Food processing and processed food intake categories beyond Nova: the PFI classification

Food processing and processed food with chemical engineering definitions for unit operations (UO) and unit processes (UP) were reviewed to establish five Food Processing Levels (FPL 0 to 4) with corresponding Processed Food Intake (PFI 0 to 4) categories. The FPL 0 to 4 scaling relates to physical changes and (bio)chemical transformations during processing, i.e., UO result in physical changes and losses of cellular structures with an FPL of 0 to 1 whereas UP involve (bio)chemical modifications and result in FPL 2 to 4. The FPL has uses in a variety of engineering and other applications, e.g., sustainability of food processing. Each FPL is differently responsible for food properties, including texture and sensory characteristics and food matrix effects in digestion with an impact on energy intake, nutritional properties and health. The PFI 4 represents formulated foods as Processed Ingredients Foods, including intermittent processing. The PFI categories allow comparison of FPL and food intake data from various PFI groups for different research, advisory, public health, general and other applications. The PFI classification is simple, and it can be used beyond Nova to relate FPL and food formulation to processed food intake and thereby to food processing impact on diet and health.