Effect of salt and phosphate on the quality of Buffalo and Goat meats

A study was conducted on the effect on certain quality parameters of adding sodium chloride (2·5%) and tetrasodium pyrophosphate (1%) to hot minced buffalo and goat meats. The effects on buffalo meat were observed in chilled and frozen conditions, those on goat meat in hot and chilled conditions. These treatments significantly increased pH, water-holding capacity (WHC) and emulsifying capacity (EC) and decreased cooking loss in both types of meat. Chilled and frozen conditions did not affect buffalo meat quality but salt additions to hot minced goat meat were superior to such additions to chilled minced meat in respect of EC and the extraction of salt-soluble proteins. Buffalo meat had poorer WHC and EC than goat meat and salt additions had a greater effect in improving EC. With goat meat, the treatment resulted in an increased WHC with a greater increase in pH. Significant correlations were observed among quality parameters.     

Use of electrical conductivity to predict water-holding capacity in post-rigor pork

This study was designed to re-examine the interrelationships among ultimate pH (pH_u), electrical conductivity (EC) and water-holding capacity (WHC), and to test if EC, using one of two EC instruments, and pH_u can be used to predict WHC. The % drip (PD) was used as measure of WHC. Forty-seven pork loins were classified either as PSE (pale, soft, exudative), RSE (reddish-pink, soft, exudative), RFN (reddish-pink, firm, non-exudative) or DFD (dark, firm, dry), based on L* values, PD and pH_u. The measurement of EC, conducted using the instrument developed at the University of Wisconsin-Madison (UW-EC) was highly correlated to PD at 24 h post mortem (CD=66%), but the pH (NWK) measure of EC was not as highly related to WHC as UW-EC. The predictive value of pH_u and EC for WHC were similar. When 47 samples were divided into three different groups, such as low (< 2% drip), medium (2–6% drip) and high (> 6% drip) drip loss, UW-EC alone grouped 80% of the samples correctly. Thus, EC seemed to be an accurate predictor of WHC in pork muscle when measured at 24 h post mortem. It is conceivable that EC can be used independently, or with even better success in combination with pH_u, to classify WHC of pork carcasses.     

Evaluation of salt, polyphosphates and their blends at different levels on physicochemical properties of buffalo meat and patties

The effects of sodium pyrophosphate (SPP), sodium tripolyphosphate (STPP), sodium hexametaphosphate (SHMP), sodium acid pyrophosphate (SAPP) and their blends at different levels (0·3, 0·5 and 0·7%), along with 2% sodium chloride on certain quality parameters of buffalo meat and patties were evaluated. The SPP, STPP and phosphate blends significantly increased pH, water-holding capacity (WHC), emulsifying capacity (EC), extractability of salt soluble proteins (SSP), colour of ground meat, decreased cooking loss (CL), improved emulsion stability (ES) and enhanced yield, texture and moisture retention of cooked patties. Compared to these phosphates, SAPP and SHMP had significantly poorer effects on improving the quality of meat and patties. The order of effectiveness of phosphates was SPP > STPP > SHMP. In general, pH, WHC, SSP, ES, yield and moisture content of patties increased progressively with increasing level of phosphate while CL decreased. Among blends containing two polyphosphates, those of 90% SPP + 10% SHMP and 75% SPP + 25% STPP were relatively more effective. A phosphate blend consisting of 65% SPP, 17·5% STPP and 17·5% SAPP was equally effective as that of SPP in improving the functionality of hot and chilled meat and had the advantage of reducing the amount of sodium by 3%.     

Influence of Pre-Rigor Processing, Mechanical Tenderization, Tumbling Method and Processing Time on the Quality and Yield of Ham

Eight market weight hogs with similar genetic and management background were conventionally slaughtered with the resulting sixteen pork carcass sides randomly assigned to treatments. Four treatments at 2 levels each (2⁴ factorial design) included muscle condition [pre-rigor (hot) or post-rigor (chilled)], mechanical knife blade tenderization [no tenderization or tenderization], vacuum tumbling [continuous or intermittent], and the processing delay time between vacuum tumbling and further processing [no delay time or 20-hr delay]. Results indicated that pre-rigor processed meat tissue exhibited higher pH, water-holding capacity (WHC), and cooked yield characteristics. Mechanical knife blade tenderization consistently increased protein content of the uncooked meat exudate, cooked yield, and palatability characteristics. Tumbling method and processing time had little influence on either uncooked or cooked meat characteristics.     

