I used to be a molecular biologist, so I’ve always believed I knew my way around biochemistry and food chemistry quite handily.
However, I recently hauled out my old wok to cook some “restaurant-style chinese food”, and thanks to the improvement in my knife skills over the years, I had a really great dinner on the table in about 20 minutes. The one fly in the ointment was that the beef wasn’t quite as tender as I might have liked.
I was contemplating using an enzyme-based tenderizer, but a friend suggested that I should dust it lightly with corn starch (a technique I’d read about, but didn’t recall being particularly impressed with) and it worked outstandingly. Before the meat was added my wok was very hot, ca 400 F (250 C).
IIRC, cornstarch consists primarily of the starch amylose, but I can’t how this could tenderize meat. It was suggested to me that it simply helped “keep the juices in”, but it actually seemed to tenderize the meat, not just make it juicier. I wouldn’t think a polysaccharride could enhance proteolysis or denature protein coiling.
Can anyone fill me in on the chemistry? Feel free to be as technical as you wish.
I have never heard of cornstarch tenderizing beef, and I can’t see any mechanism for it to do so. Is it just possible you used a more tender cut of beef? Certain cuts of beef (from muscular areas) are better for high-heat, quick cooking, and get tougher the longer you cook them. Other cuts (from fattier areas), react to slow, low heat and get more tender the longer you cook. I personally stay away from tenderizer, as it gives my meat a funny texture that I don’t like.
Sorry to dodge the OP. I’m just really skeptical that cornstarch can tenderize meat; although I’d be glad to learn if this is possible.
In my reading and cooking experience, Asian cooking uses corn starch as a sauce thickener, also as a light coating for meats. Not aware of any tenderizing abilities. A coated piece of meat traps the juices inside and would probably seem more tender than one uncoated, though.
OTOH, shouldn’t ignore the possibility that you just used a more tender piece of meat the second time around.
I used to cook Chinese food quite a bit, and if I remember correctly from those days, the cornstarch serves to seal the meat and keep juices in, resulting in a more tender beef than the shoe leather that you get when it gets dried out.
I agree that it keeps the juices in. The mechanism for that is clear. I guess I was just surprised by the magnitude of the effect.
Each time, the strips were cut from the same tasty, but not terribly tender chuck roast that I’d bought because because my sister was coming over. Something came up, and I was left with a 4 lb chunk of meat to use up. (She loves pot roast–and taking home the leftovers. She doesn’t cook. Period. If the FDA banned microwaves, she’d starve).
When I cook Chinese food, I use more vegetables than meat, so one pound of meat per meal was more than ample. That chuck roast lasted through three dinners and a lunch, with similar results each time. Fortunately, I’m enjoying the experimentation.
Chuck roast? Chuck is not a good cut for stir frying. That’s a slow, wet roaster. You want something like sirloin or flank if you’re looking at keeping the meat tender. And don’t overcook it. If it’s sliced thinly, you’re looking at a cooking time of maybe 5 minutes.
Hmm…I’m still skeptical about this cornstarch nonsense, but I’ll give it a shot and try the same cut of beef stir fried side-by-side with and sans starch.