Meat Fibers Research Articles

Prediction of enthalpy and thermal conductivity of frozen meat and fish products from composition data

In this paper we present models predicting thermophysical properties of frozen meat products purely using their composition data. Based on our previous model, predicting the water activity of (frozen) meat and fish products, while taking into account the non-ideality of the unfrozen solution, we can compute the ice fraction as a function of temperature. Knowing the composition and ice formed, the temperature dependency of heat capacities and latent heat, we can readily compute the enthalpy. For predicting the thermal conductivity a model is constructed taking into account the meat (fibrous) structure, the anisotropy of ice cyrstals, and the distribution of the composition over dispersed and continuous phases. Comparison model predictions to literature data on enthalpy and thermal conductivity shows that we can obtain reasonable prediction within engineering accuracy of 10%. The thermal conductivity model gives significant differences in conductivity parallel and perpendicular to meat fibres, in accordance with experimental data.

Growth- and breed-related changes of muscle bundle structure in cattle1

The objective of this study was to investigate the changes in muscle fiber bundles of cattle of different breeds during growth. Different numbers of muscle fibers are surrounded by connective tissue to form bundles macroscopically visible as meat fibers or meat grain, a common meat quality trait. To determine the influence of breed and age on morphological characteristics of muscle fiber bundles, 4 cattle breeds with different growth impetus and muscularity were reared and slaughtered under experimental conditions. German Angus, a typical beef cattle; Galloway, a smaller beef type; Holstein Friesian, a dairy type; and double-muscled Belgian Blue, an extreme type for muscle growth, were used. Between 5 and 15 bulls of each breed were slaughtered at 2, 4, 6, 12, or 24 mo of age, and slices of semitendinosus muscle were removed. Muscle structure characteristics were determined by computerized image analysis. During growth, the muscle cross-sectional area enlarged (P < 0.001) about 5-fold in double-muscled Belgian Blue bulls and about 4-fold in the other breeds. This was a result of the enlargement (P < 0.001) of primary bundles and muscle fibers. The bundle size was similar (P > or = 0.15) in bulls of German Angus and Galloway in all age groups and was doubled (P < 0.001) in double-muscled Belgian Blue animals from 4 mo of age on. The Holstein Friesian bulls had the smallest (P < 0.001) muscle fiber bundles at 24 mo of age. The number of muscle fibers per bundle and the number of bundles per muscle remained nearly constant (P > 0.05) during growth. This supports the existing view that the structure of the muscle is already fixed in prenatal life. The double-muscled Belgian Blue bulls showed a more than 2.5-fold greater (P < 0.001) number of muscle fibers per primary bundle compared with the other breeds investigated. The larger muscle fiber bundles led to a smaller amount of connective tissue per muscle area in double-muscled cattle. The coarser grain of meat in double-muscled Belgian Blue bulls and in older animals was not related to greater shear force values.

EFFECT OF MUSCLE‐FIBER/FIBER‐BUNDLE ALIGNMENT ON PHYSICAL AND SENSORY PROPERTIES OF RESTRUCTURED BEEF STEAKS

ABSTRACT Cold‐set restructured beef steaks (10 mm thick) were manufactured with meat fibers aligned parallel (PR), perpendicular (PP) or an equal mixture of PR and PP (MX) in relation to the cut‐steak surface. Fiber alignment had no effect (P &gt; 0.05) on the color of raw or the bind strength of both raw and cooked steaks. Raw PR steaks had higher drip loss (P &lt; 0.01) and visual appeal (P &lt; 0.001) than PP or MX steaks; however, cooked PR had higher yield (P &lt; 0.01) and lower (P &lt; 0.04) visual appeal than PP or MX steaks. In‐house panelists found the overall acceptability (P &lt; 0.01), appearance (P &lt; 0.01), texture (P &lt; 0.02) and tenderness (P &lt; 0.002) of cooked PP and MX to be more acceptable than that of PR steaks and ranked the eating quality of the PR steaks significantly lower (P &lt; 0.04) than the others.

