The acidity of the ingredients in a marinade helps to tenderise the chicken. Ingredients like lemon juice, Worcestershire sauce and ketchup break down the tough tendons in the meat so they are less chewy. Besides tenderising the meat, the marinade also soaks into the meat, giving it flavour throughout. A simple marinade combined with a low cooking temperature will produce tender chicken with great flavour.
Mix in a bowl 1 minced garlic clove, 1/2 cup of olive oil, the juice of one lemon, 1/2 cup of orange juice, 1/4 tsp of black pepper and 1/2 tsp of salt. Stir the ingredients with a wire whisk.
Place the chicken breasts in a shallow baking dish. Pour the marinade over the chicken. Cover the dish with cling film. Set the dish in the refrigerator overnight.
Preheat your oven to 163 degrees Celsius once the chicken has been marinating overnight. Remove the cling film from the dish. Cover the dish with aluminium foil. Set the dish in the oven for 50 minutes. Flip the chicken over periodically as it cooks.
Remove the dish from the oven. Cut a small slice into thickest part of the chicken with a knife; if the juices run clear, the chicken is done. Or, stick a meat thermometer into the thickest part of the chicken. When the thermometer reads 76.7 degrees Celsius, the chicken is done.
Ovens temperatures and times may vary.