1. What are the major segments of food industry?
The food industry may be divided into segments (or) components in various ways. One of the simplest is a functional division into four major segments of
- Raw material production
- Manufacture
- Distribution
- Marketing
2. Name a few allied food industries?
- Packing industry
- Aluminium companies- cans , aluminium dishes and foil for food use
- Steel manufactures make materials for the billions of cans used for food
3. What is the role of chemical engineers in food industry?
Food engineering is mostly concerned with unit operations of food processing include mechanical operations, heat transfer and mass transfer, rate process and process control instrumentation.
4. Define food science
Food science can be defined as the application of the basic science and engineering to study the fundamental physical, chemical and biochemical nature of foods and the principles of food processing.
5. Outline the importance of studying food technology
Food technology is the use of the information generated by food science in the selection, preservation, processing, packing and distribution as it affects the consumption of safe, nutritious and wholesome food.
FOOD CONSTITUENTS, QUALITY AND DERIVATIVE FACTORS
1. How does food function as a source of energy?
Plants are auto tropic and produce food in the form of carbohydrates utilizing sunlight, water, minerals and carbon monoxide by photosynthetic process. Animals and human cannot synthesis their food in the body and therefore depend on plant and other animal for food.
Energy is provided in the human by metabolic process involving the breakdown of carbohydrate, fat and protein constituents of food that is digested and absorbed.
2. What are nutrients and their functions?
- Food may be defined as substances which when eaten and absorbed by the body, maintain life and growth . (i.e) supply , build and repair tissues. The chemical components that perform these functions are called nutrients.
- Nutrients required for the growth of tissues and their maintenance include proteins, minerals and water.
3. What are the main constituents of food?
There are three main constituents of food are
- Carbohydrates
- Proteins
- Fats and derivatives of these
4. What are carbohydrates?
Carbohydrates are organic compounds with the basic structure CX(H2O)y. Carbon , hydrogen and oxygen these are the basic elements of carbohydrate.
5. Give any three types of carbohydrates?
The most important types of carbohydrates are sugar, dextrins , starches , cellulose , hemicellulose and certain germs.
6. What is mean by calories?
The energy value of food is measured heat is called calories.
A calorie is defined as the amount of heat required to raise the temperature of 1 gm of water through 283 K . A kilo calorie is one thousand calories and equal to 4.19 kilo joules.
7. Name a few means of controlling micro organisms in food?
The micro organisms like bacteria , yeast and molds are controlled by heat , cold , drying , acid , sugar and salt , smoke and air , chemicals and radiation.
8. Define quality of food?
Quality of food and food products may be defined as the degree of excellence of the various characteristics that influence consumer acceptance as well as consumer safety. (ie) sight , touch ,smell , taste and hearing.
9. What are the quality factors to be maintained in food processing?
The following quality factors can be maintained by food processing
- Appearance factors
- Textural factors
- Flavor factors
10. Outline the importance of food standards?
- Food standards are helps to ensure food quality.
- It protects health and prevent deception of the consumer.
- Federal grade standard have been set up mainly to help producers, dealers, whole salers, retailers and consumers in marketing food products.
11. List any two sources each of vitamin E and vitamin K?
- The primary source of vitamin E include the plant seed oils of olive, sunflower, soya bean, sea same, cotton and wheat germ.
- The sources of vitamin K are leafy green vegetables such as cabbage. Other important sources include peas, tomatoes, animal tissues and liver, cow and human milk.
12. Role of enzymes in food processing-explain?
Enzyme catalyzes a variety of reaction during processing and preservation of food products and forms a large group of processing aids. Food industry utilizes enzymes in the production of bakery items, dairy products, fruit and vegetable juices and products, tenderization of meat, modification of oils and fats, flavor production and preservation of food products.
13. List the food infecting micro organisms?
The food infecting micro organisms are Staphylococcus, aures, clostridium botalium, alkali genes, acenetobactes, bacillus , micrococcus, pseudomonas, lactobacillus, streptococcus, bacterioids, enterobactor, pseudomonas , etc.
14. What are the factors involved in deterioration of food?
The major factors affecting food deterioration include the following
- Growth and activities of microorganisms, principally bacteria, yeast and molds
- Activity of food and enzyme
- Infestication by insects, parasites and rodents etc.
15. Define shelf time/life.
The shelf life of a food is sometimes defined as the time it takes a product to decline to an unacceptable level. The actual length of the shelf life of any product will depend on a number of factors such as processing method, packaging and storage condition.
16. What are the methods involved in controlling of microorganism?
The most important means of controlling bacteria yeast and molds are heat, cold, drying, acid, sugar, salt, smoke, air, chemicals, and radiation.
17. Write a note on sanitary quality.
Sanitary quality usually is measured by counts of bacteria, yeast, mold and insect fragments as well as by sediment levels. X-rays can be used to reveal inclusions like glass chips, stones and metal fragments in raw materials and finished products moving at high speeds through a plant.
