This is a tricky question, because the answer from a pure phonetic perspective doesn't match the perception of most native English speakers. (Either British or American.)
In the phonological perception of native English speakers, the three allomorphs of the plural -s suffix are /s/, /z/, and /əz/. /z/ occurs after the final /l/ of 'apples', making singular /'æpəl/ into plural /'æpəlz/. As a native speaker of American English, I thought this was the whole story until I studied phonetics. If you ask other native English speakers, they will most likely agree that 'apples' ends with a /z/ sound.
From a pure phonetic perspective, the actual pronunciation of word-final /z/ in English often has very little voicing. This is surprising if you're expecting /z/ to be voiced and /s/ to be unvoiced. Since word-final /z/ may have very little voicing, as an English learner you might mistake it for /s/.
In typical speech, a big phonetic difference between word-final /s/ and /z/ is in the length of the syllable. Syllables ending with /s/ or another unvoiced obstruent are pronounced with a much shorter vowel, compared to syllables ending with /z/. In other words, native English speakers would only perceive a word like 'apples' as ending with /s/ if the pronunciation of the preceding /əl/ were very short.
Best Answer
In some dialects of American English,
is pronounced in a way that sounds something like this.
You get there as follows:
The vowels in the non-accented syllables "do" and "you" becomes a schwa, "duh yuh"
The vowel in "do" then drops out completely: "d'yuh"
The "d" and "y" sounds combine into "j": "juh"