Infant Food Testing

Della Betta, F., Vitali, L., Fett, R., & Costa, A. C. O. (2014). Talanta, 122, 23-29.

Nitrates are non-toxic and can be excreted through urine without adverse effects. However, under low pH conditions or due to the action of nitrate-reducing bacteria, nitrates can be reduced to nitrites, leading to methemoglobinemia. This condition is particularly dangerous for infants under six months old, as their immune systems are not fully developed.

This paper presents an innovative sub-minute capillary zone electrophoresis method along with a simple sample preparation procedure for the simultaneous determination of nitrates and nitrites. The novelty of this method lies in its simplicity and the ability to separate analytes in less than 0.5 minutes. The background electrolyte (BGE) consists of 10 mmol/L perchloric acid and 40 mmol/L β-alanine, with a pH of 3.96. Thiocyanate is used as an internal standard.

The method was validated according to Eurachem guidelines and applied to the analysis of 14 infant food samples. Among these samples, one had a nitrate content exceeding the level permitted by Brazilian law (250 mg/kg), while all samples had nitrite concentrations below the limit of quantification.

Vakili, H., Talebpour, Z., & Haghighi, F. (2022). Food Chemistry, 390, 133204.

This study aims to determine specific free amino acids in amino acid-based infant formula and amino acid-modified medical foods for congenital metabolic disorders to validate their quality.

A method utilizing high-performance liquid chromatography coupled with diode array detection was developed and validated. Subsequently, the overall uncertainty was estimated using a bottom-up approach. Weighted least squares regression indicated good linearity, with a coefficient of determination ≥0.9960. The limits of detection were calculated to be between 0.01 to 0.28 μg/mL. The maximum recovery rates obtained ranged from 91% to 108%, with a relative standard deviation (RSD) of ≤15%. The expanded uncertainty for most amino acids was found to be below 20%.

Kickofel, Lisliane, et al. Microchemical Journal 205 (2024): 111133.

Copper is essential for various functions in the human body, including supporting the immune system, participating in energy metabolism, processes related to hair and skin pigmentation, promoting the transport of iron in the body, and maintaining connective tissue. Additionally, copper acts as an antioxidant, helping to prevent damage caused by free radicals. The recommended dietary intake (RDI) for copper is 200 µg for infants aged 0 to 6 months, 220 µg for infants aged 7 to 11 months, and 340 µg for children aged 1 to 3 years.

This study presents, for the first time, the development of an analytical method for extracting copper from infant formula and milk-based foods using matrix solid-phase dispersion (MSPD), followed by further determination using high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). The MSPD parameters were investigated, utilizing 0.25 g of sample, 0.25 g of diatomaceous earth as the carrier, and 1 mol/L HNO₃ as the extraction solvent, stirred for 1 minute, yielding good consistency with reference values. The method demonstrated a limit of detection of 0.35 µg/g.