Meat Analysis

The determination of the kind of animal, the origin of meat, differentiation of fresh meat from that kept frozen and then thawed, and the control of veterinary medicines is of interest. The latter include antibiotics (penicillin, streptomycin, tetracyclines, etc.) used to treat dairy cattle infected with mastitis, and other chemicals, including diethyl stilbestrol, used for cattle to increase the efficiency of conversion of feed into meat. 

Following the successful development in the mid-1960s of IR milk analysers, described above, attempts were made to extend their use to the analysis of meat [28-30] as well as fish [31]. Although the results of this work demonstrated the viability of IR analysis of these types of samples, the application of the methods developed was limited because the commercially available equipment was specifically designed for milk analysis applications. 

Recently, these sampUng problems have been addressed in the development of an FTIR method for the determination of fat and protein in raw meat [32]. The use of a custom-designed high-pressure valve homogenise was found to ehminate the requirement for filtration of meat suspensions prior to IR analysis. The homogenates obtained were injected directly into a heated (65°C) flow-through transmission cell, with a 0.037-mm pathlength. The accuracy and reproducibility of the FTIR method were reported to be superior to those of the reference chemical methods 

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Koniecko, E. S. In Handbook of Meat Analysis, Avery Publishing Group, Inc. Wayne, NJ 1985, p 19. 

In contrast to milk, where samples are primarily derived from cows, meat analysis has to be performed in samples of a widely different animal origin including cattle, lamb, swine, poultry, and fish. Muscle is a complex matrix with a pH of 5.7, composed of muscle fibers, various types of connective tissue, adipose tissue, cartilage, and bones. Sarcoplasmic proteins such as myoglobin, and glycolytic enzymes are soluble in water while the myofibrillar proteins such as myosin and actin are soluble in concentrated salt solutions (14). The connective tissue proteins, collagen and elastin, are insoluble in both solvents. 

FOLLOW-UP PROBLEM 3.5 One of the most widespread environmental carcinogens (cancer-causing agents) is benzo[a]pyrene (J/t = 252.30 g/mol). It is found in coal dust, in cigarette smoke, and even in charcoal-grilled meat. Analysis of this hydrocarbon shows 95.21 mass % C and 4.79 mass % H. What is the molecular formula of benzo[a]pyrene ... 

Weinsirl, John, and Newton, E. B. Bacteriological methods for meat analysis. 

Using ICP-MS we found that the iodine concentration of pork, beef and mutton was in the range < 1.6-16 pg/kg (Schone et ai, 2002). The lower limit (<1.6pg/kg) represents the threshold for quantification of iodine as a result of freeze-drying weighed fresh meat, analysis of the ground lyophilisate, and recalculation of the results for the fresh meat. A threshold for quantification of 6.63 Pg/kg lyophilisate corresponds to 1.6pg-iodine/kg fresh meat (Schone et ai, 2006c). 

Analysis of meat using standard methods is relatively slow and does not give results that can be used to influence the manufacturing process. Major developments in meat analysis technology have occurred in both offline and online systems that give rapid analysis capability. 

Guiader, M., Cheese and meat analysis by NIR, International Near Infrared Diffuse Reflectance/Transmittance Spectroscopy Conference, Budapest, Hungary, May 1986. 

This article discusses several aspects of processed meat products including (/) health and safety concerns (2) meat processing ingredients, procedures, and machinery (J) ha2ard analysis critical control point (4) fat reduction in meat products (5) sous-vide processing and (6) nutritional labeling. 

Pimento Berry Oil. The pimento or allspice tree, Pimenta dioca L. (syn. P. officinalis, Liadl.), a native of the West Indies and Central America, yields two essential oils of commercial importance pimento berry oil and pimenta leaf oil. The leaf oil finds some use ia perfumery for its resemblance to clove leaf and cinnamon leaf oils as a result of its high content of eugenol. Pimento berry oil is an item of commerce with extensive appHcation by the flavor industry ia food products such as meat sauces, sausages, and pickles, and moderate use ia perfumery, where it is used primarily as a modifier ia the modem spicy types of men s fragrances. The oil is steam-distilled from dried, cmshed, fully grown but unripe fmits. It is a pale yellow Hquid with a warm-spicy, sweet odor with a fresh, clean topnote, a tenacious, sweet-balsamic-spicy body, and a tea-like undertone. A comparative analysis of the headspace volatiles of ripe pimento berries and a commercial oil has been performed and differences are shown ia Table 52 (95). 

Comparative studies were performed to evaluate microwave digestion with conventional sample destmction procedures. These included the analysis of shellfish, meats, rocks, and sods. Generally, comparable accuracy at much shorter digestion time was found for the MAE vs the classical digestion method (39). 

For more specific analysis, chromatographic methods have been developed. Using reverse-phase columns and uv detection, hplc methods have been appHed to the analysis of nicotinic acid and nicotinamide in biological fluids such as blood and urine and in foods such as coffee and meat. Derivatization techniques have also been employed to improve sensitivity (55). For example, the reaction of nicotinic amide with DCCI (AT-dicyclohexyl-0-methoxycoumarin-4-yl)methyl isourea to yield the fluorescent coumarin ester has been reported (56). After separation on a reversed-phase column, detection limits of 10 pmol for nicotinic acid have been reported (57). 

