Effect of Gradual Heating and Fat/Oil Type on Fat Stability,Texture, Color,and Microstructure of Meat Batters

The effects of endpoint cooking temperature (40, 50, 60, 70, 80, and 90 °C) on emulsion stability, texture, color, and microstructure of meat batters prepared with different fats/oils were studied. Canola oil treatments showed the highest cooking loss whereas hydrogenated palm oil provided the most stable meat batters. Rendered beef fat was less stable than regular beef fat. Increasing endpoint cooking temperatures resulted in a progressive reduction of water holding capacity in all treatments. As temperature was raised, meat batters showed higher hardness and cohesiveness values, but no appreciable changes in cohesiveness above 60 °C. Canola and hydrogenated palm oil treatments showed the highest hardness and chewiness values. Lightness (L^*) values of all meat batters increased significantly with increasing temperature from 40 to 60 or 70 °C; no major changes observed above 70 °C. Light microscopy revealed no substantial changes in the microstructure of all the stable meat batters cooked to between 50 and 70 °C. Heating to 90 °C changed the microstructure in all meat batters except the hydrogenated palm oil treatments, which still showed nonround fat particles and a less aggregated protein matrix.     

Effect of Different Processing Methods and Salt Content on the Physicochemical and Rheological Properties of Meat Batters

The physicochemical and rheological properties of raw and cooked batters produced by a chopping or beating process with various amounts of salt content were studied. Various meat batters were made up for this purpose: the batter processed by chopping with 2% salt, by beating with 1% salt and 2% salt, respectively. Compared with the chopping, the beating cooked batters had higher L* value, hardness, G’ value at 80°C, and lower cooking loss. Using the beating process, the batter with 1% salt had lower L* values, hardness, springiness, and higher cooking loss than the 2% salt. From the micrographs, the batters produced by beating process exhibited more uniform and compact microstructure than the chopping. The result of low-field nuclear magnetic resonance exhibited that the batters of beating had higher water holding capacity than the chopping. Overall, the beating process enabled lowering of the salt content, cooking loss, and making the cooked batter more hard and elastic.     

Reduced Fat, High Moisture Beef Frankfurters as Affected by Chopping Temperature

Six treatment combinations were studied to determine the effects of initial temperature (0, 15, 30°C) and endpoint chopping temperatures (0, 15, 30, 45°C) on texture and stability of reduced fat, high moisture beef frankfurters. Textural properties (raw batter, frankfurter) and purge loss were determined over 8 wk storage. As endpoint chopping temperature increased, batter stability and shear force decreased. In most samples, initial temperature did not affect texture or stability. Endpoint chopping temperatures of ± 15°C resulted in most stable batters. Chopping > 15°C lowered product quality.     

High pressure processing of meat batters with added walnuts

Various model systems were designed in order to analyse the way in which addition of different levels of walnut (0, 10, 20%) and processing by high pressure (HPP) (400 MPa for 10 min at 10 °C) influenced the physico‐chemical properties of cooked (70 °C for 30 min) meat batters. The addition of walnut increased the fat level and decreased the moisture content in the meat batters. All of the meat batters exhibited good water and fat binding properties. The hardness, cohesiveness, springiness and chewiness of cooked products were reduced by addition of walnut but were unaffected by HPP. Incorporation of nuts in meat products can potentially be used to confer cardiac health benefits.     

Rheological and Structural Properties of Wiener-Type Products Substituted with Vital Wheat Gluten

Mechanical properties of wiener batters substituted with vital wheat gluten (VWG) or acid-solubilized (deamidated) VWG were studied. Substitution led to decreased storage (G') and loss (G”) moduli. Cooking profiles showed initial modulus decreases due to fat melting, with G’ reaching minimum around 50-55°C, followed by rapid increases. Sharp G” and tan 5 transitions appeared near 48°C. Substitution caused upward shift in transition temperatures, and at 20%, decreased moduli. Substitution caused no significant (p < 0.05) decreases in cook yield or texture. Microscopical examination revealed random binding of gluten to meat protein, forming continuous networks. Batters containing deamidated gluten had structure similar to all-meat or VWG-substituted batters.     

