(the) seeds of/in (the) melon(s)

[Snappy]

Are the following sentence structures grammatically okay if I want to mean that melon seeds are rich in protein?

1. The seeds of the melon are rich in protein.
2. The seeds of a melon are rich in protein.
3. The seeds of melons are rich in protein.
4. A seed of the melon is rich in protein.
5. A seed of a melon is rich in protein.
6. Seeds of melons are rich in protein.
7. The seeds in the melon are rich in protein.
8. The seeds in a melon are rich in protein.
9. The seeds in melons are rich in protein.

[bhaisahab]

Are the following sentence structures grammatically okay if I want to mean that melon seeds are rich in protein?

1. The seeds of the melon are rich in protein.
2. The seeds of a melon are rich in protein.
3. The seeds of melons are rich in protein.
4. A seed of the melon is rich in protein.
5. A seed of a melon is rich in protein.
6. Seeds of melons are rich in protein.
7. The seeds in the melon are rich in protein.
8. The seeds in a melon are rich in protein.
9. The seeds in melons are rich in protein.

Yes, they are all grammatical. They are not all very natural though.

[emsr2d2]

Are the following sentence structures grammatically okay if I want to mean that melon seeds are rich in protein?

1. The seeds of the melon are rich in protein. Yes.
2. The seeds of a melon are rich in protein. Yes.
3. The seeds of melons are rich in protein. Yes.
4. A seed of the melon is rich in protein. Not really. The indefinite article doesn't really work here.
5. A seed of a melon is rich in protein. No. Same reason.
6. Seeds of melons are rich in protein. Yes.
7. The seeds in the melon are rich in protein. Yes.
8. The seeds in a melon are rich in protein. Yes.
9. The seeds in melons are rich in protein. Yes.

I have marked those I consider natural or unnatural above. I agree with Bhaisahab that none of them are the most natural. The best way to say it would be:

Melon seeds are rich in protein.