Food processing and storage effect on water soluble vitamins

Certain vitamins are sensitive to processing and storage. Processing medium or the environment is a critical factor in influencing the stability or retention of water soluble vitamin. Generally, the water soluble vitamins especially thiamin, riboflavin, and vitamin C , are more susceptible to losses due to leaching during washing and blanching.

Certain water soluble vitamin are susceptible to oxidation (thiamin and cobalamin), the processes are different from those for the fat soluble vitamins.

Tofu

Water soluble vitamins are generally more heat heat-sensitive than fat soluble vitamins. Vitamin C and thiamin are the most heat sensitive. Thiamin is extremely water soluble and destroyed by heat is much can be leached into the cooking or storing liquids during preparation of both meats and vegetables. Losses in the making of soy flour are minimal, but losses in the making of soy flour into tofu stored in water are 85% or greater.

Vitamins stable at acidic pHs include ascorbic acid, niacin, free folacin and thiamin. Biotin, thiamin, free folic acid, pantothenic acid and ascorbic acid are loss more readily at alkaline pHs.

Physical factors also contribute to the loss of vitamins during processing and storage. Electromagnetic radiation in the visible and near ultraviolet region is one such factor.

Folic acid is easily lost during storage of fresh vegetables at room temperature and through many heat processes. Oxidative destruction of 50-95% of the folate can occur with protracted cooking or canning. Riboflavin and niacin are both relatively stable on heat preservation, although riboflavin is very sensitive to light and will undergo degradation in the present of both heat and light together.
Food processing and storage effect on water soluble vitamins

Vitamin deficiency

Vitamins play an integral and an almost central role in human health and wellbeing. Significantly, the vitamins were discovered not by their presence in the diet but because of their absence.

Deficiency of vitamins may arise due to: inadequate dietary intake, decreased absorption, increased need and impaired unitization.

A lack of most of the vitamins known to be required by human resulted in typical clinical syndromes or symptoms that can be cured by adding the necessary vitamin to the diet.

Deficiency of fat soluble vitamins results in night blindness, skeletal deformation, haemorrhages and hemolysis. Deficiencies of water soluble vitamins produce beriberi, glossitis, pellagra, microcytic anaemia, megaloblastic anemia and scurvy. Since most of the water soluble vitamins are component or enzymes, their deficiency leads to blocks in metabolic reactions.

This negative approach to the function of the vitamins is a useful tool in research. The investigator obtains some clues to the metabolic role of nutrients when he observes the functional failures that result when the nutrient is absent from the diet.
Vitamin deficiency

Characteristics of water soluble vitamins

Vitamin are chemically unrelated organic substances that are grouped together because each is essential in the diet in minute amounts and is required for specific metabolic reactions within the cells. Vitamins fall into two categories: those that dissolve in water (water soluble vitamins) and those that dissolve in fat (fat soluble vitamins).

 L-ascorbic acid

The nine water-soluble vitamins – eight B vitamins and vitamin C are found in the watery components of foods, such as the juice of an orange. Water-soluble vitamins have a vital roles as coenzymes which are necessary for almost every cellular reaction in the body. These vitamins are distributed into water-filled compartment of the body, including the fluid that’s surrounds the spinal cord.

Characteristics of water-soluble vitamins:
*Most are readily absorbed in the jejunum
*Water-soluble vitamins are easily absorbed and just as easily excreted in the urine
*Human body stores very small amounts of each of these vitamins.
*Because of their limited storage, daily intake is important.
*Deficiency symptoms appear relatively quickly
*Lower risk of toxicity
*Easily absorbed into blood travel freely in blood
*In food, it easily dissolves in water and drain away with cooking water, some destroyed on exposure to light, heat or oxygen during processing
*Less stable
*Most B vitamins share similar roles, vitamin C serves many different roles on the body
Characteristics of water soluble vitamins

Antimetabolites

Certain compounds similar in structure to the vitamin molecule (or to the portion of the molecule containing the active site) can replace the vitamin by attaching themselves to the enzyme. These substances are called ‘antimetabolites’ or ‘metabolic antagonists’. They block the normal action of the co-enzyme and in effect, result in cellular deficiency of the vitamin.

The antimetabolite is a chemical substance which is shaped like the substrate. In other words, it is a structural relative or analogue of the substrates. Probably for this reason it also is able to combine with the active center of the enzyme.

