Yes, lemon juice can be used to soften tough cuts of meat. The citric acid in lemon juice helps to break down the protein fibers, tenderizing the meat.
Lemon juice acts as a natural meat tenderizer due to its acidity. Tough cuts of meat contain tightly bound muscle fibers. When you marinate meat in lemon juice, the citric acid denatures these proteins, causing them to unravel and relax. This process weakens the structure of the meat, making it more tender and easier to chew after cooking. The longer the meat marinates, the more tender it becomes, but be careful not to over-marinate, as this can make the meat mushy. A typical marinating time ranges from 30 minutes to a few hours, depending on the thickness and toughness of the meat. Besides tenderizing, lemon juice also imparts a bright, citrusy flavor to the meat.
Don't over-marinate the meat in lemon juice. Prolonged exposure to the acid can break down the proteins too much, resulting in a mushy texture. A good rule of thumb is to marinate for no more than 2-3 hours for smaller cuts and up to 6 hours for larger, tougher cuts.