Vitamin physical characteristics

Table III gives the physical and chemical properties of the M. oleifera oil. Some of the properties of the oil depend on the extraction medium. The M oleifera oil is liquid at room temperature and pale-yellow in colour. Electronic nose analysis shows that it has a flavor similar to that of peanut oil. The melting point estimated by differential scanning calorimetry is 19°C (15). The chemical properties of the oil depicted in Table III below are amongst the most important properties that determines the present condition of the oil. Free fatty acid content is a valuable measure of oil quality. The iodine value is the measure of the degree of unsaturation of the oil. The unsaponifiable matter represents other lipid- associated substances like, sterols, fat soluble vitamins, hydrocarbons and pigments. The density, iodine value, viscosity, smoke point and the colour of Moringa oil depends on the method of extraction, while the refractive index does not. Varietal differences are significant in all physical characteristics apart from refractive index and density (2). The heating profile of the M. oleifera seed oil using the differential scanning calorimetry (DSC) conventional scan rate shows that there is one major peak B and, two small shoulder peaks A and C...

The answer is a. (Murray, pp 627-661. Scriver, pp 3897-3964. Sack, pp 121-138. Wilson, pp 287-320.) Vitamins A, D, E, and K are all fat-soluble. The physical characteristics of fat-soluble vitamins derive from the hydrophobic nature of the aliphatic chains composing them. The other vitamins listed are water-soluble, efficiently administered orally, and rapidly absorbed from the intestine. Fat-soluble vitamins must be administered intramuscularly or as oral emulsions (mixtures of oil and water). In intestinal disorders such as chronic diarrhea or malabsorption due to deficient digestive enzymes, fat-soluble vitamins are poorly absorbed and can become deficient. Supplementation of fat-soluble vitamins is thus routine in disorders like cystic fibrosis (219700), a cause of respiratory and intestinal disease that is the likely diagnosis in this child. 

Pyridoxine (peer-ih-DOCK-seen) is also known as 3-Hydroxy-4,5-bis(hydroxymethyl)- -methyl pyridine 3-hydroxy-4,5-dime-thylol-2-methylpyridine and vitamin B6. It is a white, odorless, crystalline compound with a slightly bitter taste. The term pyridoxine is also used as a generic term for three compounds with biological activity classified under the term Vitamin Bfc. The three compounds are pyridoxine, pyridoxal, and pyridoxamine. Pyridoxine is usually produced commercially as the hydrochloride, CH3CSHN(0H)(CH20H)2-HC1, which has somewhat different physical characteristics from pyridoxine itself. 

Several vitamins are naturally fluorescent, a physical characteristic that can be used in their sensitive and selective detection in LC. The detection limit for riboflavin by fluorescence detection is less than 1 pmol, whereas in UV detection it is 30 times higher. The detection of an LC assay for thiamin and its phosphate esters using the fluorimetric... 

Physical Methods. Vitamins D2 and D exhibit uv absorption curves that have a maximum at 264 nm and an (absorbance) of 450—490 at 1% concentration (Table 8). The various isomers of vitamin D exhibit characteristically different uv absorption curves. Mixtures of the isomers are difficult to distinguish. However, when chromatographicaHy separated by hplc, the peaks can be identified by stop-flow techniques based on uv absorption scanning or by photodiodearray spectroscopy. The combination of elution time and characteristic uv absorption curves can be used to identify the isomers present in a sample of vitamin D. 

Lipids may be defined as a large group of molecules with a substantial portion of aliphatic or aromatic hydrocarbon. Included are molecules with diverse chemical characteristics, such as the hydrocarbons, soaps, detergents, acylglycerols, steroids, phospholipids, sphin-golipids, and fat-soluble vitamins, and, subsequently, with diverse physical behavior. One of the most important characteristics of lipids from a biological aspect is their behavior in aqueous environments, as all cells exist in an aqueous milieu. In this respect, the lipids range from almost total insolubility to nearly complete solubility. 

There is also a growing interest in drinks with associated special characteristics. These products will often contain sugars for energy, caffeine for stimulation and vitamins, amino acids and maybe herbs which impart some unique selling property as a health benefit. A very good example of this type of product is Red Bull, which is described, according to its website, thus Red Bull is much more than a soft drink - it is an energy drink. It was made for moments of increased physical and mental stress and improves endurance, alertness, concentration and reaction speed. In short it vitalizes body and mind. ... 

The formulator of liquid multivitamin pharmaceutical products such as baby drops, syrups, elixirs, and injectables encounters numerous problems in attempting to develop products having adequate physical and chemical stability as well as suitable taste, odor, color, and freedom from bacterial contamination. Many of these problems arise from the diflFering solubility and stability characteristics of the individual vitamins, particularly as these relate to the pH of the solutions and potential interactions. Despite these numerous problems, various ways have been devised for producing multivitamin combinations in liquid form containing L-ascorbic acid that have acceptable stability characteristics. Successful development of such products requires a knowledge of (i) the fundamental aspects of the physical and chemical properties of the vitamin forms available (ii) the use of adequate techniques of manufacture and (iii) the employment of suitable overages based on critical stability studies. 

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