Effects of salt reduction on the rheological and gelation properties of beef, pork and poultry meat batters

The gelation and rheological properties of beef, pork and poultry meat batters as affected by salt reduction (2·50, 1·25 and 0·00%) were studied by using a Haake rotational viscometer and a thermal scanning rigidity monitor. Beef batters showed a decrease in shear stress with the decrease in salt levels at both high and low shear rates. Pork batter showed a mixed behavior (no definite trend in shear stress versus shear rate) and the poultry meat batters showed a Bingham pseudoplastic behavior, except for the no-salt treatment. During heating the beef batters showed the highest G values followed by the pork and the poultry meat batters. The rigidity modulus profiles exhibited two major transition temperatures at 47-53°C and at 64-76°C. Beef batter with 2·50% salt developed the highest average G value (16·6 kPa) and the poultry batter with 2·50% salt the lowest (7·3 kPa).     

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.     

食盐与高温对猪肉糜品质的影响

本文研究不同食盐添加量与高温蒸煮对猪肉糜品质的影响。通过对猪肉糜的蒸煮得率、色泽、质构、流变等进行分析,研究不同食盐添加量(1%、2%、3%)和蒸煮高温(105、115和125 ℃)对猪肉糜品质的影响。结果表明:随着温度的升高,相同食盐添加量猪肉糜的a*值、b*值显著升高(p<0.05),L*值、蒸煮得率、弹性、内聚性下降显著(p<0.05);相同温度下,1%食盐处理组的L*值最小,a*值和b*值最大;3%食盐添加量显著提高(p<0.05)蒸煮肉糜的硬度、弹性和内聚性。加热到105 ℃以后,随着温度升高不同食盐添加量猪肉糜的储能模量(G')呈下降趋势,3%食盐添加量猪肉糜的G'最高。综上所述,高温能够降低猪肉糜的品质,3%食盐添加量在105 ℃时猪肉糜的品质最佳。     

OXIDATIVE STABILITY, COOKING YIELD AND TEXTURE OF PORK TREATED WITH A LOW-SODIUM SALT

The effect of a low-sodium salt mixture (LSSM) on the characteristics of cooked ground pork was investigated. LSSM, similar to NaCl, exhibited a minor but definite prooxidative effect in the system examined. The cooking yield of meat containing 1% LSSM was 69.8% compared to 74.3% for 1% NaCl. The cooking yields of samples with 2 and 3% LSSM were similar to those containing 2 and 3% of NaCl, respectively (p > 0.05). Maximum shear force values of samples containing 1% LSSM and 1% NaCl were similar. However, the maximum shear force values of meats treated with LSSM at 2 and 3% LSSM (19.1 and 24.8 kg) were lower (P < 0.05) than those containing 2 and 3% NaCl (21.9 and 27.0 kg). Addition of LSSM or NaCl to ground pork also enhanced the cooking yield and firmness over those containing no salt. The color characteristics of cooked pork remained generally unaffected by LSSM.     

CONDUCTIVITIES AND OHMIC HEATING OF MEAT EMULSION BATTERS

The conductive nature of meat emulsions and their ohmic heating rates were investigated by examining model and commercial meat batters. Results indicate that salt or other electrolytic ingredients were essential for ohmic heating, and for a given batter, an increase in salt content increased electrical conductivity and increased ohmic heating rate (P<0.001). Conversely, an increase in fat content caused a reduction in conductivity (P<0.001) leading to an increase in ohmic heating time (P<0.001). Results of a study examining the impact of nonelectrolytic dry ingredients, such as spices, potato starches and soya protein isolates on the conductivity and ohmic heating rates of emulsion batters was inconclusive and further work is needed before definite conclusions can be made in this regard. Overall results suggest ohmic heating could be used for cooking meat batters but would not be as effective for cooking meats to which no salt or other electrolytes have been added.     

