Acids In Infant Formula Research Articles

Nutrition for the pediatric office: update on vitamins, infant feeding and food allergies.

Advances in the field of pediatric nutrition continue to help the pediatric office practitioner provide excellent clinical care to their patients. In 2003, several important papers were published in the field of clinical nutrition that are reviewed. New recommendations by the American Academy of Pediatrics for vitamin D supplementation for breast-fed infants have been published that underscore the importance of routine supplementation with 200 IU vitamin D per day. Vitamin K should be provided (0.5 to 1 mg intramuscularly) to all newborns. The authors also review original reports evaluating the role of long-chain polyunsaturated fatty acids in infant formulas, the duration of exclusive breast-feeding, and the natural history of food allergies. Some observational studies support exclusive breast-feeding for 6 months. Data concerning the efficacy of long-chain polyunsaturated fatty acids are conflicting but do support the safety of these additives. Regular supplementation with vitamin D, and newborn provision of vitamin K, are important nutritional interventions for infants and children.

Determination of free amino acids in infant formulas

Abstract A fast and reliable method for the determination of free amino acids in infant formulas was developed. The method emphasizes the determination of taurine, methionine, arginine and tyrosine, as they are often added to these formulas in order to adapt them to the nutritional requirements of infants. The method involves the precipitation of the protein fraction, its separation by centrifugation, and the HPLC analysis of the o -phthaldialdehyde (OPA) derivatives of the free amino acids. The method was applied to several commercial formulas, as their actual content of free amino acids may be reduced by the development of Maillard reaction during processing and storage. The detected amounts of free taurine and methionine were often lower than those listed by the manufacturers. In some samples significant amounts of free arginine, tyrosine and methionine were detected, although they had not been listed among the added ingredients.

Requirements for long-chain polyunsaturated fatty acids in the preterm infant.

Dietary long-chain polyunsaturated fatty acids have demonstrable beneficial effects on early development. The effects on neural development are of particular interest. Human milk is the best and only time-proven source of fat and essential fatty acids in the infant diet. Technologic procedures based on chemical and physical separation of the unsaturated fatty acids have permitted the isolation of concentrated sources of docosahexaenoic acid and arachidonic acid for clinical use. Virtually all infant formulas in developed countries have increased the levels of gamma-linolenic acid, and several manufacturers in Europe and in Japan have added docosahexaenoic acid, or docosahexaenoic acid plus arachidonic acid, or have also included gamma-linolenic acid in formulas for preterm and term infants. The efficacy of this practice for preterm infants seems fairly well established. The use of stable isotope methods to evaluate biosynthesis of long-chain polyunsaturated fatty acids from dietary precursors may help to better define optimal amounts and relationships of fatty acids in infant formula.

Effect of long-chain polyunsaturated fatty acids in infant formula on problem solving at 10 months of age

Long-chain polyunsaturated fatty acids (LCPUFA) are important for normal visual and brain development. Although present in human milk, LCPUFA have until recently been absent from artificial formulas, and infants may have limited ability to synthesise LCPUFA. To determine the clinical significance of this relative deficiency of LCPUFA, we undertook a randomised trial of the relation between LCPUFA supplementation and infant cognitive behaviour. 44 term infants had been randomised to a formula supplemented with LCPUFA (21) or not supplemented with LCPUFA (23), which they had taken from birth to age 4 months. Infant cognitive behaviour was assessed at 10 months of age by a means-end problem-solving test--the intentional execution of a sequence of steps to achieve a goal. The problem required three intermediate steps to achieve the final goal, uncovering and retrieving a hidden toy. Infants who received LCPUFA-supplemented formula had significantly more intentional solutions than infants who received the no-LCPUFA formula (median 2.0 vs 0, p=0.021). Intention scores (median 14.0 vs 11.5 [maximum 18]) were also increased in this group (p=0.035). These findings suggest that term infants may benefit from LCPUFA supplementation, and that the effects persist beyond the period of supplementation. Since higher problem-solving scores in infancy are related to higher childhood IQ scores, supplementation with LCPUFA may be important for the development of childhood intelligence.

