Physical Characteristics and Microstructure of Reduced-fat Frankfurters as Affected by Salt and Emulsified Fats Stabilized with Nonmeat Proteins

Functional properties and microstructure of frankfurters containing 1.5% or 2.5% salt and 15% pre-emulsified fat (PEF) stabilized with 2% pea protein, soy protein, or sodium caseinate were studied. With the exception of frankfurters with pea protein and 1.5% NaCl, all the others made with PEF" had greater (p < 0.01) thermal stability than all-meat frankfurters. Frankfurters containing soy protein or sodium caseinate had greater (p < 0.01) shear force than those with pea protein. Reducing NaCl in the frankfurters containing PEF did not influence the shear force. Microstructure examination revealed that many fat globules were entrapped physically within soy protein or sodium caseinate, which stabilized the meat emulsions and contributed to a firmer texture. Key Words: emulsified fat, reduced-fat, low-salt, microstructure, frankfurters     

营养组合肉干成型工艺的优化

综合利用肉干碎末,采用组合技术生产新型肉干制品。以通用旋转组合试验分析了复合胶凝剂添加量、成型压力和脂肪添加量三因子及其交互作用对营养组合肉干成型的影响。分别建立了营养组合肉干的剪切力Y1、硬度Y2与复合胶凝剂添加量X1、油脂添加量X2、肉干成型时所需的压力X3的数学回归模型,并对三因子的最优组合进行了定量探讨。结果表明:营养组合肉干成型的最优生产工艺参数为:复合胶凝剂与油脂的添加量分别为10%和8%,肉干的成型压力约15kg。在此工艺条件下生产的营养组合肉干的剪切力较小(3.68kg),硬度适中(6.5kg/cm2),产品品质优良。     

不同母本西门塔尔杂交牛各部位肉品质与蛋白质功能特性的差异

为了研究西秦牛(西门塔尔牛×宁夏秦川牛)和西褐牛(西门塔尔牛×新疆褐牛)不同部位肉的差异性,对选取的牛腩、霖肉、牛腱子、黄瓜条、肩肉和臀肉6个部位肉样从营养品质、食用品质和蛋白质功能特性等多项指标进行探究。结果表明:西褐牛的牛腩保水性较好,肩肉的水分含量较高(78.75%)且脂肪含量较低(0.4%),霖肉的蛋白质含量较高(21.74%)且剪切力值较高(6.91 kg),牛腱子的胶原蛋白含量较高(22.24%);西秦牛的牛腩脂肪含量较高(5.19%),黄瓜条剪切力值较低(3.76 kg)。对肉中蛋白质功能特性进行研究,西褐牛的牛腩蛋白质乳化能力较强(15.67 mL/g),牛腱子蛋白质凝胶保水性较好(81.71%),臀肉蛋白质凝胶硬度较高(226 g);西秦牛的肩肉蛋白质乳化稳定性较好(76.34%),霖肉蛋白质凝胶弹性较高(0.61)。     

南阳黄牛不同部位肉品质特性差异分析

为探究南阳黄牛不同部位肉品质特性及加工适应性的差异，以24 月龄南阳黄牛的牛腩、牛腱、黄瓜条、肩肉和臀肉5 个部位为研究对象，分别从营养品质、pH值、剪切力、凝胶和乳化特性等方面进行分析。结果表明：相较于其他部位，肩肉水分含量（77.14%）最高，凝胶弹性最差，但pH值（5.82）最高，凝胶保水性（60.48%）最好，适宜肉糜类和烧烤类产品的开发；臀肉pH值（5.66）最低，解冻损失率（18.64%）最大，乳化稳定性（48.13%）最好，适合加工肉糜类产品；而牛腩硬度、咀嚼性、剪切力最高，嫩度较差，乳化稳定性（37.99%）最差，蒸煮损失率（34.88%）最大，但解冻损失较低，适合加工冷冻贮藏类和烧烤类产品；黄瓜条具有蛋白质含量（20.01%）较高，脂肪含量（0.71%）低的特点，且肉色鲜亮，蒸煮损失较小，适合加工蒸煮类产品；牛腱解冻损失率（6.55%）和蒸煮损失率（28.60%）最小，适合加工酱卤类产品。     

