There is never “in general” in french. We need always an article to define the object. For example : “he likes apples” will give : “Il aime les pommes”. We will never say “Il aime pommes”.

Unlike in English, the definite article in French isn’t intrinsically specific, and is in fact obligatory when a generic meaning is intended.

To mark specificity, we usually use a demonstrative or possessive determiner, both of which mark a noun phrase as specific:

Il raffole de ta tarte aux pommes.

Il raffole de cette tarte aux pommes.

Il raffole de cette tarte-là.

The definite article can be both generic or specific, but its normal reading is generic. You’d need some other element to mark a noun phrase with a definite article as specific, generally some kind of nominal or phrasal complement:

Il raffole de la tarte aux pommes de sa grand-mère

Il raffole de la tarte aux pommes que tu lui a cuisinée

(In both cases, an English translation would use a definite article here, rather than the zero article used with generics)

In some cases, doubling pronouns can be used to disambiguate between generic and specific:

Les chiens, ça aboie (Dogs bark – generic)

Les chiens, ils aboient (the dogs are barking – specific)

There are a few cases where la can be dropped:

C’est lui qui a pris le plus de tarte aux pommes (follows quantity adverb)

Il ne veux pas de tarte aux pommes (negative sentence, de la is also possible here)

Il s’est gavé de tarte aux pommes (de = preposition, colloquial, means "he force-fed himself with apple-pie")