18. Define bacteria and classify their types.
Bacteria are single-celled organism many of which can be classified into one of the three types based on the shape individual cells:
- Spherical shapes - cocci
- Rod shape - Bacilli
- Spiral - Spirilla and vibrios
19. Name some food additives used in food industry?
There are approximately 3000 intentional food additives in 12 major groups. A few types from each group listed below:
- Preservatives - Sodium and calcium propionate used in bread and cake
- Antioxidant - Prevent oxidation of fats in potato chips, breakfast cereals, and salted nuts
- Sequestrates- EDTA, Polyphosphates
NUTRITIONAL REQUIREMENTS, IMBALANCES AND DEFICIENCY DISEASES
Constituents of Food
The chief constituents of food are : (a) carbohydrates, (b) proteins, (c) fats and oils, (d) vitamins, (e) minerals, (f) water, and (g) roughage.
a) Carbohydrates : These organic compounds are intimately involved in life processes. They contain atoms C, H and O, the last two in the ratio 2:1. The general atomic composition is stoichiometrically represented as C (H2O). The simple sugars are the building blocks of carbohydrates. One gram of carbohydrate provides about 4 kcal of energy.
There are three types of carbohydrates :
(i) Monosaccharides :
simple sugars like glucose and fructose.
(ii) Disaccharides : double sugars like maltose, sucrose, etc..
(iii) Polysaccharides : complex sugars like starch, and glycogen.
Importance of carbohydrates in metabolism: Carbohydrates like glucose form respiratory substrate or fuel substances to produce energy. The excess of glucose is stored in the liver and muscles (glycogen) in animals and in the form of starch in plants. They are thus storage compounds in plants and animals respectively. Cellulose and chitin are carbohydrates which form structural materials for cell walls in plants and exoskeletons in animals like arthropods.
Bread, potato, sugarcane, plantains, grapes and cereals like wheat and corn are dietary sources of carbohydrates.
b) Proteins : These are the molecules which are the fundamental compounds of protoplasm that are indispensable for all life processes. Proteins contain "N" in addition to C, H and O and may also contain phosphorus and sulphur. These are the polymers of unit structures called amino acids. A molecule of protein yields about 4 Kcal. of energy.
Meat, fish, eggs, peas, beans and milk contain large amount of proteins.
Importance of proteins in metabolism : Proteins are the building materials forming the main constituents of protoplasm. They are also used in repairing any wear and tear of the body. Various enzymes and some hormones are protiens which control the biochemical process taking place in all cells. In addition, protiens regulate duplication and translation of DNA and RNA into thier protien gene products. Excess protein, unlike carbohydrates which are stored in the body, is broken down in the liver to form urea which is expelled in the form of urine. The remaining parts are utilized for forming other complex food substances by inter-conversion.
(c) Fats and Oils (Lipids) : Fats and their derivatives are collectively called lipids. Fats are the compounds of fatty acids and glycerol. They are composed of C, H and O but there is less oxygen than in carbohydrates.
There are mainly three types of lipids, namely the simple lipids such as fats and waxes, the compound lipids such as phospholipids and glycolipids and the derived lipids such as steroids which include cholesterol, sex hormones like estrogen, androgen, etc.
Fats are highly concentrated energy foods which produce 9.5 kcal of energy per gram, more than twice produced by carbohydrates. They are obtained from butter, cream, oil, nuts, fish, etc.
Importance of lipids in metabolism : Fats are used in the growth of living bodies. They mainly serve as compact fuel molecules because they yield more energy per unit weight than any other food substance. Fats also serve as reserve food. In animals living in cold regions, fats form an insulating coating within the body. In the case of animals like camels living in deserts, oxidation of fats yields metabolic water which enables the animal to remain without ingesting water for several days.
(d) Vitamins : These are organic food factors which are essential for healthy and well balanced growth of the body. Small amounts of vitamins are sufficient for the normal functioning of the body, as they are usually recycled in the body. If vitamins are not taken in sufficient quantities, it may lead to various "deficiency diseases" as shown in the table below.
Vitamins are not synthesized by animals but obtained directly or indirectly from plants. Vitamins are A, B-complex, C, D, E and K of which B-complex and C are water soluble while A, D, E and K, are fat-soluble.
(e) Minerals : These are necessary for the body to perform its normal functions. About 4% of our body weight is formed by minerals. Fresh fruits and green vegetables are rich in minerals. A few important minerals needed for our body functions are given below:
(i) Calcium and Phosphorus: They are essential for the development of bones and teeth. Besides, calcium is also useful in clotting of blood and phosphorus is necessary in the formation of energy rich molecule called ATP.
(ii) Iron: It is essential for the formation of red pigment hemoglobin of blood. Deficiency of iron causes anemia.
(iii) Iodine: It is necessary for the proper functioning of the thyroid gland. A deficiency of iodine leads to simple goiter.
(iv) Potassium and Sodium: These are the main constituents of body fluids, nerve cells and blood plasma, and are often ingested in mineral forms.
(v) Magnesium: This is useful in the activation of many enzymes.
(f) Water : forms about 60 to 80% of the body weight. It is essential for most of the biochemical process in cells. It is also a good solvent for a number of organic and inorganic substances. It is an essential component of blood. It also helps in the transportation of useful materials, removal of wastes and regulation of body temperature. It helps in enzymatic reactions. In fact all metabolic activities come to a stop for want of water.
(g) Roughage : This is coarse indigestible food matter that is consumed as part of regular food. It consists mainly of cellulose fibers of leafy vegetables. It stimulates the intestine, induces peristalsis and maintains proper bowel movement. A sufficient amount of roughage in the diet prevents constipation and other complications arising from it. Leafy vegetables and fruits like tomato, guava, oranges, etc. provide roughage.