Kayexalate (Sodium Polystyrene Sulfonate) Aspiration

The patient, a 63-year-old woman, had past medical history significant for diabetes mellitus, hypertension, congestive heart failure, and a pelvic mass. The serum electrolyte sample showed hyperkalemia (serum potassium 6.2 mEq/L, serum creatinine 4.1 mg/dL, blood urea nitrogen 87 mg/dL; the sample was not hemolyzed). She was taken to the emergency room. The hyperkalemia was treated with kayexalate (sodium polystyrene sulfonate) in the emergency room, and she was admitted to the hospital, where continued efforts were made to manage the hyperkalemia. However, she was found unresponsive the morning after admission, and efforts at resuscitation were unsuccessful. Postmortem examination revealed the pelvic mass to be a small cell neuroendocrine tumor, apparently arising from the cervix with extensive involvement of the uterine myometrium, extensive peritoneal implants, invasion into the wall of the bladder, compression of the ureters, and invasion of the inferior vena cava. There was no evidence of distant metastasis. She was also found to have massive cardiomegaly (dilated and hypertrophic) and nodular glomerulosclerosis. There was pulmonary congestion with edema. In addition, there were irregular, sharply angulated basophilic materials of varying sizes with little or no tissue reaction in the alveoli (Figure 1). These materials have parallel laminations (Figure 2). Degenerated bronchial cells are occasionally seen with the materials (Figure 2). These materials in the lungs are aspirated kayexalate (sodium polystyrene sulfonate). Kayexalate is a cation-exchange resin given enterally for the treatment of hyperkalemia. 1 There is characteristic basophilic, amorphous foreign material in airspaces on histologic sections. The identity of this material can be confirmed by Fourier transform infrared microspectrophotometry, 1 but this is often not necessary because of the characteristic appearance. The parallel laminations of the kayexalate are thought to be an artifact of sectioning. 2 Aspirated vegetable matter and meat fibers may be considered in the differential diagnosis, but these do not have the parallel laminations of kayexalate. Kayexalate aspiration typically does not cause pneumonia, but there have been reports of cases of pneumonitis following its aspi

Kayexalate (Sodium Polystyrene Sulfonate) Aspiration

The patient, a 63-year-old woman, had past medical history significant for diabetes mellitus, hypertension, congestive heart failure, and a pelvic mass. The serum electrolyte sample showed hyperkalemia (serum potassium 6.2 mEq/L, serum creatinine 4.1 mg/dL, blood urea nitrogen 87 mg/dL; the sample was not hemolyzed). She was taken to the emergency room. The hyperkalemia was treated with kayexalate (sodium polystyrene sulfonate) in the emergency room, and she was admitted to the hospital, where continued efforts were made to manage the hyperkalemia. However, she was found unresponsive the morning after admission, and efforts at resuscitation were unsuccessful. Postmortem examination revealed the pelvic mass to be a small cell neuroendocrine tumor, apparently arising from the cervix with extensive involvement of the uterine myometrium, extensive peritoneal implants, invasion into the wall of the bladder, compression of the ureters, and invasion of the inferior vena cava. There was no evidence of distant metastasis. She was also found to have massive cardiomegaly (dilated and hypertrophic) and nodular glomerulosclerosis. There was pulmonary congestion with edema. In addition, there were irregular, sharply angulated basophilic materials of varying sizes with little or no tissue reaction in the alveoli (Figure 1). These materials have parallel laminations (Figure 2). Degenerated bronchial cells are occasionally seen with the materials (Figure 2). These materials in the lungs are aspirated kayexalate (sodium polystyrene sulfonate). Kayexalate is a cation-exchange resin given enterally for the treatment of hyperkalemia. 1 There is characteristic basophilic, amorphous foreign material in airspaces on histologic sections. The identity of this material can be confirmed by Fourier transform infrared microspectrophotometry, 1 but this is often not necessary because of the characteristic appearance. The parallel laminations of the kayexalate are thought to be an artifact of sectioning. 2 Aspirated vegetable matter and meat fibers may be considered in the differential diagnosis, but these do not have the parallel laminations of kayexalate. Kayexalate aspiration typically does not cause pneumonia, but there have been reports of cases of pneumonitis following its aspi

