2种蛋白酶酶解肉类效果的对比分析

采用2种蛋白酶对猪肉、鸡肉和牛肉进行酶解,2种酶酶解3种底物所得酶解液在氨基酸态氮、总氮和固形物上存在一定的差距,其中,蛋白酶H2猪肉、鸡肉和牛肉酶解液的氨基酸态氮含量分别比蛋白酶H1高4.09%、2.02%和8.40%。H2猪肉和鸡肉酶解液总氮含量分别比H1高4.27%和1.46%。H2酶解猪肉、鸡肉和牛肉的固形物含量分别比H1高2.67%、0.99%和5.76%。H2的酶解效果较好,2种酶均对鸡肉的酶解效果好。H1酶解液的美拉德反应产物风味好于H1酶解液。     

Process and Characteristics for a Surimi-like Material Made from Beef or Pork

Beef or pork was chopped, screened, and washed; water was removed by centrifugation to make surimi-like, water-washed beef or pork. Processing parameters were evaluated to develop the optimum processing techniques to yield the most functional material. Regardless of fat content in the starting material, water-washed beef or pork contained <1% fat. Water-washed muscle was lighter (reduced redness and yellowness) than the original starting material but had more color than fish surimi. Washed beef or pork formed gels with greater hardness than commercial fish surimi above 55°C after heating at 0.5°C/min. Salt soluble protein of water-washed beef or pork was higher than that of commercial fish surimi.     

Effect of Fat Source and Color of Lean on Acceptability of Beef/Pork Patties

Twelve beef/pork meat blends were made from lean of mature beef and dark or mature pork carcasses. Meat blends containing about 20% beef fat were rated higher for appearance scores by a consumer panel than blends made with 20% pork fat. Visual acceptance of beef/pork patties was accomplished via use of all-beef fat and additionally by extending mature beef (MB) with mature pork (MP) or dark pork lean (DP). Agtron calorimetry scores indicate a minimum of 20% MB lean extended with 60% MP was needed to create the appropriate red color attractive to consumers. Use of 60% MP lean with about 20% beef fat resulted in patties acceptable to consumers for visual appearance and eating satisfaction.     

驴肉主要营养成分及与其它畜禽肉的分析比较

本文测定了驴肉的水分、灰分、蛋白质、粗脂肪、脂肪酸、矿物元素、氨基酸的含量,并将驴肉与其他畜禽肉的营养成分作对比分析。结果表明:驴肉蛋白质含量比羊肉、牛肉、猪肉高,而脂肪含量比羊肉、牛肉、猪肉低。驴肉的氨基酸和脂肪酸组成是比较理想的,矿物元素中Fe含量明显高于其它畜禽肉。从营养学角度看,驴肉是比较理想的动物性食品原料。     

Postmortem Loss of Carnitine from Skeletal Muscle of Pork and Beef

The carnitine content of beef muscle postmortem was more than twofold higher than the content of pork muscle. For both pork and beef, carnitine was distributed among the fractions, free carnitine ? short-chain acylcarnitine > long-chain acylcarnitine concentration. Based on total carnitine content, the only loss of carnitine from pork muscle occurred as a result of cooking. Cooking also reduced total carnitine content of beef muscle. In addition, total carnitine content of the beef steaks was lower after thawing. Time in the retail case did not influence carnitine content.     

Sensory Properties and Cooking Losses of Beef/Pork Hamburger Patties

Seventeen beef and pork blends were evaluated for palatability characteristics, color, appearance acceptability and cooking losses. Cooking losses were not significantly different among blends. Both raw patty color and appearance acceptability were significantly affected by fat and lean source. Increasing pork content changed raw patty color from dark red to pale grayish-pink and decreased appearance acceptability. Patties having high pork content appeared fatter although fat content of blends was not different. Increasing pork fat content improved patty tenderness. Juiciness, flavor, and overall acceptability were no significantly affected by lean or fat source. Results indicate beef/pork blends with 50% or more beef equal all-beef patties in palatability traits and cooking losses.     

EFFECTS OF TYPES OF FAT AND OF RATES AND TEMPERATURES OF COMMINUTION ON DISPERSION OF LIPIDS IN FRANKFURTERS

ABSTRACT— The effect of time, temperature and rpm of comminution of emulsions was determined on the dispersion of approximately 25% of beef fat, pork fat or cottonseed oil in frankfurters. The numbers of lipid particles 5 μ or less in diameter increased in frankfurters containing either beef or pork fat as comminution was continued to higher temperatures, with pork fat dispersed more thoroughly. Fat tended to separate from frankfurters containing beef fat in particles 200 μ or more in diameter. In contrast, no specific degree of dispersion of particles 5 μ or less in diameter consistently indicated emulsion stability, or its lack. Increased rpm during comminution produced an increased dispersion of beef or pork fat. Under the same conditions pork fat was dispersed more finely than beef fat. Dispersion of cottonseed oil produced finely dispersed particles beyond the resolution of light microscopy, as was confirmed by electron microscopy which showed a substantial number of particles to be less than 1 μ in diameter.     