Phosphates and antioxidants as cryoprotectants in meat batters

The gelation and rheological properties of minced beef frozen and stored at -18°C for 6 months without additives, with salt (1·5% NaCl), tripolyphosphate (TPP 0·5%), sodium acid pyrophosphate (SAPP 0·5%) and an antioxidant mix (BHA + BHT, 200 ppm) were studied. The relationships between shear rate and shear stress for the different treatments were nonlinear and resembled the Bingham pseudoplastic behaviour. Continuous evaluation of the modulus of rigidity (G) during cooking (0·5°C/min) revealed higher G values for the unfrozen phosphate treatments. Salt addition resulted in significantly lower G values of the stored meat compared to the control. Antioxidant addition retarded some of these effects. Among the phosphates, TPP was the best in maintaining the same G values as the control. Water-holding capacity (after salt addition) was increased after phosphate addition in the unfrozen meat and did not change after storage. The control, NaCl and antioxidant treatments showed an increase in WHC during storage.     

鹰嘴豆分离蛋白对减盐猪肉糜凝胶品质的影响

为探究鹰嘴豆分离蛋白(chickpea protein isolate, CPI)不同添加量对2种盐含量(质量分数1.4%和2%)猪肉糜凝胶品质的影响,将猪瘦肉与猪背膘斩拌成肉糜,分别设置不同盐含量和鹰嘴豆分离蛋白的处理组并加热制成凝胶。测定猪肉糜凝胶的色泽、乳化稳定性、质构、水分分布和流变特性。结果表明,在不添加鹰嘴豆分离蛋白的条件下,1.4%食盐质量分数的猪肉糜凝胶的汁液流失和硬度值显著高于2%食盐浓度的猪肉糜凝胶;相同食盐浓度条件下,随着CPI添加量的增加,猪肉糜凝胶的a^*值、b^*值、硬度、弹性、咀嚼性以及不易流动水比例均显著增加(P<0.05),动态流变储能模量G′值升高,汁液流失率显著降低(P<0.05),并在CPI添加量为1.2%时达到最大值或最小值;在相同CPI添加量条件下,1.4%食盐1.2%CPI的猪肉糜凝胶的储能模量G′值高于2%食盐1.2%CPI的猪肉糜凝胶,且2组凝胶的不易流动水比例、乳化稳定性、质构特性无显著差异(P>0.05)。综上,鹰嘴豆分离蛋白的添加能够在降低食盐用量的同时提升猪肉糜的凝胶品质...     

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.     

Effects of Sodium Chloride Reduction and Polyphosphate Addition on Clostridium Botulinum Toxin Production in Turkey Frankfurters

Mechanically deboned turkey meat emulsions were made with 1.0, 1.5, 2.0, 2.5, or 3.0% salt (NaCl), or with combinations of 1.5% or 2.0% salt with 0.4% sodium tripolyphosphate (TPP), sodium hexametaphosphate (HMP), or sodium acid pyrophosphate (SAPP). Sodium nitrite levels were constant at 150 ppm. Emulsions were inoculated with a mixture of 10 strains of C. botulinum (10³/g) and incubated at 27°C. Increasing NaCl content from 1.0% to 3.0% delayed toxin production by 3 days on the average. Toxin production was detected earlier when TPP was added, HMP had no effect, and SAPP delayed toxin production.     

Effect of salt content on gelation of normal and wooden breast myopathy chicken pectoralis major meat batters

This study investigated the effects of salt content (0–4%) on water holding capacity (WHC), textural characteristics, rheological properties, and microstructure of cooked normal (NOR) and wooden breast (WB) chicken meat batters. Results indicated with 0–2% salt addition, the WB batters had significantly lower WHC and storage modulus (G’) compared with the NORs (P < 0.05). However, these differences were eliminated when salt contents were increased to 3% or 4%. In addition, the NORs formed more regular and pored networks than the WBs (0–2%). Salt level significantly affected the textural properties of both batter types (P < 0.05). The hardness of the WB batters was lower than NORs at all NaCl levels (P < 0.05). Overall, compared with NORs, the WB batters showed inferior gelation properties at salt contents of 0–2%, while increasing salt content to 3–4% can improve the WHC and microstructure of gels.     

Effect of Heating Rate on Meat Batter Stability, Texture and Gelation

The effects of four heating rates (0.31, 0.51, 1.22, and 1.62°C/min) on the gelation, stability and texture of meat batters containing 2.5 and 1.25% salt were studied. In general, slower heating rates resulted in higher modulus of rigidity (G) values, and salt reduction resulted in lower G values. All the low salt treatments, except the 1.62°C/min treatment, showed a structural breakdown (above 67°C) when the scanning rigidity monitor was used. However, in the texture profile analysis (samples cooked to 50, 60 and 70°C) no structural breakdown was observed. Therefore, special care should be given to interpreting gelation profile results.     