Modelling the yield and texture of comminuted pork products using color and temperature. Effect of fat/lean ratio and starch

Practices to control the processing of finely comminuted meat products are proposed. The objective was to test the practical value of both temperature and light reflection measurements made during emulsification as potential indicators of cooking losses and resulting gel texture in pork sausages emulsified within a wide range of temperatures and starch and fat levels. Prior to cooking, pork batters were chopped for different times to ensure final emulsion temperatures ranging from 5 to 50°C. The effects of the fat/lean ratio (0.25 and 0.67) and starch addition (0.8 and 3.2% w:w) on temperature and optical reflection were also investigated. The chopping increased the temperature and decreased the light reflection of fresh meat emulsion. There was no relevant loss of emulsifying capacity at emulsion temperature below 30°C and lightness values over 70 CIE units. The losses and textural parameters of cooked emulsions could be predicted by means of non-linear regression equations based on the temperature and color of the raw emulsion. The determination coefficients obtained ranged from 0.89 to 0.99. The prediction models needed to be fitted to each batter formulation, especially in the presence of reduced levels of gelation agents (meat protein and starch). Lightness was a better predictor than chromaticity, since it decreased constantly with chopping in the range of final emulsion temperatures studied (5-50°C). This confirms previous studies that lightness could be used for monitoring emulsion stability in meat batters.     

Rheological and Stability Transitions in Meat Batters Containing Soy Protein Concentrate and Vital Wheat Gluten

Physical/rheological properties of meat batters during heat-processing were studied. Vital wheat gluten (VWG) and soy protein concentrate (SPC) were incorporated into meat batters which were heated to 40, 50, 60 and 70°C and held for 0, 30 and 60 min. Amounts of fat and aqueous fluid released during heating were determined. A two-cycle compression test and shear modulus determination were used to evaluate rheological changes. VWG and SPC did not have any significant effect on either stability or textural changes. There was a significant interaction between temperature and time for stability and textural characteristics. Significant changes in rheological and stability properties of meat batters occurred in the 50–70°C region. Shear modulus showed a major increase at 54–57°C.     

Characteristics of pressurised pork meat batters as affected by addition of plasma proteins,apple fibre and potato starch

Pork meat (low‐fat) batters were prepared without and with the addition of three non‐meat ingredients: (blood) plasma proteins, (dietary) apple fibre and potato starch. The batters were processed by cooking‐alone (70 °C) and by high‐pressure/temperature combination (400 MPa/70 °C). Protein denaturation and starch gelatinisation through the different processings were followed by differential scanning calorimetry. Batter characteristics such as water holding (weight loss) and different texture parameters (texture profile analysis) were used as quality criteria for comparisons among different formulations and processes. Plasma proteins and apple fibre behaved as inert fillers in both kinds of processed batters. Potato starch effects depended on processing conditions to the extent that these influenced the degree of gelatinisation. In pressurised batters (pressure and heating in sequence), regular preservation effects against subsequent thermal denaturation of proteins were observed. Differential scanning calorimetry revealed that starch was also pressure‐preserved from subsequent thermal gelatinisation, which was confirmed by scanning electron microscopy. The presence of native‐like proteins and ungelatinised starch produced cumulative softening effects in pressurised batters. © 2000 Society of Chemical Industry     

Formulation and Copping Temperature Effects on Beef Frankfurters

Frankfurters were manufactured using four fat and added water (AW) formulations (10% fat/30% AW; 15%/25%; 20%/20%; 30%/10%) and processed at chopping temperatures 9, 12, or 15°C. The batters were stuffed into cellulose casings, thermally processed, chilled and vacuum-packaged. Frankfurters were analyzed for proximate composition, textural properties and purge. No differences occurred among treatments for processing yield (89.8%± 1.83). Frankfurters chopped to 12°C had the highest (P < 0.05) Kramer peak force values. As expected, purge increased in all treatments as storage time increased (P < 0.05). As AW increased, hardness and cohesiveness decreased and purge increased. Water level and fat reduction were the most critical factors affecting quality.     

Kinetic Analysis of the Effect of Some Processing Factors on Changes in Color of Comminuted Meats during Processing

Changes in the psychometric color attributes lightness (L*), hue angle (H*) and chroma (C*) of porcine lean meat batters during processing were kinetically analyzed using the empirical approach of mathematical modeling. The changes during 24 hr storage at 15°C and during heating at 40°C, 50°C, and 60°C were fitted into a model and analyzed for the effects of air pressure during chopping, cutter type and enzyme inhibitors. For changes in L* and C* at 40°C, 50°C and 60°C such kinetic analysis was not possible. Among the factors studied, “air pressure” had the greatest overall effect on color. The effect of “cutter type” was intermediate and that of “enzyme inhibitors” least. The effects found could be ascribed to changes in absorption and scatter properties of the meat batters.     

