Drying process affects vitamin in food

The vitamin content of a food is, in general, reduced by drying. This is especially true for those vitamins (e.g. vitamin A and ascorbic acid) that are easily destroyed by heat in the presence of air, through oxidation.

The drying temperature has been shown to have no influence on vitamins B1, B2, B6 and niacin, whereas vitamin A losses increase with increasing drying temperatures. β-carotene which may be applied as the source of the vitamin A is shown to be far more stable than the straight vitamin.

Drying methods affect vitamin C content as well. It can be stated that the higher the drying temperature and air velocity, the greater the degradation of vitamin C durign drying.

However the application of a drying process with low temperatures for a short period of time can result in relatively high ascorbic acid retention, avoiding its sensitivity to heating processes. The sulfuring of fruit previous to drying also aids in reducing the amount of ascorbic acid destroyed during drying.
Drying process affects vitamin in food

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What are the symptoms of vitamin A deficiency?

Although dietary deficiency of vitamin A is rare in North America and Western Europe, it is the leading cause of childhood blindness worldwide, especially in Southeast Asia, parts of Africa and Central and South America.

In a well nourished person, vitamin A stores are generally sufficient to last many months on a vitamins A-deficient diet before signs of deficiency appear.

Carrots are rich in beta-carotene

Protein deficiency reduces levels of retinal-binding protein, the blood carrier protein that transport vitamin A in the blood.

The initial symptoms of vitamin A deficiency are night blindness and keratinization of hair follicles. Night blindness usually becomes apparent when the patient enters a dark place or is caught in the glare of oncoming headlights while driving at night.

Continued deficiency leads to damage to eye tissue and irreversible blindness. Vitamin A deficiency interacts with other nutrients deficiencies and with infection, worsening respiratory infections or diarrhea and causing countless deaths.
What are the symptoms of vitamin A deficiency?

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What is retinoids?

Human body gets its vitamin A from two classes of chemicals:
Retinoids
Carotenoids

The retinoids have been recognized for over 50 years for their profound impact in biological functions. The term retinoids refers to compounds whose names all start with ret: retinol, retinaldehyde, retinoic acid, and other chemically similar cofounds, both natural and synthetic.

These fat soluble substance are found in several foods of animal origin: liver and whole milk, eggs and butter. Retinoids give preformed vitamin A, the kind of nutrient that body can use right away.

The retinoids also can be synthesized by cleavage from the pro-vitamin beta-carotene.

Retinoid acid, for example, can substitute for vitamin A in maintenance of epithelial tissue and growth but is not adequate for vision or reproduction.

Retinoids also play significant roles in epithelial cell differentiation and immune function.

The standard unit for quantifying the biologic activity of the various forms of vitamin A and its precursors is known as a retinal activity equivalent (RAE).
What is retinoids?

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What is carotenoids?

Carotenoids are vitamin A precursors, chemical such as beta carotene, a deep yellow carotenoid pigment found in dark green, bright yellow, and orange fruits and vegetables. The carotenoids also found in microorganisms, insects, birds, fish and other animals.

Humans do not biosynthesis carotenoids so all carotenoids that are found in human blood and tissues must be ingested, ether in food or as supplements.

Human body transforms a vitamin A precursor into retinol-like substance. Due to functions as a source of vitamin A, it can prevent vitamin A deficiency.

Carotenoids that do not contain oxygen are called carotenes, and are deep orange on color; those that contain oxygen are called xanthophylls and are yellowish.

Carotenoids are also used as colorants in manufactured food products, and carotenoids and carotenoid-rich extracts are available as supplements.

Carotenoids absorb light primarily in the blue and green regions of the spectrum while reflecting those of the yellow, orange, and red region. Carotenoids produce the characteristics colors of carrot and oranges and the leaves plants during the fall.
What is carotenoids?

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Deficiency of vitamin A in children

Vitamin A deficiency causes visual impairment in many parts of the developing world and is the leading cause of acquired blindness in children.

Mild degree of vitamin A deficiency may increase children's risk of developing respiratory and diarrheal infections, decrease their growth rate, slow bone development, and decrease their likelihood of survival from serious illness.

Several reports suggest that all else being equal, xerophthalmia can increase the risk of mortality among malnourished, hospitalized children.

Severe vitamin A deficiency is the major cause of childhood blindness in the world, causing more than half of a million preschool children to lose their sight each year.