QUALITY OF RESTRUCTURED PORK ROASTS AS INFLUENCED BY SALT, PHOSPHATE AND ROASTING ENVIRONMENT

A split plot design was used to evaluate the effect of 3 salt (0.0, 0.5, 1.0%), 3 phosphate (0.0, 0.25, 0.5%) levels and 2 roasting environments (moist, dry) on the quality of restructured pork roasts. Emulsion stability, yield (cooked or sliced), Instron adhesion (bind), pH, water holding capacity, proximate composition and color measurements were obtained. Increasing salt or phosphate level increased emulsion stability and cooked yield. Increasing salt level and the addition of phosphate decreased expressible moisture and increased slice count and moisture content. Increased levels of salt decreased protein content, while increasing phosphate, increased pH and redness in the cooked slices. Salt and phosphate reacted synergistically to increase slice yield and adhesion bind. Roasts cooked in a moist environment were lower in pH, were darker in color and required less time to cook. Restructured pork roast quality was enhanced when salt and phosphate were included in the formulation.     

添加猪皮提取物对猪肉糜香肠品质的影响

研究添加猪皮提取物对猪肉糜香肠品质的影响.采用单因素和正交试验,考察猪皮提取物添加量、猪肉糜香肠煮制温度和煮制时间对猪肉糜香肠的质构、系水力和感官品质的影响,确定猪皮提取物在一定配方的猪肉糜香肠中的最佳添加量及煮制工艺条件.结果表明:猪皮提取物添加量为6％、75℃煮制40min时,猪肉糜香肠质构特性、保水能力和感官品质最佳.     

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。     

The influence of mechanically deboned meat and pH on the water-holding capacity and texture of emulsion type meat products

The influence of the amount of mechanically deboned pork meat (MDM) on the quality of model 'Frankfurters' was studied, and the relationship between the pH of the blends versus the texture and water-holding capacity (WHC) of the finished products was investigated. In the experiments 2·9%, 5·8% and 11·6% pork loin were exchanged with MDM. It was found that addition of MDM increased the pH and the WHC, and that moderate addition of MDM resulted in greater yield stress and elasticity modulus, while higher concentrations of MDM resulted in very soft texture. The pH of the meat blends was very important for the functional properties of the pasteurized products. It made no difference whether pH was determined by the meat raw materials alone or adjusted through addition of NaOH or MDM.     

Effect of chilling applied to suckling lamb carcasses on hygienic, physicochemical and sensory meat quality

The effect of post mortem temperature treatment on suckling lamb carcass and meat quality was study. Conventional (2°C for 24h), ultra-rapid (-20°C for 3.5h, 2°C until 24h) and slow chillings (12°C for 7h, 2°C until 24h) were compared. Total viable counts (TVC), weight losses, and pH and temperature falls were recorded on carcasses. Meat colour, water holding capacity (WHC), Warner-Bratzler shear force, sarcomere length and sensory analysis were evaluated in M. longissimus. Ultra-rapid treatment reduced TVC and weight losses. The pH decline was faster in slow chilled carcasses than in faster chilled carcasses. No significant differences were found for colour and WHC. Slow treatment carcasses showed significantly lower shear force and higher sarcomere length. In the sensory analysis, tasters also rated the early post mortem slow-treated meat as more tender, less fibrous and chewy. Therefore, delay chilling in suckling lamb carcasses made it possible to obtain meat with better organoleptic characteristics, without affecting weight loss or hygienic quality.     

响应面法优化猪肉盐溶蛋白热诱导凝胶工艺的研究

研究pH值、NaCl、MgCl2和复合磷酸盐(MP)对猪后腿肉盐溶蛋白(SSP)提取率及热诱导凝胶的保水性(WHC)和凝胶强度(BS)的影响。通过数学模型的建立和响应面分析,确定制备热诱导凝胶的最佳工艺条件。结果表明,在pH6.7、NaCl 0.7mol/L、MgCl2 0.006mol/L、MP 2.5g/kg处理条件下,盐溶蛋白提取率为9.41%、凝胶保水性为86.13%、凝胶强度为86.50g。MgCl2与MP的交互作用显著增加盐溶蛋白的溶出率。各因素间的协同作用对热诱导凝胶的品质有显著影响。     

宰后放置时间和冷冻对中式香肠品质的影响

采用均匀试验设计,以宰后放置时间和是否冷冻为考察因素,以猪肉为原料进行香肠加工,探讨宰后放置时间和是否冷冻对香肠品质的影响规律。结果表明：宰后放置时间和是否冷冻对中式香肠的感官评分没有显著影响;对pH 值、原料肉系水力、生香肠的硫代巴比妥酸反应物(TBARS)值和出品率有显著影响,且均呈非线性关系。进行优化计算得到：当所选用的原料为冷冻肉时,暂未找到共同解;当所选用的原料为未经冷冻的肉样时,宰后冷冻时间越早,出品率越大,生香肠的TBARS 值越小。因而以鲜肉为原料制作香肠,所选原料越新鲜,香肠品质越好。     

