Food analysis vitamins

The researcher in food and its analysis is keenly aware that his task will not be finished until the quality of a food product can be defined completely in precise terms of its flavor, color, texture, and nutritive value. The goal is distant but the journey is well begun. The papers contained herein describe the present state of affairs in each of as many of the fields of food analysis as time for the symposium permitted. Each has been covered by an outstanding worker in his field. It is unfortunate that B. L. Oser s excellent paper on Advances in Vitamin Determination does not appear. His more comprehensive review of food analysis which appeared in Analytical Chemistry [21, 216 (1949)] should by all means be studied along with the papers contained herein. 

Fluorescence is much more widely used for analysis than phosphorescence. Yet, the use of fluorescent detectors is limited to the restricted set of additives with fluorescent properties. Fluorescence detection is highly recommended for food analysis (e.g. vitamins), bioscience applications, and environmental analysis. As to poly-mer/additive analysis fluorescence and phosphorescence analysis of UV absorbers, optical brighteners, phenolic and aromatic amine antioxidants are most recurrent [25] with an extensive listing for 29 UVAs and AOs in an organic solvent medium at r.t. and 77 K by Kirkbright et al. [149]. 

Coupled LC-LC can separate high-boiling petroleum residues into groups of saturates, olefins, aromatics and polar compounds. However, the lack of a suitable mass-sensitive, universal detector in LC makes quantitation difficult SFC-SFC is more suitable for this purpose. Applications of multidimensional HPLC in food analysis are dominated by off-line techniques. MDHPLC has been exploited in trace component analysis (e.g. vitamin assays), in which an adequate separation for quantitation cannot be achieved on a single column [972]. LC-LC-GC-FID was used for the selective isolation of some key components among the irradiation-induced olefinic degradation products in food, e.g. dienes and trienes [946],... 

Immunosensors have been developed commercially mostly for medical purposes but would appear to have considerable potential for food analysis. The Pharmacia company has developed an optical biosensor, which is a fully automated continuous-flow system which exploits the phenomenon of surface plasmon resonance (SPR) to detect and measure biomolecular interactions. The technique has been validated for determination of folic acid and biotin in fortified foods (Indyk, 2000 Bostrom and Lindeberg, 2000), and more recently for vitamin Bi2. This type of technique has great potential for application to a wide range of food additives but its advance will be linked to the availability of specific antibodies or other receptors for the various additives. It should be possible to analyse a whole range of additives by multi-channel continuous flow systems with further miniaturisation. 

A number of criteria could be apphed to organize this chapter, depending on the point of view by which foods are considered. In this chapter, application of HPLC to food analysis will be described considering homogeneous classes of food components lipids, carbohydrates and related substances, proteins, peptides, amino acids, biogenic amines, phenolics, vitamins, and some selected contaminants. 

Retinoids The challenge in fat-soluble vitamins analysis is to separate them from the lipid fraction that contains interferents. Alkaline hydrolysis, followed by LLE, is widely applied to remove triglycerides. This technique converts the vitamin A ester to all-trani-retinol. A milder process, which does not hydrolyze vitamin A ester, is alcoholysis carried out with metha-nolic KOH solution under specific conditions that favor alcoholysis rather than saponification. A more accurate explanation of this technique is reported in the book Food Analysis by FIPLC [409]. For some kind of matrices a simple liquid extraction can be sufficient with [421-423] or without [424,425] the purification... 

Among the vitamin K vitamers, only phylloquinone is accounted for routine food analysis. Furthermore infant formulas, both milk-based and soy protein-based, are supplemented with a synthetic preparation of phylloquinone (the only form admitted) [403], which usually contain about 10% of the biologically inactive ctT-isomer [497]. 

Vitamin D2 and D3 exhibit identical UV absorption spectra and they do not possess fluorescence. Electrochemical detection is limited and only few methods are applied in food analysis [530,533], MS detection has been applied achieving satisfactory detection limit (10 mol/mL) [534,535],... 

Ball, G.F.M. 1988. Chemical and biological nature of the fat-soluble vitamins. In Fat-Soluble Vitamin Assays in Food Analysis, p. 8. Elsevier, New York. 

HPLC instrumentation and column technology have undergone major advances since the early 1970s, when HPLC made its debut in the field of vitamin analysis. Yet sample preparation in food analysis continues to rely largely on manual wet-chemical techniques, which are time consuming and labor intensive, require considerable analytical skill, and constitute the major source of error in the assay procedure. There is also the serious problem of environmental pollution and the exposure of laboratory personnel to toxic chemicals. 

LF Russell. Water-soluble vitamins. In LML Nollet, ed. Handbook of Food Analysis, vol. 1. New York Marcel Dekker, 1996, pp 649-713. 

