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).     

Use of dairy proteins in lean poultry meat batters – a comparative study

The use of dry whole milk, skimmed milk, caseinate, regular and modified whey, at 2% level (w/w) and with 2% additional protein level was studied in a chicken breast meat system with 51% water addition. At the 2% (w/w) level, all dairy proteins significantly reduced cooking loss compared with the control, with caseinate showing the best results. When compared on an equal protein level (2% total protein), the best performing ingredients were the whole milk and modified whey. A similar observation was made in their effect on the products’ hardness and fracturability. A cost analysis revealed that modified whey provided the most economical ingredient even when used in quantities three times greater than that of as caseinate. Microscopy results showed the formation of larger fine‐protein‐matrix regions in the treatments that provided higher fracturability values.     

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...     

Thermal gelation of meat batters as a function of type and level of fat and protein content

The rheological behaviour of meat batters during heating was analysed as a function of protein level (10–16%), type (pork back or perirenal/peritoneal fat) and amount (10–22%) of fat used. Fat thermal behaviour was studied by differential scanning calorimetry and rheological properties of batters were assessed using non-destructive measurements (thermal scanning rigidity monitor). The higher the protein content, the higher were the rigidity values displayed by the batters, irrespective of fat type, although the magnitude of these values appeared to be dependent on the amount and characteristics of the fat. The lower the fat content, the lower were the rigidity values of the batters. This behaviour pattern was influenced by the amount of protein present. In general, samples containing perirenal/peritoneal fat exhibited lower rigidity values at high temperatures, whereas at less than 35–40 °C, the opposite appeared to be the case.     

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 regular and hydrolysed dairy proteins on texture,microstructure and colour of lean poultry meat batters

The use of 2% milk protein isolate (MPI), and some of its fractions which included caseinate, whey protein isolate (WPI), two whey protein hydrolysates (5.2% and 8.5%; WPH‐I and WPH‐II respectively) and β‐lactoglobulin (β‐lac) was evaluated in lean chicken breast meat batters. Adding caseinate and MPI resulted in the highest fracture force values, and caseinate also provided higher yield compared with the control. Both proteins were observed to form distinct protein islands embedded within the meat protein matrix, which appeared to enhance the gel structure. The two hydrolysates provided the highest yield compared with all other treatments. However, adding WPH‐II also resulted in the lowest fracture force and hardness values, while WPH‐I provided similar values to the control. The low hardness value could be explained by the light micrograph which showed WPH‐II interfering with the binding of the meat proteins. The WPI and β‐lac provided similar yield, fracture and hardness values as the control. The colour of the products was most affected by the WHP‐I and WHP‐II; both resulted in lower lightness, yellowness and overall spectra reflectance curves. A cost analysis revealed that caseinate addition was the most economical in this lean meat system.     

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.     

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.     

Effects of levels of fat,surimi from sardine (Sardina pilchardus) and heat processing on thermal gelation of meat batters

The object of the study was to analyse the Theological behaviour occurring during heat-induced gelation (measured by thermal scanning rigidity monitor) of meat batters containing various proportions of fat (48, 106, 147 and 208 g kg^?1) and sardine surimi (0, 100, 200 and 300 g kg^?1 fish protein added with respect to total protein present) and subjected to different heat treatments (A, heating from 14 to 76?C at a rate of 1?C min^?1; B, gradual temperature increase at a rate of 1?C min^?1 up to 40?C, maintenance at this temperature for 30 min, then heating from 40 to 76?C at 1?C min^?1; C, samples kept at 4?C for 20 h and then heated in the same way as process A). The results indicate that differences in levels of fat content significantly affect the gelation patterns of pork batters, gels being stiffer the higher the fat content and the lower the water content. A highly significant correlation (r = 0.78, P < 0.01) has been established between fat content and maximum values of G, which occur at the final experimental temperature of 76?C. In contrast, in general, neither addition of surimi nor variation in the heat treatment applied has any major effect on the gelation process in the system as formulated.     

Rheological changes during thermal gelation of meat batters containing surimi from alaska pollack (Theragra chalcogramma) or sardine (Sardina pilchardus)

The objective of this study was to use a thermal scanning rigidity monitor to analyse the changes occurring in rheological behaviour during thermal gelation induced by the presence of surimi in meat batters. These studies were conducted on systems prepared with pork meat to which varying proportions of surimi from Alaska pollack (Theragra chalcogramma (Pallas)) or sardine (Sardina pilchardus) (Walb) were added. The results indicated that gelation in pork proteins did not occur in the same way as in fish proteins. Whereas the addition of Alaska pollack surimi to the meat preparations produced scarcely any change with respect to the meat alone, the sardine surimi caused major alterations. These changes depended upon the proportion of protein from surimi added: addition of 100 g kg^?1 caused a protein matrix to form, inducing the formation of stiffer gels and the appearance of the setting phenomenon, although at higher temperatures than are found with fish proteins. Such behaviour was not apparent when the proportion of protein from surimi was raised to 200 g kg^?1.     