Influence of Corn Germ Protein on Yield and Quality Characteristics of Comminuted Meat Products in a Model System

Incorporation of corn germ protein in the production of comminuted meat products was tested. Corn germ protein (2%) as stabilizer in pre-emulsified fat (PEF) preparation stabilized sausage emulsions, which were added to the batter during comminution. Corn protein as an ingredient (4%) also increased both the stability of sausage batter (by binding of fat and water) and the yield of the finished product. There were no significant effects of the corn germ protein on hardness and color of finished product. Corn germ protein as a stabilizer in PEF and ingredient resulted in increased water holding capacity and adhesiveness of batter and lower shear force of the finished products. Corn germ protein can potentially be used as an ingredient for comminuted meat production.     

THERMO-RHEOLOGY,QUALITY CHARACTERISTICS,AND MICROSTRUCTURE OF FRANKFURTERS PREPARED WITH SELECTED PLANT AND MILK ADDITIVES1

The purpose of this study was to evaluate substitution of nonmeat proteins for meat protein on the thermo-rheology, quality characteristics, and microstructure of frankfurters. Batters were formulated to contain either 2% sodium caseinate or soy protein isolate, or 3.5% whey protein concentrate or wheat germ flour. The storage modulus (G') of all treatments initially decreased during temperature ramping from 20–50C, then increased rapidly from 60–80C, with all-meat batter exhibiting the highest G' at 80C. Substitution with nonmeat proteins decreased G', shear force, compression force, and red color of meat compared with all-meat frankfurters. Increased protein content, cooking yield, and decreased fat content were obtained with nonmeat protein formulations. Electron micrographs showed that nonmeat proteins were able to bind to the meat protein and fat, forming a protein-fat matrix with less coalescence of fat droplets. Sodium caseinate, soy protein isolate, whey protein concentrate, and wheat germ flour can be used as protein additives in comminuted meat products without adversely affecting their physical characteristics.     

NaCl浓度和pH对肉糜中脂肪微粒蛋白吸收量及凝胶特性的影响

研究了不同浓度（0．2mol／L和0．6mol／L）NaCl和pH（6．0和6．5）对肉糜中脂肪微粒表面蛋白吸收量、乳化稳定性、凝胶硬度和微观结构的影响。研究结果表明,高浓度（0．6mol／L）NaCl能够显著提高肉糜中脂肪微粒表面蛋白吸收量和单位界面膜蛋白吸收量,有效地改善肉糜乳化稳定性、凝胶硬度和微观结构等指标（P〈0.05）。但在相同浓度（0．2mol／L和0．6mol／L）NaCl条件下,较大pH（6．0和6．5）对脂肪微粒表面蛋白吸收量、单位界面膜蛋白吸收量、乳化稳定性、凝胶硬度和微观结构等指标无作用效果（P〉0．05）．因此．本实验认为0．6mol／L NaCl（pH6．0和6．5）的提取条件下能够充分剪切肌肉蛋白和脂肪,肉糜乳化性能好.     

不同部位新疆褐牛肉的品质差异分析

为明确新疆褐牛不同部位肉的营养品质、食用品质和加工特性等方面的差异,测定新疆褐牛黄瓜条、臀肉、外脊、牛腩、霖肉、肩肉和牛腱7 个部位的蛋白质、水分、脂肪、胶原蛋白含量、质构、剪切力、色差、pH值及加工特性。结果表明：不同部位新疆褐牛肉的蛋白质含量19.57%～22.90%,脂肪含量0.98%～2.85%;牛腱脂肪含量显著高于其他各部位,臀肉脂肪含量较低（不足1%）;胶原蛋白含量7.01%～18.86%;牛腱水分含量最高（76.48%）,臀肉水分含量最低（73.40%）;不同部位新疆褐牛肉的加工特性也有较大差异性,其中霖肉解冻损失率最大（9.17%）,牛腱最小（1.87%）;臀肉蒸煮损失率最大（34.39%）,牛腩最小（24.55%）;乳化能力为7.66～13.91 mL/g;肩肉的乳化稳定性最好（51.43%）,牛腩的乳化稳定性最差（27.78%）;黄瓜条凝胶的硬度和弹性最好,外脊凝胶的硬度和弹性最差;臀肉的凝胶保水性最好（93.69%）,牛腩的凝胶保水性最差（86.70%）。其他指标,如pH值、剪切力、质构、色差都有较大差异,决定了不同部位肉的适宜加工方式不同,牛腩适宜酱卤、扒烧类型产品加工,肩肉和黄瓜条适宜干制品加工,霖肉和臀肉适宜卤煮类型产品加工,外脊适宜肉糜类产品加工,牛腱适宜酱卤类型产品加工。     

