Portakalı soyunca mutfak çok güzel kokuyor.

The -ı is the accusative ending, which usually marks a specific / definite direct object.

• portakal = an orange / orange in a general sense
• portakalı = the orange / that orange as a specific object being peeled

So:

• Portakal soyunca... can sound more general or less natural here
• Portakalı soyunca... clearly means a particular orange is being peeled

This is very common in Turkish when the object is definite:

• Kitabı okudum = I read the book
• Elmayı yedim = I ate the apple

-ınca / -ince / -unca / -ünce is a converb ending that often means:

• when ...
• once ...
• after ...
• sometimes as soon as ...

So soyunca comes from soymak (to peel) and means something like:

• when (someone) peels it
• once it is peeled
• after peeling it

In this sentence, it links the action of peeling to the result in the main clause.

Because the verb stem is soya- / soy-? More precisely, the dictionary form is soymak, and the stem used here is soy-. When the suffix -ınca is added, Turkish gives:

• soy + unca → soyunca

The y is already part of the verb stem soy-. It is not an extra letter added by the suffix.

Compare:

• gelmek → gelince
• bakmak → bakınca
• soymak → soyunca

It most naturally means when / once / after peeling in this sentence.

The exact English translation depends on context, because Turkish -ınca is a little flexible. Here the idea is that the smell appears as a result of peeling the orange.

So the sense is closer to:

• When you peel the orange...
• Once the orange is peeled...
• After peeling the orange...

It is usually not the first choice if you specifically want a strong if meaning. For a clear conditional, Turkish more often uses -sa / -se:

• Portakalı soyar-san... = If you peel the orange...

Turkish often leaves subjects unstated when they are understood from context.

In Portakalı soyunca mutfak çok güzel kokuyor, the person doing the peeling is not explicitly named. It could be:

• I peel the orange
• you peel the orange
• someone peels the orange

The sentence has a slightly general feel: when the orange gets peeled / when you peel the orange, the kitchen smells nice.

If you want to make the peeler explicit, Turkish can do that:

• Portakalı soyduğumda mutfak çok güzel kokuyor. = When I peel the orange, the kitchen smells very nice.
• Portakalı soyduğunda mutfak çok güzel kokuyor. = When you peel the orange, the kitchen smells very nice.

Yes. In the main clause, mutfak is the subject:

• mutfak = the kitchen
• çok güzel kokuyor = smells very nice

So grammatically, the kitchen is what is smelling nice.

This matches English too:

• The kitchen smells nice.

Turkish often puts the time/background clause first:

• Portakalı soyunca = when the orange is peeled / when you peel the orange
• mutfak çok güzel kokuyor = the kitchen smells very nice

Turkish has no articles like a or the.

So mutfak can mean:

• a kitchen
• the kitchen

Context tells you which one is meant. In this sentence, it is naturally understood as the kitchen.

This is normal in Turkish:

• Kapı açık. = The door is open.
• Çocuk uyuyor. = The child is sleeping.

kokuyor is the present continuous form and here it often corresponds to English smells or is smelling depending on context.

• kokuyor = is smelling / smells
• koktu = smelled / started to smell
• kokar = smells / tends to smell / will smell depending on context, often more habitual or general

In this sentence, kokuyor gives a vivid, current result:

• you peel the orange
• the kitchen smells wonderful right then

So it feels natural and immediate.

Yes, in effect it is. Turkish often uses adjectives in ways that English would translate with an adverb or adjective depending on the verb.

güzel kokmak is a very common expression meaning:

• to smell nice
• to smell good

So:

• güzel kokuyor = it smells nice
• çok güzel kokuyor = it smells very nice

This is more natural than trying to interpret it word-for-word as smells beautifully.

Similar patterns:

• iyi görünmek = to look good
• kötü hissetmek = to feel bad

Yes. The given order is very natural:

• Portakalı soyunca = background/time clause first
• mutfak çok güzel kokuyor = main clause second

This is a common Turkish pattern: put the when/if/after clause before the main statement.

You could rearrange it for emphasis, but the original is the most straightforward:

• Mutfak, portakalı soyunca çok güzel kokuyor.

That version is possible, but the original sounds smoother and more neutral for most contexts.

Not necessarily better—just more specific.

• Portakalı soyunca = when/once the orange is peeled; subject of peeling is left general or understood from context
• Portakalı soyduğumda = when I peel / when I peeled the orange depending on context; specifically I

So if you want to say When I peel the orange, the kitchen smells very nice, then soyduğumda is clearer.

But if you want a more general statement like When you peel an orange, the kitchen smells great, soyunca works very naturally.

Yes, it can. Even though portakalı is grammatically definite, the whole sentence can still be understood as a general observation depending on context.

Turkish often allows a sentence to feel either:

• specific: this orange, this moment
• general: when an orange is peeled, this happens

Here, context decides. If someone is talking while peeling an orange, it feels immediate and specific. If someone is making a general comment about citrus smells, it feels more general.

Yes, a small amount:

1. Who peels the orange?
   The subject of soyunca is not stated.

2. Is it one specific moment or a general truth?
   It can be either, depending on context.

3. Does it mean exactly when, after, or once?
   -ınca covers all of those shades pretty naturally.

That kind of flexibility is very normal in Turkish, and learners usually get used to it through exposure rather than by forcing one exact English equivalent every time.