Microbiological food safety of infant foods is key due to the relatively undeveloped infant gut microflora and immune system. As Dr. Roy Betts explains in a recent article, the permeable and immature infant gut is more susceptible to invasion by harmful bacteria that can cause severe illnesses.1
When it comes to gut colonization, the first foods eaten by an infant matter. Interestingly, the gut flora of formula fed and breastfed infants differ in composition, with Enterobacteriaceae, Staphylococcus, Clostridium, Bifidobacterium, Enterococcus and Bacteroides spp. identified in the gut of formula fed infants. In breast fed infants, gut flora is made up of mainly lactobacilli, bifidobacteria and streptococci. For the health and safety of infants, foods, including formulas and pureed foods, are carefully preserved and sealed during manufacturing.
Looking to improve the safety of foods for infants, in 2005, The European Commission issued the European Regulation on Microbiological Criteria for Foods (EC2073/2005) which requires manufacturers to test powdered infant foods for Enterobacteriaceae, Bacillus cereus, Salmonella and Enterobacter sakazakii (Cronobacter spp.) in powdered infant feeds. Additional testing for Listeria monocytogenes must be completed for foods considered ready-to-eat.
The International Commission on Microbiological Specifications for Foods (ICMSF) has also given examples of microbiological criteria for powdered infant foods requiring reconstitution. In 2011, their book 8 review offered the most stringent requirements with special consideration for Cronobacter species (formally known as Enterobacter sakazakii), and coliforms.
Dry infant formula manufacturers need to be aware of the potential risks for contamination. Dr. Betts advises that dry cleaning techniques should always be the preferred option in dry production/mixing areas. Wet cleaning can create optimal growth for Enterobacteriaceae such as Salmonella and Cronobacter that could find their way into the food products. For this reason, the current recommendations published by the UK Department of Health advises consumers to rehydrate infant formula with water at a temperature of 70°C or higher. Of course, formulas must also cool to a safe temperature so that they do not pose a risk of scalding, but not for so long that any surviving microorganisms are able to grow and multiply.
Another type of food given to infants, pureed jarred or pouch-type foods, are considered commercially sterile since most bacteria will be killed after heat treatment at the relatively low temperature, of 70°C for two minutes. For these foods, the most dangerous organism is Clostridium botulinum, which can produce dangerous neurotoxins capable of causing paralysis and death. To control C. botulinum, experts recommend using a pack heat process in excess of 121°C for three minutes, or in foods with a pH of less than 4.5, a pasteurization process of less than 121°C for three minutes. Some foods, like honey for example, have the potential to harbor inactive botulism spores. While not a risk for the majority of the population, children younger than 12 months, should not be fed honey due to a risk of contracting infant botulism.
As the most vulnerable population, Dr. Betts advises that great care should be taken when producing foods for infants.
1. Betts, Roy “Microbial Update: Infant feeds“