Ask a Teacher

Search



i have a seminar on topic "food preservation and how to consume it with care", my role is to give introductory speech on this subject. So help me out ?
Food preservation is a very popular process used throughout the world and is also one of the oldest technologies discovered by humans.Maintaining food
(salting, cooling, cooking) is beneficial because it stops or greatly slows down spoilage to prevent food borne illnesses.
Food has not been well preserved if it becomes dry, hard, or if it does not taste good. Another essential element of food preservation is preventing bacteria, fungi and other
micro-organisms from growing. The food becomes unhealthy when micro-organisms are growing on it. Preservation techniques must also destroy enzymes naturally found in a food that
cause it to spoil or discolor quickly, asserts Brain. Enzymes are delicate because they act as a catalyst for
a chemical reaction since they are a necessary component of a special protein (Brain, n.d.). Brain also
states that when the temperature of food reaches 150 degrees Fahrenheit (66 degrees Celsius),
enzymes are destroyed. All food contains bacteria if not sterilized or sealed . Therefore,sterile food contains no bacteria and prevents spoilage. Two or three hours after milk is left on a kitchen counter, the bacteria will already have spoiled the milk, therefore by putting it in the fridge, it will not eliminate the bacteria already there but slow down the creation of bacteria enough for the milk to stay
fresh a week or two, states Brain. Behind all forms of food preservation, we have discovered there are two main reasons for the process: to slow down the activity of disease-causing bacteria and to kill the bacteria altogether.
Because most foods remain edible for only a brief period of time, people since the earliest ages have experimented with methods for successful food preservation. Among the products of early food conservation were cheese and butter, raisins, pemmican, sausage, bacon, and grain.

As scientific investigations regarding the causes of food spoilage were undertaken, they pointed the way to a wider application of methods already in use and to the discovery of new ones. Before 1860 changes in food were explained on the theory of spontaneous generation. Pasteur demonstrated that ferments, molds, and some forms of putrefaction were caused by the presence of microorganisms widely distributed in the environment. Since these microorganisms are the main cause of food spoilage, food preservation depends on rendering conditions unfavorable for their growth. Processes of preservation may be generally classified as drying, heating, refrigeration etc.


comments powered by Disqus