Fruit Archives - Beef Buff

After I found out that some fruits can tenderize meat very well, I asked myself if kiwi could tenderize meat. I recently did a post about how pineapple can tenderize meat, and I marinated a chuck steak to show how the steak could become tender after marinating it with pineapple. So, I decided to now tenderize a flat iron steak with Kiwi. Kiwi does tenderize meat and is one of several fruits that has protease enzymes. These protease enzymes break down protein and more importantly collagen protein. Collagen protein is what makes meat tough, so meat becomes more tender when this protein is broken down. Collagen protein is very good for you, so it is good for you to eat a tough piece of meat. I don’t believe the average person gets enough of it and I did a previous post about bone broth which talks a lot more about collagen. Now that we know that kiwi does tenderize meat through its protease enzymes, let's look at why and how kiwi is a good meat tenderizer. As well as how to tenderize meat with kiwi. A couple of other things you may be wondering is how long to leave meat in kiwi and if you can use kiwi juice. We will talk about those below as well but let's first talk about why. Why is Kiwi a good meat tenderizer? Kiwi is a good meat tenderizer because it has a protease enzyme in it called actinidin. This enzyme is supposed to break down protein in meat without turning it into mush. However, the protease enzyme in kiwi can still turn meat into mush if you let it marinate and tenderize meat for too long. The actinidin found in kiwifruit — specifically green-variety kiwifruit — is highly effective in breaking down the protein and connective tissues of meat without turning it into mush. zespri.com You do not want your meat to be too tenderized and become mushy. Kiwi helps avoid this and is less tenderizing than some other fruits such as pineapple. The degree to which your meat gets tenderized will still depend on the length of time that you marinate your meat as well as other factors. How long to leave meat in kiwi? Tenderizing steak with kiwi for about 30 minutes is the best practice. If you do it for much longer, the steak will probably be too mushy. Although with a steak that has less connective tissue like a flat iron, the risk of it becoming too mushy is lower. There are two factors that determine the amount of time that you should let kiwi marinate your steak. One is the tenderness of the piece of meat and the other is the thickness of the piece of meat. If you are tenderizing a steak with kiwi, I will help you get an idea of which cuts of beef are tender and which are tough. Tough cuts: Chuck Round Flank Skirt Tender cuts: Ribeye Sirloin T-bone Flat Iron Filet Mignon Tougher cuts will need to get marinated for a longer time to get tenderized whereas tender cuts will need to get marinated for a shorter time to get tenderized. Another thing that determines how long you should tenderize your meat in kiwi for is its thickness. A piece of meat that is a half and inch thick or less will need to be tenderied for less time and a piece of meat that is more than half an inch thick and is closer to an inch or more will need to be tenderized for a longer time. The kiwi takes a longer time to seep through the meat to be able to tenderize it with a thicker piece of meat. It is always best to keep checking your meat consistently throughout the tenderization process to make sure that it does not start to get tenderized too much. You also want to keep in mind that when you wash off the kiwi from the meat after you are done marinating it, it may still have some enzymes on there that are still tenderizing the meat. So it is best to cook the meat right after you are done marinating in for it to not become too mushy. How does kiwi tenderize meat? Protease enzymes in kiwi weaken the structure of the meat and break down the protein into smaller segments. When the protein gets broken down into smaller segments the meat becomes tender. But if you are not careful it can become too tender and get mushy. This is exactly what proteases do as shown in a quote from discoveryexpresskids.com: A proteolytic enzyme (aka protease) is a protein that digests other proteins by breaking them down into smaller pieces. discoveryexpresskids.com The breaking down of the protein fibers in meat by enzymes is what tenderizes the meat. The longer you let the meat tenderize the more likely your meat will become mush. Now let’s look at how I tenderized my flat iron steak with kiwi. How to tenderize steak with kiwi? The last time I tenderized meat with fruit I used pineapple on a chuck steak and this time I used kiwi on a flat iron steak. A chuck steak is a lot tougher than a flat iron steak so I expected a different outcome especially with using a different fruit. To tenderize a steak with kiwi you will have to first blend the kiwi. This will turn it into more of a liquid and will allow you to spread it onto the steak. You then want to spread the kiwi purée around the entire steak so that the entire steak can get tenderized. If you only put the kiwi on part of the steak then only that part will get tenderized. Then use the blended kiwi to marinate the steak for the right amount of time to