Center in Wyndmoor Pennsylvania is developing advanced technologies for the analysis of endosulfan in meat, poultry and eggs (FEDRIP 1999). This technique will include the use of a supercritical fluid extractor in order to reduce the amount of organic solvent use and to speed up extraction times. 

In the last fifteen years there has been considerable interest in the analysis of volatile N-nitrosamines in foods. The primary focus has been on meat cured with nitrite (3 ) although nitrosamines have been shown to occur occasionally in other foods such as fish and cheese (, 3) Recently, attention has been directed to volatile nitrosamines in beer and other alcoholic beverages. The purpose of this paper is to review current information on the presence of nitrosamines in beer, and to discuss work done in our laboratory and elsewhere on the mode of formation of nitrosamines in beer. 

Our objective in this manuscript is twofold — first to describe the biological setting (meat) in which the chemistry of nitrite occurs, and second to provide an analysis of research accomplishments relating directly to what is known about reaction of nitrite with the constituents of meat. In the relatively short time span of the ten years mentioned above, a substantial amount of literature has appeared. It would be duplicative effort to repeat all of the pertinent details here. Rather, the reader is referred to a recent review on reactions of nitrite in meat (1 which provides extensive documentation and enumerates several other pertinent major reviews. 

Of probably greater importance is the effect of local concentration gradients. For example, analysis for a given constituent in the entire meat mass does not reflect the real concentration at a given point. For example, DNA is localized in the nuclei and lipid is localized predominantly in the adipose cells. Another factor of potential influence in reaction schemes for nitrite is the fact that polar-nonpolar interfaces are present as a result of structural compartmentalization. In an adipose cell, the lipid is contained as the body of the cell, but it is surrounded by a thin layer of sarcoplasmic protein. Therefore, large surface areas are involved. 

In fact, as will be indicated later in this manuscript, the proteins of meat are the major constituent with which nitrite reacts and explain the largest proportion of the nitrite lost from analytical detection during curing. While considerable discussion has occurred about this so called protein bound nitrite, little has been substantiated about identification and quantitation of the reaction products. Protein bound nitrite has been of concern in analysis for free nitrite because depending on conditions of analysis, some portion of it may be released and measured. 

It is obvious from the foregoing that to select and quantitate a reaction of nitrite with a given constituent of meat is a tremendous challenge. Another approach has been to conduct bookkeeping type experiments with a label in order to balance nitrite loss from analysis against detection of the label in another form. 

Obana, H., Eurata, M., and Tanaka, Y., Analysis of 2-aUcylcyclobutanones with accelerated solvent extraction to detect irradiated meat and fish, J. Agric. Food Chem., 53, 6603, 2005. 

The oranges were washed, chopped in a meat mincer and homogenised by a Fryma mill. Water (0.6 volumes) were added before the slurry was heat treated by steam injection at 100°C for 2 minutes. The enzyme treatment was carried out for 1 hour at 40°C with 10 lU/g slurry of PME and 25 pg enzyme protein/g slurry of the other enzymes for each of the enzymes. The gelated orange slurry were treated at 85°C for 3 minutes to inactivate the enzymes before the strength of the gel was measured by a SMS TeJrture Analyser TA-XT2 (Stable Micro Systems, XT. RA Dimensions, Operations Manual versions) by compression analysis using a flat cylinder (20 mm dia.) with a speed of 2 mm/s. The force to provide a 20% compression was recorded. 

W.R. Hruschka, Data analysis wavelength selection methods, pp. 35-55 in P.C. Williams and K. Norris, eds. Near-infrared Reflectance Spectroscopy. Am. Cereal Assoc., St. Paul MI, 1987. P. Geladi, D. McDougall and H. Martens, Linearization and scatter-correction for near-infrared reflectance spectra of meat. Appl. Spectrosc., 39 (1985) 491-500. 

Beilken et al. [ 12] have applied a number of instrumental measuring methods to assess the mechanical strength of 12 different meat patties. In all, 20 different physical/chemical properties were measured. The products were tasted twice by 12 panellists divided over 4 sessions in which 6 products were evaluated for 9 textural attributes (rubberiness, chewiness, juiciness, etc.). Beilken etal. [12] subjected the two sets of data, viz. the instrumental data and the sensory data, to separate principal component analyses. The relation between the two data sets, mechanical measurements versus sensory attributes, was studied by their intercorrelations. Although useful information can be derived from such bivariate indicators, a truly multivariate regression analysis may give a simpler overall picture of the relation. 

Silverlight and Jackman developed an immunoassay for levamisole in meat and milk. The LOD in both milk and meat samples was 1 xg kg The assay was applied to milk directly, and muscle samples required only homogenization in the presence of 10-fold of buffer prior to analysis. The linear range of the assay was between 5 and 50 pg kg for meat and between 0.2 and 25 qg kg for milk. The linear range of the assay was below the MRL for milk (10 qg kg ) and meat (50 qg kg ). 

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