The maize as a food grain plays a significant role throughout the world, particularly in Pakistan and India. Its flour is used in the preparation of nutritious and tasty meals such as snacks, cakes, pizza, bread, pasta, cookies and soup and as a source of dextrose.

Its bran has been found very effective in decreasing faecal transit times. Maize-based fibrous food can solve these problems. Major constituents of fibres are cellulose, hemi-cellulose and lignin.

Maize proximate analysis per 100 gram is as follows:

S.No Contents Unit Quantity

01 Moisture % 14.90

02 Protein gm 11.10

03 Fat gm 3.60

04 Mineral gm 1.50

05 Fibre gm 2.70

06 Carbohydrate gm 66.20

07 Energy K.cal 342.0

08 Calcium mg 10.00

9 Phosphorous mg 348

10 Iron mg 2.00

11 Thiamine mg 0.42

12 Riboflavin mg 0.10

13 Niacin mg 1.80

14 Vitamin C mg 0.00

15 Carotene mg 90.00

The grain has lower nutritive value than wheat. It is deficient in nicotinic acid and is relatively poor in proteins. It also lacks in essential amino acids like lysine and tryptophane. Among people who mainly use maize as food, pellagra is common which niacin deficiency disease. About 50-80 per cent of niacin in maize occurs in bound form which is biologically unavailable.

Maize is mostly eaten in the form of Roti with pulses, meat, vegetables or milk products. Blended with 20 per cent wheat flour, it is used for making cakes, biscuits and snacks. Maize breakfast foods like corn flakes, pop corns, corn soups, baby corn, pizzas and pastas are fast catching up in this country.

For making maize suitable for food and industrial products, milling is necessary. Dry and wet milling processes are adopted in accordance with the need. For making various types of food items, dry milling is normally adopted whereas for producing industrial products like starch, corn oil and animal feeds wet milling is desirable.

In dry milling, maize grain is cleaned of dust, husk and other foreign materials. Before dry grinding, the grain is de-germinated, conditioned, dried and cooled. After grading, it is grinded dry in mills, followed by shifting, purifying, drying and packing. The flour produced in a water mill is considered superior. This product is subsequently used for preparing food products and for industrial uses.

All cereals contain a good quantity of starch. In its natural form starch is insoluble in water and therefore, can not be utilised by human body. However, to make it fit for human consumption, it must be cooked. During cooking heat gelatinises starch, which becomes susceptible to starch dissociating enzymes of digestive system.

Modern wet millings methods help condense steep water for animal feed. The ground maize slurry thus produced is further refined into corn oil and starch. Mechanical and solvent extraction methodologies are combined to extract oil from germ. The germ left over is used as component of animal feed. Removal of free fatty acids and phospholipids produces corn oil resistant to smoking and discoloration having excellent dry quality. It is pleasantly tasteful, resists developing off flavours and offers poly unsaturated fats.

Its oil is rich in essential fatty acids has a specific gravity of 0.922-0.925 and is used in salad dressings. Its high smoke point value also makes it suitable for use as cooking oil. It is used in the production of many food items such as imitation butter and non-dairy products. After extraction of oil, the press cake is again used as animal feed.

The slurry containing starch gluten and fibre flows over fixed concave screens which separates fibre but allows starch and gluten to pass through. The fibre is again washed, screened and collected for making animal feed. The starch gluten slurry called mill starch is piped to starch separators. Low density gluten is separated by centrifugation from the slurry. The remaining suspension is dried and marketed as unmodified starch may be processed into modified starch. It can be further converted into corn syrups and dextrose.

Starch is consumed by paper and textiles industries in sizing, surface coating and adhesive applications. Special starch is used in oil research as drilling mud which cools superheated drills. It is also used as anti-caking, mould release, dusting power and thickening agents.

Alcohol production is a measure for industrialisation of any nation along with sulphuric acid and steel. Maize starch is used for alcohol production by fermentation. It is being used as fuel extender because it enhances efficiency of fuel-octane and it is safe alternative to lead additives which are being phased out due to ozone and carbon mono oxide pollution. The mixture of petrol and alcohol called gasohol has become popular in South Africa and Brazil where there is no any natural oil resources.