Slicing frozen meat with an oscillating knife

The forces, and hence fracture energies, required to cut frozen meat are presented in this paper and the merits of applying vibrations to a cutting blade are considered. A knife oscillating in a slicing action was used to cut horse M. semimembranosus and loin muscle M. longissimus dorsi over a range of temperatures (−1.5°C to −30°C) and vibration frequencies (0–1000 Hz). The blade required less force to cut when slicing than when not slicing; the decrease in force was proportional to the velocity of the slicing motion. If the average relative slicing velocity of the blade with respect to the meat was greater than 164 mm/s then the cutting force reduced significantly. The reduction was due to a lower requirement for energy to produce the new material surface (up to 80% reduction) and also a reduction in the plastic energy required to deform the off-cut by the blade (up to 30% reduction). The surface energy was reduced because the fracture mechanism was altered by the slicing action. The plastic energy was reduced because the slicing blade fractured the meat fibres with less strain (and hence less material deformation around the process zone) than a blade pressed directly into the meat. Vibration frequencies of 10–100 Hz were required to generate the required slicing motion with the equipment available. A vibrating cutting blade could have a combination of chopping and slicing motions superimposed upon it. These would reduce both the friction between the knife blade and the meat, as well as the surface and plastic energy required to cut the meat.

Water transport in meat during reheating

A study of heat and water transport in meat during a heating process was conducted. The meat samples were heated from 10 to 10 °C in a conventional oven at 175 °C and local water content and temperatures were measured during the heating process. Using whole meat from bovine muscles, the mechanism behind water transport inside the sample during heating was investigated. The anisotropy of meat in terms of heat and water transport was also studied. The study yielded two main results: When heating commences, water moves towards the centre of the samples. At a centre temperature of ~ 70 °C, water transport stops and changes direction. A theory for transport phenomena has been developed and is described in this paper. The results also indicate that, as expected, both water transport and heat transport are faster parallel to the meat fibres than perpendicular to them.

The Serrated Teeth of Tyrannosaurid Dinosaurs, and Biting Structures in Other Animals

The function of serrated teeth is analyzed by experimental comparison with the action of artificially made steel blades. Serrated blades cut compliant materials with a grip-and-rip mechanism, whereas smooth, sharp blades cut by concentrating a large downward force on a tiny area.Tyrannosaurid teeth from the Cretaceous Judith River Formation bear rows of serrations that have thick, rounded enamel caps, gripping slots between neighboring serrations, thick enamel bodies inside the teeth underneath the gripping slots, and a root beneath each serration. In contrast, the carnivorous dinosaurTroodonhas teeth with exposed pointed serrations, thin enamel, and possibly serration roots.Serrations on the teeth ofTroodonand the fossil sharkCarcharodon,cut compliant materials in the same way as a serrated hacksaw blade. In contrast, the cutting action of tyrannosaurid teeth most closely resembles that of a dull smooth blade. The spaces between the serrations act as minute frictional vises that grip and hold meat fibers; chambers between neighboring serrations receive and retain small fragments of meat, and inevitably would have acted as havens where bacteria could be stored. These spaces may therefore have led to infections in wounds, analogous to those inflicted by the living Komodo dragon or ora. By analogy, the hunting and feeding behavior of tyrannosaurs may have resembled that of the ora.Serrations and slots are widely distributed among cutting devices in the natural world, and many of these deserve further study. For example, the carnassial teeth of mammalian carnivores cut by a combination of static force at the cutting edge, a crushing or scissoring action at the advancing junction between upper and lower teeth, and by lateral gripping and compression in a slot, like that seen on a much smaller scale in tyrannosaurid serrations. Mammalian teeth operate well only when deployed with sophisticated control over jaw movement, however, and the fine neural control necessary to operate them may have formed the basis for the later development of intelligence in mammals.Previously, being interested in mammals was largely a matter of being interested in teeth, whereas being interested in reptiles was largely a matter of being interested in everything but teeth. I suggest that the teeth of at least some reptiles are as rich in information as the teeth of any mammals.

