http://www.finchinfo.com/diet/safe_toxi ... _foods.php
Protease inhibitors inhibit digestive enzymes and, when present in high levels in the diet, may decrease the avian body's to digest proteins and lead to pancreatic hypertrophy. Although these enzyme inhibitors are present to a degree in all plants, significant levels are found in all legumes,
corn,
lettuce,
oats,
peas, peanuts, barley, beets,
buckwheat,
wheat,
rice, rye, turnips, sweet potatoes and potatoes (in VERY high amounts).5 Luckily protease inhibitors are readily inactivated by cooking,5 so if any of the above-listed food sources are going to constitute a major part of your birds' diet, you should cook them first.
Other various inhibitors are present in a wide variety of food stuffs. Briefly, they include: amylase inhibitor (in
wheat,
rye,
sorghum,
beans), plasmin inhibitor which inhibits blood clotting5 (in some beans), cholinesterase inhibitors (in
carrots, cabbage, asparagus,
broccoli,
celery, radishes, raspberries, strawberries, oranges, pumpkin, peppers, tomatoes, turnips, apples, eggplant, and especially potatoes), and kallikrein inhibitor which reduces antibody formation5 (in potatoes).
There are many more things listed on that link.
Worth a read, everything in moderation