Structural Position and Amount of Palmitic Acid in Infant Formulas: Effects on Fat, Fatty Acid, and Mineral Balance

SummaryThe structure of the triglycerides (TG) in human milk (HM) differs from those of vegetable oils used in infant formulas. In HM, palmitic acid is predominantly esterified to the center or β‐position of the TG, in vegetable oil, it is mainly at the external or α‐positions. These differences in configuration affect intestinal fat absorption. Fat and mineral balances were investigated in three groups of 9 healthy term infants aged 5 weeks. Infants were randomly assigned to receive one of the three study formulas from birth: (a) formula beta, resembling the structure of HM fat most closely (24% palmitic acid, 66% esterified to β‐position), (b) formula intermediate (24% palmitic acid, 39% esterified to the β‐position), and (c) regular formula (20% palmitic acid; 13% esterified to the β‐position). Fat absorption was highest in infants fed the beta formula (97.6 ± 0.9%), intermediate in those fed with the intermediate formula (93.0 ± 1.8%), and lowest in infants receiving the regular formula (90.4 ± 4.6%). Fecal calcium excretion was significantly lower in the beta group than in the other two groups (43.3 ± 18.1 vs. 59.9 ± 15.1 vs. 68.4 ± 22.3 mg · kg‐1 · day‐1 for beta, intermediate, and regular respectively). Dietary TG containing palmitic acid predominantly at the β‐position, as in HM, have significant beneficial effects on the intestinal absorption of fat and calcium in healthy term infants.

Red blood cell and tissue phospholipid fatty acid profiles of weanling rats fed infant formula fat blends containing soy and/or corn oil.

Soy oil or corn oil may be employed to provide essential fatty acids in infant formulas. Both of these sources are high in linoleic acid; soy oil contains modest levels of alpha-linolenic acid, while corn oil contains very low levels of this essential omega 3 fatty acid. We examined the omega 3 long-chain polyunsaturated fatty acid (LCP) accretion in red blood cells, liver, and brain phospholipids of rats on diets containing infant formula fat blends with essential fatty acids provided from soy and/or corn oil. Although modest alterations occurred in the red blood cell omega 3 LCP fatty acid status, substantially larger changes were noted in liver LCP profiles. Due to the relatively mature nature of the rats employed in this experiment, no alterations were noted in brain fatty acid profiles. In conclusion, we have observed substantial tissue differences in animals fed soy or corn oil containing diets. It appears that corn oil is inappropriate for use in infant formulas.

Comparison of voltammetric and high performance liquid chromatographic methods for ascorbic acid determination in infant formulas

Two methods — voltammetric and high performance liquid Chromatographic (HPLC) — useful for determining ascorbic acid in foods, were compared to ascertain which of them could be used for routine determination of ascorbic acid in infant formulas. Both methods were used to assay 10 identical samples of an adapted cow's milk infant formula and 10 samples of soya protein formula. Precision was determined, the variance of each method was measured, and the methods were compared with each other. The variances of the two methods were not statistically different nor was there any significant difference between the results from the two methods. Therefore, it was concluded that both methods can be used for determination of ascorbic acid in infant formulas. The voltammetric method, because of its simplicity, cheapness and less time-consuming nature, could be used for routine determination.

The role of fatty acid composition and positional distribution in fat absorption in infants

Fat digestion and absorption in the infant is a multistep process. An initial gastric phase of lipolysis generates modest amounts of diglycerides, monoglycerides, and free fatty acids. These initial digestion products, as well as bile salts, are required for optimal activity of the intestinal phase of lipolysis. Colipase-dependent pancreatic lipase catalyzes the intraduodenal phase of triglyceride digestion in formula-fed infants; in breast-fed infants this process is also mediated by bile salt-stimulated lipase. Triglyceride fatty acid positional distribution may modulate the efficiency of nutrient absorption. Human milk contains palmitic acid (C16:0) primarily in the sn-2 position; infant formula fat blends contain palmitic acid predominantly in the sn-1 and sn-3 positions. Because pancreatic lipase selectively hydrolyzes triglycerides at the sn-1 and sn-3 positions, free fatty acids and 2-monoglycerides are produced. Free palmitic acid, but not 2-monopalmitin (which is efficiently absorbed), may be lost as a calcium-fatty acid soap in the feces. As a result, many infant formulas contain substantial levels of well-absorbed saturated fatty acids of shorter chain lengths (e.g., C12:0) in place of palmitic acid. Means of increasing the proportion of 2-palmitic acid in infant formula may make possible fat blends closer to that of human milk with acceptable absorption characteristics.

Liquid Chromatographic Determination of Folic Acid in Infant Formula and Adult Medical Nutritionals

Abstract A liquid chromatographic method for the determination of pteroylglutamic acid (folic acid) in infant formula and liquid medical nutritional diets is described. Extraction of folic acid from the sample matrix is facilitated by a partial enzymatic digestion of the sample proteins. An aliquot of the sample preparation is injected onto a strong anion exchange column (SAX) for preliminary separation, using a pH 5.3 mobile phase of 0.02M sodium acetate and 0.02M sodium sulfate. Before the elution of the folic acid from the SAX column, the eluant is directed onto an octyl bonded-phase column (C8) by using automated switching valves. After the folic acid has been transferred to the C8 column, the SAX column is removed from the flow path. The folic acid is eluted from the Cs column by using an acetonitrile gradient. Detection is by absorption at 345 nm. The mean coefficient of variation is 3.6%, and the range of the recoveries of added folic acid is 95.5-100.2%. The method detection limit and method quantitation limit for infant formula are 10 and 28 µg/kg, respectively. This method is used routinely for the determination of folic acid in infant formula and liquid medical nutritional diets.

