Extracts, ground meat

Basic Protocol 1 Analysis of Metmyoglobin in Ground Meat Extracts F3.3.1... 

Meat discoloration studies typically involve a maximum of 5 days, with discoloration analy-sis being performed every day or on alternate days. The actual experimental time involved in the objective assessment of discoloration is not extensive and depends on the number of samples being analyzed. Colorimetric measurements with hand-held colorimeters are very rapid (three measurements per meat surface in < 1 min). Spectral scans of meat surfaces require 1 to 2 min. Extraction and analysis of ground meat products has the added step of homogenization and filtration prior to spectrophotometry, but relative to many laboratory procedures, this is relatively quick. Isolation and purification of preparative amounts of myoglobin requires only 2 to 3 days once appropriate preparations are made. Finally, metmyoglobin can be reduced to oxymyoglobin in 15 to 20 min. 

Stir the ground meat for 15 min after addition of 2.5 L extraction buffer 1 with a solid glass rod and subsequently centrifuge the slurry at 4,000 x for 7 min. 

In addition to these inherent characteristics of the fat itself, contact of the fat in meat with an aqueous solution containing surface-active substances, accelerators and inhibitors of rancidity, creates a very different situation from conditions which exist in a container of rendered lard. The author has noted on a number of occasions that the keeping time of fat rendered from pork tissues did not correlate with rancidity development in the ground meat. Schreiber et al. (1947) reported that the stability of fat, as measured by accelerated tests on the extracted fat from fresh birds, was not a good indication of the stability of poultry fat in situ during freezer storage. 

Paprika contains capsombin and capsanthin (Fig. 8.3) which occur mainly as the lauric acid esters, and about 20 other carotenoid pigments. Paprika is produced in many countries which have developed their own specialties. Cayenne or cayenne pepper, produced from a different cultivar of C. annum, is usually more pungent. C. frutescens is the source of the very pungent Tabasco sauce. Paprika oleoresin is produced by solvent extraction of the ground powder. Obviously paprika supplies both flavor and color and its use is limited to those products compatible with the flavor. The recent rise in demand for tomato products in the form of pizza, salsa, etc., has increased the demand for paprika. Paprika is used in meat products, soups, sauces, salad dressings, processed cheese, snacks, confectionery and baked goods.1018... 

Four aspects of research involving the use of SFE for the improvement of quality of muscle food products are briefly discussed. These include supercritical CO2 extraction of lipids fi om fresh ground beef and from dried muscle foods the extraction and separation of lipid and cholesterol from beef tallow supercritical CO2 extraction of flavor volatiles from beef and pork lipids for use as additives in synthetic meat flavors and identification and quantitation of flavor volatiles extracted with SC-CO2. 

Applications of the Karl Fischer method are numerous food stuffs (butter, margarine, powdered milk, sugar, cheese, processed meats, etc.), solvents, paper, gas, petroleum, etc. Before the determination can be made, solid components that are not soluble must either be ground into powders, extracted with anhydrous solvents, eliminated as azeotropes or heated to eliminate water. Problems are encountered with very acidic or basic media that denature reactants and transform ketones and aldehydes into acetals that interfere with the titration. Special reagents must be used in these instances. 

Before selecting a method to measure a specific aspect of protein functionality, one must decide on the complexity of the testing matrix. Researchers have used a single purified protein, a crude extract of proteins, a prototype food product, or an actual product to study protein functionality. For meat studies, formulated meat systems, ground muscle, myofibrillar proteins, salt-soluble proteins, actomyosin,... 

Turning to assays using sensors that require more than a simple cut in the sample, Bergann et al. [37] paid considerable attention to sample preparation in attempts to measure lactate in meat with a sensor (not thick film) based on reaction of hydrogen peroxide with a platinum electrode or on the reaction of ferrocene carboxylate with the active site of lactate oxidase. Sample preparation entailed extraction into buffer following grinding. In some cases, ground samples were left to allow the lactate to diffuse into the buffer solution. This was quite effective but slow (up to 90 min). Ultimately, the quality of the assay was dependent on the method of sample preparation. 

Love and Pearson (6) have described a model meat system in which bovine muscle was ground and extracted with distilled, deionized water at 4°C until it was devoid of color, indicating the removal of all meat pigments, i.e., myoglobin and hemoglobin. Other water-soluble components would also be partially or completely extracted by this procedure. The remaining extracted muscle was then used as a model system to which purified myoglobin, ferrous iron and ferric iron were added back to ascertain their role in WOF. 

The oil content of flaxseed ranges from 400 to 450g/kg and the byproduct of mechanical oil extraction - flaxseed (or linseed) meal - can be used in organic poultry feeding. There is also interest in feeding the ground whole oil-containing seed to poultry for two main reasons to produce meat with a fatty acid profile in the fat that confers health benefits to the consumer (Conners, 2000) and to impart an enhanced flavour to the meat. 

Foster and Gonzales [10] reported a collaborative study by 11 laboratories of Soxtec and Soxhlet methods for the determination of total fat in meat and meat products. Each lab analyzed six samples canned ham, ground beef, frankfurters, fresh pork sausage, hard salami, and beef patties with added soy. In general, results for the Soxtec system showed improved performance. The method was first adopted by AOAC International for the extraction of fat from meat. Membrado et al. [11] tested Soxtec against Soxhlet extraction for the extraction of coal and coal-derived products. Optimization of Soxtec operating conditions reduced the total extraction time to 10% of what was needed by Soxhlet extraction. The recovery and precision by the two methods were comparable. 

The stability of As species in the waterD methanol rice extract stored at+4°C for at least one month was demonstrated. Once the rice grains were ground, MMA and As(V) were unstable under any storage conditions probably due to microbiological activity. When ground rice was y-irradiated, As species remained stable [24]. The stability of As species in a chicken meat candidate CRM for at least 12 months was demonstrated [26],... 

Copra Cake. Copra cake is a by-product of oil extraction from coconut. The dehusked coconut is split and the meat is scraped from the kernel cup and dried. The oil is extracted via expeller or solvent processes from the dried coconut meat copra. This product is available throughout the year, making it a cheap local source of animal feed. The cake is ground to meal for use in feed for poultry, cattle, sheep, and swine. Copra cake can be used as a substitute for hsh meal in swine feed but may cause conshpahon. Germany has been an importer of the majority of the cake produced in the Philippines (61). 

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