Foods and home making

What makes fruit spoil ? Let us see : Experiment 32: To show how uncooked fruit spoils. (a) Place a piece of lemon on a saucer. Cover it with a cup. Let it stand for at least two da:ys. Examine the lemon. Do you notice a hairlike growth on the fruit? If so, molds have grown on the lemon. (&) Repeat (a) using a piece of apple or banana. After two or more days, what do you see on the fruit? 512 Food Preservation Molds are plants. They exist in the air and dust. They grow on foods, especially those that contain acids. Since all fruits contain acid, we can understand why molds grow on fruits. Fruit spoils when molds grow on it. There are plants other than molds which grow on food and spoil it. Wild yeast plants exist in the air. These sometimes grow on food. Bacteria , about which you learned on page 39, also grow on certain kinds of foods and spoil them. Bacteria are very tiny plants — so tiny that you cannot see them without a powerful microscope. It is the growth of yeasts , molds, or bacteria on foods that makes foods spoil. Do cooked foods spoil? Housekeepers sometimes cook fruits when they want to keep them from spoiling. Let us see whether cooked fruit will spoil as soon as uncooked fruit. Experiment 33: To show how cooked fruits spoil. (a) Put some cooked apple or other fruit on a saucer. Cover it with a cup. After two or more days examine it. Have molds grown on the fruit ? (b) Let the fruit stand for at least two days more. Then examine. Have molds grown on the fruit? We see from this experiment that even though fruit is cooked, it will spoil eventually. Fruit does not usually spoil so quickly when it is cooked, because the molds, bacteria, or yeasts which may be on the food are destroyed, or at least partially destroyed, by cooking. But even though all the tiny plants which make food spoil are destroyed by cooking, there are more of these microscopic plants in the air. Some of these soon get on the food, begin to grow, and cause the food to spoil. How are foods preserved ? We have learned that air contains the tiny plants which may cause foods to spoil. If foods are well cooked, we can keep them from spoiling by keeping the air away. This can be done by sealing the cooked fruit in jars. The jars must be sealed securely so that no air can seep in. Canning Fruits 513 The tiny plants causing foods to spoil may be not only in the air, but on the jars. To destroy those plants, the jars, then, must be heated or scalded. One way of preserving food is to cook it and to seal it in scalded jars. The process of cooking food and sealing it in jars is called canning. What kind of fruit should be selected for canning ? Decayed fruit is not fit for canning. To be sure, fruit that is partially decayed may sometimes be cut into pieces and used for making jam or marmalade provided all the decayed portion is cut away. When fruit is canned in large pieces, it should be fresh, sound, and slightly underripe. In fresh, sound fruit, it is easier to destroy the organisms which may cause it to spoil, and in under- ripe fruit it is easier to keep the pieces whole during the canning process.