languages property
The languages field should be used to set the desired taxonomy language(s) when a taxonomy is requested with fields in one or more languages. The taxonomy's text fields should be filled with the requested languages in a prioritized manner based on the order supplied.
Please see https://github.com/openfoodfacts/openfoodfacts-dart/blob/master/DOCUMENTATION.md#about-languages-mechanics for detailed explanation on how to work with multiple languages.
Implementation
final List<OpenFoodFactsLanguage> languages;