Changes in lightness of porcine lean meat batters during processing

The pattern of changes of lightness (L^*) for porcine lean meat batters (PLMBs) with time was divided in two phases: chopping process (Phase 1) resulting in a sharp increase of L^*, and the subsequent storage of the batters for 24 h at 15°C (Phase 2). During Phase 2, L^*-values decreased with time approximating a plateau. The subjects of study were effects on the course of L^* of: (1) added sodium chloride and phosphate in Phase 2, (2) the fate of air bubbles embedded in the batters in Phases 1 and 2, and (3) changes in light absorption by the pigment myoglobin in Phase 2.

(1) Sodium chloride and phosphate appeared to have very little impact on the changes in L^* during storage of the PLMBs at 15°C, although microstructural changes were distinct.

(2) Continuous entrapment of air during the chopping process had a major effect on the increase of L^* in Phase 1, air bubbles being scattering elements in the PLMB. Disproportionation caused a decrease in the number of small air bubbles, resulting in a decrease of L^* during the early stage of Phase 2 (about 35 min), immediately after the chopping stage was finished.

(3) Strong evidence was obtained that shifts in the absorption traits of pigments (red nitric oxide myoglobin was formed at the cost of grey met-myoglobin) during the period from 1 to 5 h, caused a marked decrease in the pattern of L^* during Phase 2.     

Characteristics of meat batters with added native and preheated defatted walnut

Effects of incorporation of native and preheated defatted walnut on the physicochemical, emulsifying and rheological properties of meat batters, as affected by final heating temperature were investigated. Replacing meat protein with native defatted walnut in meat product formulations reduced (P < 0.05) gel strength and emulsifying properties and hence the firmness and stability of meat batters but enhanced water- and fat-binding properties and hence the yield of a processed meat product. However, incorporation of preheated defatted walnut, in addition to improving (P < 0.05) water- and fat-binding properties during thermal treatment, improved the gelling ability of myofibrillar proteins, probably because the preheating of the defatted walnut promoted interactions between walnut proteins and muscle proteins.     

Streptococcus parauberis associated with modified atmosphere packaged broiler meat products and air samples from a poultry meat processing plant

Lactic acid bacteria (LAB) isolated from marinated or non-marinated, modified atmosphere packaged (MAP) broiler leg products and air samples of a large-scale broiler meat processing plant were identified and analyzed for their phenotypic properties. Previously, these strains had been found to be coccal LAB. However, the use of a 16 and 23S rRNA gene RFLP database had not resulted in species identification because none of the typically meat-associated LAB type strains had clustered together with these strains in the numerical analysis of the RFLP patterns. To establish the taxonomic position of these isolates, 16S rRNA gene sequence analysis, numerical analysis of ribopatterns, and DNA-DNA hybridization experiments were done. The 16S rRNA gene sequences of three isolates possessed the highest similarities (over 99%) with the sequence of S. parauberis type strain. However, in the numerical analysis of HindIII ribopatterns, the type strain did not cluster together with these isolates. Reassociation values between S. parauberis type or reference strain and the strains studied varied from 82 to 97%, confirming that these strains belong to S. parauberis. Unexpectedly, most of the broiler meat-originating strains studied for their phenotypical properties did not utilize lactose at all and the same strains fermented also galactose very weakly, properties considered atypical for S. parauberis. This is, to our knowledge, the first report of lactose negative S. parauberis strains and also the first report associating S. parauberis with broiler slaughter and meat products.     

High pressure/thermal treatment of meat batters prepared from freeze-thawed pork

Various meat batters were prepared from pork subjected to different freeze–thaw cycles. These batters were pressurized (300 MPa, 30 min) at low, non-denaturing temperature (10°C) followed by heating (70°C) (PLT+H) and at high, denaturing temperature (70°C) (HUPC). Nonpressurized (NP), heated-only (70°C) sample were also produced. Freezing of meat influenced water binding and textural properties of meat batters; the influence on texture was affected by thermal and pressure conditions. Pressure prior to heating produced a coarse, irregular and loose protein matrix, favoring the formation of weaker gel structures than were found in non-pressurized samples. Pressurization at denaturing temperatures reduced the level of protein denaturation induced by the thermal treatment. The resulting gel structures had better water binding properties but were weaker than non-pressurized samples and samples pressurized prior to heating.     

Color compensation in nitrite-reduced meat batters incorporating paprika or tomato paste