低变温高湿解冻对猪肉理化特性、蛋白热变性及流变特性的影响

本研究以鲜肉和传统低温（4 ℃,相对湿度（relative humidity,RH）65%～73%）肉为对照,探究低变温（2 ℃→6 ℃→2 ℃）下,不同相对湿度（80%、85%、90%、95%）解冻对猪肉品质的影响,分析不同处理对肉样解冻效率、保水性、色泽、嫩度、新鲜度等理化特性、蛋白热变性及流变特性的影响。结果表明：相较于传统低温解冻,低变温高湿度可有效提高解冻效率,显著改善猪肉的保水性、色泽、嫩度,显著降低脂肪氧化程度（P＜0.05）;其中RH 90%、RH 95%条件下解冻效率明显高于RH 80%、RH 85%两组,能有效改善解冻后猪肉的保水性、色泽、嫩度,降低脂肪氧化程度,提高蛋白溶解性,维持猪肉较好的凝胶结构,且猪肉蛋白变性程度显著较低（P＜0.05）;但RH 95%处理组解冻后猪肉的菌落总数（3.97（lg（CFU/g）））和挥发性盐基氮含量（1.40 mg/100 g）显著高于其他组;且环境湿度越大,能耗就越高。因此低变温RH 90%可作为合适的猪肉解冻条件。     

高湿度结合不同温度解冻对猪肉理化及蛋白特性的影响

探究相对湿度（relative humidity,RH）90%下,不同温度（0、4、8?℃和12?℃）解冻对猪肉品质特性的影响,以鲜肉和传统低温（4?℃,RH?65%～73%）解冻肉为对照,分析处理组和对照组的解冻效率、保水性、嫩度、色泽、脂质过氧化、pH值、新鲜度的变化,并利用差示扫描量热仪和流变仪测定蛋白热变性及动态流变特性。结果表明：相较于传统低温解冻,高湿（RH?90%）、低温（0～12?℃）解冻可提高解冻效率,且解冻后猪肉的保水性、色泽、嫩度显著提高（P＜0.05）,明显抑制脂肪氧化程度,降低蛋白变性程度,可最大限度维持“鲜肉”的品质;其中,高湿环境下4?℃和8?℃解冻效果明显优于0、12?℃处理组,解冻后猪肉的保水性、色泽、嫩度得到改善,脂肪氧化程度降低,同时4?℃和8?℃解冻后猪肉蛋白变性程度较低,G′较高。因此RH?90%、4～8?℃解冻是较合适的解冻条件,该条件可提高解冻效率、维持猪肉品质。     

茶多酚和大蒜素在冷却肉涂膜保鲜中的应用

采用茶多酚、大蒜素与天然可食性膜溶液研制成涂膜保鲜剂进行冷却肉的涂膜保鲜研究。以感官指标、pH 值、挥发性盐基氮(TVB-N)和细菌总数为考察指标,通过L9(34)正交试验筛选出最佳比例组合,提高冷却肉的保鲜度和延长冷却肉的保鲜期。结果表明：0.7% 茶多酚、0.4% 大蒜素和乙种膜溶液(3% 可溶性淀粉、0.6% 海藻酸钠、0.2% 单甘酯)组成的涂膜保鲜剂,对冷却肉的涂膜保鲜效果良好。用此涂膜保鲜剂处理冷却猪肉,在0～4℃条件下贮藏保鲜19d 以上。     

Effect of high pressure and salt on pork meat quality and microstructure

The interaction of salt (0%, 1.5%, and 3% in the final product) and a high-pressure treatment (500 MPa, 20 °C, 6 min) was investigated using pork biceps femoris muscle. The Warner-Bratzler shear force and the water holding capacity (WHC) were assessed and linked to the microstructure evaluation by environmental scanning electronic microscopy (ESEM). Pressure-treated and cooked samples showed a high Warner-Bratzler shear force with a low WHC compared to control cooked samples. These negative effects could be linked to the general shrinkage of the structure as observed by ESEM. The addition of 1.5% salt was sufficient to improve the technological properties of the high-pressure-treated samples and to counteract the negative effect of high pressure on texture and WHC. This phenomenon could be linked to the breakdown in structure observed by ESEM. This study states that it is possible to produce pressurized pork products of good eating quality by adding limited salt levels.     