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.     

MgCl_2对低钠盐κ-卡拉胶-肌球蛋白凝胶特性的影响

针对减脂减盐引起的肉凝胶品质劣变问题,基于镁离子的生理功能和κ-卡拉胶(κ-carrageenan,KCG)食用及补偿作用,以肉中具有凝胶形成能力的肌球蛋白(myosin,M)为研究对象,考察MgCl_2添加量(0~12 mmol/L)对KCG-M(质量比15∶85)混合凝胶保水性(water-holding capacity,WHC)和硬度的影响,并从KCG-M混合溶胶流变特性、热学特性及凝胶微观结构角度,探讨其影响机制。结果表明,添加6~10 mmol/L的MgCl_2可减弱KCG-M、M-M等分子间相互作用,降低混合体系的热稳定性(热相变温度Tpeak1值减小)和热诱导凝胶能力,并通过形成细密的三维网状凝胶结构而截留水分子,由此显著提高了低钠盐KCG-M混合凝胶的WHC,并降低了凝胶的硬度(P0.05)。这一结果将为开发适于老年人等特定人群消费的低钠盐、多汁性肉制品提供了可能性。     

亲水胶体类脂肪代用品在低脂肉糜制品中的应用

本文将几种不同的亲水胶体进行复配后应用于低脂肉糜制品中，通过肉糜制品的热稳定性和全质构分析以及感官特性的评定，筛选出一种复配型亲水胶体作为脂肪代用品，具有与高脂参照样（含脂肪３０％）相似的可接受性。本文还通过几种低脂肉制品配方的比较，详细阐述了复配胶对低脂肉制品的凝胶强度、弹性、持水率、感官评分以及超微结构等方面所起的作用。     

福瑞鲤与黄河鲤、建鲤鱼肉品质的比较及影响肉质的主成分分析

为研究福瑞鲤和黄河鲤、建鲤的肉质差异,选取了体质量相近、相同养殖条件下的3 种鲤鱼,分析其质构特性、肉色、pH值变化及营养成分。结果表明：福瑞鲤剪切力、硬度、胶黏性、咀嚼性指标低于黄河鲤和建鲤,而黏附性高于黄河鲤;水分含量、脂肪含量极显著低于黄河鲤及建鲤（P＜0.01）,灰分含量、蛋白质含量没有显著差异（P＞0.05）,Ser、Cys含量以及必需氨基酸（essential amino acids,EAA）含量较高,Thr含量较黄河鲤、建鲤有很大提升。整体上来说,福瑞鲤鱼肉品质在质构性能和营养价值上要优于黄河鲤和建鲤。而相关性分析表明剪切力、硬度、胶黏性、咀嚼性4 项指标均与粗蛋白、粗脂肪含量两项指标成显著正相关（P＜0.05）;黏附性与粗脂肪含量成负相关（P＜0.05）;从12 项指标中提取出3 个主成分,硬度、剪切力、粗脂肪、粗蛋白为影响肉质性能的最主要因素。     

Incorporation of sardine surimi in Bologna sausage containing different fat levels

The object of this research was to assess the effects produced on binding properties, texture and microstructure by the incorporation of varying proportions of sardine surimi (0%, 6·5%, 13% and 20%) as an ingredient in Bologna sausage containing various levels of fat (4·8%, 10·6% and 20·8%). When the fat level is reduced, there is a significant decline both the in binding properties and in the shear force and penetration force of the products. These phenomena are consistent with the formation of microstructures presenting a less dense matrix. The incorporation of surimi produces scarcely any alteration in the fat and water binding properties and the rheological characteristics of meat products.     

