Introduc? on Food science is a ? eld embodying the applica? on of modern science and engineering to the produc? on, processing, diversi? ca? on, preserva? on and u? liza? on of food. Food is very essen? al to man’s survival and great a? en? on should be paid to food produc? on, distribu? on, wholesomeness and preserva? on.
To ensure that food is clean and safe for human consump? on and having keeping quality, food scien? sts are responsible in seeing that the crop harvested, the ? sh caught, that animal slaughtered, the egg laid and the milk produced reach the consumer in the most acceptable, nutri? ous safe and wholesome condi?on by carefully studying the chemical complexi? es of food, their vulnerability to spoilage, their disease vectors and varying sources of produc? on.
Food scien? sts try to eliminate seasonal gluts and shortage by providing a technologically sound base for the levelling out of food surpluses and shortages with and among countries and regions.
They also see to the remedy for the malady of post-harvest losses in food grains in the highly industrialised socie? es has been the development, along with increase in yield poten? al of adequate storage and low- cost processing technologies to preserve and store the harvest.
The development and produc? on and new nutri? ous foods to improve the diet of people su%ering from malnutri? on, the provision of adequate group – speci? c diets for the young and adults performing under condi? ons of stress, pregnant and lacta? ng mothers, kwashiorkor and diabe? cs pa? ents.
Scope of food science The scope of food science is in threefold: 1. To make it possible to assemble the great quan?? es of food required by a crowded popula? on.
2. To make the food agreeable to the consumers that is to say, to provide them so far as is possible with the kind and quality of food they demand at all ? mes of the year doing this partly by carefully controlling the quan? ty and uni-forrming of the commodi? es produced and partly by constant e%ort to produce something new ( a new breakfast food, a new kind of co%ee essence or indeed a new kind food altogether and by these mean keeping up with popula? on demands).
3. To maintain and improve the nutri? onal value of the total food supply and hence the health of the community ea? ng it. Basic principles of food science Food processing and preserva? on either local or interna? onal mist follow basic principles 1. Working surface and environment must be kept clean and spillage must be wiped o%.
2. Food processor must observe personal hygiene, which involves cleanliness and care of the body to prevent the spread of infec? ons. 3. Cleaning utensils should be used during the processing food in order to prevent food contamina? on. 4.
The process ad preserva? on area must be clean always so that the task of the food prepara? on and preserva? on may be performed without hazards to the body. Brief history and growth of food science The history of food science can be traced back to ancient ? mes from ? me immemorial individuals and community have organised themselves in various way to provide for the preven? on of food microorganisms which leads to deteriora? on of food, processing and preserva? on which leads to treatment and promo? on of health eaten wholesome food.
In 1840 industrial revolu? on was started in England, which brought about of food science during this period. There was extensive industrial use of newly developed machine e. g. the steam engine and mass produc? on techniques. Also during the ? rst and second world wars, there was increase in the bulk manufacture of food as a result of commercial feeding in most part of the world. Therefore the prepara? on centre became over u? lized including sta%, which eventually results to the gross contamina? on of food.
This helps in crea? ng the awareness from ? me to ? me to safeguard the produc? on of food, and totally free from micro organism from food which are meant for consump? on. Rela? onship between food science nutri? on and diete? cs Food science deals with the basic chemical, bio chemical, physical and biophysical proper? es of foods and their cons? tuents, thus very closely related to nutri? on which is the study of the nutrients in rela? on to their func? ons in the body. It also involves the study of the chemical and physical proper? es of the nutrients, their food source, de? ciency symptoms and their appropriate propor? on in a balanced diet.
These two (food science and nutri? on) are related to diete? cs in the sense that the diete? c is the prac? cal applica? on of the principle of nutri? on, which includes the planning of meals for the healthy and the sick. Assignment What is rela? onship between food science catering and hotel management. Food processing. There are methods involved in prepara? on of food.
These methods include material handling (washing, cleaning e. t. c ) during, mixing, crushing, hea?ng, cooling or freezing and packing). Reasons for food processing 1. To prevent food spoilage. 2. To prolong shelf life. 3. To avoid was? ng of food especially when they are in season. 4. To allow for the use of food during the o% – season. 5. To introduce variety into the family menu.
6. To eliminate the purchase of the food when they are most expensive. 7. To be able to take care of emergency situa? ons. Food preserva? on Food preserva? on is the act of keeping food for a longer period of ? me before it is consumed. It may involve the addi? on of other substances or changing the form of the foodstu% to another food through processing or keeping the food especially designed containers or equipment.
Principle underlying food preserva? on The act of food preserva? on is based on the following: a. Destruc? on of microorganisms. b. Preven? on of microorganism entering into the food. c. Arrest of the ac? on of food enzymes. 10 methods of food prepara? on Drying: this is the process which the water content of the food is reduced. Both food enzymes and food microorganisms require water for ac? on and growth. The removal of water from the food creates an unfavourable environment for their ac? on and growth, hence they are unable to cause food spoilage.
Drying can be achieved by sun drying or by ar?? cial dryer or roas? ng on a ? re. Examples of food preserved by drying is legumes, cereals, meat, ? sh etc. the preserva? on of food by drying can either be by dehydra? on or concentra? on. A i. Dehydra? on: is the process by which all the water content of the food is removed and the resul? ng product is very dry and break with a snappy sound, food items usually dehydrated are ? sh, meat, yam cassava, cereals and legumes. ii. Concentra? on: is the removal of a considerate amount of water from food stu%s by the applica? on of heat, cooking e. g. tomato puree, pepper puree etc.
There are di%erent types of drying which are solar drying, oven drying, freezing, roller drying, vacuum drying, tunnel drying and spray drying B. Applica? on of low temperature: this is the process of keeping food at a low temperature e. g. chilling and freezing. In chilling, the food is kept in the refrigerator while in freezing, the food is kept in the freezer. Freezing is keeping the food at a temperature below 0oC or 32oF, which solidi? es the food. Freezing keeps food longer and completely arrest the growth o% microorganisms and the ac? on of food enzymes.
Chilling on the other hand does not completely arrest enzymes ac?on and bacteria growth. Food items preserved with this method are ? sh, meat, milk, fruits and vegetables C. Applica? on of high temperature: this involves the destruc? on of food enzymes and microorganisms by hea? ng. Both enzymes and microorganisms are proteinous in nature and when they are heated; their protein becomes denatured and hence rendered inac? ve. This method can either be by pasteuriza? on, steriliza? on or blanching. I. Pasteuriza? on: is the applica? on of heat to foodstu% under 10oC. the objec? ves of the heat is not to destroy all the microorganisms present in the food but only the pathogenic ones.
Pasteuriza?on has a minimum e%ect on the nutri? onal proper? es of the food. It is usually carried out in three forms. Low temperature long ? me (LTLT), High Temperature Short Time (HTST), Ultra High Temperature (UHT) in this process the hea? ng temperature is very high but the dura? on is very short e. g. milk can be heated at 125. 25oC for 14 seconds. II. Steriliza? on: is the heat treatment of food at a very high temperature. The objec? ve of steriliza? on is the destruc? on of all the microorganisms present in food. Thus it is a more severe heat treatment of food than pasteuriza? on e. g. tomato puree, canned meat and ? sh etc. III. Blanching.