How food manufacturing is classified?

Primary

Primary food processing turns agricultural products, such as raw wheat kernels or livestock, into something that can eventually be eaten

This category includes ingredients that are produced by ancient processes such as drying, threshing, winnowing, and milling grain, shelling nuts, and butchering animals for meat

It also includes deboning and cutting meat, freezing and smoking fish and meat, extracting and filtering oils, canning food, preserving food through food irradiation, and candling eggs, as well as homogenizing and pasteurizing milk

Contamination and spoilage problems in primary food processing can lead to significant public health threats, as the resulting foods are used so widely

However, many forms of processing contribute to improved food safety and longer shelf life before the food spoils

Commercial food processing uses control systems such as hazard analysis and critical control points (HACCP) and failure mode and effects analysis (FMEA) to reduce the risk of harm

Secondary

Baking bread is an example of secondary food processing

Secondary food processing is the everyday process of creating food from ingredients that are ready to use

Baking bread, regardless of whether it is made at home, in a small bakery, or in a large factory, is an example of secondary food processing

Fermenting fish and making wine, beer, and other alcoholic products are traditional forms of secondary food processing

Sausages are a common form of secondary processed meat, formed by comminution (grinding) of meat that has already undergone primary processing

Most of the secondary food processing methods known to human kind are commonly described as cooking methods

Tertiary

Tertiary food processing is the commercial production of what is commonly called processed food

These are ready-to-eat or heat-and-serve foods, such as TV dinners and re-heated airline meals