Baking directly in the oven without preheating will affect the taste of food and the quality of finished products. Because it takes a certain time for the oven temperature to rise from room temperature to the required temperature, if the oven is not preheated, the cooking time of food will become longer and the ideal effect will not be achieved; The surface of food will be overheated, while the internal temperature is still very low, resulting in bad taste and even burning of food.