Applications vitamin contents

Other early food applications included the analysis of pesticide residues in fruits and vegetables, organic acids, lipids, amino acids, toxins (e.g., aflatox-ins in peanuts, ergot in rye), and contaminants. As with pharmaceutical analysis, HPLC provides the ability to analyze for vitamin content in food... 

After sampling, the sample is prepared for analysis. Usually, each different type of sample material requires specially adapted sample preparation, extracting the vitamins from the matrix. This is often combined with a preliminary concentration and purification step. Roughly three application fields can be differentiated that pose different demands determination of vitamin content in samples from human subjects and animals, e.g., plasma and tissue determination of vitamin content in feed, food, plants, processed plants, plant products, and microorganisms and determination of added vitamin content in fortified products, e.g., tablets, feed, or food. 

The book covers food analysis for beneficial compounds, such as the determination of folate, vitamin content analysis, applications for avocado metabolite studies, virgin olive oil component analysis, lactose determination in milk, and analysis of minor components of cocoa and phenolic compounds in fruits and vegetables. With contributions by experts in interdisciplinary fields, this reference offers practical information for readers in research and development, production, and routing analysis of foods and food products. 

Currently employed HPLC methods for pantothenic acid and/or pantothenates have been applied solely to pharmaceuticals and simple matrices such as fortified infant formulas, whereas assays of coenzyme A and its acyl analogs have also been successfully performed on animal tissues. In the last few years, chiral stationary phases have been developed for optical resolution of pantothenic acid and related compounds by HPLC, and also HPLC-MS has become a promising technique. However, the newly developed HPLC procedures still require increased sensitivity and selectivity to make them applicable for the analysis of the total vitamin content in complex matrices such as foods and feeds. 

Squalene is an isoprenoid compound that is found in large quantities in shark liver and in smaller quantities in olives, rice bran and wheat germ. It is a bactericidal compound and an antioxidant and it aids in skin nutrition. Several cosmetic applications of rice bran and rice bran oil arise from the biological effects of their squalene, vitamin E and y-oryzanol content. Since these compounds are fat-soluble, rice bran oil is used for all these preparations. 

Niacin (vitamin B3) has broad applications in the treatment of lipid disorders when used at higher doses than those used as a nutritional supplement. Niacin inhibits fatty acid release from adipose tissue and inhibits fatty acid and triglyceride production in liver cells. This results in an increased intracellular degradation of apolipoprotein B, and in turn, a reduction in the number of VLDL particles secreted (Fig. 9-4). The lower VLDL levels and the lower triglyceride content in these particles leads to an overall reduction in LDL cholesterol as well as a decrease in the number of small, dense LDL particles. Niacin also reduces the uptake of HDL-apolipoprotein A1 particles and increases uptake of cholesterol esters by the liver, thus improving the efficiency of reverse cholesterol transport between HDL particles and vascular tissue (Fig. 9-4). Niacin is indicated for patients with elevated triglycerides, low HDL cholesterol, and elevated LDL cholesterol.3... 

Thermal treatment, applied to honey, may destroy vitamins and bionutrients, and produce a simultaneous decrease in diastase activity and an increase in HMF content. Honey treatment temperature and time must be limited when pasteurising and stabilising it both diastase activity and HMF content are national and international parameters used as controls so as to limit thermal treatment application. HMF can be formed by hexose dehydration in acid media or by the Maillaid reaction [11,12]. According to Ibarz et al., HMF formation can be described by a second order kinetics (auto-catalytic), with the following equation as expression model [13] ... 

Modern LSD detectors yield good results even under gradient elution. No disturbance is observed when solvent composition changes. Organic solvents (acetone, propanol, chloroform) can be used in the mobile phase. In reversed-phase mode, water content up to 25% and small amounts of buffers are not a problem. Typical applications are lipids, phospholipids, sugars, and vitamins. 

Com oil s flavor, color, stability, 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 applications (50%) and margarine formulations (35%). 

Preferably, high pressure liquid chromatography (hplc) is used to separate the active pre- and cis-isomers of vitamin D3 from other isomers and allows theic analysis by comparison with the chromatograph of a sample of pure reference j-vitamin D3, which is equilibrated to a mixture of pre- and cis-isomers (82,84,85). This method is more sensitive and provides information on isomer distribution as well as the active pre- and cis-isomer content of a vitamin D sample. It is applicable to most forms of vitamin D, including the more dilute formulations, ie, multivitamin preparations containing at least 1 lU/g (AOAC Methods 979.24 980.26 981.17 982.29 985.27) (82). The practical problem of isolation of the vitamin material from interfering and extraneous components is the limiting factor in the assay of low level formulations. 

Microbial fermentation of CSM, which was proposed to detoxify FG in the CSM (Zhang et ah, 2006a,b), seems promising because some exoenzymes such as cellulolytic enzymes, amylase, protease, and lipolytic enzymes that are secreted by certain microorganisms, and some vitamins, as well as some unknown active substances are produced in the fermented CSM (Brock et ah, 1994), which adds nutritional value of the fermented CSM. Recently, Qian et ah (2008) reported that in situ alkaline-catalyzed transesterification could produce a CSM with FG and TG contents below the FAO standard. However, the requirement for a high amount of methanol usage in the in situ transesterification and the potential energy consumption to remove the methanol in the meal may be an obstacle for its practical application. 

About one tenth of the total amount of vitamin E produced is semi-synthetic, isomerically pure (2R,4 K,8 R)-a-tocopherol (RRR-3) which is used almost exclusively in human applications (mainly pharma). This product, originating from natural sources, is obtained from soya deodorizer distillates (SDD). Vegetable oils refined on a large scale are the major sources of vitamin E compounds [26-28]. The deodorizer distillate, originally a waste stream, contains considerable amounts (up to 10%) of a-, [I-, y- and b-tocopherols (RRR-3 to RRR-6) which are isolated by several separation methods. To increase the value of the vitamin E concentrate of mixed tocopherols obtained from SDD, the lower (I-, y- and d-homologues (RRR-4 to RRR-6, content ca. 90%) have to be transformed subsequently into the biologically more active a-tocopherol (RRR-3, only ca. 5% in the original mixture) by permethylation reactions. Permethylations are performed by chloro-, amino-, or hydroxymethylation reactions to provide functionalized alkylated intermediates, which are reductively converted into RRR-3 (Fig. 3) [29]. 

---