temperature of the food as a whole quickly rises Metal foil and utensils can be put in the microwave oven with moist foods without causing problems, provided they’re reasonably large and kept some distance from the walls and each other to prevent arcing Fine metallic decoration on china will spark and suffer damage Foil is useful for partly shielding some foods from the radiation, the thin edges of fish fillets, for example Microwave ovens are a recent invention In 1945 Dr Percy Spencer, a scientist working for Raytheon in Waltham, Massachusetts, filed a patent for the use of microwaves in cooking after he had successfully popped corn with them This kind of radiation had already been used in diathermy, or deep heat treatment for patients with arthritis, as well as in communications and navigation Microwave ovens became a popular appliance in the 1970s Advantages and Disadvantages of Microwaves Microwave radiation has one great advantage over infrared: the fact that it cooks food much faster Microwaves can penetrate food to a depth of about an inch/2.5 cm, while infrared energy is almost entirely absorbed at the surface Because heat radiation can travel to the center of foods only by the slow process of conduction, it’s easily beaten by microwaves, with their substantially deeper reach This reach, along with the microwaves’ concentration on heating the food and not its surroundings, results in a very efficient use of energy Microwave cooking has several disadvantages One is that, in the case of meats, speedy heating can cause greater fluid loss and so a drier texture, and makes it more difficult to control doneness This can be partly overcome by pulsing the oven on and off to slow the heating Another problem is that microwaves cannot brown many foods ... entirely absorbed at the surface Because heat radiation can travel to the center of foods only by the slow process of conduction, it’s easily beaten by microwaves, with their substantially deeper... along with the microwaves’ concentration on heating the food and not its surroundings, results in a very efficient use of energy Microwave cooking has several disadvantages One is that, in the case of. .. One is that, in the case of meats, speedy heating can cause greater fluid loss and so a drier texture, and makes it more difficult to control doneness This can be partly overcome by pulsing the oven on and off to slow the heating