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.     

肉品高效斩拌乳化技术研究进展

在肉制品加工中,斩拌乳化工艺主要起保水和保油作用。斩拌乳化效果主要受工艺参数和原辅料两方面因素的影响。在工艺方面,斩拌温度、斩拌速度、斩拌时间、物料pH等参数是乳化技术的关键参数;在原料方面,原料肉的种类、非肉蛋白、乳化剂、亲水性胶体等因素直接影响乳化效果。本文重点综述了肉品斩拌乳化技术在这两个方面的研究进展。     

A novel fiber optic sensor to monitor beef meat emulsion stability using visible light scattering

Accurate control of the meat emulsification process for a consistent product quality entails the development of an on-line optical sensor technology to determine the optimum chopping end-point yielding minimum cooking loss and a fine texture. Previous studies suggested that light backscatter measurements can be used to monitor physical-chemical changes during emulsification in comminuted meat products if appropriate spacing between the emitting and detecting optical fibers is used. Light backscatter intensity from beef emulsions manufactured with different fat/lean ratio (0.075, 0.250, and 0.330) and chopping duration (2, 5, and 8min) were obtained using a dedicated fiber optic prototype. Optical measurements were collected at three radial distances (2, 2.5, and 3mm) from the light source using a fiber optic spectrometer (300-1100nm). Light backscatter intensity decreased logarithmically with increasing fiber optic spacing. Light propagation through the emulsion decreased significantly with increasing chopping duration and fat concentration. Cooking loss increased with increasing fat/lean ratio and with under- or over-chopping. The maximum emulsion stability was observed at 5min of chopping. Several optically derived parameters were found to be significantly correlated with fat loss during cooking. Typically, those correlations were observed to increase with decreasing fiber distance. Based on these findings, an optical configuration is proposed that would compensate for the emulsion heterogeneity, maximizing the existing correlation between the optical signal and the emulsion quality metrics.     

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。     

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.     

Optimization of the chopping process using at-line human evaluations and response surface methodology

The objective of this investigation was to test the hypothesis that it is possible to optimize processing conditions using Response Surface Methodology and human measurements, called sensory indicators, directly at the processing line. Chopping during the manufacture of meat emulsion was studied. The independent variables were process parameters: chopping duration (D), speed (S), temperature (T) and pressure (P). The effects of these four variables on a global index called chopping degree (CD) were determined. CD was calculated by the fusion of five sensory indicators via the implementation of the fuzzy sets theory. The statistical analysis showed that D and S had a significant influence on CD. Utilizing an economic compromise, optimum‐processing conditions for CD consisted of a speed of 2000 r.p.m. for duration of 3 min.     

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.     

Rheological and Water-Holding Properties of Comminuted Turkey Breast and Thigh: Effects of Initial pH

The effect of pH on properties of comminuted turkey breast and thigh was investigated by adding acid or base during chopping or dialyzing meat batters against buffers. Cooking yield was a function of meat pH and independent of pH-adjustment method. Thigh meat gels (pH 6.4) had higher cooking yield, held-water, and shear stress and shear strain at failure than breast meat gels (pH 5.9). Functional properties of breast meat adjusted to pH 6.4 during chopping were similar to those of thigh, whereas thigh adjusted to pH 5.9 remained different from breast. Rheological properties of breast meat gels did not increase when pH was adjusted by dialysis, suggesting that pH during chopping is important to rheological properties.     

Mechanisms of meat batter stabilization: a review.

Comminuted meat products are a complex mixture of muscle tissue, solubilized proteins, fat, salt, and water. The two theories that have been presented to explain meat batters stabilization are reviewed. The emulsion theory explains stabilization by the formation of a protein film around fat globules, whereas the physical entrapment theory emphasizes the role of the protein matrix in holding the fat in place during chopping and subsequent heating. However, some aspects of stabilization cannot be explained adequately by either one of these theories. In this article the role of meat proteins, aqueous phase, and lipid phase are examined in light of past and recent research findings.     