A study of digestive absorption in four cases of Down's syndrome. Down's syndrome, malnutrition, malabsorption, and Alzheimer's disease

Many data suggest that patients with Down's syndrome (DS) suffer from digestive malabsorption. A fecal test of absorption (search for undigested meat fibers following the ingestion of a measured diet) was conducted in 4 patients with DS. The results point to malabsorption in these patients and support the hypothesis of malabsorption in DS. The etiology of probable malabsorption in DS is discussed. Data are presented suggesting that chronic malnutrition caused by malabsorption could be the cause of the neuropathologic signs of Alzheimer's disease occurring at or slightly before the fourth decade in all patients with DS.

Effect of Sample Weight and Orientation in the Shear Press Testing of Canadian Style Bacon

ABSTRACTShear press experiments were performed on rectangular slices of Canadian style bacon with sample weights of 5 and 10g. Maximum peak force and area under the curve (then converted to energy) were obtained from the Instron force‐deformation curves. General linear modeling was performed on these results to see if, at these sample weights, the peak force and shear energy were affected by either sample weight or by the manner in which the sample was arranged within the shear test cell. Results showed that for the magnitude of sample weights tested, the peak force and shear energy were affected by sample weight and the sample orientation within the shear cell attachment. Factors tested included the direction in which the meat fibers were aligned (with respect to the blades in the cell), sample thickness and sample weight.

Salt-induced swelling of meat: The effect of storage time, pH, ion-type and concentration

The effect of hypertonic salt solutions on meat fibres has been studied as a function of post-mortem storage. Rabbit longissimus dorsi fibres (after about 20 h post-mortem storage at 4°C), were found to swell in hypertonic salt solutions, such as 0·25 m KI or 0·6 m KCl, to two to three times their original diameter. This swelling occurred in the fibre transverse plane only. X-ray diffraction shows swelling occurs by a combination of an increase in the myofilament lattice spacing and a loss of myofilament order. Fibre swelling is highly co-operative. At pHs below the isoelectric point of the myofibrillar proteins, hypertonic salt solutions induce fibre shrinkage. The post-mortem time course of response shows a peak at 18–35 h bounded by periods of minimal or zero response. We propose that the collagenous endomysial sheath acts as a restraint to myofibril swelling and that the characteristics of post-mortem swelling are a balance of the myofibrillar propensity to swell and the constraint of the endomysium.

Occult blood testing using tetramethylbenzidine in an extraction procedure for patients on unrestricted diets.

An extraction test for stool occult blood was developed using 3,3', 5,5' tetramethylbenzidine (TMB), which gave reliable results in the presence of interfering substances, such as vitamin C, meat fibers, and vegetable enzymes. The new test was applied to 1,320 fecal specimens from hospitalized patients not on dietary restrictions. Of 189 specimens unequivocally positive by slide tests, 48 were negative by the extraction test, 42 were trace reactions, and 99 were 2+ to 4+. Extraction testing was performed on 351 of the 1,082 specimens negative by slide tests. Four of these were from patients taking supplemental vitamin C. Two of these specimens were extraction test positive ( ) and two were extraction test negative. One other specimen, from a patient not on supplemental vitamin C, was extraction test positive. Forty-nine specimens gave equivocal results, with two commercial slide tests for occult blood. By the extraction test, 26 of these were negative, 13 had trace amounts of blood, and 10 were 2+ or 4+.

