Quality Of Infant Formula Research Articles

Use of micellar mobile phases for the chromatographic determination of melamine in dietetic supplements

Melamine is a nitrogen-rich industrial chemical which is occasionally used to increase the apparent protein content of different products destined for human and animal consumption. In this work, a liquid chromatographic procedure that uses micellar mobile phases of sodium dodecyl sulfate (SDS) buffered at pH 3, a C18 column and UV detection is reported for the determination of melamine in dietetic supplements. Samples were reconstituted with a SDS solution and were directly injected, thus avoiding long extraction and experimental procedures. Melamine was eluted in less than 10 min with no interference by other compounds of the matrices. The optimum mobile phase composition was taken by a chemometrical approach that considers the retention factor, efficiency and peak shape. Validation was performed following the indications of the European Commission (Decision 2002/657/EC). The following parameters were considered: linearity (0.02-100 μg mL(-1); R(2) = 0.9996), intra- and inter-day precisions (<12.4%), accuracy (90.0-101.3%), and robustness (less than 9.8% and 5.1%, for retention time and peak area, respectively). The limits of detection and quantification were 9 and 20 ng mL(-1), respectively. Recoveries for several spiked samples were in the 85.8-114.3% range. These results indicate that the proposed methodology is useful for routine analysis of control quality of infant formula and adult dietetic supplements.

Type of milk feeding affects hematological parameters and serum lipid profile in Japanese infants

Type and volume of infant feeding determines infant growth, hematological parameters, and serum lipids. Study subjects consisted of 103 infants who were born vaginally at term, with birthweight >2200 g. Milk feeding amount, type, and anthropometry were measured at 1 and 6 months. Hematological tests and serum lipid profile were assessed at 1 and 6 months. Thirty-four infants were breast-fed and 36 were formula-fed at 6 months. Breast-fed infants demonstrated similar growth patterns compared with partially breast-fed or formula-fed infants, despite the lower milk intake. Infants with higher breast milk intake at 6 months, however, tended to have lower hemoglobin levels. In contrast, higher formula intake at 6 months was related to lower serum total cholesterol. Japanese breast-fed infants were more likely to be anemic at 6 months, while formula-fed infants were likely to have low serum lipid levels. Iron-fortified infant foods may be useful to prevent anemia in breast-fed infants. Fat quality of infant formulas should be improved to enhance lipid status of formula-fed infants.

The FAST index – A highly sensitive indicator of the heat impact on infant formula model

Infant formulas are highly sensitive to the Maillard reaction during manufacturing, while this reaction induces significant loss in protein nutritional value and safety. The indicators mostly used to monitor the reaction during heat treatment are furosine, carboxymethyllysine and hydroxymethylfurfural, but analysis of these molecules is time-consuming and expensive. The FAST method, based on simple fluorescence measurements on clear milk supernatant, is a good alternative for Maillard reaction monitoring in milk products. The aim of this study was to determine the respective sensitivity of the various indicators of heat damage to infant formula, including the FAST index. A realistic infant formula model was developed, to compare the reaction kinetics at different temperatures (80–110 °C) for lactulosyllysine, measured as furosine, hydroxymethylfurfural and carboxymethyllysine. By comparing the Arrhenius plots of the three Maillard products to that of the FAST index, the latter was identified as the most sensitive indicator for infant formula quality monitoring during heat treatment.

