Microwaves, Heating Your Food With Electromagnetic Radiation - Essay Example

MICROWAVES – MICROWAVE COOKING By Name Course Instructor Institution City/State Date Microwaves – Microwave Cooking Introduction Microwaves according to Food and Environmental Hygiene Department (2005, p.2) are electromagnetic waves with a frequency ranging between 300 to 300,000 MHz. After the absorption of the microwave energy, polar ions as well as molecules in the food will collide or rotate consistently with the changing heat and electromagnetic field is then generated for cooking. As mentioned by Wayne and Newell (2011), utilising microwave oven offers a suitable means for cooking, thawing and reheating foods. Still, the microwaved food safety has stirred some interest from the public. Electromagnetic waves as stated by Wayne and Newell (2011) are waves of magnetic as well as electrical energy that move together through space. They consist of microwaves; ultraviolet radiation; gamma rays; visible light; x-rays; as well as radio waves (see Figure 1). Essentially, microwaves can go through materials such as ceramic, paper, glass, plastic and are absorbed by water as well as foods. Through illustrations and diagrams this paper provides a critical analysis of microwave cooking. Fig 1: Electromagnetic waves spectrum (Food and Environmental Hygiene Department, 2005) Discussion Application of microwaves is diverse; for instance, they are utilised for detecting over speeding automobiles, sending television, radio, and telephone communications as well as treating muscle ache, raising doughnuts and bread, curing resins and rubber, curing and drying plywood, in addition to cooking. Still, application of microwaves in a microwave oven is normally utilised by consumers. In this case, magnetron generates microwaves which feed through a waveguide to the cooking chamber. Furthermore, the cuboid chamber doubles up as a Faraday cage because it has metallic walls while metal grids are used to cover the light bulb cavity. According to Vollmer (2004, p.75), the grids’ holes are small than the microwaves’ wavelength; therefore, the grids act as the metal plates. The majority of the microwaves cook on the chamber’s rotating turntable, but a number of designs have a rotating reflector that act as a stirrer. Models which are more expensive have thermometers, extra facilities for conventional cooking like grills, refrigeration and oven heaters. The figure below shows a schematic diagram of an ordinary microwave oven: Fig 2: Microwave Oven As stated earlier, microwaves are a type of electromagnetic energy akin to radio waves or light waves occupying some part of the electromagnetic spectrum of energy or power. In the current digital age, microwaves are utilized for relaying long distance television programs, telephone signals as well as computer data all over the world or to a space satellite. However, microwave as a source of energy is widely utilized for cooking. All microwave oven have a magnetron, a tube wherein electric and magnetic fields affect the electrons in a way that generate micro wavelength radiation at almost 2450MHz or 2.45GHz. In this regard, the generated microwave radiation interacts with the food molecules and the wave energy alter the polarity from positive to negative in all the wave cycles (Rashad, 2013, p.217). The changes in polarity in microwaves take place over million times per second. The molecules of food, particularly water molecules have a negative as well as positive end just like a magnet that has south and north polarity. The commercial microwave ovens have almost a 1000 watts power input of alternating current (AC) and the generated microwaves from the magnetron makes the polar molecules to rotate million times per second. The agitation results in a molecular ‘friction’, which consequently heats up the food (Rashad, 2013, p.218). This uncommon form of heating brings about a significant damage to the adjacent molecules, normally dismantling them or deforming them forcefully. Contrary, microwaves generated by the sun are anchored in the pulsed direct current principles, which do not generate frictional heat while microwave ovens utilize AC that creates frictional heat. In this case, a microwave oven generates a spiked energy wavelength with all the power/energy focused on an energy spectrum having a narrow frequency. According to Food and Environmental Hygiene Department (2005, p.18), using microwaves for cooking is not very safe; for instance heating water through microwaves may lead to superheated water; that is to say, the temperature attained by water is beyond the boiling point temperature, but still the water appears not to have boiled. Water disturbances while in a microwave oven; for example the cup movement or adding other ingredients to the water, may result in an eruption of the boiling water leading to injuries. In order to avoid superheating the water, Food and Environmental Hygiene Department (2005, p.18) suggests that one must avoid heating the liquids or water excessively in the microwave oven, or should allow the cup containing the liquid or water to stand for half a minute prior to moving it or adding other ingredients. Another example is cooking an egg while still in its shell; it can result in build-up of steam inside the shell and the egg can consequently explode. This can be avoided by cooking the eggs in microwave oven after removing the egg shell. By and large, the alternating electromagnetic field produced by the microwave oven may result in collision/rotation, excitation of polar ions as well as molecules in the cooked food. Such molecular frictions may produce heat and then result in the rise of temperature. Therefore the two key techniques, specifically ionic and dipolar and interactions, clarify how heat is generated in the food. Upon absorption of the microwave energy, polar molecules like molecules of water in the food start rotating consistently with the alternating electromagnetic field. Therefore, the molecule of water is a ‘dipole’ with one end negatively charged and the other end positively charged. Akin to the magnet action, Food and Environmental Hygiene Department (2005, p.5) posits that the ‘dipoles’ when subjected to an electromagnetic field they orient themselves. The water molecules’ rotation then generates the heat needed for cooking. Besides the dipole molecules of water, food ionic compounds (such as dissolved salts) are also accelerated by the electromagnetic field; thus, colliding with other molecules so as to generate heat. Therefore, the food composition affects how the food is heated up in the microwave oven. Food having higher content of moisture is always heated up faster due to what Okeke et al. (2014, p.29) refer as dipolar interaction. When the ions concentration increases, (for example the dissolved salts), the heating rate as well increases due to the ionic interaction with the microwaves. Although molecules of oil are non-ionic and to some extent are less polar as compared to the molecules of water, food products having high content of oil have a high rate of heating since the specific