Preparation of Vitamin Premixes
In preparing vitamin premixes, whether commercial or experimental, several preparing should be considered.
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- The carrier material should be uniform in texture and particle size. If it is a carbohydrate, it should not contain free aldehyde groups. That means dextrose and lactose should be avoided as carriers.
- Both thiamin and folacin have free amino groups that can react with free carboxyl groups to form Maillard linkages that cannot be broken by digestive enzymes in the upper small intestine.
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- High potency vitamin premixes used for fortification of purified diets generally should not contain either choline or vitamin E activity.
- Pure choline choride is extremely hygroscopic and pure DL tocopheryl acetate is a liquid. As such, these substances are not suitable components of purified vitamin premixes. All-rac-α-tocopheryl acetate can be dissolved in ether or blanded with fat, premixed with carbohydrate, screened, and then added directly to the diet.
- Commercial vitamin premixed generally use choline and vitamin E sources that are already premixed (i.e., diluted) and this makes them suitable as components of complete (feed grade) vitamin premix.
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- Once prepared, vitamin premix should be stored in a dark container that is as air-tight and oxygen-free as possible and kept in a cool, dry place. Avoding heat, light oxygen, and moisture will minimize loss of potency.
- Generally, the fat-soluble vitamins are less heat labile than the water-soluble vitamins, although the former can lose biopotency when subjected to high temperatures in the presence of oxygen. Among the water-soluble vitamins, thiamin, folacin, pantothenic and, and ascorbic acid are considered the most heat labile.
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pH of premix is also important. For maximal retention of vitamin A activity, premixes should be as moisture free as possible and have a pH above 5.
- Low pH causes isomerization of all-trans vitamin A to less potent cis forms and also results in deeterification of vitamins present in commercial supplements are presented in Table.
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| Vitamins | From available to the commercial foods & feeds | Form Present in natural feed stuffs |
| Vitamin A | Vitamin A esters. Current commercial source are generally “coated” esters of acetate or palmitat that contain a synthetic antioxidant in beadlet form.AD3 beadlet form (cross linking). Crystalline B-carotene is absorbed from the gut more efficiently than that exist in foods and feeds. | Animal tissues and milk contain vitamin A while plan materials contain provitamin A Carotenoids |
| Vitamin K | Water-soluble forms of menadione (k3Menadione dimethy1 pyrimidione nicotinamide bisulfate (MNB)-most stable. | Green Plants and oil seeds contain phylloquinone (k1) And fermented feed has menaquinone (k2) |
| Vitamin D | D3 beadlet form (cross linking), Mineral stable (MS) form | Ergosterols in plants 7-dehydrocholesterol in animals |
| Vitamin E | Vitamin E alcohol, vitamin E acetate, d1-a-tocophery1 acetate gelatin beadlets | Alchols, tocopherols and tocotrienols in plant materials of all the above a tocopherol is more active. |
| Thiamin | Crystalline thimamin is available as thiamin hydrochloride and thiamin mononmitrate latter being better. Stable up to 100’ C And readyily soluble in water. |
Largely in phosphorylated forms, either as protein-phosphate complex or as thiamin mono-/ortriphosphates. |
| Riboflavin | Crystalline riboflavin. Considered quite stable although it is easily destroyed by UV light when in soluation | Primarily as nucleotide coenzymes, FAD And FMN. |
| Niacin | Nicotinic acid is a very stable compound when added to feed or premixes, being little affected by heat, light, oxygen on moisture. | IN plants it is present in the form of nicotinic acid. Much of the niacin activity exists as nicotinamid nucleotides in animals. |
| Pantothenic acid (PA) | Crystalline form as either D-or DL-calcium PA Free flowing, nonhygroscopic D- Calcium pantothenate is available through complexing procedures | Most of the PA is contained in coenzyme A, acyl Co A Synthetase, and acyl carrier protein. |
| Vitamin B12 | Crytalline cyanocobalamin is considered very stable when stored in feeds and premixes. | Plant food stuf are devoid of B 12 Microorganisms are the sole source of B12 in natural and this account for the B12 activity in animal and fermentation based feedstuffs, B12 exist boud to protein in themethyl form (methylcobalamin) or the 5-deoxyadenosy1 form (adenosylcobalamin). |
| choline | In its crystalline form, choline chloride (87% choline) is hygroscopic and is considered a stress agent to other vitamins in a vitamins-minerals premix. Choline bitartrate salt is also available. | Feed ingredients and crude upprocessed fat sources contain most of the choline as phospholipid-bound phosphalipidl choline. |
| Biotin | Crystalline D- biotin | Much of its exits in a bound form. ∈- N-biotinyl-L-lysine (biocytin) which is a component of it varies and it is dependent on the digestibility on the digestibility of the proteins in which its is found. |
| Vitamin B6 |
Crystalline pyridoxine hydrochloride. | Exits in food either in the free or the phosphory lated form.Plant products are rich in pyridoxine; some may have pyridoxine glucoside. Animal products contain primarily phosphory lated pyridoxal. |
| Folic acid | Crystalline folacin | Folacin exists largely as polyglutametes. A group of intestinal enzymes known as conjugates remove all but the last glutamate residue and thought to be absorbed into enterocyte. |
| Vitamin C | Crystalline L –ascrobic acid 50% fat coated L- ascorbic acid, 97.5% ehtylcelluslose coated L- ascorbic acid, Ascorbyl phosphate ( the most stable form) |