Evaluation of antioxidant capacity and aroma quality of breast milk

Objective It is important to understand the difference and similarity in antioxidant capacity and aroma quality between formula and breast milk for purposes of modifying infant formulas. We evaluated the antioxidant properties and aroma quality of infant formula and breast milk. Methods Six breast milk samples and four infant formulas were used. Antioxidant properties were measured using the following methods: 2,2-diphenyl-1-picryhydrazyl free radical scavenging capacity, oxygen radical absorbance capacity, total phenolic content, and phenolic composition. Aroma quality was determined using the electronic nose. Results The 2,2-diphenyl-1-picryhydrazyl free radical scavenging activity for formula and breast milk ranged from 45.3% to 61.8% and from 52.8% to 61.2%, respectively. Oxygen radical absorbance capacity ranged from 28.8 to 31.9 g/kg for formula and from 25.5 to 39.2 g/kg for breast milk. Total phenolic content ranged from 422 to 751 mg/kg and from 329to 797 mg/kg for formula and milk, respectively. p-Hydroxybenzoic acid, p-coumaric acid, and ferulic acid were detected with values ranging from 614 to 635, 1391 to 1444, and 1425 to 1490 μg/kg in breast milk and from 783 to 3594, 1449 to 1510, and 1447 to 1561 μg/kg in formulas. Electronic nose results indicated that the aroma quality of formula controls 2, 3, and 4 was similar to that of breast milk. Conclusion Differences and similarities in antioxidant properties and aroma quality were found among some of the formulas and breast milk. The contribution of phenolic acids to total antioxidant capacity was limited.

Nutritional Adequacy of Commercial Infant Milk Formulas

The nutritional adequacy of six commonly consumed commercial infant milk formulas were evaluated chemically and biologically in growing rats. Infant formulas (per 100 kcal) provided protein (2.2–2.6 g), fat (4.9–5.4 g), available carbohydrates (10.3–11.4 g), Ca (62.5–80.8 mg), P (31.3–66.1 mg), Fe (0.7–1.8 mg), Zn (0.5–0.8 mg), and Cu (0.05–0.08 mg). The energy density varied between 503 and 526 kcal/100 g. Higher levels of linoleic and saturated fatty acids than in human milk were found. Methionine, tryptophan and lysine were the first, second, and third limiting amino acids in all infant formulas. The true protein digestibility (TD), net protein utilization (NPU), biological value (BV) and utilizable protein (UP) varied from 93–96%, 0.75–0.79, 80–82% and 8.7–10.5% respectively. The protein quality of infant formulas was lower than in cow's milk and human milk.

Progress in Promoting Breast-Feeding, Combating Malnutrition, and Composition and Use of Infant Formula, 1981–2006

More than 90% of women in developing countries and 50 to 90% of women in industrialized countries now initiate breast-feeding, a marked improvement from 25 y ago. The duration of breast-feeding has lengthened, but fewer than 35% of infants worldwide are still exclusively breast-fed at 4 mo of age. Considerable progress has also been made in combating infant malnutrition. In 1980, 47% of under-5-y-old children in developing countries were stunted. This percentage declined to 29% in 2005. Major advances in formula use and composition include the introduction of formulas tailored to the perceived needs of low-birth-weight infants and the development of fortifiers to overcome the nutritional deficits of human milk for the preterm infant. More recently, postdischarge formulas were introduced and are now being used widely, often in combination with breast-feeding. Formulas for term infants also have undergone a number of changes in the past 25 y to better reproduce the composition of human milk and/or the response of the breast-fed infant. The use of whey-predominant rather than casein-predominant formulas has increased, as has the use of iron-fortified formulas. Cow’s milk is introduced into the infant’s diet much later than 25 y ago. Despite the progress that has been made in promoting breast-feeding and in the quality of infant formulas, further improvements in the duration of breast-feeding and in the composition of infant formulas are needed.

Nutrient Requirements For Preterm Infant Formulas

Achieving appropriate growth and nutrient accretion of preterm and low birth weight (LBW) infants is often difficult during hospitalization because of metabolic and gastrointestinal immaturity and other complicating medical conditions. Advances in the care of preterm-LBW infants, including improved nutrition, have reduced mortality rates for these infants from 9.6 to 6.2% from 1983 to 1997. The Food and Drug Administration (FDA) has responsibility for ensuring the safety and nutritional quality of infant formulas based on current scientific knowledge. Consequently, under FDA contract, an ad hoc Expert Panel was convened by the Life Sciences Research Office of the American Society for Nutritional Sciences to make recommendations for the nutrient content of formulas for preterm-LBW infants based on current scientific knowledge and expert opinion. Recommendations were developed from different criteria than that used for recommendations for term infant formula. To ensure nutrient adequacy, the Panel considered intrauterine accretion rate, organ development, factorial estimates of requirements, nutrient interactions and supplemental feeding studies. Consideration was also given to long-term developmental outcome. Some recommendations were based on current use in domestic preterm formula. Included were recommendations for nutrients not required in formula for term infants such as lactose and arginine. Recommendations, examples, and sample calculations were based on a 1000 g preterm infant consuming 120 kcal/kg and 150 mL/d of an 810 kcal/L formula. A summary of recommendations for energy and 45 nutrient components of enteral formulas for preterm-LBW infants are presented. Recommendations for five nutrient:nutrient ratios are also presented. In addition, critical areas for future research on the nutritional requirements specific for preterm-LBW infants are identified.