oil heat is almost half that of water. With their capability of heat materials rapidly, Microwaves are normally utilized as a heat source, and recently they are used as an alternative drying technique in the food industry. As observed by Haghi and Amanifard (2008, p.491), microwave energy is widely utilized in the food industry where it is used not just for cooking, but also for tempering, thawing, freeze-drying, drying, as well as sterilization of food. Microwave cooking is fast, energy efficient and more uniform than the conventional cooking methods. Besides that, cooking using microwaves saves space and is energy efficient, considering that the majority of the electromagnetic energy is changed to heat. The majority of people find microwave ovens fast and convenient; it comes at a costly price. When cooking with microwave oven, the food’s nutritional value is stripped of by the microwave radiation, which consequently adversely affects the body because of the manner through which food is cooked by the microwaves. As pointed out earlier, when the food water molecules are subjected to microwaves the polarity is reverses: the negative ends becoming positive while the positive ends becoming negative. This takes place repeatedly at high speeds to and fro until the molecules are knocked so hard to the extent that the motion generates friction. Therefore, it is the friction brought about by such recurring changes that generate heat used for cooking. However, during the cooking process the water molecules disruption becomes exceedingly intense to an extent that they literally become deformed and torn apart structurally. This phenomenon has been named by chemists as structural ‘isomerism’. Basically, the energy fields of what people eat in addition to their own bioelectric energy fields should not experience this form of polarity switching that is incredibly chaotic and rapid. All cells when exposed to microwave ovens they lose their electrical charge. When an organism electrical charge is damaged, the organism will malfunction. According to the United States Census figures, there are more than 120 million microwave ovens in the US households. Besides that, a report by IMPI Consumer Survey in 2011 showed that more than 80 per cent of consumers had a power output of 900 watts microwave ovens which proves that more than 20 million ovens have a power output of no more than 900 watts. Understanding how a math-challenged consumer can manage to calculate the needed cooking time is hard. Besides that, there are other questions concerning the safe heating of Not-Ready-To-Eat (NRTE) products; for example, IMPI Consumer Survey report established that almost 58.9 per cent of people use kitchen thermometers so as to determine the food’s final temperature: this is so, for people who have kitchen thermometer. Essentially, as stated by the IMPI Consumer Survey for people with kitchen thermometers, 58.1 per cent pointed out that they never utilize together with the microwave-prepared foods. According to Abgrall and Misner (1998), in microwave cooking areas of uneven cooking normally referred as cold spots are the biggest safety concern. Different microwaved foods’ components absorb microwaves in a different way; thus, leaving a number of areas under-cooked. Furthermore, bacteria if present, may flourish in such environments that are moist and warm. This can lead to gastro-intestinal illness, which ranges from minor stomach distress to diarrhea and vomiting. For this reason, Abgrall and Misner (1998) suggest that the food items have to be arranged uniformly in a dish that is covered with microwave-safe glass lid or plastic wrap, and ensuring that the lid is vented and is not in contact with the cooked food. Furthermore, a liquid in small quantity have to be added. Food covering enables the steam to kill the existing bacteria and making sure the heating is uniform. All through the cooking process, the food should be stirred, and the dish turned severally (particularly for casseroles, stews and soups). In order to confirm safe temperatures for food while cooking, a meat thermometer or temperature probe should be used. Poultry and meat products should be checked in a number of places, and avoiding bone and fat. Importantly, the internal temperature while cooking red meat must be of 73°C and 76.6°C for Poultry while Leftovers must be reheated to a minimum internal temperature of 73.8°C. Steaming is the best way of cook vegetables while using a microwave oven in order to retain most of its nutrients, but a number of factors affect the vegetables’ cooking time. These factors include texture, age, size, freshness as well as shape and their cooking temperature. The processes of cooking, particularly those that require high temperatures such as baking and grilling can possibly result in the production of carcinogens. According to Wayne and Newell (2011), microwave cooking can increase the production of mutagens or carcinogens in foods. However, there is no present scientific proof that shows carcinogenic substances production may increase when a microwave is used for heating. For instance, a study carried out to examine the mutagen production in cooked beef provided no proof of mutagenicity in meat cooked by microwave. Conclusion In conclusion, the essay through illustrations and diagrams has provided a critical analysis of microwave cooking. As indicated in the essay, microwaves provide a rapid means of cooking and may be used to cook different types of foods ranging from meat to vegetables. Increasing concerns with regard to cooking time have motivated a lot of people to adopt microwave technology which rapid and safe. As indicated in the essay, microwave oven offers a convenient way of cooking food these days. However, there are some speculations that microwave cooking result in possible loss of nutrients. However, a number of studies have established that microwave cooked foods’ nutrient quality and safety were similar to those cooked by traditional means, as long as the consumers follow the provided instructions. References Abgrall, M. & Misner, S., 1998. Microwave Cooking. [Online] Available at: http://ag.arizona.edu/pubs/health/foodsafety/az1081.html [Accessed 4 September 2015]. Food and Environmental Hygiene Department, 2005. Microwave Cooking and Food Safety. Risk Assessment Studies. Queensway, Hong Kong: Food and Environmental Hygiene Department. Haghi, A.K. & Amanifard, N., 2008. Analysis of heat and mass transfer during microwave drying of food products. Brazilian Journal of Chemical Engineering, vol. 25, no. 3, pp.491 - 501. Okeke, C., Abioye, A.E. & Omosun, Y., 2014. Microwave Heating Applications in Food Processing. IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE), vol. 9, no. 4, pp.29-34. Rashad, R., 2013. Rashid Rashad. Bloomington, Indiana: Xlibris Corporation. Vollmer, M., 2004. Physics of the microwave oven. PHYSICS EDUCATION, vol. 39, no. 1, pp.74-81. Wayne, A. & Newell, L., 2011. The Hidden Hazards of Microwave Cooking. [Online] Available at: http://www.health-science.com/microwave_hazards.html [Accessed 4 August 2014]. Read More