Effect of Temperatures on Fish Alkaline Protease, Protein Interaction and Texture Quality

The effect of the activity of fish alkaline protease and protein denaturation on texture changes in mullet muscle during heating were studied. The proteolytic enzyme and the urea denatured hemoglobin substrate were incubated at different pH values and various temperatures. The enzyme activity was optimal at pH 8 and at 65°C. The extent of protein-protein interactions in mullet actomyosin solutions increased with increasing temperature. The rate of protein-protein interactions increased sharply as temperature increased from 35°C to 45°C at pH 6. When mullet muscle was heated at various temperatures ranging from 55°-85°C, the shear force value increased (toughening) during the initial stage of heating and then decreased (softening). The toughening of fish flesh is probably due to muscle protein interactions, and the later tenderizing of fish flesh may be explained by alkaline protease activity (hydrolysis) masking the protein denaturation effect. When fish flesh was cooked at 100°C, no tenderizing effect was observed. This was probably due to loss of enzyme activity and only protein denaturation had significant effect on texture quality.     

Microstructure of Reduced Salt Meat Batters as Affected by Polyphosphates and Chopping Time

Microstructural and textural changes due to salt reduction (2.5% to 1.5%), 0.4% tripolyphosphate (TPP), hexametaphosphate (HMP) or sodium acid pyrophosphate (SAPP) addition and chopping time (40 vs 100 cutter revolutions) were studied in poultry meat batters. Salt reduction significantly increased liquid and fat losses in the long chopping but not in the short chopping treatments. Scanning electron micrographs of reduced salt batters revealed fat globules which lost fat during cooking. HMP and SAPP addition significantly improved emulsion stability. Average fat globule size decreased as chopping time increased and/or salt decreased. Hardness was higher in the NaCl treatments in the short chopping as compared to the long chopping. The opposite was observed when phosphates were added.     

剪切时间对肉糜中微粒分散特性的影响

为形成乳化性良好的肉糜,研究不同剪切时间对肉糜中脂肪微粒粒径的影响。实验以猪背最长肌和背膘为原料肉,在3000r/min剪切速率下分别斩拌1、3、5、7min制成生肉糜,利用激光粒度分析仪测定不同剪切时间下肉糜中脂肪微粒大小和粒度分布特点。结果显示：剪切5min和7min条件下,肉糜中脂肪微粒粒径比较小、粒度分布集中,且无显著性差异。     

Thermal Denaturation and Aggregation of Actomyosin from Atlantic Croaker

The denaturation of croaker actomyosin was studied with respect to the important role of coagulation and gelation phenomena in the manufacture of gel-type meat and fish products. Measurements of turbidity (A₆₀₀), viscosity, calcium ATPase activity, total sulfhydryl groups and protein coagulation of croaker actomyosin solutions during heating at a constant temperature increase of 1°C/min revealed no loss of enzymic activity nor evidence of protein aggregation prior to reaching a temperature of 37–40°C, at which point the protein coagulated with corresponding loss of ATPase activity and sulfhydryl groups and an increase in turbidity. The degree of protein coagulation was highly dependent on the protein concentration. An observed increase in the apparent viscosity over the 30–35°C temperature range was postulated to result from interaction of protein molecules due to noncovalent forces.     

Effects of pre-heating temperature and formulation on porosity,moisture content,and fat content of fried batters

The effect of pre-heating temperatures on moisture and fat contents, and porosity of fried batters was studied. Batter pre-heated at 60 °C showed higher moisture content, lower fat content and lower porosity than non-pre-heated batter and batters pre-heated at 70 and 80 °C. Moisture content, fat content, and porosity at 4 min frying for batters with different pre-heating treatments ranged from 35.08 to 39.37, 3.92 to 5.16, and 13.14 to 45.31 %, respectively. Because of significant reduction in fat content, 60 °C pre-heating temperature was chosen to study the effect of batter formulations on moisture and fat contents, and porosity. Different wheat to rice flour ratios were prepared, and then each batter was pre-heated at 60 °C. Batters with higher wheat flour content showed higher moisture content, and lower fat content and porosity than batters with higher rice flour.     

