The samples, together with their original packaging, were
placed securely in a sterile re-sealable plastic bag, and then transported
promptly to the laboratory in ice boxes, if necessary. Details
of each sample, including the manufacturer, ‘best-before’ date,
packing date, country of origin and retailer, were recorded
systematically. All samples were analysed within 24 h after time of
purchase, keeping them in their original storage conditions as
much as possible in the meantime. Fresh-cut salads were analysed
before their ‘best-before’ dates. This ensured that the conditions of
the samples represent the product accurately, as retailers should
not be selling products that are past the ‘best-before’ date (CFIA,
2001). Before samples were taken out of their original packaging,
the surfaces of the packaging were carefully sterilised using ethanol
swaps to prevent cross-contamination. Samples that had been
damaged, unpackaged or visibly compromised before analysis were
discarded.