Expression of natural antimicrobial human lysozyme in rice grains

In the present study, we explored the expression of human lysozyme in maturing rice grains. Particle bombardment-mediated transformation was utilized to deliver the codon-optimized structural gene for human lysozyme to the callus of rice cultivar Taipei 309. Lysozyme expression is controlled by the promoter and signal peptide sequence for rice storage protein Glutelin 1. A total of 33 fertile plants were regenerated from independent transformation events and 12 of them with significant expression levels of lysozyme were advanced to further generations. The transgenes were characterized by PCR and Southern blot analysis. Segregation analysis indicated a typical Mendelian 3: 1 inheritance, suggesting a single locus or closely linked loci of gene insertion. The expression levels of lysozyme reached 0.6% of the brown rice weight or 45% of soluble proteins. Seven transgenic breeding lines have been selected and followed over six generations. Lysozyme expression levels were maintained in all generations. Biochemical, biophysical and functional comparisons of native and recombinant human lysozyme revealed identical N-terminal sequence, molecular weight, pI and specific activity. Similar thermal and pH stability was observed for lysozyme from two sources. Furthermore, similar bactericidal activity was displayed towards a laboratory strain of E. coli. The possibility of improving medical and nutritional quality of infant formulas and baby foods with rice flour or rice extract containing recombinant human lysozyme is discussed.

Implementation of a HACCP system for on-site hospital preparation of infant formula

Hazard Analysis and Critical Control Point (HACCP) system was introduced to infant formula preparation rooms in four hospitals in Salvador, Bahia, Brazil. The homogenization of powdered milk and ingredients, refrigeration and holding steps before service were identified as critical control points (CCPs). Utensils and workers’ hands were identified as sources of cross contamination. Educational training courses emphasizing food safety and good preparation practices were introduced to the personnel of the rooms. Corrective actions were adopted at the CCPs that were found to be out-of-control. Implementation of HACCP system improved infant formula quality by reducing total aerobic microbial counts in the formula, and on utensils and workers’ hands of approximately 4.0, 3.0 and 4.0 log cycles, respectively. S. aureus and fecal coliforms were no longer found.

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

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.

Solubility and digestibility of milk proteins in infant formulas exposed to different heat treatments.

There are presently several fundamentally different technologies to produce infant formulas (IF), such as sterilization, spray-drying, and treatment at ultrahigh temperature (UHT). The effects of heat treatment on milk proteins in IF were analyzed by column chromatography, gel electrophoresis, and Kjeldahl analysis, revealing strong protein-protein and protein-lipid interactions in processed milk. These interactions were more pronounced in conventionally (in-can) sterilized than in spray-dried (powdered) and UHT products confirming their temperature dependency. Analysis of raw materials, intermediate and end products of IF processing revealed that after homogenization the first indications of protein denaturation occurred, but that in-can sterilization as the final heat treatment caused irreversible denaturation of proteins and strong protein-lipid interactions. Lowering of the pH to 4-5, which is physiological for the stomach of young infants, enhanced the interactions. Support for an impairment of protein digestibility was given by in vitro analysis of protein digestibility, demonstrating significantly lower digestibility of in-can sterilized IF compared to their spray-dried and UHT counterparts. To investigate the effect of heat treatment on chemical reactions, i.e., occurrence of Maillard products, we showed by a fluorimetric assay that the amount of "available" lysine is lower in sterilized than in powdered IF. Our findings suggest that a more differentiated view regarding the protein quality of IF is needed.

