EU food labeling regulation has following requirement (Article 22):
1. The indication of the quantity of an ingredient or category of ingredients used in the manufacture or preparation of a food shall be required where the ingredient or category of ingredients concerned:
(a) appears in the name of the food or is usually associated with that name by the consumer;
(b) is emphasised on the labelling in words, pictures or graphics; or
(c) is essential to characterise a food and to distinguish it from products with which it might be confused because of its name or appearance.
There is also the general base requirement of not being misleading in Article 7:
1. Food information shall not be misleading, particularly:
(a) as to the characteristics of the food and, in particular, as to its nature, identity, properties, composition, quantity, durability, country of origin or place of provenance, method of manufacture or production;
(b) by attributing to the food effects or properties which it does not possess;
(c) by suggesting that the food possesses special characteristics when in fact all similar foods possess such characteristics, in particular by specifically emphasising the presence or absence of certain ingredients and/or nutrients;
(d) by suggesting, by means of the appearance, the description or pictorial representations, the presence of a particular food or an ingredient, while in reality a component naturally present or an ingredient normally used in that food has been substituted with a different component or a different ingredient.
1. The indication of the quantity of an ingredient or category of ingredients used in the manufacture or preparation of a food shall be required where the ingredient or category of ingredients concerned:
(a) appears in the name of the food or is usually associated with that name by the consumer;
(b) is emphasised on the labelling in words, pictures or graphics; or
(c) is essential to characterise a food and to distinguish it from products with which it might be confused because of its name or appearance.
https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CEL...
There is also the general base requirement of not being misleading in Article 7:
1. Food information shall not be misleading, particularly:
(a) as to the characteristics of the food and, in particular, as to its nature, identity, properties, composition, quantity, durability, country of origin or place of provenance, method of manufacture or production;
(b) by attributing to the food effects or properties which it does not possess;
(c) by suggesting that the food possesses special characteristics when in fact all similar foods possess such characteristics, in particular by specifically emphasising the presence or absence of certain ingredients and/or nutrients;
(d) by suggesting, by means of the appearance, the description or pictorial representations, the presence of a particular food or an ingredient, while in reality a component naturally present or an ingredient normally used in that food has been substituted with a different component or a different ingredient.
https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CEL...