大豆分离蛋白添加量对低盐木质化鸡肉糜凝胶特性的影响

探究大豆分离蛋白(soy protein isolates,SPI)添加量对低盐和正常盐木质化鸡胸肉糜凝胶特性的影响.实验设置正常鸡胸肉为对照组.将不同量(0％、1％、2％)SPI分别添加到含1％和2％食盐的木质化和正常鸡胸肉糜中,测定热诱导凝胶的质构特性、颜色、蒸煮损失、水分分布以及蛋白质二级结构等指标.结果表明:相...     

甲基纤维素添加量对低盐肉糜凝胶特性的影响

将甲基纤维素(methyl cellulose,MC)作为替代物加入肉糜中等量替代食盐,采用5个不同MC添加量(0％、0.4％、0.8％、1.2％、1.6％)即肉糜中的食盐质量分数分别为2％、1.6％、1.2％、0.8％、0.4％.通过测定肉糜凝胶的蒸煮损失率、色泽、质构、低场核磁共振横向弛豫时间(T2)以及流变特性,...     

Effect of Nitrite and Sorbate on Total Number of Aerobic Microorganisms in Chicken White and Dark Meat Patties

The effects of nitrite, sorbate and combinations of these two ingredients plus salt on the number of aerobic microorganisms in chicken white and dark meat patties were examined. All patties were stored at 4–5°C for 12 days. Nitrite concentrations of 400 and 2500 ppm were effective in preventing bacterial growth in chicken white meat patties while 2500 ppm was required to prevent growth in dark meat. A reduction in bacterial growth (4–10 days) was demonstrated with 100 and 150 ppm nitrite in chicken white meat patties. Four hundred ppm nitrite reduced bacterial growth in dark meat patties for 6 days. In white meat patties, the use of sorbate (0.26%) in combination with nitrite (40 ppm) was as effective in reducing bacterial growth as higher concentrations of nitrite, salt (2.5%) alone or in combination with sorbate (0.26%) or nitrite (40 ppm) inhibited bacterial growth in both white and dark meat patties during the first 4–6 days of storage.     

FLOW BEHAVIOR OF REGULAR AND PEANUT-FORTIFIED IDLI BATTERS

Regular and peanut-fortified idli batters showed shear-thinning behavior before and after fermentation. Fermentation increased batter viscosity and degree of shear thinning of regular and peanut-fortified batters. Fortification with defatted peanut flour (DPF) (up to 20%) significantly increased viscosity and the batters became more shear thinning at the 25–30% DPF fortification level.     

ATTRIBUTES OF BEEF SAUSAGE BATTERS, PATTIES AND RESTRUCTURED ROASTS FROM TWO BONING SYSTEMS

Sausage batters, patties, hot-set (HS) and cold-set (CS) roasts were processed from electrically stimulated hot-boned or nonstimulated cold-boned beef (two of the boning systems used in New Zealand) that had been held for 1 month at-18C (ESHBF or NSCBF) or at 0 to 1 C (ESHBC or NSCBC). Also, patties were made from 50:50 mixes of frozen and chilled ESHB or NSCB beef. Meat treatment did not affect the cook yield or shear stress and strain of sausage batters or the bind and extension of HS roast. Cook yield (P<0.001) and compressive strength were higher (P<0.05) for patties made from chilled or a mix of frozen and chilled meat than for those made solely from frozen beef. Cooking increased the bind strength but decreased the extension (P<0.001) ofCS roast. Meat storage temperature had more effect on beef products attributes than the boning systems.     

