At the risk of opening a can of worms, or perhaps that should be a can of pineapple chunks, I will try to answer your questions. The Buddhist Monastic Discipline
is complex, and rarely understood by lay people who don't live in close association with well-trained monks.
In Mahāsi Yeikthā, all fruits are cut up before being presented to the monks, but this may be more out of concern for the many temporary monks who may be over-scrupulous, or just to avoid waste and mess.
It is, of course, absurd to insist that all food must be cut up before offering it to bhikkhus, but there are training rules about biting off chunks, or otherwise eating in ways that might seem "gross." Training Rules About Food
If a sandwich is offered, a bhikkhu can break it up with his hand before eating it. If a mango is offered whole, he can cut it up, discharge the seed, then eat the pieces. If a monk eats a seed in an orange by mistake, not realising it is there, then there is no offence. Any fruit with seeds can be made allowable for monks by a layperson, who simply has to cut it with a knife or a fingernail to break the skin, telling the monk that it is now allowable.
The bhikkhu may say, "Make it allowable. (kappiyaṃ karohi)."
The lay person (or novice) then cuts the fruit, and says, "It is allowable, venerable sir (kappiyaṃ bhante)."
These meticulous rules were made because Jains believed that all living things, including plants and water, were alive, and they complained about the bhikkhus destroying life that was one-facultied. So the Buddha made a rule so that they could not longer complain — since a lay person had already done the "dirty"
"I allow mango peels." ... "I allow that fruit made allowable for contemplatives in any of five ways be consumed: damaged by fire, damaged by a knife, damaged by a fingernail, seedless, or with the seeds removed. I allow that fruit made allowable for contemplatives in any of these five ways be consumed." — Cv.V.5.2
"I allow that fruit that has not been made allowable be consumed if it is without seeds, or if the seeds are discharged." — Mv.VI.21
One also needs to know the non-offense clauses, which for the biting food rule
anāpatti asañcicca, assatiyā, ajānantassa, gilānassa, khajjake, phalāphale, āpadāsu, ummattakassa, ādikammikassāti.
There is no offence if it is unintentional, if it is done inadvertently, unknowingly, if he is sick, if it is solid food (biscuits, sandwiches, or chicken drum-sticks — not rice and curry), fruits, or if he is in pain (force-fed for example), if he is mad.
YMMV may vary, depending on how these rules are interpreted in the monastery where you stay (respect the local traditions). They were mostly made because the Group of Six Monks behaved shamelessly to try to embarass Anāthapindaka, who reported their misbehaviour to the Buddha. Scrupulous monks who are not greedy to get more, and are not trying to be disrespecful to the donors, but just eat mindfully will probably not be breaking any rules.
I remember once being told off by Ajahn Sucitto for "scraping the bowl with my spoon
," but this was not being done because I wanted to get more food. If eating with a spoon it is not at all easy to avoid making the slightest sound, and there is no offence if one scrapes the bowl unintentionally, unknowingly, or just to gather together the last morsels so as not to waste anything.
One should eat mindfully — if one does then one will not make a lot of noise.