Methods of Comparing Protein Quality of Soybean Infant Formulas in the Rat

Abstract Rat bioassay was used to assess the protein quality of powdered infant formulas and to evaluate the feasibility of using modified casein diets (containing the same source and level of fat and carbohydrate contributed by the infant formulas) as reference standards. Modification of the casein diet to match the milk-based formulas caused a significant reduction in weekly protein efficiency ratios (PER) and net protein ratios (NPR) at the third and fourth weeks. Modification of the casein diet to simulate the soy-based formulas had no significant effect on NPR values; PER values were more varied. When PER and NPR values of the powdered milk-based formulas were expressed relative to the unmodified reference standard, the relative values were lower than when each matched reference was used. With few exceptions, the relative weekly PER values of the soy-based formulas were similar regardless of the standard used. The relative NPR values of the formulas had a pattern similar to the relative PER values. The data indicate that protein quality evaluation of infant formulas using rat bioassay warrants the use of matched casein reference diets for each type of formula.

Download Full-text

Use of Amino Acid Profiles of Pretermand Term Human Milks in Evaluating Scoring Patterns for Routine Protein Quality Assessment of Infant Formulas

Journal of AOAC International ◽

10.1093/jaoac/79.2.498 ◽

1996 ◽

Vol 79 (2) ◽

pp. 498-502 ◽

Cited By ~ 8

Author(s):

Ghulam Sarwar ◽

Pauline Darling ◽

Mariko Ujiie ◽

Herbert G Botting ◽

Paul B Pencharz

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Human Milk ◽

G Protein ◽

Protein Quality ◽

World Health ◽

Complete Analysis ◽

Infant Formulas ◽

Health Organization

Abstract Reports on the amino acid composition of human milk vary considerably with respect to concentrations of sulfur amino acids. Often, analyses forego tryptophan determination. A complete analysis of protein and amino acid concentrations was performed on human milk samples (5-10 days postpartum) collected from mothers of preterm (gestations of 25-32 weeks) and term (gestations of >36 weeks) infants. Careful attention was given to quantitate amino acids such as cysteine and tryptophan, which are vulnerable to acidic hydrolysis conditions. Differences in concentrations of total amino acids (expressed on protein basis) between preterm and term milks were small, despite the higher true protein content of preterm milk versus term milk (19.20 versus 12.60 g/L). The methionine + cyst(e)ine contents of term and preterm milks (3.72-3.84 g/100 g protein) were comparable with those reported in 1991 by the Food and Agricultural Organization/World Health Organization (FAO/WHO) for mature human milk (4.20 g/100 g protein) but higher than those reported in 1991 by the European Commission (2.9 g/100 g protein).The amino acid pattern of human milk obtained in this study confirms that the 1991 FAO/WHO amino acid scoring pattern for predicting protein quality of infant formulas is representative of the amino acid quality of both preterm and term human milks.

Download Full-text

Effect of amino acid supplementation on protein quality of soy-based infant formulas fed to rats

Plant Foods for Human Nutrition ◽

10.1007/bf01886228 ◽

1993 ◽

Vol 43 (3) ◽

pp. 259-266 ◽

Cited By ~ 7

Author(s):

G. Sarwar ◽

R. W. Peace ◽

H. G. Botting

Keyword(s):

Amino Acid ◽

Protein Quality ◽

Infant Formulas ◽

Amino Acid Supplementation ◽

Acid Supplementation

Download Full-text

The effects of different thawing methods on protein quality of frozen fish

Journal of FisheriesSciences com ◽

10.3153/jfscom.2008010 ◽

2008 ◽

Author(s):

Bahar Tokur

Keyword(s):

Protein Quality ◽

Frozen Fish

Download Full-text

Evaluation of Changes in Protein Quality of High-Pressure Treated Aqueous Aquafaba

Molecules ◽

10.3390/molecules26010234 ◽

2021 ◽

Vol 26 (1) ◽

pp. 234

Author(s):

Fatemah B. Alsalman ◽

Hosahalli S. Ramaswamy

Keyword(s):

High Pressure ◽

Protein Quality ◽

Treatment Time ◽

Control Sample ◽

Thermal Characteristics ◽

Protein Digestibility ◽

Foaming Properties ◽

Freeze Dried ◽

Cooking Water

Chickpea cooking water (CCW), known as aquafaba, has potential as a replacement for egg whites due to its emulsion and foaming properties which come from the proteins and starch that leach out from chickpeas into the cooking water. High pressure (HP) processing has the ability to modify the functional characteristics of proteins. It is hypothesized that HP processing could favorably affect the functional properties of CCW proteins by influencing their structure. The objective of this study to evaluate the effect of HP treatment on the associated secondary structure, emulsion properties and thermal characteristics of CCW proteins. A central composite rotatable design is used with pressure level (227–573 MPa) and treatment time (6–24 min) as HP variables, and concentration of freeze dried CCW aquafaba powder (11–29%) as product variable, and compared to untreated CCW powder. HP improves aquafaba emulsion properties compared to control sample. HP reduces protein aggregates by 33.3%, while β-sheets decreases by 4.2–87.6% in which both correlated to increasing protein digestibility. α-helices drops by 50%. It affects the intensity of some HP treated samples, but not the trend of bands in most of them. HP treatment decreases Td and enthalpy because of increasing the degree of denaturation.

Download Full-text