The Conversation: Food quality can deteriorate before we perceive obvious signs of spoilage. If allowed to grow to high levels, some microbes that may contaminate foods (collectively called ‘pathogens’) can cause foodborne illness, or ‘food poisoning’. Often these microbes don’t visibly spoil the food so we can’t tell if a food has become unsafe.

To protect consumers against poor quality or potentially hazardous foods, governments have introduced ‘date codes’ to help consumers evaluate the ‘freshness’ of foods. Food producers also embrace date codes to help them provide safe, high quality products to consumers.