Certain other antimetabolites exhibit anti-vitamins activity because they are capable of blocking biosynthesis of the coenzyme molecule; such compounds may or may not resemble the vitamin in structure.

In either case, a condition similar to true vitamins deficiency is produced. Antimetabolites are useful in producing experimental vitamin deficiencies, especially those deficiency that developed slowly from dietary restriction alone.

Antimetabolites also useful adjuncts in delineating the biochemical pathways in which the vitamin is involved, and in relating metabolic disturbances to symptoms of deficiency.

The use of vitamin metabolites created new opportunities for inducing a studying many aspects of s wide range and variety of malformations and fortuitously led to an avenue of human studies.

A variety of antagonists of vitamins, hormones and cell metabolites had been synthesized after Donald Woods of Oxford University discovered in 1940 that sulfonamides exerted their antibacterial action by antagonizing the role of 4-aminobenzoic acid, a growth factor for  bacteria. Such antagonists were described as antimetabolites.
Antimetabolites

B complex vitamin of Inositol

Inositol is a vitamin-like substance. Sometimes it referred to as Vitamin B8, is a water soluble substance that is required by the body for the formation of healthy cells.

It is a carbocyclic polyols compound required for cell growth and survival that is incorporated into lung cell membranes and serves as a precursor for surfactant synthesis.  It has many duties including helping to transmit nerve signals and preventing the buildup of fats in the liver and other organs.

The nine isomers of inositol are ubiquitous cyclic carbohydrates with a basic 6-carbon rung structure.

Three forms of inositol occur in nature: phytic acid, free myo-inositol, and inositol-containing phospholipid.

Inositol is synthesized easily by almost all higher vertebrates and has long been known as a vitamin in arthropods, including the crustaceans.

Inositol is manufactured naturally in the human body by the action of beneficial bacterial in the gut on the fiber in plants, and it is also found in healthy amounts in legumes and whole grains and in lecithin.  Breast milk is a rich source of inositol as well as meats and dairy products.

It is the only ‘vitamin’ which has an energetic value.
B complex vitamin of Inositol 

Water soluble vitamin

Scientists classify vitamins as ‘fat soluble’ and ‘water soluble’. Vitamin A, D, E and K are lipid-like molecules that soluble in fat. The B vitamins and vitamin C are soluble in water. Vitamin B complex consists of eight different B vitamins.

Water soluble vitamins are more fragile than fat-soluble vitamins, and some cooking practices are particularly harmful.

Water soluble vitamins also are hydrophilic by nature, and water will leach them from vegetables during cooking.

The body handles the water0soluble vitamins differently from the way it handles the fat-soluble vitamins.

They are absorbed mostly in the small intestine and to a lesser extend in the stomach. The water soluble vitamins are absorbed into portal blood and with the exception of cobalamin they cannot be retained for long periods in the body.

Their bioavailability through absorption can be influenced by many factors, including nutritional status, other nutrients and substance in foods, medication, age and illness.

The vitamins are stored in the body or are used to meet its daily requirements. Reserves of these vitamin can last many months. Water soluble vitamins are distributed into water filled compartments of the body, including the fluid that surrounds the spinal cord.

Water soluble vitamins are excreted in the urine whenever plasma levels exceed renal threshold, therefore toxicity due to water soluble vitamins is uncommon.

Water soluble vitamin 

Classification of Vitamins

Classification of Vitamins
Classically, vitamins have been divided into two groups based on their solubilities in fat solvents or in water.

Thus, fat-soluble vitamins include A, D, E and K, while vitamin of the B-complex and C are classified water soluble.

Fat soluble vitamins are found in foodstuffs in association with lipids.

The fat soluble vitamins are absorbed along with dietary fats, apparently by mechanisms similar to those involve in fat absorption.

Conditions favorable to fat absorption, such as adequate bile flow and good micelle formation, also favor absorption of the fat-soluble vitamins.

Water soluble vitamins are not associated with fats, and alterations in fat absorption do not affect their absorption.

Three of the four fat-soluble vitamins (vitamins A, D and E) are well stored in appreciable amounts in the animal body. Except for vitamin B12, water soluble vitamins are not well stored, and excesses are rapidly excreted.

A continual dietary supply of the water soluble vitamins and vitamin K is needed to avoid deficiencies.