脂肪含量对肉糜性质影响

在低脂肉制品制作中脂肪被水所取代 ,通过对不同脂肪含量 (30 %、2 0 %、1 0 % )肉糜乳化稳定性、色泽、质构等性质的测量 ,发现随着脂肪含量的降低 ,产品硬度值下降。各样品产量、成品稳定性与乳化稳定性具有相关性。试验结果表明 ,高温产品各种性质较低温产品差     

Comparison of instrumental and sensory evaluation of texture of cured and cooked beef meat

The instrumental and sensory texture attributes of beef muscles (M. longissimus dorsi and M. semimembranosus) were compared after curing and thermal treatments. Shear, compression and puncture tests were carried out with an UTM Instron 4301 and the sensory evaluation was made with the score method. The force values obtained for puncture test gave a greater degree of correlation with the sensory tenderness, hardness and elasticity than the shear test forces. The shear test forces were found to significantly correlate with sensory tenderness only for muscles with perpendicular orientation of fibres to the direction of shear blade movement. The evaluation of beef texture with compression test was dependent on the level of sample deformation degree. The force values of compression were found to correlate significantly with elasticity and juiciness of meat up to 60% deformation levels, but at deformation levels higher than 60% appeared significant correlation with tenderness and hardness. The obtained results showed the usefulness of puncture test with proposed parameters for the instrumental measurements of beef texture.     

Konjac gel fat analogue for use in meat products: Comparison with pork fats

The paper reports a study of the characteristics of konjac gel fat analogue as compared to types of pork fat for use in fat reduction strategies for meat products. Various characteristics—colour, mechanical/rheological behaviour and thermal properties—of pork fats (backfat-PBF and trimmed fat-PTF) and konjac gel (KFG) with different physical structures (intact or ground to 4 and 8 mm) were studied. Pork fat melting processes were evaluated by differential scanning calorimetry (DSC) at above- and below-zero temperature ranges with PBF and PTF always showing similar net results. KFG did not show any thermal event in the range from −40 to 100 °C except the freezing/melting of its constitutional water. While water and fat binding properties of pork fats were affected by fat type and structural disintegration (ranging between 0 and 77%), in all cases KFG presented excellent thermal water binding (<1%). As compared to KFG, PBF showed greater (P < 0.05) hardness, chewiness, penetration force, gel strength, extrusion force and work of extrusion. These differences were minimized after grinding. Kramer shear values in KFG were greater (P < 0.05) than in PBF when this was ground to 4 mm, but lower (P < 0.05) at 8 mm. The highest Kramer shear values (P < 0.05) were recorded in PTF irrespective of the degree of disintegration. Rheological analyses indicate that the behaviour of KFG, which is thermally stable, is predominantly elastic during heating and exhibits rheological thermal behaviour (at over 40 °C) similar to that of pork backfat.     

油炸对鹅肉理化性质、质构与微观结构的影响

为选择鹅肉合适的油炸条件,采用常规物化特性测定方法,研究油炸对鹅肉理化性质、质构与微观结构的影响。结果表明,随油炸温度升高、时间延长,油炸损失率逐渐增加,135℃油炸5 min比120℃油炸2.5 min的损失率增加了12.87%(P0.05);p H值与剪切力的变化规律相似,呈现出了总体上升趋势,120℃与135℃油炸5 min时,剪切力值分别为40.432 N与55.783 N(P0.05);油炸后,鹅肉L*值降低,a*值与b*值逐渐增加,135℃油炸5 min的a*值与b*值分别比油炸2.5 min的增加了27.85%与32.95%;油炸后鹅肉硬度、咀嚼性总体变大,弹性、凝聚力、黏性及恢复性总体变小。120℃油炸3.5 min时,肌束膜内出现少许颗粒,125℃油炸3.5 min时,肌束膜变形严重,部分溶解,至135℃油炸5 min时,肌细胞结构已十分模糊。130℃油炸3 min是鹅肉较好的油炸条件,在此条件下,鹅肉损失率为38.24%、剪切力值为41.897 N、色泽金黄、质构特性良好。     

