A large group of adjectives in Apicius’ De re coquinaria is formed with the suffix -atus. Although they contain a suffix which is typical of the perfect participle, their base is not verbal, but nominal: this is their peculiarity. They are all adjectives referring to food; their meaning is possessing “the quality/condition expressed by the base-noun” (e. g. Apic. 8. 7. 14 liquamen piperatum). Many of them are Apicius’ creations and attested only in his cooking book (e. g. allecatum, coriandratus, syringiatus); a great number of them have a Greek origin. This paper proposes not only a semantic analysis of denominal adjectives with the suffix -atus, but also a comparison with adjectives ending in -osus, which have the meaning “full of ”. The formations in -atus of De re coquinaria are also examined according to the qualia theory, the principles of which are clearly recognisable in these adjectives. Apicius’ denominal adjectives in -atus can be compared to suffixed adjectives in some modern languages (Italian -ato, Spanish -ado, French -é), which express the concept of possession of a quality, and which derive from a noun, not from a verb, although they are formally identical to past participle, as it happens in Latin