No, you should not feed your kitten adult foods before the age of 1 year, these foods are specifically produced with the exact nutritional requirements for each life stage, kittens needing higher proteins, lipids (fats) and an less dietary fibre than adult cats. Some people will feed their cats adult foods, but you run the risk of causing kidney damage and also causing intestinal problems such as allergies and colitis.
I am fully trained, and passed animal feeding and animal nutrition at distinction level so I know what I am talking about.
Would you feed a baby food meant for adults? With the extra salt and fibre in, of course not, exactly the same applies to young animals.
I am quite passionate about animal care, so try to give the best advice I can but understand some people may disagree. Xx