Indicator Of Adulteration Research Articles

Analysis of cow and goat milk by spr: adulteration detection and differences in protein adsorption

The article discusses using Surface Plasmon Resonance (SPR) to detect adulteration of goat milk with cow milk. The SPR technique is based on changes in the refractive index and can be used to monitor the adsorption of proteins on the sensor surface. The SPR technique can differentiate between pure cow milk and pure goat milk by measuring the initial refractive index, which is higher for cow milk. The article then describes the changes in the refractive index that occur when goat milk is adulterated with cow milk and how adding a bovine casein film on the sensor surface can make it more selective for cow milk. The differences in the chemical compositions and molecular structures of cow and goat milk and how these differences affect the adsorption of proteins and fatty acids on the sensor surface. Finally, other proteins, such as α-lactalbumin and β-lactoglobulin, are used as indicators of adulteration.

Evaluation of physicochemical parameters as indicators of diesel adulteration

Diesel adulteration not only reduces engine performance and lifespan but also has a stiffening effect on the economy. Therefore, regulatory agencies and petroleum laboratories are constantly adopting various methods to ensure that commercial diesel is pure and of good quality. Despite the introduction of solvent tracer analysis as a reliable means of detecting adulteration, most laboratories still depend on the physicochemical parameters of diesel as an indicator of adulteration. This research aimed to document the feasibility of using quality parameters to detect diesel adulteration. Neat diesel samples were mixed with some common adulterants (kerosene, premix, and condensate) at varying concentrations. The quality of each admixture was analysed using the ERASPEC fuel analyser and physicochemical parameters including density, kinematic viscosity, cetane index, and flashpoint were recorded. A negative correlation was observed between adulteration and all quality parameters. At low levels of adulteration, physicochemical parameters were within the required range. However, diesel with adulterants above 20 % v/v had cetane index, density, and flashpoint values not conforming with quality standards. Kinematic viscosity of diesel remained within the required limits despite the levels of adulteration. Physicochemical parameters, though generally accepted as good indicators of fuel quality, were not reliable indicators of diesel adulteration, especially at low levels. At higher levels of adulteration, the type of adulterant present must be considered if physicochemical parameters are to be used to predict adulteration. However, it is recommended that physicochemical parameters be used in combination with other techniques to detect diesel adulteration.

An example of the role of exotic flora in the geographical characterisation of honey: Schinus molle L. in the Canary Islands (Spain)

Melissopalynological analyses of honey from the Canary Islands highlights the importance of introduced plants in the bee honey flora. This information on the introduced flora is important in the geographical characterisation of Canary Islands' honey as the composition indicates local provenance and is not an indicator of adulteration. Pollen of Schinus molle was found in 31 (26%) of 121 analysed samples of honey from the Canaries. Eleven of those samples were from the island of La Palma (17% of those analysed from that island), 11 from Tenerife (69%), four from La Gomera (100%), four from Gran Canaria (67%), and one sample from El Hierro (3%). After qualitative analysis, 13 proved to be unifloral (42%) and 18 were multifloral (58%). Within the unifloral samples, five were of heather (Erica arborea), two of saltbush (Mesembryanthemum crystallinum), two of chestnut (Castanea sativa), two of broom (Spartocytisus supranubius), one of fennel (Foeniculum vulgare), and one of a short pod mustard (Hirschfeldia incana).

Microbial quality and associated health risks of raw milk marketed in the Tanga region of Tanzania

Objective To evaluate microbial quality and associated health risks of raw milk marketed in the Tanga region of Tanzania. Methods A microbial quality assessment of marketed raw milk was undertaken by evaluating 59 samples of milk from selling points (collecting centres =15), bicycle boys (12) and kiosks/restaurants (32) in Tanga city during April-May 2005. Quality and milk-borne hazards were assessed using a combination of tests in order to quantify the occurrence of Brucellosis (milk ring test), Escherichia coli ( E. coli) O157:H7 (culture), the coliform bacteria as well as standard plate count (SPC). Specific gravity (SG) determination was used as an indicator of adulteration. Results The mean coliform plate count (c.f.u/mL) of milk handled by bicycle boys (4.2 × 10 6) was significantly higher than that handled by collecting centres (3.0 × 10 6) and kiosk/restaurants (1.4 × 10 6), respectively ( P < 0.05). Of the 59 milk samples collected, 33 (56%) were Brucella milk ring test (MRT)-positive and 78% and 17% of the samples graded satisfactorily based on SG and coliform plate counts as prescribed by East African Community standards for raw milk. There was no verocytotoxigenic E. coli (VTEC) O157: H7 in any of the milk samples collected and analysed during the present study. Conclusions It can be concluded that raw market milk in the study area is of poor bacteriological quality and hazardous for human consumption. This highlights the need to implement good hygiene practices and effective monitoring from production through the delivery chain to the consumer. Further studies are needed for detection of toxins that are produced by E. coli, other pathogenic spore forming bacteria ( Bacillus spp. and Clostridium spp.) and other harmful microorganisms.

