Infant formula biotin

INDYK HE et al. (2000), Determination of biotin and folate in infant formula and milk by optical biosensor-based immunoassay , JAOCS, 83(5), 1141-8. 

The literature contains very little on methods for biotin determination in foods. Microbiological assays of biotin predominate in food work (19,180). Table 23 summarizes a recent HPLC method for the analysis of biotin in infant formula. 

Biotin and biotin analogs Infant formula Protein precipitation using concentrated hydrochloric acid neutralization with 6 M NaOH lipid extraction with n-hexane Precolumn Microsorb C18 (15 X 4.6 mm, 5 jam Rainin). Analytical Microsorb C18 (250 X 4.6 mm, 5 /zm Rainin). Isocratic 100 mM phosphate buffer, pH 7.0 + methanol (80 + 20, v/v). 0.4 ml/min. Postcolumn reaction system UV absorbance at 220 nm followed by streptavidin-fluorescein isothiocyanate (2.0 mg/L) knitted open tubular reaction system (10.0 m x 0.5-mm ID) at a flow rate External standardization. 184 Linear range = 0.08-1.00 fjM biotin. LoD = 0.02 /zM or 97 pg biotin at SNR = 3. Repeatability CV 3.5% for biotin in infant formula. 

The bioassay was used to determine the bioavailability of zinc in milk-base and soy-base infant formulas (7). The results are shown in Figure 2 and Table 1. The low zinc basal diet contained (%) spray dried egg white powder, 20 com oil, 10 non-nutritive fibre, 3 starch, 25 biotin, 0.0004 vitamin mixture, 1 salt mixture, excluding zinc, 4 dextrose, 37. 

The UPLC-MS/MS method has also been developed for fast simultaneous separation and determination of 14 different water-soluble vitamins and vitamin-like compounds in infant formula (thiamine, riboflavin, pantothenic acid, nicotinic acid, nicotinamide, pyridoxine, pyridoxal, biotin, fohc acid, cyanocobalamin, ascorbic acid, L-camitine, choline, and taurine) [91], Methotrexate was also used as an internal standard for riboflavin, cyanocobalamin, biotin, and folic acid, while nicotinamide was used as an internal standard for the other compounds. 

The relative binding response is interpolated from a calibration curve in order to compute concentration. As an inhibition assay, the response is inversely related to biotin concentration and exhibits a sigmoidal dose-response relationship that is typical of most ligand-binding assays. With respect to specificity, the routine compliance assay is targeted to the quantitation of free biotin only in nutritional dairy products, and therefore does not include biocytin (Indyk et al. 2000). However, in milk and supplemented infant formulas, the overwhelming majority of biotin is present in the free form. 

Human milk is the primary agent for infant nutriture and thereby guides the composition of manufactured infant formula and milk substitutes. The reported concentration of biotin in human milk is variable with lactation (and unfortunately between analytical methods), but is more than sufficient to supply the newborn infant with the RDI of 5-6pg/day, as evidenced by the absence of reported deficiency syndromes in breast-fed babies. Interestingly, most biotin in milk is present in a free form and therefore unbound with any macromolecules. As expected, when milk is separated into its fat and aqueous fractions, the water-soluble biotin is found predominantly in the skim-milk phase. Biotin has some lipophilidty and so a small percentage is carried into the cream as part of the fat-globule membrane. The total concentration of human milk is not large and somewhat similar to bovine milk. With respect to breast milk substitutes, it is necessary to ensure the biotin status remains comparable, thus international guidelines recommend 0.4-2.4pg/100 kJ of reconstituted or ready-to-feed infant formula. 

Campos-Gimenez, E.C., Trisconi, M-J., Kilinc, T., and Andrieux, P., 2010. Optimization and validation of an LC-FLD method for biotin in infant formula, infant cereals, cocoa-malt beverages and clinical nutrition products. Journal of AOAC International. 93 1494—1502. 

Thompson, L.B., Schmitz, D.J., and Pan, S-J., 2006. Determination of biotin by high-performance liquid chromatography in infant formula, medical nutritional products and vitamin premixes. Journal of AO AC International. 89 1515-1518. 

Watanabe, Y., Ohya, T., Ohira, T., Okada, J., Fukui, T., Watanabe, T., Inokuchi, T., Yoshino M., and Matsuishi, T., 2010. Secondary biotin deficiency observed in two Japanese infants due to chronic use of hypoallergic infant formula. Journal of Inherited Metabolic Disease. 33(Suppl 1) SI69 549-P. 

Infants fed on dairy-based formulae need additional biotin added to their food. 

Fujimoto, W., Inaoki, M., Fukui, T., Inoue, Y., and Kuhara, T., 2005. Biotin deficiency in an infant fed with amino acid formula. The Journal of Dermatology. 32 256-261. 

MINERAL AND VITAMIN SUPPLEMENTS. There is considerable controversy among nutritionists and pediatricians regarding the amounts and types of nutrient supplements that are required by infants, since breast-fed infants have long been given little or no supplementation. Furthermore, the need for supplementation depends upon a variety of factors such as (1) status of the infant at birth, since preterm or low birth weight infants have higher nutritional requirements to attain the rates of growth and development of normal infants (2) type of milk or formula used (3) affliction of the infant with diarrhea, fever, infection, and/or other stresses and (4) age at which supplemental foods are introduced. It is noteworthy that even breast milk is low in iron, copper, fluoride, vitamins A, D, and E, and biotin, folacin, niacin, thiamin, and vitamin B-6. Furthermore, diluted evaporated milk is notably inferior to breast milk with respect to the contents of iron, zinc, vitamin A, vitamin E, and vitamin C. Therefore, the need for nutrient supplements should be evaluated by a health professional who is familiar with the diet and the overall health status of the infant. 

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