Detection of Adulteration

In a similar vein, Wilson et al. [61] recorded the FTIR spectra of fruit jams of different types using a diffuse reflectance (DRIFT) samphng accessory. Despite distortions in the spectra, associated with the use of the DRIFT technique, the different jams were found to exhibit characteristic and reproducible patterns, indicating that jams of different fruit content can be differentiated on the basis of their FTIR spectra. The authors suggested the potential utihty of this technique for the detection of adulteration of jams, for instance, by the substitution of fruit content by cheaper vegetable material. 

Introduction to Practical Infrared Spectroscopy, Butterworths, London (1960). 

Cotton, Chemical Applications of Group Theory, John Wiley Sons, New York (1971). 

Griffiths and J. A. de Haseth, Fourier Transform Infrared Spectrometry, John WUey Sons, New York (1986). 

Crocombe, M. L. Olson, and S. L. Hill, in Computerized Quantitative Infrared Analysis, ASTM STP 934, G.L. McClure (ed.), American Society for Testing and Materials, Philadelphia, pp. 95-130 (1987). 

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In milk fat, cholesterol is associated with Hpoproteins in the milk fat globule. It is also a component of animal membranes and controls rigidity and permeabihty of the membranes. Cholesterol has interesting surface properties and can occur in Hquid crystalline forms. Plants contain sterols such as P-sitosterol [83-46-5] (4b) or stigmasterol [83-48-7] (4c). Their functions in plant metaboHsm are not yet well understood. Analysis of sterols has proven useful for detection of adulteration of edible fats (9). 

Kerkvliet, J. D., Shrestha, M., Tuladhar, K., and Manandhar, H. (1995). Microscopic detection of adulteration of honey with cane sugar and cane sugar products. Apidologie 26,131-139. 

Padovan, G. J., De Jong, D., Rodrigues, L. P., and Marchini, J. S. (2003). Detection of adulteration of commercial honey samples by the isotopic ratio. Food Chem. 82,... 

White, J. W. and Winters, K. (1989). Honey protein as internal standard for stable carbon isotope ratio detection of adulteration of honey. J. Assoc. Ojfic. Anal. Chem. 72,907-911. 

The application of 13C NMR for the rapid analysis of the oil composition of oil seeds is well known [16], 13C NMR has recently been applied to the quantitative analysis of the most abundant fatty acids in olive oil [17]. The values obtained by this method differed by only up to 5% compared with GLC analysis. The quantitative analysis was applied to the olefmic region of the high resolution 13C NMR spectrum of virgin olive oil to detect adulteration by other oils which differed significantly in their fatty acid composition. The application of the methodology for the detection of adulteration of olive oil by hazelnut oil is more challenging as both oils have similar chemical profiles and further experiments are in progress. 

New spectrophotometric and RP-HPLC methods were developed for the detection of adulteration in cochineals. The insects were cleaned over as sieve and dried at 60°C. The dried... 

It was concluded from the data that the method is suitable for the differentiation between fruits and may help the detection of adulteration [241],... 

Fanton, C. Delogu, G. Maccioni, E. Podda, G. Seraglia, R. Traldi, P. MALDI-MS in die Dairy Industry 2. The Protein Fingerprint of Ewe Cheese and Its Application to Detection of Adulteration by Bovine Milk. Rapid Commun. Mass Spectrom. 1998,12, 1569-1573. 

Saz and Marina [148] published a comprehensive review on HPLC methods and their developments to characterize soybean proteins and to analyze soybean proteins in meals. In the case of soybean derived products, a number of papers dealing with cultivar identification [149,150], quantification of soybean proteins [151-154], detection of adulteration with bovine milk proteins [151,155-158], and characterization of commercial soybean products on the basis of their chromatographic protein profile [159,160] have been published in the last years. Other studies deal with the analysis of soybean proteins added to meat [161-165], dairy [151,165-167], and bakery products [156,163,168,169]. The same research group developed perfusion RP-HPLC methods for very rapid separation of maize proteins (3.4 min) and characterization of commercial maize products using multivariate analysis [170], and for the characterization of European and North American inbred and hybrid maize lines [171]. 

Parra, V., Arrieta, A. A., Fernandez-Escudero, J.-A., Rodriguez-Mendez, M. L., and De Saja, J. A. (2006b). Electronic tongue based on chemically modified electrodes and voltammetry for the detection of adulterations in wines. Sens. Actuators B 118(1-2), 448-453. 

Isotopic distribution within an element will vary between living organisms depending on the biosynthetic pathways that lead to its formation. Furthermore, the rate at which a molecule crosses cellular membranes will depend on the molecule s isotopic distribution. Hence, detectable differences in isotopic composition can be observed in the products formed. Detection of adulterated vegetable oils, flavourings and fruit juices, as well as the study of metabolism in plants and numerous biomedical applications, use isotopic abundance as a tool. For example, the... 