RHEOLOGICAL PROPERTIES AND APPLICATIONS OF MESQUITE TREE (PROSOPIS JULIFLORA) GUM. 1. RHEOLOGICAL PROPERTIES OF AQUEOUS MESQUITE GUM SOLUTIONS

The viscosities of aqueous mesquite gum solutions were measured at gum concentrations extending to 16.7% (w/v). Very dilute solutions exhibited typical polyelectrolyte behavior with respect to the influence of gum concentration on the reduced viscosity in the absence and presence of electrolyte. Shear thickening was exhibited at concentrations of 1–16.67% (w/v) when the shear rate exceeded ∼100 s⁻¹, whereas shear thinning was exhibited at lower shear rates. Shear thickening was attributed to configurational changes in the gum molecules at high shear rates. Electrolytes (0.1N NaCl and 0.1N CaCl₂) reduced the viscosity of concentrated solutions at high shear rates to a larger extent than increasing the pH. Charge screening by electrolyte permits the gum molecules to assume a more compact configuration.     

Effect of post-slaughter processing and freezing on the functionality of hot-boned meat from young bull

The effects of variation in the times of mincing post mortem (2, 4, or 6 h), pre-rigor salting (1.5% wt wt ) and freezing rate [fast (10 min, liquid nitrogen); medium (4-6 h at -40 °C and 0.8 m s(-1) air velocity); or slow (36-38 h at -10 °C and 0.1 m s(-1) air velocity followed by 12 h at -20 °C and 0.1 m s(-1) air velocity)] on the functionality of young bull meat were examined using hot-boned forequarters. At 52 h post packaging, the meat was thawed (72 h at 4 °C), its pH measured, and it was used to make finely comminuted batters. Cook yield and stress and strain of the cooked batters were measured. Time of mincing had no effect on meat pH, cook yield or stress and strain. There was a significant interaction (P < 0.05) between pre-rigor salting and freezing rate for pH. Freezing rate did not affect the pH of pre-rigor salted meat whereas the pH of unsalted pre-rigor meat was highest at the fastest freezing rate. Meat salted pre-rigor had a significantly (P < 0.05) higher pH than the post-rigor chilled control. Pre-rigor salting decreased the stress values of cooked batter whereas the slowest freezing rate increased stress. Stress and strain values for cooked batters from thawed meat were not significantly different from the values for batters made from the unfrozen control. Cook yields of batters made from pre-rigor frozen meat were higher than that of the postrigor control but not significantly so. The results indicate that suppliers can use pre-rigor salted and frozen meat when manufacturing comminuted products without major detrimental effects on the cook yield and texture of the finished product.     

IMPORTANCE OF FAT EMULSIFICATION AND PROTEIN MATRIX CHARACTERISTICS IN MEAT BATTER STABILITY

Finely comminuted meat products are a mixture of proteins, fat particles, water, salt and often carbohydrates. During preparation of the raw meat batter, fat is chopped into tiny particles which are thoroughly mixed within the comminuted lean meat. During cooking, the challenge is to minimize/prevent fat and moisture separation from the product. During the past 3–4 decades two major, but differently oriented, research thrusts have been presented to explain the mechanism(s) by which meat batters are stabilized. They include the emulsion theory and the physical entrapment theory. The first emphasizes the importance of fat emulsification (i.e., forming an interfacial protein film around the fat globules) whereas the physical entrapment theory stresses the importance of the protein matrix in binding the fat. The exact mechanism by which finely comminuted meat batters are stabilized is still uncertain. In this review arguments presented to support both research thrusts are discussed.     

TEXTURAL PROPERTIES AND COLOR CHARACTERISTICS OF RESTRUCTURED BEEF STEAKS WITH SELECTED BINDERS AND NOMEAT ADJUNCTS

Restructured steaks were evaluated using subjective and objective texture and color analyses. Treatments included: intact muscle, restructured steaks with no additives, salt/sodium tripolyphosphate (NaCl/STP), calcium alginate, crude myosin extract (CME) with 0.1% Nad and 0.4% STP [low salt & phosphate (LSP)], CME with 1.0 NaCl and 0.4% STP [high salt & phosphate (HSP)], surimi LSP and surimi HSP. Restructured steaks made from CME (HSP) or surimi (HSP) exhibited superior (P < 0.05) sensory textural evaluation, tensile strength values, cooking loss properties, color and color stability (subjective and objective) when compared to other restructured steaks except CME (LSP) and NaCl/STP (in some parameters). Restructured steaks made with CME or surimi in combination with 1% NaCl and 0.4% STP improved or maintained textural properties as well as color and color stability of restructured steaks.