DSC study on the influence of meat source, salt and fat levels, and processing parameters on batters pressurisation

 Hydrostatic high-pressure/temperature treatments were conducted at low (10 °C) and high temperatures (60, 70, and 80°C) on different types of meat batters. Pressure-induced effects on proteins were intensified by sodium chloride molarity at low and high temperatures. Treatments at 10°C under pressurisation yielded net thermal destabilisation effects on meat proteins pertaining either to muscle or batter systems. Heating at usual cooking temperature of 70°C under pressure yielded net stabilising effects on meat batter proteins. Overheating at 80°C was needed for entire protein denaturation. Pork and chicken meats were very similar in behaviour but chicken batters exhibited relatively higher thermal- and pressure-induced protein denaturation. Both kinds of physical destabilisation/stabilisation of proteins by pressure-induced effects increased with pressure level. Received: 30 December 1999 / Revised version: 14 February 2000     

Optimizing palm oil and palm stearin utilization for sensory and textural properties of chicken frankfurters

This study was designed to explore the potential of refined, bleached and deodorized (RBD) palm oil (PO) and palm stearin (POs) utilization in chicken frankfurters. A 10 points augmented simplex-centroid design was used to study the effect of chicken fat (CF), PO and POs as well as the interaction of these fats on the emulsion, textural and sensory properties of chicken frankfurters. All frankfurters were formulated to contain approx 25% fat, 52% moisture and 10% protein. No significant difference was found in end chopping temperatures of all meat batters even though the temperature of PO and POs upon incorporation into meat batters was 50°C higher than CF. Strong emulsions were formed as no fluid losses were observed in all the meat batters tested after heating. Texture profiles of the frankfurters containing PO and/or CF were quite similar, but increment of POs raised hardness, chewiness, and shear hardness of the frankfurters. Acceptability of the frankfurters was evaluated using hedonic test. Panelists found no difference in hardness preference between frankfurters made from totally CF and PO, while frankfurters made from POs were rated as hard and brittle. CF was important in determining acceptability of the frankfurters, as reduction of CF in formulation resulted in lower scores in chicken flavor, juiciness, oiliness and overall acceptance of the frankfurters. Frankfurters with sensory acceptability comparable to a commercial one were found to comprise of more than 17% CF, and less than 67% PO and 17% POs of the fat blend.     

Presalting effects on water retention of pork and beef batters

Presalting effects were studied by measuring cooking loss as a function of chopping time for pork and beef batters. Presalting (ground meat/salt/water = 100/3/20, by weight, 24h) as compared with direct salting in the chopper, substantially reduced the cooking loss of pork batters, but only when the batters were relatively coarsely chopped. With more extensive chopping (exceeding 10–15 min at low chopper speed) no presalting effects were found, indicating that salt diffusion, protein dissolution and myofibril swelling were completed also in control batters salted in the chopper. Presalting of beef had a much weaker, although similar, effect on water retention properties.The practical implications are that presalting may help in reducing cooking loss of coarsely comminuted sausages, particularly pork products. Presalting, however, has no beneficial effect on finely comminuted, bowlchopper-produced sausages.     

Effects of Collagen and Alkaline Phosphate on Time of Chopping, Emulsion Stability and Protein Solubility of Fine-Cut Meat Systems

Four meat emulsions were prepared with two levels of collagen and alkaline phosphate. Samples were taken at five different chopping temperatures and evaluated for total chopping time, emulsion stability and protein solubility. Adding additional collagen to meat emulsions shortened total chopping time, and decreased emulsion stability but had no effect on protein solubility. The addition of 0.25% sodium tripolyphosphate (STPP) improved emulsion stability but resulted in no significant (p>0.05) change in chopping time or protein solubility. The high-collagen-phosphate (HCP) treatment resulted in less fat, gelliquid, solid and total cookout when compared with high-collagen no-phosphate (HC) and low-collagen no- phosphate (LC) treatments. Maximum emulsion stability was obtained at 13°C.     

A comparative quality appraisal of finely comminuted batters produced using three types of knives

The aim of this study was to compare the work efficiency of three types of knives mounted successively on a knife roll of a cutter by evaluating the quality and structure of produced finely comminuted batters as well as power consumption and electric energy consumption during chopping. Experimental material comprised finely comminuted meat batters produced under commercial scale production conditions using smooth knives, knives with riffles and knives with holes. Parameters measured in batter included temperature, water, fat, free water, apparent viscosity, thermal drip and batter structure using computer image analysis.