Last class we decided to test out some meat tenderizing techniques. A while back I had purchased a Jaccard knife and we use it regularly to tenderize tougher veal cutlets, skirt steaks etc. I tell the students about how it is used on a larger scale by many portion cutting processors and has its attributes for introducing marinades deeper into the meat. It also has come under some scrutiny because of the problem of possible crosscontamination of bacteria into a steak type cut that will be cooked to medium rare or less. http://www.ars.usda.gov/research/publications/publications.htm?seq_no_115=250404
The Jaccard has its place in the kitchen and if used and cleaned properly it can be a good way to get cuts that are sitting on the tenderness "fence" to be made more palatable.
On to our testing. We chose to use the Beef Sirloin Flap which is palatable but often a little tough to be served as an unsliced portion. While the Jaccard works well we decided to try some other techniques that will do the job. We experimented with two other methods, applying Papya and Kiwi fruit to steak cuts. We peeled and sliced both fruits and messaged them into two separate steaks and left them loose wrapped over night. The third steak was simply Jaccarded without any marinade or spice. When it came time to cook them we seasoned all three with salt and pepper, lightly so as not to interrupt the naturally occuring tastes. They were cooked to medium rare individually in a heavy black skillet with a little rendered beef fat in the pan to prevent sticking.
The results? All three methods were effective in tenderizing the meat with the two fruit methods differing somewhat from the Jaccard. The mechanical method worked well but without any marinade, it turned out a little dry. It also cooked faster due to the ability for heat to "chimney" up the tiny holes that were pierced through it. Moisture had leaked out of the meat but it was still palatable.
The Papya worked well but left a lightly sweet flavor and carmelized quite a bit in the pan. Papya contains a protease enzyme, papain, which chemically breaks down the collagen muscle fiber sheaths within the muscle. Kiwi fruit also contains protease enzymes and the effects from placing it over the steak was also very effective. The Kiwi didn't have quite the same amount of sweetness but did leave a residual flavor. Both fruits broke down the fibers about equally resulting in a steak that could be cut with a regular steak knife with ease. At 24 hrs we did not experience a "mushy" texture that can happen when steaks are left too long. In a previous test we left a steak with Papya over a weekend and it became overly tenderized and very soft which resulted in an unatural texture. The meat fibers had basically disolved.
None of the three in this test were disagreable in taste but there were certainly differences. The question is how would they be used in the kitchen? If you are trying to maintain the original flavor of the meat, the mechanical system is probably best. There is no added flavor. If looking for an ingredient that will add some flavor and can do a nice job tenderizing these two fruits worked well. Other fruits containing protease enzymes are figs, pineapple, and honey dew melon. All of these will do the job but will also add flavor. Be sure not to over marinate due to the mush factor. A half of a kiwi can be enough for about 4 lbs of meat and it is easy to overuse it. http://www.thekitchn.com/thekitchn/tips-techniques/tip-tenderizing-with-kiwi-011683