Detecting vegetable oil adulteration in hazelnut paste (Corylus avellana L.)

SummaryThe possibilities of detecting hazelnut paste adulterated with refined and non‐refined vegetable oils have been studied. Research was focussed mainly on peanut, high oleic‐acid sunflower, corn and soybean oils which have a similar composition to hazelnut oil. The analytical procedures to detect fatty acid (FA), triacylglycerol (TAG) and tocopherol profiles as indicators of adulteration were determined. The better indicators experimentally determined were seven FA (palmitic, stearic, linoleic, linolenic, arachidonic, behenic and lignoceric acids) and different TAG with three unsaturated FA (the code letters used for FA are: P = C16:0; S = C18:0; O = C18:1; L = C18:2;; Ln = C18:3) (LLLn, LLL and OOO), two unsaturated FA (POL, PLL and SOO), and one unsaturated FA (PPL). As expected, when refined vegetable oils were added to hazelnut paste, the increment of stigmasta‐3,5‐diene allowed detection at levels of 2% oil added. Limits of detection were measured using standard and adulterated hazelnut with different amounts of non‐refined vegetable oils added (5%, 10%, 20% and 30%). The distribution of tocopherols and tocotrienols is highly useful, except in the case of added sunflower oil. The differences between the experimental and theoretical values of the TAG with equivalent carbon number (ΔECN) of 42 does not improve the detection limit of hazelnut paste adulterated with peanut or sunflower oils. Similarly, tocopherols usually added to refined vegetable oils as an antioxidant were also determined.

A STUDY ON THE RELATION BETWEEN ANTHOCYANIN CONTENT AND PRODUCT QUALITY: SHALGAM AS A MODEL BEVERAGE

ABSTRACT The anthocyanin content and the amount of lactic and acetic acids present in commercial shalgam samples randomly collected from domestic markets were determined both by high‐performance liquid chromatography (HPLC) and spectral measurements. Shalgam samples produced under laboratory conditions were termed as the control group (Group I). The commercial samples were divided into three groups based on their production date: samples stored for 6–9 months as Group II; samples stored for 9–12 months as Group III; and samples stored longer than 12 months as Group IV. The HPLC chromatograms indicated that black carrot was the only source of anthocyanin present in the samples. The acylated to nonacylated anthocyanin ratio increased significantly in Group IV samples, whereas there were no significant differences among the Groups II, III and control (P &lt; 0.05). The % polymeric color negatively correlated to the total anthocyanin content was significantly higher in Group IV samples (P &lt; 0.05). The presence of high acetic acid content might be an indication of added pickle juice to the shalgam samples. The variance of the level of lactic acid found in commercial samples shows up as a problem of incidental enrichment of the lactic acid bacteria.PRACTICAL APPLICATIONSAnthocyanin profiles of food materials are unique. Therefore, the anthocyanin profile in a commercial beverage can be used to determine whether there is an adulteration or not. The total anthocyanin content and the ratio of acylated to nonacylated anthocyanins, together with the degree of polymerization and browning index, serve as indicators of the time–temperature history of the product. Applying first‐order degradation kinetics to the anthocyanin under question the initial hypothetical amounts of the juice bearing that anthocyanin can be evaluated.In the specific beverage investigated, shalgam, the level of lactic acid refers to the amount of bulgur used for fermentation. The amount of acetic acid and its negative correlation with the total anthocyanin content can be used as an indicator of adulteration with pickle juice.

Propriedades físico-químicas de amostras comerciais de mel com própolis do estado de São Paulo

O mel contém principalmente açúcares em alta concentração, provenientes do néctar das flores, e a própolis é coletada principalmente das folhas, brotos, exsudatos e resinas das mais variadas espécies botânicas. Tanto a composição química do mel quanto a da própolis podem variar conforme uma série de fatores, que podem estar direta ou indiretamente relacionados com as abelhas e o meio em que vivem. No entanto, esse produto pode sofrer adulterações e/ou problemas relacionados à qualidade ou adição de ingredientes de baixo valor comercial. Na tentativa de detectar esse problema, este trabalho teve como objetivo realizar um estudo de algumas características físico-químicas do mel com própolis, com o intuito de verificar possíveis alterações ou adulterações em amostras comerciais do Estado de São Paulo. Foram adquiridas onze amostras comerciais de mel com própolis e realizadas as análises: umidade, HMF, açúcares redutores, sacarose aparente, proteínas, reações de Fiehe, Lugol e Lund. Os resultados obtidos nas análises das amostras indicaram que todas elas continham mel verdadeiro e que não houve indícios de adulteração do produto com água, amido ou açúcar comercial.

