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The effects of various test parameters on stress relaxation analysis measuring viscoelastic properties of beef products, and the suitability of different models to describe that test data were investigated. Three types of processed meat products were evaluated: finely comminuted (frankfurter), ground beef (salami), and whole muscle (corned beef). Cylindrical specimens of meat products, 10, 15 or 20 mm in diameter and 10 mm in length were compressed to 10%, 20% or 30% of their original height for 9 min. The data were fitted using the Maxwell model with two elements and other available models in the literature. Stress was calculated by dividing the force by initial cross sectional area of the sample, and modulus by dividing stress by strain. Both sample size and compression ratio affected model parameters. A diameter to length ratio (D/L) of 1.5 and any compression ration were suitable for the whole muscle product; D/L of 1.5 and 10% or lower compression for ground beef; and D/L of 2 and 10% or lower compression ratio for finely comminuted products were the suitable test conditions. 相似文献
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Influence of Sodium, Potassium and Magnesium Chloride on Thermal Properties of Beef Muscle 总被引:2,自引:0,他引:2
Sodium, potassium and magnesium chloride, at 1.25, 2.50 and 5.00%, were studied using differential scanning calorimetry. Increasing NaCl resulted in decrease in myosin transition temperature (T1, first transition) and enthalpy (H1); both showed significant (P<0.05) linear response. The sarcoplasmic proteins and collagen denaturation temperature (T2, second transition) increased significantly over the control when 1.25% NaCl was added, but were the same as control when 2.5% and 5.0% were used. Actin denaturation temperature (T3, third transition) tended to increase when NaCl was added, but enthalpy decreased. Potassium chloride showed similar effects to NaCl on T1, T2, H1 and H3. Increasing magnesium chloride had much more pronounced effect on decreasing second enthalpy compared to the monovalent salts. At 5% MgCl2 T1 increased significantly. 相似文献
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SHAI BARBUT 《Journal of food quality》2003,26(1):55-64
The effect of three commonly used light sources on the color acceptability of oranges, lemons and limes was investigated. The color of the oranges under incandescent (INC) and metal halide (MH) lights was more preferred (P<0.05), by the panelists than when presented under fluorescent (FL). The main reason was the dull orange color seen under FL light. Relative luminance data, collected via a fiber optic probe connected to a photo diode array, demonstrated the reason to be insufficient red light reflected from oranges presented under FL. The yellow lemons were also preferred more under INC and MH than under FL: the latter resulted in a greenish tinge appearance. The color of the limes was more preferred under INC light than under FL, but preferred equally to the product presented under MH. 相似文献
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The effects of various chemical modifications on gelation and texture of finely comminuted lean beef mixes were investigated. Urea, which disrupts non-covalent bonds, significantly increased (at 95% level) the modulus of rigidity (G) and hardness values compared to the control (no additive). Oxidation of free sulphdryl groups by H2 O2 resulted in lower G but similar hardness values of the control. The β-mercaptoethanol (ME) treatment was similar to the control in G values but higher in hardness, gumminess and chewiness. Ethylenediamine tetraacetic acid (EDTA) addition resulted in excessive cooking losses, the lowest G value and the hardest texture. Polyoxyethylene sorbitan monooleate did not have any significant effect on the textural characteristics of the finely comminuted mixes but resulted in lower G compared to the control. 相似文献
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Water holding capacity (WHC) of ground beef was measured by the press method. Three levels of applied force, test duration, sample mass, and salt concentration were investigated. Three types of deformations – plastic, elastic and permanent were used to explain the effects of applied force on WHC. Viscoelastic properties explained the effects of test duration. In general, WHC decreased with additional applied force and test duration, and increased with a larger sample size and salt concentration. Recommended test conditions are: 1 g sample size, 20 kN force for 2 min at a salt concentration of 0, 1 or 2%. 相似文献
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Cryo scanning electron microscopy (Cryo SEM) was used to study the microstructure of raw and cooked meat batters and compared with conventional SEM and transmission electron microscopy (TEM). Cryo SEM revealed that raw batters consisted of an organized, highly interconnected protein matrix in which fat globules were dispersed. Cryo SEM resulted in much better preservation of protein gel structure compared to conventional SEM which caused shrinkage of the specimen, resulting in a closed gel matrix structure. TEM confirmed the differences between the matrices of raw and cooked batters shown by cryo SEM. Methods for preparation of specimen for cryo SEM were developed. 相似文献
7.
Rheological and Gelation Properties of Meat Batters Prepared with Three Chloride Salts 总被引:1,自引:0,他引:1
The gelation and rheological properties of poultry meat emulsions prepared with three chloride salts (NaCl, KCl, MgCl2) and 50/50 mixtures of the above salts at isoionic strength (IS = 0.42) were studied. The relationship between shear rate and shear stress for the different raw meat emulsions was found to be nonlinear and followed Bingham pseudoplastic behavior. The yield stress for the emulsion containing only MgCl2 was significantly lower as compared to all the other treatments. The highest rigidity modulus values obtained during cooking were observed in the NaCl + MgCl2 treatment followed by the NaCl + KCl, NaCl and KCl. The emulsion containing MgCl2 only broke down at the initial stages of cooking, exhibiting the destabilizing effect of the magnesium cation. 相似文献
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Increasing whey protein concentration (from 6 to 10% w/v) decreased gel opacity but increased gel strength and water-holding capacity (WHC). Increasing CaCl2, concentration (from 5 to 150 mM) increased gel opacity and gel strength at the high protein concentration (i.e., 10%). However, it lowered gel strength at protein concentration > 10%. Young's modulus and distance to fracture values indicated that gels were most rigid at 30 mM CaCl2, at which point the extent of aggregation (measured by turbidity) was the highest. Increasing CaCl2 concentration from 5 to 150 mM slightly affected the WHC of Ca2+-induced gels. Protein concentration was the major factor in determining fracture properties and WHC. 相似文献
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