Generalization of a method for the characterization of quick frozen beef

The lack of standardized tests for determining if a product can be defined as ‘quick frozen’ is a source of difficulty in the commercialization of foods. An even greater difficulty is the fact that there is no one definition of a quick frozen food. With the aim of partially filling this gap, a previous paper developed a simple physical method of characterizing quick frozen beef. The study was carried out with meat cuts cooled by means of heat transfer perpendicular, in a sense, to the meat fibres with ‘quick frozen’ being defined by a minimum average freezing rate. In the present paper the characterization method is generalized for either heat transfer perpendicular with, or parallel to, beef fibres, ‘quick frozen’ being defined either by a maximum freezing time or a minimum freezing rate.

Functional properties of proteins in foods

AbstractThe measurement of functionality of protein food ingredients has developed somewhat haphazardly, probably due to the wide range of proteins used as ingredients and the diversity of foods. Studies of the physiochemical properties of proteins should enable prediction of a proteins response to process environments and prove more fruitful than many of the empirical measurements of functionality. The effects of pH, salt type and concentration on the phase behaviour of the oilseed globulin and arachin, demonstrates the complexity of protein solubility and the inadequacies of simple tests that have arisen. Studies of the effects of salts and conditioning on meat fibres, coupled with measurement of the location of water in pellets from water holding tests enable the latter to be applied with increased confidence. Comparison of the endothermic transitions observed on heating with the development of storage and loss moduli allow the contributions of domains of skeletal muscle myosin to gel structure to be investigated.

The occurrence of leukemia in patients with the Shwachman syndrome

THE SHWACHMAN SYNDROME is a rare autosomal recessive disease associated with exocrine pancreatic insufficiency, skeletal anomalies such as metaphyseal dysostosis, growth retardation, recurrent infections, and hypoplastic hematologic abnormalities, commonly presenting as neutropenia but also with hypoplastic anemia, thrombocytopenia , or pancytopenia. 1-a Recently, several isolated cases of leukemia have been identified in patients with the Shwachman syndrome? -~ Two additional cases of leukemia associated with EPI are described. A common palhophysiologic process in these patients is suggested. CASE REPORTS Patient 1, a 20-month-old boy, presented with diffuse edema, ascites, and failure to thrive. Height and weight were less than the fifth percentile for age. Laboratory studies documented hypoalbuminemia (1.5 gm/dl) with a total protein concentration of 3.4 gm/dl, hemoglobin of 10 gm/dl, white blood count of 14,300/p,1 with normal differential (47% granulocytes), and platelet count of 538,000//d. Urinalysis and sweat chloride determinations were normal. The stools contained markedly increased fat and undigested meat fibers. Duodenal intubation revealed absent trypsin activity in the fluid obtained, and a small bowel biopsy demonstrated subtotal villus atrophy consistent with a malnourished state. The patient was given an elemental diet with resolution of the edema, and subsequently he was advanced to a normal diet with oral pancreatic enzyme and vitamin replacement. Two months later a complete blood count revealed hemoglobin of 13 gm/dl, platelet count 687,000//d, and WBC 11,800/td with an absolute neutrophll count of 2,600/#1. Acute leg pain occurred one month later, when the hemoglobin concentration was 10.4 gm/dl, platelet count 136,000//B, and WBC 33,500/,al with 5% granulocytes and 67% leukemia cells. Bone marrow aspirate and biopsy confirmed the diagnosis of acute lymphocytic leukemia, L-I morphology, with positive periodic acid Schiff staining lymphoblasts. Hematologic remission was successfully induced with vincristine, prednisone, and L-asparaginase. Central nervous system prophylaxis was administered and the patient has

Changes in the Tenderness of Meat Cooked at 50–65°C

ABSTRACTWarner‐Bratzler (WB) shear force values obtained for stretched veal muscles decreased as cooking temperatures were increased from 50 to 60°C. Increased proteolytic enzyme activity at these temperatures to give accelerated aging did not appear to explain the effects since there was still a substantial decrease in shear force with increase in cooking temperature from 50 to 60°C, even when well aged (7 wk at 5–6°C) meat and meat cooked for 24 hr was used. A more likely explanation was that, even at these relatively low temperatures, changes in connective tissue were involved since (a) the magnitude and direction of the change in shear force with increasing temperature was dependent on animal age and cooking time; (b) the effect of recooking at 80°C was dependent on animal age; and (c) the effects of increasing the cooking temperature and/or time on adhesion between the meat fibres was significantly greater for the samples from the younger animals.

