FUNDAMENTALS OF FOOD TECHNOLOGY (1+1)

RIBOFLAVIN (B2)

• Riboflavin is dimethyl- iso-alloxazine attached to ribose. It is slightly soluble in water and stable in acid medium. In alkaline medium it is easily destroyed. Bright light also destroys riboflavin.
Functions

• Riboflavin is part of food co-enzymes as riboflavin monophosphate or flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD)
• Riboflavin is closely related to biological oxidations in cells
• Flavoprotein enzyme system is present in different parts of our body. It takes part in cell respiration
• Cellular growth cannot evolve in the absence of riboflavin
• Riboflavin through the enzyme system possesses the ability of transferring hydrogen in chemical reactions. Thus, it takes part in carbohydrate and protein metabolism
• Riboflavin is essential for the health of skin, mucous membraneous structures of alimentary canal and eyes
• For normal vision riboflavin is essential. The retina has free riboflavin which is converted by light to a compound that stimulates optic nerves

Deficiency


• In mild deficiency of riboflavin weakness, anorexia, apathy, burning at the angles of mouth, in the eyes and over the skin occurs. Normal metabolism of carbohydrate and protein is affected.
• Riboflavin deficiency symptoms are generally known as ariboflavinosis.
• Ariboflavinosis consists of angular stomatitis with cheilosis, glossitis, skin changes, seborrheic dermatitis and vascularisation of the cornea.
  
• The angles of the mouth become pale and crust is formed in the corners.
• Fissures occur at the corners of the mouth and it is known as angular stomatitis .
• Crust is formed on the surface of lips and removal of it makes it red in colour, called cheilosis.
• Papillae of the tongue are peeled off and the tongue shows a ‘magenta’ or red tint on the surface. This is referred to as glossitis.

Glossitis




On the nasolabial folds, ears, vulva in the female reproductive organs and on the scrotum in the male, scaly desquamation of the skin takes place.
These are known as nasolabial seborrhoea or nasolabial dyssebacia and scrotal lesions. The lesions are cured by the administration of riboflavin
Even in a mild deficiency state burning and watering of the eyes, sensitivity to light and dimness of vision take place.
Vascularisation of the cornea and abnormal pigmentation of the iris are the other symptoms manifested.
Vision is blurred and conjunctive and itching may occur in riboflavin deficiency.

Sources
Rich sources – Liver, egg, skimmed milk powder and other milk products
Good sources - Milk, meat, fish, whole cereals, legumes, dals, oilseeds, nuts andleafy vegetables
Fair sources - Milled cereals and flours, roots and tubers and other vegetables.


RDA of Riboflavin

Age group		mg/day
		ICMR 1989	FAO/WHO 2004	NRC 1989
Infants	0-6 m	0.35 (0.6 mg/ 1000 kcal)	0.3	0.4
	7-12 m	0.52	0.4	0.5
Children	1-3 y	0.7	0.5	0.8
	4-6 y	1.0	0.6	1.1
	7–9 y	1.2	0.9	1.2 (7-10 y)
Boys	10-12 y	1.3	1.3	1.5 (11-14 y)
	13-15 y	1.5	1.3
	16-18 y	1.6	1.3	1.8 (15-18 y)
Girls	10-12 y	1.2	1.0	1.3 (11-14 y)
	13-15 y	1.2	1.0
	16-18 y	1.7	1.0	1.3 (15-18 y)
Male		1.4-1.9 Sedentary Heavy	1.3	1.7 (19-50 y) 1.4 (50+ y)
Female		1.1–1.5 Sedentary* Heavy*	1.1	1.3
Pregnancy		+ 0.2	1.4	1.6
actation	0-6 m	+0.3	1.6	1.8
	7-12 m	+0.2	1.5	1.8
*Minimum intake of 1.2 mg/1000 kcal is recommended.