Beef composition

NaturaHy occurring and synthetic estrogens and androgens have been extensively and safely used to improve efficiency and carcass composition ia growing beef catde in the United States since the early 1950s. Several anaboHc steroid implants have been approved for use in beef catde in the United States, but only one, zeranol [55331-29-8] is approved for use in lambs. Anabolic steroids are not used for growth regulation in swine or poultry (see Steroids). 

Ethanol and choline glycerolipids were isolated from calf brain and beef heart lipids by PTLC using silica gel H plates. Pure ethanol amine and choline plasmalogens were obtained with a yield of 80% [74]. Four phosphohpid components in the purple membrane (Bacteriorhodopsin) of Halobacterium halobium were isolated and identified by PTLC. Separated phosphohpids were add-hydrolyzed and further analyzed by GC. Silica gel G pates were used to fractionate alkylglycerol according to the number of carbon atoms in the aliphatic moiety [24]. Sterol esters, wax esters, free sterols, and polar lipids in dogskin hpids were separated by PTLC. The fatty acid composition of each group was determined by GC. 

In a number of methods, isolation of the nucleoprotein complex (stage 2) is avoided. In the isolation of ribonucleic acid from beef pancreas,1241 nuclear material and cell debris are removed from a normal-saline extract of the minced tissue, which is then brought to half-saturation with sodium chloride (to dissociate the protein from the nucleic acid). After removal of the protein, the nucleic acid is precipitated with alcohol. However, the suggestion has been made126 that it is more satisfactory to isolate the nucleoprotein first, and this has been carried out, for instance, in the extraction of the ribonucleic acid from fowl sarcoma GRCH 15.126 Nucleoprotein complexes have also been isolated from baker s yeast127 and have been separated into various fractions, the nucleic acids from which differ slightly in composition. In addition, nucleoproteins have been isolated by complex formation with cetyltrimethylammonium bromide.128... 

Table V shows the composition of the liquid meals for this study. As in the previous study, two levels each of cottage cheese and beef were fed to the subjects. In addition, 45 g of protein from soy isolate was also fed. The phytic acid content of this meal was 126 mg. A basal diet containing all nutrients except protein was also included in this study. It was necessary to reduce the fat content of the basal diet for palatability the total energy for this meal only was 250 kcal. In this study, the calcium and phosphorus levels of each meal were equalized across all levels and sources of protein. Levels of other meal components were maintained as constant as possible and are shown at the bottom of Table V.

An evaluation of the composition of the cooking juices, as presented in Table IV, demonstrates, by difference, that fat is retained to a greater extent by the soy concentrate meat product than by the soy flour meat product or the ground beef. The meat product containing soy flour lost more fat during cooking than did the all-beef (Table IV). Similar results were reported by Anderson and Lind ( ). When soy protein concentrates are used in canned meat products like chili, the fat islands within the chopped meat products and the fat cap are eliminated (10). When 4% soy concentrate was added to a minced pork product, cook out of fat and moisture was reduced 31% for pasteurized product and 34% for sterilized product. 

Only one study thus far has evaluated the effect of CCM fortification of the diet on serum lipid profiles. It was a randomized, single-blind, crossover metabolic diet study with two 10-day periods separated by a 10-day washout (Denke et al, 1993). The subjects included 13 healthy men (mean SD 43 4 years) classified as moderately hypercholesterolemic (mean SD 6.19 0.37 mmol serum cholesterol at baseline) and with a low baseline Ca intake (mean SD 466 199 mg Ca/day). The low-Ca basal diet contained 34% energy from fat (primarily as beef tallow), 13% from saturated fat, 240 mg cholesterol/day, and 410 mg Ca/day. The high-Ca diet was similar in composition except that CCM... 

The flavor enhancer monosodium glutamate (MSG) is currently used in virtually every type of savory prepared-food. Unfortunately, MSG has several deleterious side effects on a large proportion of the population. Fortunately, a naturally occurring peptide isolated from a muscle food (beef) can serve not only as a potential replacement for MSG but also as a nutritional adjuvant. The peptide, called BMP or beefy meaty peptide, acts as a flavor enhancer and is found to occur naturally in beef Chapter 6). Research on BMP suggest that it is not only non-allergenic but, by virtue of its protein composition, is a nutritionally sound replacement for MSG. 