Detection of adulteration of locust bean gum with guar gum by capillary electrophoresis and polarized light microscopy

Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH3CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH2PO4-20.6 mm Na2b4O7 buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of ‘true’ positives and the elimination of ‘false’ positives.

Characterization of Olive Oil by Carbon Isotope Analysis of Individual Fatty Acids: Implications for Authentication and Palaeoclimatological Changes in the Mediterranean Basin

The olive tree is the oldest (600 B.C.) cultivated tree in the soils around the Mediterrranean basin. Olive oils are available in different qualities in the EU countries. In this communication we present the chemical and isotopic composition of the fatty acids of olive oils of distinct quality grade from the most important European Union (EU) producer countries. The analytical approach utilized combined capillary column gas chromatography mass spectrometry (GC/MS) and the novel technique of compound specific isotope analysis (CSIA) through gas chromatography coupled to a stable isotope ratio mass spectrometer (IRMS) via a combustion (C) interface (GC/C/IRMS). This approach provides further insights into the control of the purity and geographical origin of oils sold as cold pressed extra virgin olive oil with certified origin appellation. The results indicate that substantial enrichment in heavy carbon isotope (13C) of the bulk oil and of individual fatty acids are related to (1) a thermally induced degradation due to deodorization or steam washing of the olive oils and (2) the potential blend with refined olive oil or other vegetable oils. The interpretation of the data is based on principal component analysis of the fatty acids concentrations and isotopic data (~13Coil, ~13C16:0 , 813C18:1) and on the ~13C16:0 vs 813C18:1 covariations. The differences in the 813C values of palmitic and oleic acids are discussed in term of biosynthesis of these acids in the plant tissue and admixture of distinct oils. The results demonstrate the importance of elucidating the metabolism and biosynthesis (chain elongation and unsaturation) of the fatty acids which cause the 13C/12C discriminations observed in the individual lipids of the vegetable oils, in order to better utilize the 613C values as indicators of adulteration and environmental changes. The effects of environment or physical factors on the carbon isotope composition of plant and trees have revealed long-term trends in the global environment changes, including the increased atmospheric CO2 excess (e.g. Freyer and Belay, 1983; Walcrof t et al., 1997). The Mediterranean region is highly affected by population increases, industrial expansion, and anthropogenic or accidental biomass burning (e.g. forest fires at Sothern France and Spain). The subject of a current project is to trace the palaeoclimatic changes in this region by using carbon isotope composition of the major fatty acids in genuine olive oil. This will enable reconstruction of climate variabilities in the late Holocene in Central Europe.

A Simplified Method for Determining Undeclared Sweeteners Added to Pure Orange Juice

Previous research has described methods for monitoring unique oligosaccharides as indicators of adulteration of pure orange juice with undeclared sweeteners. Modifications are reported here that streamline the method for routine analysis of large numbers of samples. Sample preparation is faster and more efficient, allowing preparation of up to 24 samples at one time. Oligosaccharides are eluted isocratically at 30 degrees C, decreasing retention times and eliminating the need for column reequilibration between injections. Oligosaccharide profiles of commercially available sweeteners and fortified orange juice samples analyzed under the modified conditions demonstrate that the method reduces analysis time by > 50%, while at the same time improving resolution and maintaining established detection limits.

Mycocontamination of Illicit Samples of Heroin and Cocaine as an Indicator of Adulteration

Abstract The authors studied the fungal spectrum of the drugs most frequently sold in the streets in Spain (brown heroin, white heroin, and cocaine) in order to ascertain their potential use as indicators of the degree of manipulation or adulteration, as well as the potential pathogenicity of the taxa found. For this purpose we analyzed 205 drug samples (106 brown heroin, 69 white heroin, and 30 cocaine) from sachets seized by the Spanish police; they were cultured in appropriate media, from which 391 colonies of micellar fungi from 53 taxa, of which only 8 were encountered in the three types of drugs, were isolated. The results obtained were subjected to a variance analysis with a single source of variation and to a hierarchical variance analysis, in which brown heroin was shown to be significantly more contaminated by fungi than the other two drugs. This can be explained by considering that brown heroin is the most liable to manipulation of all three drugs because of its characteristics.

Evaluation of Apple Juice Authenticity by Organic Acid Analysis

Abstract An organic acid profile provides valuable information regarding authenticity of apple juice. The presence of D-malic acid is a clear indication of adulteration because this isomer does not occur naturally. Fumaric and citric acid levels above trace amounts are also inconsistent with pure apple juice; therefore, measurement of these organic acids may also be used as an authenticity check. Citric acid, total malic acid, and fumaric acid were determined in a single scan by liquid chromatography (LC) for 30 known pure apple juice samples. The L-isomer of malic acid was measured by an enzyme-specific method, and the D-isomer was calculated as the difference between total malic acid and L-malic acid.