乳化肉制品保油保水性关键作用机制研究进展

斩拌和乳化处理对乳化肉制品的质构和保油保水性质起到决定性作用,但斩拌或乳化工序不合理均会造成出油、出水、结构松散等质量缺陷,因此如何提高产品质量是肉制品加工行业面临的关键技术难题。乳化凝胶稳定性涉及肌球蛋白聚集行为、热诱导凝胶及界面膜乳化-吸附行为,因此本文以蛋白质水合作用为切入点,综述了斩拌和乳化过程中肌球蛋白空间构象对乳化凝胶稳定性影响,并重点阐述斩拌阶段水合特征与肌球蛋白聚集体的空间构象对热诱导凝胶网络结构的影响,以及界面蛋白膜结构对乳化凝胶稳定性的影响。讨论乳化-吸附过程中肌球蛋白与水、脂肪和蛋白三者之间的交互作用,并明确界面蛋白膜结构、厚度和黏弹特性对乳化稳定性具有重要意义,从而完善乳化凝胶稳定机制。水凝胶具有良好的凝胶和乳化性质,因而作为动物脂肪替代物实现肉制品“降脂”的目的;并改善肌肉蛋白的流变特性和机械性质,从而提高肉制品打印能力,因此水凝胶应用到3D打印肉制品中将成为一种新的策略,进而改善肉制品的保油、保水和质构性质。     

Application of light extinction to determine stability of beef emulsions

One of the major concerns in the meat processing industry is the loss of emulsion stability resulting in cooking losses. An optical sensor technology to control the emulsification process would minimize this problem. The normalized light intensity (I_N) as a function of fat/lean ratio (R_FL; 0.075, 0.25, 0.33) and chopping time (CT; 2, 5, 8 min) were measured at three radial distances (2, 2.5, 3 mm) from the light source to calculate the optical density (OD) and the loss of intensity (I_Loss), using a fiber optic spectrometer. ANOVA results were highly significant for I_N, I_Loss. Normalized intensity decreased with increased chopping time as a result of emulsion homogenization, and with increased distance. Chopping time had a positive correlation with fat losses during cooking, which in turn had a negative correlation with I_N and I_Loss. These results suggest that light extinction spectroscopy could provide information about emulsion stability.     

功能大豆浓缩蛋白在乳化肉制品中的应用

<正> 高质量乳化肉制品的生产,取决于产品中能否形成赋予产品良好组织和咬感的功能性蛋白膜。具高强乳化能力和保水性的功能浓缩蛋白,就能起到辅助功能性蛋白膜生成的作用。具体来说,功能浓缩蛋白能提高产品的出品率、组织结构,并保持产品的口感和外观质量;与此同时,它更可减少真空包装出水的现象,有助于增加产品吸引力和延长货架期。本文将介绍生产优质乳化肉制品的基本工艺要点,以及如何利用功能性添加剂优化乳化工艺。     

剪切时间对脂肪微粒大小和肉糜品质的影响

为研究剪切时间对肉糜中脂肪微粒大小和品质的影响,研究分别测定4种不同剪切时间(1、3、5min和7min)下肉糜中脂肪微粒粒径大小和粒度分布特点、乳化稳定性和凝胶强度大小。结果表明,剪切时间为5min和7min的肉糜中脂肪微粒比较小、粒度均匀,乳化稳定性好,凝胶强度大,但这两处理组间差异并不显著(P>0.05)。因而,试验研究认为3000r/min剪切速度下剪切5min就可制成品质好的肉糜。     

斩拌速度和时间对乳化肠质构的影响

研究斩拌速度、时间与乳化型香肠质构之间的关系.采用响应曲面设计,选用斩拌速度和斩拌时间为试验因素,测定不同斩拌时间和速度下产品的硬度、弹性、内聚性、咀嚼性和回复性.结果表明,斩拌速度对乳化肠的硬度、弹性和回复性均有显著影响,斩拌时间对回复性有显著的影响,斩拌速度和斩拌时间的交互作用对硬度和回复性有显著的影响;斩拌速度为6 000 r/min,斩拌时间为9 min时,形成的乳化肠的硬度、弹性、内聚性、咀嚼性和回复性最佳,满足乳化肠质构的要求.     

肉品高效斩拌乳化技术研究进展(英文)

Effective emulsification technology was applied in meat processing to achieve water holding and oil stability in the meat products. The effects of chopping emulsification technology are mainly affected by factors, which was chopping parameters and raw meat materials. Chopping parameters such as chopping temperature, chopping speed, chopping time are crucial factors in chopping emulsification technology. While raw materials such as raw meat type, non-meat proteins, emulsifiers and hydrophilic gums are also important factors directly influencing emulsification. The paper mainly reviewed the advance on chopping emulsification technology in meat processing from aforementioned aspects.     