EFFECT OF POSTMORTEM AGING ON BEEF PROTEIN COMPOSITION ... 

The chemical, instrumental and sensory data presented above indicated that storage of cooked beef affects the lipid composition and concomitantly, the flavor of beef. The data also indicated that primary tastes like bitter and sour are affected by storage. 

Figure 9. The effect of storage on protein and peptide composition in cooked ground beef stored in a refrigerator of 4 days (adapted from 7). Upper graph represents the size exclusion chromatography of acidic extracts of fresh, cooked, and cooked-stored beef. Lx)wer graph represents the reverse phase HPLC of peak II from the size exclusion chromatography.

The changes in the protein composition and flavor of "cooked" and "cooked- -stored" beef seemed to be related to degradation by free radical species induced during lipid oxidation 1-10, 16, 22, 23), Based on the information presented in the aforementioned publication, it seemed reasonable to suggest that the appearance of "bitter" and "sour" tastes and the disappearance of "meaty" and "beefy" flavors were a result of the activity of the free radicals derived from lipid oxidation on flavor proteins (2, 24-28),... 

Food-derived anticarcinogens, conjugated dienoic derivatives of linoleic acid, 262-270 Food quality health concerns, 5-6 maintenance by natural and synthetic compounds, 56-76 molecular s proaches to study, 1-6 related to antimicrobial peptides, 303-318 Foodbome pathogens, ionizing radiation, 296-298 Free radical(s) beef flavor peptides, 89-91 oxidation generating system, 88-89,91/ protein composition, 88-89,91/... 

Apart from differences between muscle tissues from various parts of an animal, there are qualitative and quantitative differences in composition between animal species. Therefore, analytical methods will always have lo be tested on material from each individual species, since differences in fat composition, in the presence of species-specific proteins, and in colored components such as in the case of myoglobin in poultry and beef may influence both the extraction and the separation of the analytes. As an example, a recovery higher than 70% was obtained for furazolidone after spiking chicken and veal calf muscle tissue but only 10% after spiking pork tissue (16). In this study, the recovery from pork meat could markedly be improved by addition to the aqueous exfraction solvent of about 25% acetonitrile, an observation indicating binding of furazolidone to pork-specific proteins. 

The specific peptide composition can be used to characterize foods. Abe (124) separated the peptides carnosine, anserine, and balenine from the white and red muscle of nine species of marine fishes. Carnegie et al. (37,38) developed an HPLC method using a Partisil-lOSCX column with 0.2 M lithium formate at a pH of 2.9 and a temperature of 40°C under isocratic conditions with postcolumn derivatization using OPA to separate the dipeptides of histidine, anserine, carnosine, and balenine from the muscles of various species (pork, chicken, beef, lamb, and mutton) in order to identify the origin of the meat used in meat products. The concentration of balenine and the balenineranserine ratio were higher in pork than in the other meats, and these relationships were useful in determining the presence of pork in mixtures with other meats. 

In the framework of an investigation of the mechanisms of flavor formation, Caboni et al. observed that cooking did not have a significant effect on the PL composition and the fatty acid content of the single PL in ground beef (31). However, SPH decreased uniformly in all cooked... 

Iron oxide painted rabbit hair with beef tallow binder Iron oxide painted common milkweed, Charred 20 min. Copper hydroxide Seip 32, copper painted , green stains, composite layers... 

Meat, as defined above vanes widely in composition, not merely with the individual animal yielding it, but also according to the breed, age, etc, of the animal, to the part of the body from which it is obtained, and to the method of slaughtenng employed The total nitrogenous substances are mostly about 20%, and the fat and water vary together, the one increasing as the other diminishes, for instance, fat beef with 32-50% of water may contain 55-1% of fat, while lean meat with 74 20% of water may contain only 3 45% of fat. 

Table IV. Average Composition of Total Odor Concentrates from Nonirradiated and Irradiated Beef...

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