Phosphoric acid (E338)

No. Phosphoric acid (E338) is not one of the markers Open Food Facts uses to classify a food as processed or ultra-processed, so on its own it doesn't raise a product's NOVA group.

What it is

Antioxidants are substances which prolong the shelf-life of foods by protecting them against deterioration caused by oxidation, such as fat rancidity and colour changes.

A product that contains it can still be ultra-processed for other reasons: 226 of the 235 products here that contain phosphoric acid (E338) (96%) are in group 4 because of other ingredients or additives.

Function

Antioxidant: Antioxidants are substances which prolong the shelf-life of foods by protecting them against deterioration caused by oxidation, such as fat rancidity and colour changes.
Sequestrant: Sequestrants are substances which form chemical complexes with metallic ions.

Functional class definitions from the EU food additives regulation, via Open Food Facts.

More about phosphoric acid (E338) on Wikidata

Where it turns up

Phosphoric acid (E338) appears in 235 of the 40,000 products on this site (1%).

Diet cola soft drink 62 of 67 products
Colas 52 of 142 products
Sodas 21 of 612 products
Salad dressings 20 of 252 products
Iced teas 10 of 73 products
Diet sodas 9 of 102 products

Products containing phosphoric acid (E338)

Showing the 60 most popular of 235.

How the NOVA classification works