A model for the thermal conductivity of frozen meat

Even though extensive work on the experimental determination of the thermal conductivities of foodstuffs at different temperatures has been published, only a few predictive models for this important property have been developed. Calculation of freezing times in foods, such as meat, over the range from −1°C to −30°C, requires the use of mathematical models in which information on the thermal conductivity of partially frozen meat as a function of ice content in the tissue is provided. In the present paper a model for the thermal conductivity of meat as a function of temperature, which also accounts for its anisotropic properties, is proposed. Both directions, parallel and perpendicular to meat fibres, are considered and the model applies to unfrozen as well as to partially frozen meat. Results show good agreement with published experimental data obtained by a steady state method for different temperatures.

A comparison of the effects of some post‐slaughter treatments on the tenderness of beef

SummaryThe tenderness of most of the major muscles in beef animals, subjected to different hanging treatments at 0–1°C after slaughter, have been compared at 2–3 days post‐slaughter (non‐aged) and at 21 days post‐slaughter (aged). It has been shown that hanging from the aitch bone gives tenderness values for the non‐aged meat equivalent to 21 days ageing at 0–1°G for meat obtained from sides hung from the Achilles tendon. Adhesion between meat fibres was significantly reduced by stretching, but was not affected by ageing. The objective and subjective measurements showed that while stretching substantially reduced toughness due to the meat fibres, the effect of stretching on connective tissue was not always large enough to give tender meat.

EFFECT OF MODE OF REHYDRATION ON TEXTURAL PARAMETERS OF PRECOOKED FREEZE-DRIED SLICED BEEF.

Rehydration procedure had a significant effect on microscopic appearance, manner of liquid release on mechanical chewing, numerical values for the mechanical parameters of texture, correlations between objective measurements (Warner-Bratzler Tenderometer, Kramer Shear Press and General Foods Texturometer) and the ability of instrumental measurements to show grade and cooking level effects. To a lesser extent, it also affected residual errors and coefficients of variation. As compared to cold distilled water, rehydration in warm 1% NaCl appeared to toughen the meat fibers while allowing more water to be absorbed intrafibrally. This water did not release easily on mechanical chewing. Overnight equilibration of drained samples increased the diameter of meat fibers, roughness of those rehydrated in the hot salt solution and smoothness of those rehydrated in cold distilled water. Best approximation to the microscopic appearance of fresh cooked beef was obtained by 20 min rehydration in room temperature distilled water followed by overnight equilibration in the refrigerator. This procedure also offered good differentiation of meat grade and cooking time effects by instrumental texture measurements.

Factors Affecting Poultry Flavor : 1. Inorganic Constituents

ABSTRACT PUBLISHED information on the properties and identity of compounds which impart flavor to poultry is not extensive. Bouthilet (1949, 1950, 1951) observed that the meaty flavor in chicken meat was due to a compound associated with the meat fibers rather than the fat. When the properties of these water-soluble flavoring compounds were compared with those of known chemical compounds, the flavoring precursor had properties similar to glutathione. It was suggested by Bouthilet (1951) that poultry flavor might be soluble in the chicken fat. Pippen, Campbell and Streeter (1954) observed that poultry flavor was derived mainly from the meat, with minor amounts in the skin and bones and almost none in the fat. The broth prepared from half carcasses of commercial “yearling” chickens immersed in ice water for 5 hours had less flavor than the broth prepared from the air-chilled birds. Pippen and Klose (1955) reported that the reincorporation of material . . .