk destroy its beneficial peptides?

It depends on the temperature. Mild heating at 65°C actually produced the most bioactive peptides during digestion. But higher temperatures (above 75°C) broke these beneficial peptides into smaller fragments that may have less biological activity. So the processing temperature is a key factor in preserving nutritional benefits.

Is goat milk better digested than cow milk for infants?

This study focused only on goat milk at different temperatures, not on comparing goat and cow milk. However, the researchers found that how goat milk is processed significantly affects how well its proteins are digested and what bioactive peptides are released, suggesting that processing matters as much as the milk source.

Read the original research

Heating affects protein digestion of skimmed goat milk under simulated infant conditions.

Food chemistry, 402, 134261

View on PubMed ↗Publisher’s paper ↗

Citation

Ren, Qing; Boiani, Mattia; He, Tao; Wichers, Harry J; Hettinga, Kasper A. (2023). Heating affects protein digestion of skimmed goat milk under simulated infant conditions.. Food chemistry, 402, 134261. https://doi.org/10.1016/j.foodchem.2022.134261