Scientists from the Vetmeduni Vienna examined the microbiological safety, packaging and labelling of raw milk cheeses sold online.
They said a growing tendency to market cheese via the Internet has raised serious concerns as to how safe it is to deliver by post.
Of 108 cheeses from seven different countries, only 19 fulfilled all European guideline requirements.
Pathogens in cheese
More than half were not cooled properly during delivery and two were contaminated with Listeria monocytogenes - a semi-hard cheese produced in the Netherlands and a soft cheese made in France. Salmonella could not be detected in any samples.
E. coli and coagulase positive staphylococci (SA) could be detected in 29.6% (≥10 CFU/g; 32/108) and 8.3% (≥100 CFU/g; 9/108) of samples, indicating poor conditions of hygiene.
Delivery duration ranged from 24 hours to six days. Initial measurements took place immediately, or at the latest three days, following delivery.
Labelled product origins comprised seven European countries, of which 60.2% of all samples came from France and 13.9%, 11.1% and 9.3% from Italy, the Netherlands and Germany.
Dagmar Schoder, from the Institute of Milk Hygiene at the Vetmeduni Vienna, said they chose raw milk cheese because it is a high-risk product.
“As raw milk is unpasteurised, it can be easily contaminated with harmful bacteria. Even a small amount of bacteria, for which raw milk cheese offers ideal growing conditions, can reach critical proportions after a longer ripening, storage and transport time.
“The product is then no longer edible and may even make consumers ill. For this reason, special care must be taken during production, storage and transport.”
All 108 samples were described on websites as raw milk cheeses however 4.6% (5/108) were labelled as being manufactured from heat-treated or pasteurized milk.
Package temperatures ranged between 5.1 and 23.4 °C and in 61.5% (8/13) of all deliveries the temperature was higher than 15 °C.
“Some of the producers apparently have shortcomings in terms of hygiene. Furthermore, when making online purchases, I recommend consumers to check if a product is adequately packaged and cooled when it arrives,” said Schoder.
“Cheese must be cooled. But this was not the case with 61.5% of the raw milk products purchased. If raw milk cheese is not cooled, bacteria will grow more quickly. A longer transport journey and improper packaging increase the risk for consumers.”
Only 17.6% (19/108) of cheeses were properly labelled and fulfilled all European guideline requirements (EC Guideline 2000/13 and Regulation No. 853/2004).
Information, such as: specific storage requirements, name and address of the manufacturer/packager or seller, net weight, and shelf life was missing.
Water activity (aw) and pH values were measured at up to three time points before “use by date”.
None of the 108 investigated cheeses showed a pH ≤ 5.0 and aw value ≤0.94. For two samples and 11 samples the pH and the aw value was ≤4.4 or ≤0.92 at least at one of the three time points.
Existing guidelines and infrastructures are not adequate to administer online trade in these perishable commodities, said the researchers.
“The current novelty of buying food online seriously raises concerns that all these issues must be questionable in the absence of reactionary regulatory oversight. The problems are exacerbated by long transportation times of packaged portions taken from a whole product,” they said.
“Obligations to consumers must not be discounted and this places renewed responsibilities on manufacturers, suppliers and authorities to respect microbiological criteria to safeguard consumer health. Authorities in particular must be challenged to react to the new commercial structures taking place.”
Source: Food Control, volume 54, August 2015 pages 225-230
Online ahead of print, DOI: 10.1016/j.foodcont.2014.12.034
“How safe is European Internet cheese? A purchase and microbiological investigation”
Authors: Dagmar Schoder, Anja Strauß, Kati Szakmary-Brändle, Martin Wagner