The commercial microwave ovens have almost a 1000 watts power input of alternating current (AC) and the generated microwaves from the magnetron makes the polar molecules to rotate million times per second. The agitation results in a molecular ‘friction’, which consequently heats up the food (Rashad, 2013, p.218). This uncommon form of heating brings about a significant damage to the adjacent molecules, normally dismantling them or deforming them forcefully. Contrary, microwaves generated by the sun are anchored in the pulsed direct current principles, which do not generate frictional heat while microwave ovens utilize AC that creates frictional heat.

In this case, a microwave oven generates a spiked energy wavelength with all the power/energy focused on an energy spectrum having a narrow frequency. According to Food and Environmental Hygiene Department (2005, p.18), using microwaves for cooking is not very safe; for instance heating water through microwaves may lead to superheated water; that is to say, the temperature attained by water is beyond the boiling point temperature, but still the water appears not to have boiled. Water disturbances while in a microwave oven; for example the cup movement or adding other ingredients to the water, may result in an eruption of the boiling water leading to injuries.

In order to avoid superheating the water, Food and Environmental Hygiene Department (2005, p.18) suggests that one must avoid heating the liquids or water excessively in the microwave oven, or should allow the cup containing the liquid or water to stand for half a minute prior to moving it or adding other ingredients. Another example is cooking an egg while still in its shell; it can result in build-up of steam inside the shell and the egg can consequently explode. This can be avoided by cooking the eggs in microwave oven after removing the egg shell.

By and large, the alternating electromagnetic field produced by the microwave oven may result in collision/rotation, excitation of polar ions as well as molecules in the cooked food. Such molecular frictions may produce heat and then result in the rise of temperature. Therefore the two key techniques, specifically ionic and dipolar and interactions, clarify how heat is generated in the food. Upon absorption of the microwave energy, polar molecules like molecules of water in the food start rotating consistently with the alternating electromagnetic field.

Therefore, the molecule of water is a ‘dipole’ with one end negatively charged and the other end positively charged. Akin to the magnet action, Food and Environmental Hygiene Department (2005, p.5) posits that the ‘dipoles’ when subjected to an electromagnetic field they orient themselves. The water molecules’ rotation then generates the heat needed for cooking. Besides the dipole molecules of water, food ionic compounds (such as dissolved salts) are also accelerated by the electromagnetic field; thus, colliding with other molecules so as to generate heat.

Therefore, the food composition affects how the food is heated up in the microwave oven. Food having higher content of moisture is always heated up faster due to what Okeke et al. (2014, p.29) refer as dipolar interaction. When the ions concentration increases, (for example the dissolved salts), the heating rate as well increases due to the ionic interaction with the microwaves. Although molecules of oil are non-ionic and to some extent are less polar as compared to the molecules of water, food products having high content of oil have a high rate of heating since the specific oil heat is almost half that of water.

With their capability of heat materials rapidly, Microwaves are normally utilized as a heat source, and recently they are used as an alternative drying technique in the food industry. As observed by Haghi and Amanifard (2008, p.491), microwave energy is widely utilized in the food industry where it is used not just for cooking, but also for tempering, thawing, freeze-drying, drying, as well as sterilization of food.

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