:salam2:
Aapa, I read about L-Cysteine a few years ago, so I've forgotten whether its haram or makrooh. I just can't imagine scholars voting *human hair* as halal.
Edit: Looked it up. It's haram if they're using hair. This is helpful:
http://www.albalagh.net/halal/col2.shtml
I've never heard L-Cysteine was used in cheese though. The more dangerous thing with cheese is the use of pork rennet, or haraam-slaughtered rennet from beef or chicken. Kraft is definitely a no-zone for muslims. I emailed them quite a while back and asked them what rennet they used. They replied they used pork rennet, beef rennet and microbial rennet in their products, but they couldn't guarantee which cheese batch used which rennet. So I stayed away from Kraft ever since then.
http://cheese.joyousliving.com/CheeseListBrand.aspx This website lists all the top cheese brands which are halal (or use microbial rennet for vegetarians living in the US.. same thing).
Most companies' processed cheeses use animal substitutes, and their natural cheeses are better. Aapa, you wouldn't believe the amount of research I once did upon this subject when I was in the US, so let me know if you need any more info.