Vitamin composites

The elemental and vitamin compositions of some representative yeasts are Hsted in Table 1. The principal carbon and energy sources for yeasts are carbohydrates (usually sugars), alcohols, and organic acids, as weU as a few other specific hydrocarbons. Nitrogen is usually suppHed as ammonia, urea, amino acids or oligopeptides. The main essential mineral elements are phosphoms (suppHed as phosphoric acid), and potassium, with smaller amounts of magnesium and trace amounts of copper, zinc, and iron. These requirements are characteristic of all yeasts. The vitamin requirements, however, differ among species. Eor laboratory and many industrial cultures, a commercial yeast extract contains all the required nutrients (see also Mineral nutrients). 

There have been relatively few studies comparing the mineral and vitamin composition of milk from different dairy systems. Toledo et al. (2002) compared milk samples from organic and conventional dairy systems in Sweden, for iodine and selenium, and found that levels of selenium but not iodine were lower in organic milk. Studies in Denmark compared the vitamin E... 

A review of the vitamin composition of grapes and musts has been reported in recent texts (2, 3). Also, vitamins in grapes were reported by Amerine (21) in an extensive review of organic components of wines. 

TABLE 1.9 Vitamin composition quinoa flour, oat, barley (mg/100 g)... 

Bhatty and Cherdkiatgumchai (1990) have reported the mineral and vitamin composition of Canadian grown flaxseeds (Table 8). Flaxseed (lOOg) may provide 100% of the... 

TABLE 3.6 Mineral and Vitamin Composition of Cereal Grains.104... 

Com oil s flavor, color, stabiHty, retained clarity at refrigerator temperatures, polyunsaturated fatty acid composition, and vitamin E content make it a premium vegetable oil. The major uses are frying or salad appHcations (50%) and margarine formulations (35%). 

The nutrient sparing effect of antibiotics may result from reduction or elimination of bacteria competing for consumed and available nutrients. It is also recognized that certain bacteria synthesize vitamins (qv), amino acids (qv), or proteins that may be utilized by the host animal. Support of this mode of action is found in the observed nutritional interactions with subtherapeutic use of antibiotics in animal feeds. Protein concentration and digestibiHty, and amino acid composition of consumed proteins may all influence the magnitude of response to feeding antibiotics. Positive effects appear to be largest... 

Composition. Molasses composition depends on several factors, eg, locality, variety, sod, climate, and processing. Cane molasses is generally at pH 5.5—6.5 and contains 30—40 wt % sucrose and 15—20 wt % reducing sugars. Beet molasses is ca 7.5—8.6 pH, and contains ca 50—60 wt % sucrose, a trace of reducing sugars, and 0.5—2.0 wt % raffinose. Cane molasses contains less ash, less nitrogenous material, but considerably more vitamins than beet molasses. Composition of selected molasses products is Hsted in Table 7. Procedures for molasses analysis are avadable (59). 

To obtain optimal performance of farm animals, foHc acid supplementation is required (86) and as is the case with most of the vitamins, the majority of worldwide consumption is as feed supplements. The foHc acid requirement for chickens and pigs is about 0.2—0.5 mg of foHc acid/kg diet and 0.3 mg/kg diet, respectively. Increased amounts, 0.5—1.0 mg/kg feed for chickens and 0.5—2.0 mg/kg for swiae, are recommended under commercial production conditions (87). The degree of intestinal foHc acid synthesis and the utilization by the animal dictates the foHc acid requirements for monogastric species. Also, the self-synthesis of folaciais dependent on dietary composition (88). 

The equihbtium composition is normally ca 80% vitamin D and 20% previtamin D. This reaction is an intramolecular 1 7 Ft sigmatropic shift... 

Nutritional Requirements. The nutrient requirements of mammalian cells are many, varied, and complex. In addition to typical metaboHc requirements such as sugars, amino acids (qv), vitamins (qv), and minerals, cells also need growth factors and other proteins. Some of the proteins are not consumed, but play a catalytic role in the cell growth process. Historically, fetal calf semm of 1—20 vol % of the medium has been used as a rich source of all these complex protein requirements. However, the composition of semm varies from lot to lot, introducing significant variabiUty in manufacture of products from the mammalian cells. 

Table 3 iadicates the autritioaal composition of the three types of egg products, plus the shell egg itself. Eggs, coasidered to be oae of the most autritious foods, have the highest quaHty proteia of any food, and are important as a source of minerals and certain vitamins. Lipids ia eggs are easily digested, and the amount of unsaturated fatty acids is greater than ia most animal products. 

The use of foods by organisms is termed nutrition. The ability of an organism to use a particular food material depends upon its chemical composition and upon the metabolic pathways available to the organism. In addition to essential fiber, food includes the macronutrients—protein, carbohydrate, and lipid—and the micronutrients—including vitamins and minerals. 

The ultraviolet spectrum of vitamin Be, or pyridoxine, measured in aqueous ethanol varies with the composition of the solvent indicating that this compound is in equilibrium with the zwitterion form 38. The equilibrium constant in pure water was obtained by extrapolation. Prior to this, equilibria which involved tautomers of type 39 had been suggested for vitamin Be, but see Section VI,A. In the case of pyridoxal, an additional equilibrium, 40 41, occurs (cf. Section VIII) other pyridoxal analogs have also been studied (Table II). 

Suppose that an analytical laboratory reported a composition of 40.9% carbon, 4.58% hydrogen, and 54.5% oxygen for a sample of vitamin C. In what atom ratios are the elements present in vitamin C ... 

Natural products, such as enzymes and vitamins, are almost invariably extracted from mixtures. To analyze the composition of any sample that we suspect is a mixture, we first separate its components by physical means and then identify each individual substance present (Fig. G.5). Common physical separation techniques include decanting, filtration, chromatography, and distillation. 

Complexes of the composition RCo (dioximeH)2L (R = alkyl, L = neutral ligand) and their parent complexes with BR2 bridges RCo(dioxime-BR2)2L 127 (Fig. 33) are known as organocobaloximes [173-178] and have received attention being models for vitamin B12 (cobalamines) [183]. A series of related complexes of the composition Fe (dioxime-BR2)LL 128 (Fig. 33) without the metal-carbon bond is also known [179, 180]. 

Seven diets were constructed from purified natural ingredients obtained from either C3 (beet sugar, rice starch, cottonseed oil, wood cellulose, Australian Cohuna brand casein, soy protein or wheat gluten for protein) or C4 foodwebs (cane sugar, corn starch, com oil, processed corn bran for fiber, Kenya casein for protein) supplemented with appropriate amounts of vitamins and minerals (Ambrose and Norr 1993 Table 3a). The amino acid compositions of wheat gluten and soy protein differ significantly from that of casein (Ambrose and Norr 1993). 

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