Value Per Nutrient Food 0.36 g 100 grams Cystine Pork, fresh, variety meats and by-products, kidneys, raw 0.36 g 100 grams Cystine Beef, round, outside round, bottom round, steak, separable lean and fat, trimmed to 0" fat, select, cooked, grilled 0.36 g 100 grams Cystine Beef, top sirloin, steak, separable lean and fat, trimmed to 1/8" fat, choice, cooked, broiled 0.36 g 100 grams Cystine Beef, round, bottom round, roast, separable lean only, trimmed to 1/8" fat, all grades, cooked 0.36 g 100 grams Cystine Beef, flank, steak, separable lean only, trimmed to 0" fat, select, cooked, broiled 0.36 g 100 grams Cystine Pork, fresh, variety meats and by-products, spleen, cooked, braised 0.36 g 100 grams Cystine Beef, rib eye, small end (ribs 10-12), separable lean and fat, trimmed to 0" fat, select, cooked, broiled 0.36 g 100 grams Cystine Duck, domesticated, meat only, cooked, roasted