Determination of the optimal ratio of linoleic acid to α-linolenic acid in infant formulas

The fatty acid composition of erythrocyte total lipids taken from a group of term infants 10 weeks after being fed a commercial infant formula with a high ratio of linoleic acid (18:2n-6) (LA) to alpha-linolenic acid (18:3n-3) (ALA) (19:1; LA, 14%; ALA, 0.7%; group A, n = 10) was compared with the fatty acid composition of erythrocytes from infants fed formulas that contained LA/ALA ratios reduced by either increasing ALA (4:1; LA, 13%; ALA, 3.3%; group B, n = 11) or decreasing LA (3:1; LA, 3.5%; ALA, 1.1%; group C, n = 8). Results were compared with those in an age-controlled group (n = 9) of breast-fed infants. Decreasing the LA/ALA ratio increased n-3 C20 and C22 fatty acid incorporation (formula B = 8.98% +/- 0.65%; formula C = 9.30% +/- 0.95%) relative to formula A (5.97% +/- 0.76%; p less than 0.05). Although docosahexaenoic acid (22:6n-3) (DHA) incorporation was highest in infants fed formulas B and C (4.78% +/- 0.45% and 4.48% +/- 0.49%, respectively) relative to formula A (3.47% +/- 0.46%; p less than 0.05), it did not reach levels found in breast-fed infants (6.55% +/- 1.23%; p less than 0.05). In addition, levels of arachidonic acid (20:4n-6) (AA) were lower in all formula-fed groups (p less than 0.05) relative to those in breast-fed infants. Based on some equations, it is predicted that AA levels in tissues of infants fed lower LA/ALA ratios would be reduced even further. Because both AA and DHA are probably essential for normal neural development of the infant, formulas with LA/ALA ratios below 4:1 are likely to result in fatty acid profiles notably different from those of breast-fed infants.

Upper Limits of Intakes of Total Fat and Polyunsaturated Fatty Acids in Infant Formulas

The upper limit for fat in infant formulas in the United States is 6 g per 100 kcal. This concentration of fat, similar to that of human milk, seems appropriate for fats that are well absorbed. The upper limit for linoleic acid recommended by the working party in the United Kingdom was 1200 mg per 100 kcal. However, there seems to be no evidence that a higher percentage does the infant any temporary or permanent harm.

Upper Limits of Intakes of Total Fat and Polyunsaturated Fatty Acids in Infant Formulas

The upper limit for fat in infant formulas in the United States is 6 g per 100 kcal. This concentration of fat, similar to that of human milk, seems appropriate for fats that are well absorbed. The upper limit for linoleic acid recommended by the working party in the United Kingdom was 1200 mg per 100 kcal. However, there seems to be no evidence that a higher percentage does the infant any temporary or permanent harm.

Quantitative Determination of Linoleic Acid in Infant Formulas by Gas Chromatography

A method has been developed for the quantitative determination of linoleic acid in infant formulas by gas chromatography (GC). A known amount of triheptadecanoin was spiked into the sample. Total lipid was extracted from the product by an ethyl ether-petroleum ether-ethanol system in a Mojonnier flask. The sample was saponified by methanolic KOH after the solvents were evaporated. Methyl esters of the fatty acids were prepared by boron trifluoride (BF3) in methanol and analyzed by gas chromatography. A glass column packed with 10% SP-2340 (75% cyanopropyl silicone) was used to separate and identify the methyl linoleate and the methyl heptadecanoate. The quantity of methyl linoleate was calculated by comparing the integrated peak areas of these 2 fatty acid methyl esters. This method was satisfactory for both milk protein-based and soy protein-based matrixes. The results obtained by this method are comparable to those obtained by the AOAC spectrophotometric method 28.082-28.085.

Unsaturated fatty acids in infant formula

Unsaturated fatty acids in infant formula

Unsaturated Fatty Acids in Infant Formula

To the Editor.— I read with great interest the article entitled Science of Infant Nutrition and the Art of Infant Feeding by Calvin W. Woodruff, MD (240:657, 1978). The article is a rather complete review of this matter. I would like, however, to correct a misstatement that appears in the article. It is stated that vegetable oils that make up the fat component [of prepared infant formulas] contain more unsaturated fatty acids than human This statement is true when applied to infant formulas other than S-M-A. Our extensive research has been able to bring S-M-A closer in its chemical composition to breast milk than other infant formulas. This is true as it relates to its protein quality (60:40), electrolyte content, and, especially, fat composition. The fat in S-M-A contains approximately the same amount of unsaturated fatty acids as that found in human milk. For this reason S-M-A does