Fat-soluble vitamins are excreted primarily in the feces via the bile, whereas water soluble vitamins are excreted mainly in the urine.
Classification of Vitamins

Fat Soluble and Water Soluble Vitamins

Fat Soluble and Water Soluble Vitamins
Vitamins can be defined as essential organic micronutrients that are involved in fundamental functions of the body, such as growth, maintenance of health and metabolism. Because of these substances must be supplied wholly or partially by the diet. Although the clinician should be able to recognize the syndrome caused by a lack of the vitamin in the case of a deficiency, it is more relevant in this country of abundant and varied food supply for the nutrition professional to think in terms of what a specific vitamin does rather than what disease it [prevents. Unfortunately, at the present time it is often impossible to relate directly the function of the vitamin to its deficiency syndrome.

Vitamins for the most part are not related chemically and differ in their physiologic roles. The broad classifications of water soluble vitamins and fat soluble vitamins are made because of certain properties common to each group. For instance, absorption and transport of fat soluble vitamins are closely associated with the absorption and transport of lipids; optimal absorption requires the presence of bile slats, these vitamins can also be stored in body lipids, although the amounts stored varies widely among the four fat soluble vitamins.

The water soluble vitamins are handled quite differently by the body. Their absorption requires no formation of micelles and with the exception of cyanocobalamin (vitamin B12), they cannot be retained by the body for long periods. Any storage occurring, results from their binding to enzymes and transport proteins. Water soluble vitamins are excreted in the urine wherever plasma levels exceed renal thresholds.
Fat Soluble and Water Soluble Vitamins

Vitamins in General

Vitamins in General
20th century marks the most exciting era in the history of nutrition science. It was during this time that the discovery of vitamins or “accessory growth factors,” began. Researchers found that for life and growth animals required something more than a chemically defined diet consisting of purified carbohydrate, protein, and aft, the essential mineral, and water.

The first of these dietary essentials discovered was and antiberiberi substance isolated from rice polishing by Funk, a Polish biochemist. Because the substance was an amine and necessary for life, Funk gave it the name vitamine. Very shortly thereafter McCollum and Davis extracted a factor from butter fat that they called fat soluble A to distinguish it from the water soluble antiberiberi substance. These two essential factors became known as vitamine A and vitamine B. As each additional vitamin was discovered, it was assigned a letter; the e on vitamine was dropped to give the general name vitamin because only a few of the essential substances were found to be amines.

As the chemical structure of the vitamin became known through its isolation and synthesis; it was given a chemical name. When the chemical name was assigned, it was assumed that the name applied to one substance with one specific activity. Now it is evident that a vitamin may have a variety of functions and that vitamin activity may be found in several closely related compounds known as vitamers. An excellent example of this is vitamin A, which has several seemly unrelated functions and encompasses not only retinol but also retinal and retinoic acid.
Vitamins in General

B Vitamins – Thiamin and Riboflavin

B Vitamins – Thiamin and Riboflavin
Thiamin
The B vitamins are water soluble. Thiamin – vitamin B1 is involved in all bodily oxidations that lead to the formation of carbon dioxide. It is necessary for nerve function, appetite, and normal digestion. It is also required for growth, fertility, and lactation. The symptoms of vitamin deficiency are retardation of growth, palpitation and enlargement of the heart, hypertension, and beriberi. The various effects of a disturbance of the nerve centers such as forgetfulness or difficulty in thinking are other manifestations of vitamin B1 deficiency. The vitamin is often lacking in the diet because much of the naturally occurring amounts of it in food are destroyed during the processing of the food. The adult requirement of vitamin B1 is related to the food (calorie) intake. Fresh pork is an excellent source of vitamin B1 and the heart, liver, and kidneys of pork, beef and lamb are fair sources.

Riboflavin
Riboflavin – vitamin B2 is water soluble. This vitamin makes up a part of enzyme systems involved in the oxidation and reduction of different materials in the body. Deficiency of riboflavin generally results in growth retardation and may result in vision impairment, sealing of the skin, and lesions on mucous tissue. Neuritis is another deficiency effect. The minimum intake of riboflavin for an adult is about 2.0mg per day. The liver and kidney of pork, beef, and lamb are excellent sources of riboflavin, and the heart of these animals is a good source. Fair amounts of riboflavin are found in the muscular tissues of pork, beef, and lamb, while more is found in veal.
B Vitamins – Thiamin and Riboflavin