High-temperature sterilisation, explained

Freshcon says its pre-cooked range is made with “HT Technology”: “Our ‘High Temperature Sterilization’ ensures safe, preservative-free products with preserved flavors, textures, and nutrients.” This page explains the general food-science principle. Freshcon’s own process parameters are not public.

The principle

In thermal sterilisation, often called retort processing, food is sealed in an airtight container (a can, jar or multi-layer pouch) and then heated under pressure to temperatures above boiling, typically around 115–121 °C. It is held there long enough to destroy harmful microorganisms and their heat-resistant spores. The container is then cooled.

Commercial sterility

The aim is “commercial sterility”: no microorganisms remain that could grow in the sealed pack at normal storage temperatures. The process is designed especially around Clostridium botulinum spores, the main hazard in low-acid foods such as legumes and corn.

Why no preservatives are needed

Because the food is sterilised inside a hermetically sealed pack, nothing can recontaminate it until it is opened. That is why properly processed retort foods can be stored at room temperature for months without added preservatives or refrigeration. Once opened, treat the food like any freshly cooked food.

Taste and texture

Modern flexible pouches are thinner than cans, so heat gets through them faster. Shorter heating generally helps keep texture, colour and flavour.

Related: Shelf life without preservatives · How Freshcon products are made

General explainer. Statements attributed to Freshcon are quoted from its own published pages.