How to Ensure the Chemical Safety of Infant Formula and Baby Foods
Author: Lukas Vaclavik, Contaminants Senior Staff Scientist
The quality and safety of infant formula and baby food are a major concern for parents, public health authorities, and regulatory bodies worldwide. Considering specific nutritional requirements and increased vulnerability of infants and young children to hazards associated with chemical and microbiological contamination, stringent regulations enforced by official control apply to these products. Infant formula and baby food producers need to design comprehensive testing plans to ensure that their supply chain and finished products are free of harmful chemicals and pathogens.
Potential Contaminants in Infant Formula and Baby Foods
The main potential sources of chemical contaminants in infant formula and baby foods include: (i) contaminated raw materials used in preparation of the final product, (ii) heat-treatment during the production process, and (iii) migration from food contact materials.
There are a number of chemicals that enter the environment and food chain as a result of anthropogenic activities. These include a wide range of pesticides used to protect and increase the yield of crops, veterinary drugs administered to animals as therapeutic, prophylactic, and growth promotion agents, as well as various industrial pollutants, such as heavy metals, dioxins, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), brominated flame retardants (BFRs) and other persistent organic pollutants. Many of these compounds can accumulate in cow’s milk or contaminate other infant formula ingredients and survive the production process. Similarly, the use of tainted cereals, fruits, vegetables, or meat in the production of baby food may result in contamination of finished products.
Mycotoxins represent a diverse group of naturally formed chemicals that are of high concern with regard to their toxicity. Mycotoxins, including aflatoxins, fumonisins, trichothecenes, ochratoxins, and zearalenones, are secondary metabolites of fungi that may contaminate agricultural commodities before, during, or after their harvest. In addition to direct contamination of raw materials, toxic metabolites of aflatoxins can be formed and deposited in cow’s milk as a result of exposure of animals via contaminated feed.
Heat-treatment steps are often employed in production of both infant formula and baby food ingredients and finished products. Besides losses of important nutrients (e.g. vitamins, minerals, and amino acids), treatment at high temperatures may lead to the formation of harmful molecules through various reaction pathways. Examples of processing contaminants include acrylamide, furan, or monochloropropanediol and glycidol esters.
Another route of contamination is associated with use of unsuitable materials for packaging of finished products. If the material in contact with the food matrix is not of sufficient quality, migration of compounds, such as bisphenol A, phthalates or semicarbazide, may occur.
Contaminant Testing: Challenges and Solutions
Routine testing of contaminants and chemical residues in infant formula and baby food represents a challenging task. The methods used for testing need to fulfill strict performance requirements in terms of accuracy and precision, be able to provide quantitative results at trace concentrations, and reliably identify positive findings. Fast and streamlined procedures with a short turn-around time (time from sample receipt to reporting of results) are needed, as the results are expected to be available as soon as possible in order to release the particular test item to the marketplace or to use tested ingredient in the production.
To address these challenges, automation of sample preparation and other strategies that enable increased analysis throughput along with advanced analytical techniques are required. A number of different analytical techniques are used in chemical food safety testing. Depending on the purpose of the analysis, these range from rapid bioassays, such as enzyme-linked immunosorbent assay (ELISA), to advanced instrumental techniques including infrared (IR) spectroscopy, nuclear magnetic resonance (NMR), or mass spectrometry (MS). The last mentioned technique, especially in hyphenation with liquid chromatography (LC) or gas chromatography (GC), is currently the most frequently employed tool in this endeavor. There is a clear trend towards finding new ways to analyze as many contaminants and residues as possible in a single method. Modern workflows, based on LC-MS and GC-MS, can determine hundreds or even close to a thousand analytes in a single analytical run.
Pesticide Residue Analysis
With hundreds of compounds of interest, strict regulation, and method performance guidance documents in place, pesticide residue analysis is a good example of a challenging area in testing of infant formula and baby food. The European Commission introduced regulatory requirements that set maximum residue levels (MRLs) for pesticides in infant formula and baby food at 0.01 mg/kg. Certain pesticides have even more stringent limits (MRLs ranging from 0.004 - 0.008 mg/kg) or should not be used at all in agricultural production intended for infant formula and baby food. These analytes need to be tested down to 0.003 mg/kg. The above requirements are dictated by the Commission Directives 2006/141/EC and 2006/125/EC and apply to products as proposed ready for consumption or as reconstituted according to the instructions of the manufacturers.
Multi-residue methods used in the pesticide testing arena are usually based on the combination of the QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample preparation and LC-MS/MS and GC-MS/MS determinative steps. Both LC-MS/MS and GC-MS/MS techniques need to be used to determine LC and GC-amenable pesticides that differ in their physico-chemical properties. Tandem mass spectrometric detection provides the sensitivity and selectivity needed to monitor the analytes at low concentrations and ensure the test product meets the regulatory requirements. State-of-the-art multi-residue methods enable to cover analysis of over 500 pesticides.
Certain pesticides do not fit into the scope of multi-residue methods, either because of different properties or due to definition of their MRL, and need to be analyzed with specially tailored methods. For example, propineb (pesticide belonging to a group of dithiocarbamate fungicides) has a specific MRL of 0.006 mg/kg for the sum of propineb and its metabolite propylenethiourea (PTU) in infant formula and baby food. Propineb and PTU need to be analyzed using dedicated single residue methods. Selective determination of propineb is particularly difficult considering problems with solubility and stability of this pesticide. Traditional residue analysis based on the conversion of dithiocarbamates to carbon disulphide followed by GC analysis cannot distinguish individual dithiocarbamates, such as propineb, and is prone to generating false-positive results. To address this issue, an alternative LC-MS/MS-based method was developed and implemented at Eurofins Food Chemistry Testing laboratories. This method allows reliable and selective determination of propineb in infant formula, baby food, and related ingredients in compliance with applicable EU regulations.
Data Quality Assurance
Assuring the quality of the analytical results is of paramount importance when testing for contaminants and residues in infant formula and baby food. Methods to be used need to be thoroughly validated and the laboratories providing the testing services accredited according to ISO/IEC 17025 standard. Ongoing technical competence and performance of the laboratories for specific tests should be periodically demonstrated through participation in proficiency tests.
Eurofins Food Chemistry Testing in Madison, WI provides comprehensive chemical contaminant and residue testing services meeting the requirements of infant formula and baby food regulations. Visit Eurofins Infant Formula and get in touch to design or review your testing program and increase its quality and efficiency.
