An OT note on the question about food expiry dating. The use-by date on food is the least of your worries for food poisonings. First of all use-by dates on almost everything is way shorter than the time the actual item begins to degrade. Secondly, expiration dates on foods have more to do with freshness and taste that food safety. The biggest risk of food poisoning are food handling during and after preparation or items that are contaminated with a pathogen and are still well within their use by date.