Solubility and Digestibility of Milk Proteins in Infant Formulas Exposed to Different Heat Treatments

SummaryThere are presently several fundamentally different technologies to produce infant formulas (IF), such as sterilization, spray‐drying, and treatment at ultrahigh temperature (UHT). The effects of heat treatment on milk proteins in IF were analyzed by column chromatography, gel electrophoresis, and Kjeldahl analysis, revealing strong protein‐protein and protein‐lipid interactions in processed milk. These interactions were more pronounced in conventionally (in‐can) sterilized than in spray‐dried (powdered) and UHT products confirming their temperature dependency. Analysis of raw materials, intermediate and end products of IF processing revealed that after homogenization the first indications of protein denaturation occurred, but that in‐can sterilization as the final heat treatment caused irreversible denaturation of proteins and strong protein‐lipid interactions. Lowering of the pH to 4–5, which is physiological for the stomach of young infants, enhanced the interactions. Support for an impairment of protein digestibility was given by in vitro analysis of protein digestibility, demonstrating significantly lower digestibility of in‐can sterilized IF compared to their spray‐dried and UHT counterparts. To investigate the effect of heat treatment on chemical reactions, i.e., occurrence of Maillard products, we showed by a fluorimetric assay that the amount of “available” lysine is lower in sterilized than in powdered IF. Our findings suggest that a more differentiated view regarding the protein quality of IF is needed.

Evaluating the nutritional quality of infant formula

A rat bioassay was developed to pre-clinically screen infant formula. Weight gain coefficients, slopes of linear regression lines relating total and fat-free carcass weight gains and feed intake, were determined for six infant formulas and a high lactose diet. Weight gain coefficients for a whole milk-based formula and the high lactose diet were similar to each other and to two formulas that were whey-nonfat milk-based. Coefficients for the former two were higher than those for the nonfat milk- and soy protein isolate-based formulas, with there being no differences among coefficients for the latter formulas. Applications for this bioassay include pre-clinical screening of new or reformulated infant formula.

DEFECTIVE INFANT FORMULA:

Two soy-bared infant formulas (Neo-Mull-Soy and Cho-Free) were recalled in 1979 when it was discovered that they lacked an essential ingredient-chloride. However, thousands of infants nationwide had already used the defective formulas. Many of these infants were found to be in serious states of hypochloremic metabolic alkalosis. No one knows what the effects will be on their long-term growth and development. Two women whose infant sons had used the defective Neo-Mull-Soy discovered that the Federal government had not establishcd quality control procedures or nutrient standards for infant formulas. The two women pressed the Food and Drug Administration and the Congress to ensure the safety and quality of infant formula. Their effow resulted in the enactment of the Infant Formula Act of 1980 which sets nutrient standards for all infant formula and, for the first time, requires routine testing by manufacturers to ensure that each lnfant formula meets these nutrient standards.

Protein Evaluation in Growing Rats of Breast Milk and Breast Milk Substitutes with Special Reference to the Content of Non-Protein Nitrogen

The levels of individual proteins and other nitrogen containing substances differ considerably between cow's milk and human milk. Therefore, during manufacture of infant formulas, attempts are made to simulate the protein composition of human milk. However, the composition and nutritional characteristics of human milk protein are incompletely known. In this paper, the protein quality of breast milk protein with and without the non-protein-nitrogen (NPN) substances present in human milk was studied with growing rats and compared to two formulas, one "adapted" commercial infant formula and a suggested further modified, possibly improved, infant formula. Detailed examinations of protein and amino acid composition of the test diets are given. Breast milk protein with added NPN substances showed a lower protein quality than all other test proteins. Breast milk protein without NPN substances and the protein of the suggested infant formula were of similar quality while the protein of the commercial adapted formula was significantly better than all other test proteins. The use of rat growth assays in the evaluation of protein quality of infant formulas is discussed.