BACKGROUND: Nitrite is a key ingredient the manufacture of meat products, forming a stable pink color characteristic of cured products, retarding the development of rancidity and off‐odors and flavors during storage, and preventing microbial growth. The negative aspects of nitrite and the demands for healthy foods result in the need to reduce nitrite in cured meat products. Paprika or tomato has been employed as natural pigments in meat products. The objective of this work was to determine the effect of incorporating paprika powder or tomato paste on the texture, rancidity and instrumental and sensory color compensation in nitrite‐reduced meat batters. RESULTS: Addition of tomato paste improved moisture content, resulting in harder but less cohesive samples as compared to control and paprika‐containing meat batters. Color characteristics of reduced nitrite samples obtained higher a* red coloration (8.9 for paprika and 7.7–8.0 for tomato paste), as compared to control samples (5.65). Instrumental color was low in control samples, with high values for tomato paste and paprika samples. Nonetheless, tomato paste used to compensate color in nitrite‐reduced meat batters was ranked closer to the control sample in sensory evaluation. CONCLUSION: Color characteristics—instrumental and sensory—in these kinds of meat products were enhanced by the addition of 2.5–3.0% of tomato paste, presenting results close to the non‐reduced nitrite control. Similarly, antioxidant components of tomato paste or paprika reduced lipid oxidation. Nitrite reduction from 150 to 100 ppm could be achieved employing tomato paste as a natural pigment to improve color and texture. Copyright © 2011 Society of Chemical Industry     

添加含磷与非磷保水剂对牦牛肉肉糜保水性的影响

为了将不同水平的无磷保水剂海藻酸钠、柠檬酸三钠和乳酸钠分别加入牦牛肉肉糜中,研究其对牦牛肉肉糜持水力、蒸煮损失、离心损失和冻后失重率的影响,并与复合磷酸盐的保水效果做对比分析。结果表明:三种无磷保水剂都可以替代复合磷酸盐。柠檬酸三钠可以明显提高肉糜的持水力,当添加量为1.20%时,蒸煮损失和离心损失率最小;当海藻酸钠的添加量为0.20%时,离心损失和冻后失重率最小;当乳酸钠的添加量为0.20%时,持水力可提高约4%,蒸煮损失、离心损失和冻后失重率可降低约3%;复合磷酸盐的添加量为0.30%时,可产生良好的持水效果且肉糜的蒸煮损失也最小。      

添加含磷与非磷保水剂对牦牛肉肉糜蛋白质氧化的影响

以添加复合磷酸盐、乳酸钠和柠檬酸三钠作为保水剂制作牦牛肉肉糜,以不添加任何保水剂处理的为对照,通过测定牦牛肉肉糜色度值、表面疏水性、总巯基含量和羰基含量,探讨三种保水剂的抗蛋白氧化性,并比较三者抗蛋白氧化性的差异。实验结果表明:在4℃冷藏条件下,7 d贮藏期间,保水剂确实可以延缓肉糜的蛋白氧化,保水剂的种类显著影响牦牛肉肉糜中蛋白质的氧化程度(p<0.05);其中柠檬酸三钠对肉色的改善效果最佳,在第7 d时比其它组的色度值都低为1.26;复合磷酸盐对降低蛋白质表面疏水性的效果最好,在第7 d时表面疏水性为108.70 nmol/mg,仅比第1 d增加了12.73%;乳酸钠对保护蛋白质巯基和减少羰基生成的效果最好,在第7 d时与其它组相比巯基值最大为94.94 nmol/mg,羰基值最小为25.25 nmol/mg。本研究为减少肉制品中蛋白质氧化提供了新途径。      

Oxymyoglobin formation in meat and poultry

Display-packaged samples of beef steak and of ground beef were delivered to the homes of 120 panelists. Each panelist received a set of samples of each meat. Each set consisted of one sample freshly prepared for retail display from vacuum-packaged product, one retail-packaged and then stored in a master pack under N₂ and one retail-packaged and the stored under CO₂. The samples in each set were prepared from the same strip loin or batch of coarsely ground beef and had been stored for between 21 and 23 days at 2°C. The panelists completed questionnaires on the attributes of the meats while they were packaged, when they were unpackaged for cooking, and when they were eaten. The responses to each question were tabulated, and the probability of the χ² statistics was calculated for each table.

There were no significant differences in the general acceptability of the steaks from the three storage treatments. Significant numbers of panelists judged that ground beef prepared from vacuum-packaged product was of better colour and had less exudate, but was of poorer eating quality than the product from master packs. However, the majority of panelists did not distinguish between ground beef from the three storage treatments. The consumer responses indicate that controlled-atmosphere master packaging of display packs may offer a means of preserving display-ready beef for times that would allow wide distribution of the product through current commercial systems.     

Thermal gelation properties of surimi-like material made fromsheep meat

Thermal gelation properties of surimi-like material made from sheep meat were investigated. The sheep meat was ground, washed 3 times at a meat to water ratio of 1:5 and dewatered by centrifugation. The effects of washing on the composition, functional properties and colour of the mince, were studied. The washing method resulted in a sharp reduction of the fat content and an increase of the water content and pH of the mince. Lightness (L*) and yellowness (b*) of the mince were improved by washing. A significant reduction (p<0.001) of a* (redness) value and a decrease in the a*/b* ratios and saturation index value of the washed mince were recorded. Gels were prepared from washed and unwashed mince after being blended with 2% NaCl and heated at 75°C for 20 min. The washed mince produced excellent gels as measured by the fold test, elasticity modulus and the percentage recovery. The gels made of washed mince had lower expressible fluid compared to that of unwashed mince. A fibrous protein network structure was evidenced in the gel made from washed mince while observed under a transmission electron microscope.