Dairy an 'excellent' source of protein for children, study says
Dairy is an “excellent” source of protein for children. PHOTO | FILE
What you need to know:
- The researchers determined standardised ileal – of the third portion of the small intestine – digestibility of crude protein and amino acids in protein isolate, protein concentrate, milk protein concentrate, skimmed milk powder, soy protein isolate, soy flour and wholegrain wheat.
- All dairy proteins tested in the study met FAO standards as “excellent/high” – quality sources of protein for people six months of age or older, with DIAAS values of 100 or greater.
DAIRY IS AN “excellent” source of protein for children, a study by researchers at the University of Illinois in the United States shows, the institution said in a press release on Wednesday.
The researchers used pigs as a model to study the best way of evaluating protein quality in foods eaten by children, a method that had been proposed by the Food and Agriculture Organisation (FAO) of the United Nations in 2011. They conducted a study to calculate protein scores for eight sources of protein derived from both plants and animals.
The researchers determined standardised ileal – of the third portion of the small intestine – digestibility of crude protein and amino acids in protein isolate, protein concentrate, milk protein concentrate, skimmed milk powder, soy protein isolate, soy flour and wholegrain wheat.
They derived Digestible Indispensable Amino Acid Scores (DIAASs) from the digestibility values they found. They also calculated Protein Digestibility-Corrected Amino Acid–like (PDCAAS-like) scores by applying the total tract digestibility of crude protein in the ingredients to all amino acids.
All dairy proteins tested in the study met FAO standards as “excellent/high” – quality sources of protein for people six months of age or older, with DIAAS values of 100 or greater.
Soy protein isolate and soy flour qualified as “good” sources of protein, with a score between 75 and 100. With scores below 75, pea protein concentrate and wheat did not qualify to make recommendations regarding protein quality.
Dr Hans H Stein, the principal investigator of the research, acknowledges certain limitations in the study: “The protein sources used in this experiment were fed raw, and foods processed as they typically are for human consumption might well have different protein values.” However, he says, it represents a step forward in determining protein quality.
The paper, “Values for digestible indispensable amino acid scores for some dairy and plant proteins may better describe protein quality than values calculated using the concept for protein digestibility-corrected amino acid scores” is in the British Journal of Nutrition.