Extraction and characterisation of meat from the claws of freshwater crayfish using dense media

The purpose of this study was to investigate the effectiveness of a two‐phase (flotation and filtration) separation of claw meat from the shell of freshwater crayfish using dense media, and to evaluate modifications to physicochemical and functional properties of the recovered meat, which could be subsequently incorporated in value‐added commodities. The media used were 10% (w/w) brine, 30% glucose syrup and a 30:70 ratio of glucose syrup to 2, 5 and 10% brine, with specific gravities ranging from 1.08 to 1.16. Extraction recovery of food‐grade mince ranged between 33.3 and 43.5%, which compared favourably with that of the control (hand‐picked meat, 33.2%). Compared with the control, the meat recovered from the two phases (treated meat) was significantly firmer in texture, lower in moisture and pH and less bright in colour. Meat salt content was reflective of the salt concentration in the recovery medium used. The treated meat also had a significantly lower apparent emulsification (20%) and water‐binding (60%) capacity than the hand‐picked meat. Comparing the two extraction phases, filtration‐phase meat had a significantly lower emulsion capability, was less firm and was brighter in colour than flotation‐phase meat. © 2000 Society of Chemical Industry     

亚麻籽胶在乳化肠中添加方式的研究

为最佳地发挥亚麻籽胶在乳化肠中的应用效果,考察亚麻籽胶以不同的方式加入以及加入后斩拌时间对乳化肠水油渗出率、保水性、质构的影响。结果表明：亚麻籽胶的添加量为0.2g/100g和0.3g/100g时,以乳化物方式加入亚麻籽胶生产的乳化肠析水率显著低于以粉末方式加入的乳化肠（P〈0.05）;以乳化物方式添加亚麻籽胶的乳化肠水油渗出率低,但差异不显著（P〉0.05）。以乳化物方式加入亚麻籽胶的乳化肠硬度显著低于以粉末方式加入的乳化肠（P〈0.05）;对乳化肠的弹性影响差异不显著（P〉0.05）。在4℃贮藏期间,以乳化物方式加入亚麻籽胶的乳化肠更好地保持了其质构稳定性。以乳化物方式加入亚麻籽胶后,比较斩拌1、2、3min的乳化肠发现,斩拌3min的乳化肠贮藏期间质构稳定,持水持油性较好。     

斩拌条件和添加成分对肉糜类制品质量的影响

在肉糜类制品的生产加工中斩拌工序起着至关重要的作用,此工序的工艺参数稍有变化,就会对产品品质有很大影响。因此,对此工序的深入研究在提高产品品质方面显得尤为重要。本文从斩拌的作用、原理及对产品的影响效果等方面介绍了肉糜类制品加工中斩拌工序的研究进展。并着重探讨、总结了影响斩拌效果的因素及斩拌的最佳工艺参数。对于提高肉糜制品的品质,提供技术支持和理论指导具有一定的意义。     

Effect of comminution temperature on the quality and shelf life of buffalo meat nuggets

Buffalo meat nuggets were prepared after equilibrating the ingredients to temperatures of 4, 10, 25 and 37 °C. Following comminution for 6 min, the temperatures of the batters were 16.3, 19.3, 27.4 and 34.8 °C and their pH and emulsion stability ranged from 6.18 to 6.29 and 88.76 to 95.33%, respectively. Increasing temperature of comminution led to increased cooking losses and TBARS values. However, even at 37 °C, complete emulsion breakdown did not occur as the cooking losses were still only about 12%. Texture profile analysis revealed an inverse relationship between chopping temperature and shear force. Sensory evaluation indicated that, at least up to comminution temperatures of 27.4 °C, the nuggets were acceptable. The aerobic mesophilic bacterial counts were higher for the nuggets made from batters with higher temperatures but, even at the 21st day of storage, the counts were well below the levels likely to cause spoilage in meat products. Results suggested that comminuted buffalo meat products can be manufactured in conditions where refrigeration is not available, by a preservation system (mostly chemical) to decrease microbial and chemical spoilage and also by devising an efficient marketing system for their early distribution (preferably 14 days).     

冷鲜牛肉贮藏过程中线粒体变化与肌红蛋白氧化状态的相关性

为探索冷鲜牛肉贮藏过程中线粒体功能结构的变化,采用透射电子显微镜与原子力显微镜对线粒体内、外部超微结构的检测来确定贮藏时间对肌细胞线粒体变化的影响。结果发现：在4 ℃贮藏过程中（0～21 d）,Flameng线粒体评分从0.986 8升高到2.533 8,表明线粒体结构完整性逐渐降低;线粒体膜电位与线粒体呼吸控制率、ATP含量均呈极显著正相关,相关系数分别达到0.936、0.926（P＜0.01）,说明线粒体结构与功能之间关系密切;线粒体呼吸控制率与氧合肌红蛋白相对含量呈极显著正相关（r＝0.885）（P＜0.01）,线粒体膜电位与高铁肌红蛋白相对含量呈极显著负相关（r＝－0.902）（P＜0.01）,表明线粒体结构、功能变化与肉色稳定性有密切的关系。