花椒提取物对调理猪肉饼冷藏期间品质的影响研究

探究不同添加量的花椒提取物对调理猪肉饼冷藏期间品质及氧化程度的影响。将0.01%、0.02%和0.03%的花椒提取物添加到调理猪肉饼中,研究其在1、4、7、10 d冷藏期间的pH、颜色、质构、硫代巴比妥酸值(thiobarbituric acid reactive substance,TBARS)和巯基值的变化,并与0.02%二丁基羟基甲苯(butylated hydroxytoluene,BHT)作比较。研究结果表明,添加花椒提取物对调理猪肉饼冷藏期间的pH、颜色无显著影响(p>0.05),在一定程度上降低了其硬度和咀嚼性。此外,添加花椒提取物可显著降低猪肉饼脂肪氧化和蛋白质氧化程度(p<0.05)。当添加量为0.01%和0.02%时,花椒提取物处理组抑制脂肪氧化的效果与0.02%的BHT效果相当,而当添加量增加至0.03%时,花椒提取物组抗脂肪氧化效果优于0.02%的BHT,且其蛋白氧化程度在整个冷藏期间均显著低于对照组(p<0.05),表明花椒提取物可有效抑制猪肉饼中脂肪和蛋白质氧化,其中0.03%花椒提取物组效果最好,甚至优于0.02%的BHT。     

Is colour brightness (L-value) a reliable indicator of water-holding capacity in porcine muscle?

A total of 265 pork carcasses representing a broad variation in quality was used to examine the relationship between colour (L-value) and water-holding capacity (WHC) in the longissimus thoracis et lumborum. Thirty-four samples appeared to possess 'normal' reddish pink colour (L-value 52·0-58·0) but had 'unacceptable' WHC (>5·0% drip loss). Conversely, 25 samples were pale in colour (L-value >58·0) but were 'acceptable' in WHC. When muscles were dark (L-value 52·0) the WHC was always acceptable. Some samples were subjected to further analysis. Variations in iron content, haematin content, sarcomere length and degree of soluble protein denaturation failed to explain why brightness and WHC were not more closely related. When L-value and WHC were compared to pH(45) (pH, 45 min post mortem), WHC exhibited a biphasic relationship to pH(45) whereas L-value did not. These results indicate that WHC and brightness are determined by independent pre-rigor biological phenomena, strengthening the argument that brightness is not necessarily a reliable predictor of WHC. Researchers selecting pork for specific investigations, or commercial companies using fresh pork for either further processing or for retail, should not rely on colour brightness alone to insure that other quality properties such as WHC and firmness will also be acceptable.     

斩拌初始温度对白鲢鱼糜物理特性的影响

斩拌是鱼糜制品生产中最重要的工序之一。以生鲜鱼糜和冷冻鱼糜为原料,考察加工过程中斩拌初始温度对生鲜鱼糜凝胶和冷冻鱼糜凝胶强度、保水性、折曲实验及色度的影响。结果表明：从凝胶强度的观点看,生鲜鱼糜斩拌适宜初始温度为5～15℃,从保水性的观点看,适宜初始温度为5～20℃;而冷冻鱼糜的适宜温度范围分别在1～15℃和5～20℃。综合考虑,5～15℃为鱼糜的最适斩拌初始温度。     

Evaluation of surimi, fat and water content in a low/no added pork sausage formulation using response surface methodology

Response surface methodology (RSM) was employed for simultaneous analysis of the effects of added surimi (0-40%), fat (5-30%) and water (10-35%), on the physical, textural and sensory characteristics of fresh breakfast pork sausages. Experimental design allowed for evaluation of potential interactive effects between these ingredients. Sausages were evaluated for texture, colour, water holding capacity (WHC) and sensory attributes. Three optimum recipes, R1 (25.3% surimi, 22.2% fat, 12.7% water, 25.3% pork), R2 (12.2% surimi, 5.5% fat, 38.7% water, 33.2% pork) and R3 (25.3% surimi, 6.3% fat, 28.5% water, 25.3% pork), were determined and these were evaluated against a full-fat commercial control (R4). Force values of R1 were not significantly different to R4, however, force values for R2 and R3 were lower (P<0.001). No significant differences were observed between R1, R3 and R4 for visual colour or sensory acceptability scores throughout the study, whereas scores for R2 were lower. Sensory analysis indicated that R2 had lower scores for texture (P<0.01), chewiness (P<0.01), acceptability (P<0.01), flavour (P<0.05) and preference (P<0.01). Results from this study suggest that it is possible to successfully replace pork meat with functional fish proteins in the manufacture of sausage type products.     

猪肉色泽和保水性的相关性研究

以猪瘦肉为原料展开猪肉色泽和保水性之间的相关性研究,一部分以来源于同一猪胴体的肉样为原料,另一部分采用从市场上随机抽样的样品为原料,研究肉样的保水性和肉色之间的相关性。结果表明：对于来源于同一个体的肉样而言,保水性与色泽无关;而来源于不同个体的肉样,加压系水力(WHC)与亮度(L 值)呈负相关,蒸煮损失与L 值和黄度(b 值)呈正相关,即L 越大,b 越大,保水性越差;在实验测定的范围内,pH 值与蒸煮损失呈负相关,与加压系水力呈正相关,表明pH 值越高的肉样,保水性越好;来源于同一个体的肉样,随着宰后时间的延长,其保水性有增强的趋势,表现为蒸煮损失与时间呈负相关,加压系水力与时间呈正相关。