tenderize the steak enough but not too much. Here is a list so that you can easily see the steps: Blend kiwi Marinate steak Wash off the kiwi from the steak Salt brine steak Cook Let rest I used the skin on a pineapple when I used it to marinate steak because the skin contains enzymes. Although, I will no longer use the skin on fruit anymore because it was terrible to get it off of the steak before cooking it. The skin on the kiwi is easy to get off. I usually slice one in half and scoop out the flesh with a spoon. You can use a peeler to get off the skin of the kiwi as well. For my steak, I used a flat iron steak which is lean and tender. It doesn’t need to be tenderized but I wanted to do it anyways and see how it comes out. I blended only two kiwis and it was enough for my steak. After they were blended I put the steak in a container and poured over the kiwi. I made sure that the kiwi covered the entire surface of the steak. If the kiwi did not touch the entire surface of the steak then that part of the steak will not get tenderized. I tenderized the with the kiwi for about 25-30 minutes. You don’t want to let it marinate for too long otherwise it has a good chance of becoming mushy. After that, I rinsed off the kiwi so that it didn’t leave any funky aftertaste. Doing this step well is a must. You want to get off all of the Kiwi. The next step is to add a lot of salt to the steak. Salt is what gives the steak that flavor and without it, you will have a very bland steak. To learn more about the importance of salt on steak check out my post. I let the salt sit on the steak and salt brine for about ten minutes. This allows the salt to get absorbed into the steak and will give the steak a better flavor. Next, I used a cast iron pan to cook the steak. A cast iron pan is a great way to cook a steak because it retains heat and will sear the steak really well. Check out more info about cast iron pans in my post. I cooked the steak until it was a good medium rare and then I pulled it out of the pan and let it rest. This is another crucial step and it allows the steak to reabsorb the juices. I’ve noticed by doing this step that the steak is less bloody afterward as well. Can you use kiwi juice to tenderize steak? Yes, you can use kiwi juice to tenderize steak. Kiwi juice should have the enzymes to break down the proteins in the steak. You want to use fresh kiwi juice which should have the highest amount of enzymes. Do not get any processed kiwi juice at the store. Most juice at the store is pasteurized. This process destroys the enzymes in kiwi that tenderize meat. Just like the kiwi puree, you want to make sure the juice gets on the entire steak. Kiwi juice will seep through the meat a lot easier and tenderize the deeper parts of the meat. You still get a lot of juice blending kiwi and making it into a puree. If you are going to make your own kiwi juice I recommend buying your own juicer. It's easy to use and when you make the juice you want to make sure the skin is off of the kiwi. How many kiwis to use to marinate a piece of meat? Use about 2-3 kiwis for an 8-ounce piece of meat to blend and use for a marinade. The size of the kiwi matters for how many you will need, and if they are smaller then you may need more, and if you have a bigger piece of meat you will need more. The ripeness doesn't really matter but if you want to have a greater amount of enzymes in your kiwi then you will want to have riper kiwi. The enzyme that is responsible for breaking down protein is highest in riper kiwi: The actinidin activity in kiwifruit increased 3-fold after 3 weeks postharvest ripening at 5°C with a 15% decrease in specific activity. Actinidin activity is highest in the pulp of ripe fruit at 27,600 U/kg fruit researchgate.net How many kiwis you use, how large they are, and how ripe they are will all play a role in how well your meat will be tenderized. How long to leave meat in kiwi juice? On average 30 minutes but not more than an hour. Kiwi juice should tenderize similar to kiwi puree but will be able to seep into the deeper parts of the meat better. You may need to tenderize your meat for a shorter amount of time with kiwi juice than the kiwi puree. Fully submerging the meat in kiwi juice will be the most effective method to tenderize your meat. It may over tenderize and make it too mushy because of how much kiwi juice there is. I would be extra careful with submerging your meat in kiwi juice and check it frequently without letting it marinate for too long. Conclusion After tasting the steak, I was sadly disappointed. I expected it to come out more tender but it wasn’t. I think it was the type of steak that I used. Flat iron steak is a very lean cut of steak and has very little connective tissue. It is a steak that is already tender. So I think that tenderizing it with kiwi did not make it much more tender than it already was. The best steak I have had that I tenderized with fruit was a ribeye with mango. It was probably the best steak I have ever had. I encourage you to check out my post. I also marinated a chuck steak in pineapple, which is another fruit that tenderizes meat. And it is a more powerful tenderizer than kiwi. You also may think that it tastes better on a steak than kiwi.