Children living in the United States who are considered to be at increased risk for subclinical vitamin A deficiency include:
*toddlers and preschool age children
*children living at or below the poverty level
*children with inadequate health care or immunizations
*children living in areas with known nutritional deficiencies
*recent immigrants or refugees from developing countries with high incidence of vitamin A deficiency or measles, and
*children with diseases of the pancreas, liver, intestines, or with inadequate fat digestion/absorption.

To solve the root cause of vitamin A deficiency, more vitamin A must be present in the diets of vulnerable people.

The basis for lifelong health begins in childhood. Vitamin A is a crucial component. Since breast milk is a natural source of vitamin A, prompting breastfeeding is the best way to protect babies from vitamin A deficiency.

The American Academy of Pediatrics recommends vitamins A supplementation for certain of measles infected infants and children.

Program planners and development leaders in health, agriculture, education and other sectors must understand the culture and ecology of food availability and consumption at the local level.
Deficiency of vitamin A in children

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Food fortification with vitamin A

Food fortification involves adding nutrients to foods in order to maintain or improve the quality of the diet of a targeted group or population.

WHO has a goal of worldwide elimination of vitamin A deficiency and its tragic consequences, including blindness, disease and premature death.

The combination of breastfeeding and vitamin A food fortification holds the promise of achieving combating vitamin deficiency.

The aims is to add vitamin A to a regularly dietary constituent of the targeted population at a specified level that will correct an existing dietary deficiency without posing significant risks of overdosing those who habitually consume the largest quantity of the fortified product.

Food fortification is a highly effectively strategy to correct underlying low intake of vitamin A and is widely used in developing countries to prevent deficiencies of multiple nutrients.

Vitamin A fortification of staple foods, such as margarine and sugar has made significant stride since eradicating blindness and promoting growth in children in developing countries.

Although fortification can take several years to initiate and longer still to penetrate poor markets and reach sufficient proportions of those at risk, some priority countries have made significant progress.

Food fortification with vitamin A

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Vitamin A in human body

The term vitamin A is generally used to refer to a group of compounds that possess the biological activity of all-trans retinol.

Vitamin A is a fat soluble vitamin. It is found only in animals, although a number of plants contain carotene, from which vitamin A can be produced in the body once the plants contain carotene are eaten.

The main physiological active forms of vitamin A are retinaldehyde and retinoic acid, both of which are derive from retinol.

Retinaldehyde functions in the visual system as the prosthetic group of the opsins, while retinoic acid modulates gene expression and tissue differentiation, acting by way of nuclear receptors.

Vitamin A may be formed in the body from the yellow pigments (containing carotene) of many fruits and vegetables, especially carrots.

Vitamin A is converted to light sensitive pigments in receptor cells of the retina, the light sensitive layer of the eye.

Vitamin A is also required for healthy reproduction and lactation. Vitamin A helps form and maintain healthy teeth, mucous membranes, skeletal and soft tissues and skin.

This vitamin also required for resistance to infection. One of its physiological functions is the formation and maintenance do epithelial tissue, which contributes to the body immune system. Scientists claim that vitamin A is ‘the anti-infective vitamin,’ enabling body surfaces to act as a barriers to invading micro-organism and toxins.

Epithelial cells (those cells present in the lining of body cavities and in the skin and glands) require vitamin A.

Lack of vitamin A in the diet will result in the drying up of the body cells which could lead to dermatitis, dry hair or night blindness.

Vitamin A in human body

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Vitamin A Deficiency

Vitamin A deficiency is common among children. Night blindness and eye changes are often early sign.

This nutritional deficiency is widespread in developing countries, and the problem is exacerbated by a tendency by some to withhold vegetables from children for cultural or other reason.

Where it is the limiting nutrient, vitamin A deficiency causes anemia, growth retardation and xerophthalmia; increases the incidence and/or severity of infectious episodes.

Reduced survival is the most severe and potentially the most widespread consequence of vitamin A deficiency, and the one that has generated the most interest.

It is also common knowledge that an adequate levels of vitamin A is essential for animal vision and that prolonged low levels of vitamin A can lead to xerophthalmia and ultimately, blindness.

Vitamin A deficiency decreases resistance to infections and increases the severity, complications and risk of death from various diseases.

When vitamin A deficient, the epithelial cells of growth skin, oral cavities and respiratory, genitourinary and gastrointestinal tracts become dry and flat, hardening so that absorption of nutrients is reduced.

Moreover, vitamin A deficiency may increase the risk of bacteria colonization or delay recovery.

Vitamin A Deficiency

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