FUNDAMENTALS OF FOOD TECHNOLOGY (1+1)

ZINC

• In an adult 2 to 3 g of zinc is present. It is present in certain parts of the eye, certain glands and in their secretion. Liver, muscles, bone and hair contain some of the remaining zinc. Blood, especially the RBC, has some zinc. In small amounts it is present in tissues and bone cells.

Functions

1. The important function of zinc is its role in enzymatic action. In 25 enzymes of digestive and metabolic action zinc takes part.
2. It is also present in an enzyme carbonic anhydrase which is essential for the transport and elimination of carbon dioxide. Co-carboxypeptidase and alkaline phosphatase contain zinc in them.
3. Zinc plays an essential role in the formation of DNA and RNA. It is a constitution of insulin and it is necessary for the formation of connective tissues.

Zinc also aids in the healing of burns and wounds.

Deficiency

• Zinc deficiency in animals results in growth failure, loss of appetite, degeneration of the male sex glands, testes, skin lesions, alopecia or loss of hair, changes in the epithelial and cutaneous tissues, dermatitis and scaling and cracking of the paws.
• Abnormal bone formation, thickening and metabolism also occur during zinc deficiency.
• In human beings zinc deficiency produces anemia, growth retardation and delayed genital maturation.

 

Sources

• Sea foods, meat, poultry and eggs are good sources of zinc. Cereals, legumes and nuts contain considerable amounts, on milling, eighty per cent of zinc is lost. Fruits and vegetables are poor sources.

Requirement
RDA for zinc (mg/d) in different age and physiological groups

Group		FAO/ WHO**
Young children (1-3 years)		5.5 (3.3-11)
Pre-adolescents (11-14 years)	Male	9.3-12.1
	Female	8.4-10.3
Adults (25-50 years)	Male	9.4
	Female	6.5
Pregnancy		7.3-13.3
Lactation		12.7-9.6