腌制预处理对红烧肉品质的影响

为探明原料肉腌制处理对红烧肉品质的影响,采用注射腌制（injection marination,IM）和静态变压腌制 （variable pressure static marination,VPSM）处理原料肉,以非腌制组作为对照,分析不同腌制处理的中间品和 成品的腌制吸收率、出品率、pH值、食盐含量、水分含量、蛋白质与脂肪含量、色泽、剪切力与质构、滴水损失 率、离心损失率、水分存在状态和微观结构,探讨原料肉经腌制、红烧后产品品质的形成规律。结果表明：VPSM 组腌制吸收率为2.46%,显著高于IM组（P＜0.05）。与对照组相比,原料肉经腌制后,中间品与红烧成品的水分含 量、出品率均显著提高（P＜0.05）;从原料肉到腌制后中间品直到红烧后成品,滴水损失率和离心损失率均显著降 低（P＜0.05）,且VPSM组最低。与IM组相比,VPSM组保水性更优,红烧肉出品率显著提高（P＜0.05）。经腌制 红烧后,与对照组相比,实验组脂肪含量显著下降,蛋白质含量呈先显著升高后显著下降的趋势（P＜0.05）。就 亮度值（L*）而言,与原料肉相比,IM组与VPSM组中间品L*值均显著上升,IM组成品L*值显著升高,而VPSM组 则显著下降（P＜0.05）。而与原料肉和对照组相比,VPSM成品的红度值（a*）、黄度值（b*）均最高,且差异显 著（P＜0.05）。与对照组相比,腌制预处理会显著降低成品红烧肉的剪切力与硬度（P＜0.05）。在预处理组中, VPSM效果最优。低场核磁共振T2弛豫时间检测结果显示原料肉经腌制后,不易流动水含量上升,且VPSM组高于IM 组。扫描电子显微镜观察结果显示,经腌制红烧后的成品纤维结构受到破坏,且VPSM组结构更为松散,纤维间隙最 大,有利于提高其保水性。VPSM可有效改善红烧肉加工品质,为改善红烧肉加工工艺提供了理论支持。     

Physicochemical Effects of the Lipid Phase and Protein Level on Meat Emulsion Stability,Texture, and Microstructure

ABSTRACT: The effects of beef fat (25%) substitution with rendered beef fat, canola oil, palm oil, or hydrogenated palm oil at varying meat protein levels (8%, 11%, and 14%) were studied in emulsified beef meat batters. There was no significant difference in fat loss among meat batters made with beef fat, rendered beef fat, or palm oil. Hydrogenated palm oil provided the most stable batters at all protein levels. Increasing meat protein to 14% resulted in high fat loss in batters prepared with canola oil, which did not occur in the other formulations. This indicates that the physicochemical characteristics of fat/oil affect emulsion stability. Cooked batter hardness was higher (P < 0.05) when protein level was raised; highest in hydrogenated palm oil batters when compared at similar protein levels. As protein level was raised springiness values were increased in all the meat treatments. Springiness was higher in the canola oil treatments. Light microscopy revealed fat globule coalescence in canola oil meat batters prepared with 14% protein, as well as the development of fat channels and more protein aggregation; both seem to result in lower emulsion stability. Hydrogenated palm oil batters showed fat particles with sharp edges as opposed to the round ones seen in all other treatments.     

Feasibility of X-ray microcomputed tomography for microstructure analysis and its relationship with hardness in non-acid lean fermented sausages

X-ray microcomputed tomography (μCT) was used for microstructure analysis on four different types of non-acid pork lean fermented sausages, three of them supplemented with 5% pork back fat, sunflower oil or diacylglycerols (DAGs). The data from the μCT analysis were related to instrumental texture (hardness). Although μCT analysis identified fat particles and air holes, the technique was not accurate enough to distinguish between pork lean and fat when these constituents were emulsified. Only μCT geometrical parameters related to the meat matrix (emulsion of pork lean and fat) provided useful information on the microstructure of the product. Parameters such as percent object volume (POV), object surface/volume ratio (OSVR), degree of anisotropy (DA), structure thickness (ST) and number of objects (NO) were correlated with instrumental hardness.