The first edition of Food Analysis by HPLC fulfilled a need because no other book was available on all major topics of food compounds for the food analyst or engineer. In this second edition, completely revised chapters on amino acids, peptides, proteins, lipids, carbohydrates, vitamins, organic acids, organic bases, toxins, additives, antibacterials, pesticide residues, brewery products, nitrosamines, and anions and cations contain the most recent information on sample cleanup, derivatization, separation, and detection. New chapters have been added on alcohols, phenolic compounds, pigments, and residues of growth promoters. 

There are many examples in the literature for applications of LC-NMR in the pharmaceutical industry. In the area of natural products, LC-NMR has been applied to screen plant constituents from crude extracts [54,57,67,68] and to analyze plant and marine alkaloids [69-72], flavonoids [73], sesquiterpene lactones [74,75], saponins [58,76], vitamin E homologues [77], and antifungal and bacterial constituents [56,78,79] as examples. In the field of drug metabolism, LC-NMR has been extensively applied for the identihcation of metabolites [42, 80-88] and even polar [89] or unstable metabolites [43]. And hnally, LC-NMR has been used for areas such degradation products [90-93], drug impurities [94-102], drug discovery [103,104], and food analysis [105-107]. 

A number of very good reviews on food analysis can be found in the literature [7-12]. Table 3 presents a very limited representation of the kind of work involved in a food laboratory. All basic constituents of foodstuffs - proteins, lipids, carbohydrates and vitamins - are amenable to liquid chromatography. Various types of columns and detectors used for those analysis demonstrate the versatility of the technique. Almost any type of food matrix can be extracted in order to identify and quantitate trace amounts of analytes. 

There is a very real need for a simple assay for vitamin B12 analysis of food. Since colored, turbid, or precipitated debris do not interfere with this RMA, we were hopeful that it might prove applicable to this problem and undertook an evaluation of this technique for food analysis (30). Comparison of 22 foods of varying matrices that were high, moderate, and low in vitamin B12 levels (egg yolk, whole milk, nonfat dry milk, canned salmon, canned sardines, canned tuna, fresh rockfish, chicken, pork, veal, beef sirloin, lamb, ground beef, liverwurst, oatmeal, and various baby foods) by the RMA and the TMA gave an excellent... 

Fluorescence spectroscopy plays an important function in modern food analysis as can be seen from its wide use in the determination of numerous food components, contaminants, additives, and adulterants. This technique has made available very sensitive and selective methods that satisfy the requirements of food analysis, which are usually very complex, taking into account the large number of species to be determined, frequently at very low concentrations, and the wide variety of foodstuffs available. Initially, the use of fluorescence spectroscopy in food analysis was limited to the determination of species with intrinsic fluorescence (e.g., vitamins, aflatoxins, and some polycyclic aromatic hydrocarbons (PAHs)), but now it is widely applied to nonfluorescent species, using several physicochemical means such as chemical or photochemical derivatization reactions. Numerous techniques involve fluorescence detection in liquid chromatography (LC), frequently using pre- or postcolumn derivatization. In addition to conventional fluorime-try, which is commonly chosen for this purpose, other fluorimetric techniques such as laser-induced... 

High-performance LC (HPLC) is the technique used most frequently in food analysis for measuring carbohydrates, vitamins, additives (sweeteners, antioxidants, colorants, preservatives, etc.), mycotoxins, amino acids, proteins, tryglicerides in fats and oils, lipids, chiral compounds and pigments, among others (Table 1). Some of these applications will be discussed in this article. 

Radioimmunoassay has been used for assay of pantothenic acid in physiological samples (sensitivity 250 nmol 1 ), and an enzyme-linked immunosorbent assay (ELISA) has been used for this vitamin in food analysis. 

TLC analysis of agricultural products, foods, beverages, and plant constituents is described by Sherma in a review paper. In laboratories throughout the world, TLC is widely used for food analysis and qualitative control. Numerous applications of TLC have been reported in the area of food composition, involving determinations of compounds such as lipids, sugars, amines, vitamins, and organic acids such as amino acids and fatty acids. 

Rychlik, M. 2011. Stable isotope dilntion assays in vitamin analysis-A review of principles and applications. In Fortified Foods with Vitamins, edited by M. Rychlik, pp. 1-19. Wiley-VCH Verlag GmbH Co. KGaA. 

Ball, G. 2006. Vitamins in Foods. Analysis, Bioavailability, and Stability. CRC Press, Boca Raton, Florida. 

Due to its high sensitivity and selectivity, liquid chromatography-mass spectrometry (LC-MS) is a powerful technique. It is used for various applications, often involving the detection and identification of chemicals in a complex mixture. Ultra Performance Liquid Chromatography Mass Spectrometry Evaluation and Applications in Food Analysis presents a unique collection of up-to-date UPLC-MS/MS methods for the separation and quantitative determination of components, contaminants, vitamins, and aroma and flavor compounds in a wide variety of foods and food products. 

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