B. M. Cordero, and M. Forina, Electronic Nose Based on Metal Oxide Semiconductor Sensors as a Fast Alternative for the Detection of Adulteration of Virgin Olive Oils, Anal. Chim. Acta 2002,459, 219 C. L. Honeyboume, Organic Vapor Sensors for Food Quality Assessment, J. Chem. Ed. 2000, 77, 338 E. Zubritsky, E-Noses Keep an Eye on the Future. Anal. Chem. 2000, 72. 

F Siewek, R Galensa, K Hermann. Detection of adulteration of black currant products by red currants by HPLC determination. Z Lebensm Unters Forsch 179 315-321, 1984. 

Individual anthocyanin composition is distinctive for any given plant, so anthocyanin analysis is very useful in distinguishing between species. Chemotaxonomic differentiation is commonly based on qualitative differences (163), furthermore within one cultivar (e.g., grapes) even varieties can be discriminated by quantitative differences (164). The anthocyanic profiles of 11 different grape varieties obtained with RP-HPLC are shown in Fig. 15 (165). The characteristic differences in anthocyanin patterns have also been successfully applied to the detection of adulterations in products of cranberries (166), black currants (166), blackberries (167), and grapes (168). 

The detection of adulteration and its quantification have spawned some elegant scientific techniques, some borrowed from other fields and some developed specifically for use in fruit juice work. 

The ester number for any essential oil may vary within more or less wide limits (see Table XXXIV), but its determination is of importance in the identification of an oil, the detection of adulteration, and for judging of the quality of the oil. With some oils, the esters represent the odoriferous principle, e.g., linalyl acetate in bergamot, lavender and petit-grain oils, bomyl acetate in pine-needle oil and menthyl acetate in mint oil, the value of these Oils being deduced from the ester content. 

The rotation is valueless as regards detection of adulterants, but it may indicate the origin of the oil. It may, however, be noted that mineral oils are virtually inactive and that pinewood oils are dextro-rotatory. 

The principal reactions and tests used for the identification of different tanning materials and for the detection of adulterations are described briefly below. 

Detection of Adulterations of Sumac.—These consist of tt branches and twigs of the plant itself and also of other plants of less vain especially Pistacia lentiscus (Stinko or lentisco) and Tamarix africaru Among the methods suggested for the detection of such frauds (beside microscopic examination of the powdered leaves and quantitative deter initiations of the tannins and non-tannins, see later), are the following test to be made on the solution or aqueous decoction. 

Investigation of these pigments comprises certain technical tests for determining their practical value for the desired purpose and also chemical analysis with the object of identification, determination of the composition and the degree of purity, and detection of adulterants. 

In testing extracts, it suffices to dissolve or dilute them with water. The solutions are subjected to the above tests, also to others described below for the detection of adulterations, and to those indicated" later for the more important separate extracts. From the commercial point of view, interest attaches also to the specific gravity of liquid extracts, this being measured with a hydrometer and usually expressed in degrees BaumA... 

Their examination comprises especially certain qualitative tests for the identification of the product and for the detection of adulteration, and a dyeing test sometimes certain quantitative determinations are required. The analytical methods followed are indicated below. 

Methods for the Detection of Adulteration in Processed Citrus Products... 

Chapter 18 reports the investigations of Petrus and relates the room temperature fluorescence, and visible and UV spectral characteristics of citrus juices and related products to the detection of adulteration. 

Royo Iranzo and Garcia (151) suggested that analyses for juice characterization and detection of adulteration be conducted on the serum. They reported that sodium, calcium and phosphorus were all higher in the pulp than in the serum. The values for magnesium were about the same for pulp and serum potassium was slightly higher in the serum than in the pulp. 

D Amore and Corigliano (155) indicated the intense fluorescence of Mediterrean mandarin oil at 415 nm might be useful for characterization and detection of adulteration. Slater (156) reported the ratio of some infrared peak intensities might be useful for detection of adulteration or storage abuse in citrus oils. 

Each situation may be unique and requires a careful balancing of all factors. Continued research will be necessary to more fully understand the many factors affecting the composition of citrus products. One single, simple, inexpensive adulteration test may never be available. The current technology for adulteration detection can be applied, keeping in mind the statistical limitations of the selected parameters. With the current trends towards multiconstituent analyses and an increasing awareness of statistical interpretations, detection of adulteration should become more sensitive and accurate in the future. 

In conclusion, it has been shown that the visible and ultraviolet absorption, and room temperature fluorescence spectra, obtained from alcoholic solutions of orange juice and related products, may be used for product characterization. The complementary absorption and fluorescence spectra may be utilized for the qualitative detection of adulteration of reconstituted frozen concentrated and single-strength orange juice with pulpwash. Previous investigations (chemical and elemental profile analyses)... 

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