Evaluation of infant formula protein quality: comparison of in vitro with in vivo methods.
Two-week protein efficiency ratio (2-wk PER), net protein ratio (NPR), calculated-protein efficiency ratio (C-PER), and discriminant computed-protein efficiency ratio (DC-PER) of milk- and soy-based infant formulas were compared to a 4-week protein efficiency ratio (PER). Expressed relative to ANRC casein, 2-week PER and NPR correlated significantly (P less than 0.01, r = 0.90) with PER. Although C-PER and DC-PER also correlated significantly (P less than 0.01) with PER, r = 0.71 and r = 0.87, respectively, these in vitro methods did not distinguish differences in protein quality among soy-based infant formulas. C-PER and DC-PER, as currently designed, are not applicable to the measurement of protein quality for all types of infant formulas.
Harris
D A
DA
Mead Johnson Nutritional Group, Department of Food and Nutrition Research, Evansville, IN 47721.
Burns
R A
RA
Ali
R
R
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D004044:Dietary Proteins / Q000032:analysis*; D066298:In Vitro Techniques; D007225:Infant Food / Q000032:analysis*; D008297:Male; D009753:Nutritive Value; D011786:Quality Control; D051381:Rats; D011919:Rats, Inbred Strains
D000596:Amino Acids; D004044:Dietary Proteins