Nem kontrolü vakumlu poşetleri kuru tutuyor.

Because nem kontrolü is a very common Turkish structure: a noun compound.

In this pattern:

• the first noun stays bare: nem
• the second noun takes a compound ending: kontrolü

So nem kontrolü means moisture control / humidity control as a general concept.

By contrast, nemin kontrolü is a more literal the control of the moisture/humidity structure, with a genitive relationship. That version is more specific and less like a standard label or category.

So for names of systems, functions, or product features, nem kontrolü is the natural form.

Here, -ü is not the direct-object ending.

It is the ending used on the second noun in a noun compound. In other words, kontrolü is part of the fixed phrase nem kontrolü.

Compare:

• su şişesi = water bottle
• telefon numarası = phone number
• nem kontrolü = moisture control

So even though kontrolü looks a bit like an accusative form, in this sentence it is simply part of the subject phrase.

There are two main clues:

1. Meaning and structure
   Nem kontrolü is a complete noun phrase meaning moisture control.

2. The object is marked elsewhere
   vakumlu poşetleri has the marking that shows it is the direct object.

So the sentence structure is:

• Nem kontrolü = subject
• vakumlu poşetleri = object
• kuru = the state/result
• tutuyor = keeps

So the sentence means: Moisture control keeps the vacuum bags dry.

Here poşetleri is:

• poşet = bag
• -ler = plural
• -i = definite direct-object marker

Together, that gives poşetleri.

So in this sentence, it means the bags as a specific direct object: the vacuum bags.

A useful point: poşetleri can be ambiguous by itself in some contexts, because forms like this can sometimes also mean his/her/their bags. But in this sentence, the context clearly shows it is the plural definite object.

Vakumlu comes from vakum plus the suffix -lı / -li / -lu / -lü, which often means with, having, containing.

So:

• vakum = vacuum
• vakumlu = with vacuum / vacuum-type / vacuum-sealed

That is why vakumlu poşet means something like:

• vacuum bag
• vacuum-sealed bag

This suffix is very common:

• tuzlu = salty / with salt
• şekerli = with sugar
• sisli = foggy / with fog

Because kuru is acting as an adjective complement in the pattern:

X-i adjective tutmak = to keep X adjective

So here:

• poşetleri = the bags
• kuru = dry
• tutuyor = keeps

Together: keeps the bags dry

This is a very common Turkish pattern. For example:

• Kapıyı açık tut. = Keep the door open.
• Yemeği sıcak tutuyor. = It keeps the food warm.
• Orayı temiz tutun. = Keep that place clean.

So kuru does not need extra marking here.

Yes, tutmak often does mean to hold, but it has several meanings.

In the pattern adjective + tutmak, it often means:

• to keep
• to maintain in a certain state

So:

• kuru tutmak = to keep dry
• açık tutmak = to keep open
• temiz tutmak = to keep clean

So in this sentence, tutuyor is not holding the bags physically. It means keeping them dry.

Because the Turkish -yor form often covers both:

• an action happening now
• a present, current, or practical function

In English, when we describe what something generally does, we often prefer the simple present:

• Moisture control keeps the vacuum bags dry.

That sounds more natural in English than is keeping, especially if this is a general statement, product description, or feature explanation.

So the Turkish form is tutuyor, but the best English translation in context is often keeps.

Yes, often you could.

The difference is roughly this:

• kuru tutuyor = sounds more descriptive, current, or conversational
• kuru tutar = sounds more general, habitual, or like a product claim

So:

• Nem kontrolü vakumlu poşetleri kuru tutuyor.
• Nem kontrolü vakumlu poşetleri kuru tutar.

Both can work, depending on context. The -yor version is very natural in everyday Turkish.

The word order here is the neutral Turkish order:

Subject + Object + Complement + Verb

So:

• Nem kontrolü = subject
• vakumlu poşetleri = object
• kuru = complement
• tutuyor = verb

Turkish often puts the verb at the end, and in this kind of sentence kuru usually stays close to tutuyor, because kuru tutmak works like a unit.

You can change the order for emphasis, for example:

• Vakumlu poşetleri nem kontrolü kuru tutuyor.

But the original version is the most neutral and straightforward.

Turkish usually does not use articles the way English does.

Instead, Turkish shows definiteness and specificity through:

• context
• word order
• case marking

In this sentence, poşetleri is understood as a specific object partly because of the object marking. So English needs the vacuum bags, but Turkish does not need a separate word for the.

That is very normal in Turkish.