Enzymes are dissolution large complex molecules like proteins, carbohydrates, and fats into smaller ones. They are secreted by the salivary glands and gastric mucosa of the stomach, pancreas, and small intestine, also present in many fruits and vegetables in significant amounts. The objective of this study was to review the available literature on the naturally available enzyme on food like fruits and vegetables and the impact of heat on their activity. Foods that contain natural digestive enzymes include pineapples, papayas, mangoes, bananas, avocados, kiwifruit, and ginger indicating that enzyme disintegration is influenced by temperature. The optimum temperature for protease activity of kiwifruit, papaya, zinger, and pineapple was at 40 degrees Celsius (ºC) and active between 8 to 70°C. Amylase of banana, mango has been testified to activity between 8°C and 38°C and the optimum temperature was 30, starting to be denatured at 38°C and being fully denaturized after 5 minutes at 100°C. The Avocados lipase was active in the temperature ranging from 5 to 65°C and the optimum temperature for lipase action was observed to be 37°C.