aoa wrb,plz answer the following questions in light of quran,ahadith and proper refrences.
1.iv heard from some people in my country that we should to Wuzu before we cook food,and the food cooked in such a way will produce noor inside us we we eat it,is it true?
2.is it makruh (disliked) to eat prawns,crabs and other such sea food etc.?
3.the spinal cord and brain of a chicken are called haram-maghaz(haram-gray matter)in my country.some people say it is haram to eat these parts,is it ture?
Jazak Allahu Khair

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

We are not aware of any evidence that suggests the excellence of performing ablution before cooking food; such a matter can only be confirmed by a text from our infallible Prophet .

With regard to the ruling of eating prawns and crabs, then we discussed this issue in Fataawa 85741 and 87405, so kindly refer to them.

As regards the ruling on eating the brain and spinal cord of the chicken, then this is permissible. If an animal is slaughtered according to Islamic rites, all its parts are lawful to eat except its blood that is spilled out when it is slaughtered. Therefore, the statement that it is forbidden to eat the brain and spinal cord of the chicken is not correct. 

Allaah Knows best.