大豆素丸和三种肉丸的营养成分与质构特性比较

比较以大豆拉丝蛋白为主要原料、经棕榈油炸制的大豆拉丝蛋白素丸子,与自制猪肉丸子、市售鱼肉和牛肉丸子的营养成分与质构特性,探讨其应用价值。采用国标法检测丸子的营养成分,质构仪检测四种丸子的质地。蛋白质含量从高到低依次为拉丝蛋白丸子39.06 mg N/g、猪肉丸子30.11 mg N/g、牛肉丸子19.91 mg N/g、鱼肉丸子12.79 mg N/g。胆固醇含量从高到低依次为牛肉丸子28.71 mg/100 g、猪肉丸子25.27 mg/100 g、鱼肉丸子14.83 mg/100 g、拉丝蛋白素丸子1.21 mg/100 g。猪肉丸子的脂肪含量显著高于其他三种丸子(p0.05)。大豆拉丝蛋白素丸子的总氨基酸、必需氨基酸、鲜味氨基酸含量最高,分别为15.44±0.59、5.33±0.20、8.89±0.34(g/100g)。四种丸子的不饱和脂肪酸比例很高,占各自总脂肪含量的59%到73%。大豆拉丝蛋白素丸子的弹性、回复性最好,分别为96.84%±1.43%、52.77%±0.56%。研究表明大豆拉丝蛋白素丸子的蛋白质含量高、胆固醇低、氨基酸含量高、有丰富的不饱和脂肪酸、营养价值高、口感佳,可以作为传统肉丸的替代品。     

Composition of Surimi-like Material from Beef or Pork

A surimi-like material was made from finely minced beef or pork by water washing followed by screening to remove connective tissue. Changes in component proteins, amino acid composition and vitamin, mineral and cholesterol content occurring during preparation were investigated. Total amino acid nitrogen contents of water-washed beef and pork were higher than those of the respective muscle by 7% and 6.5%. Among 16 amino acids measured, histidine and glycine decreased in both water-washed beef and pork, while others increased compared to original muscle. Thiamin content decreased after washing. Surimi-like beef and pork had less cytoplasmic minerals (K, Na, Mg) but more minerals associated with proteins or subcellular organelles (Ca, Cu, Zn, Fe). Fat content decreased, although cholesterol concentration was not changed by washing.     

猪肉蛋白和牛肉蛋白对生长期大鼠生理功能的影响

目的：研究长期摄入猪肉蛋白和牛肉蛋白对生长期大鼠生长性能、生理功能的影响。方法：30 只雄性Sprague-Dawley（SD）大鼠随机分为3 组,分别饲喂添加酪蛋白、猪肉蛋白和牛肉蛋白作为蛋白质来源的半合成饲料,实验期为90 d,观察其对大鼠生理指标的影响。结果：相对于酪蛋白组,猪肉蛋白组和牛肉蛋白组大鼠的生长速率变缓,脂肪沉积减少（P＜0.05）,但有较高的谷丙转氨酶和谷草转氨酶活力（P＜0.05）。猪肉蛋白和牛肉蛋白可降低大鼠血清中的甘油三酯浓度（P＜0.05）,牛肉蛋白还可降低总胆固醇和血糖浓度（P＜0.05）,猪肉蛋白则对其没有显著影响（P＞0.05）。猪肉蛋白组和牛肉蛋白组的大鼠有较低的血清游离氨基酸水平（P＜0.05）。结论：长期摄入猪肉蛋白和牛肉蛋白会对大鼠机体代谢产生不同的影响,这与蛋白质来源及其消化和吸收有关。猪肉蛋白和牛肉蛋白有控制大鼠体质量增长的作用,牛肉蛋白还可以降低大鼠肝脏代谢水平,具有降血脂的功能。     

SELECTED SENSORY AND CHEMICAL ATTRIBUTES OF CHICKEN BREAKFAST SAUSAGES FROM DIFFERENT ANIMAL FAT SOURCES

Four breakfast sausage formulations were prepared to contain: (1) chicken lean + chicken fat (CF), (2) chicken lean + beef fat (BF), (3) chicken lean + pork fat (PF), or (4) chicken lean + high-oleic pork fat (PO). Formulations were targeted to contain 15% fat. Acceptability, tenderness, juiciness and flavor scores for each of the formulations as measured by a consumer taste panel (n = 71), were not different (P> 0.05). Sausages prepared with CF had a higher (P < 0.05) cooking loss and lower fat content than those prepared with BF. Thibarbituric acid (TBA) values for PO were significantly lower than those containing BF, PF, or CF. Sausage products containing chicken fat exhibited the highest TBA values during 9 days of storage at 4°C. These results suggested that chicken, beef, pork or high-oleic fats can be used as the fat source in low-fat chicken breakfast sausages without affecting the product acceptability.     

Organoleptic Identification of Roasted Beef, Veal, Lamb and Pork as Affected by Fat

SUMMARY— A taste panel was used to study the identification of roasted beef, pork, lamb and veal by flavor alone and the effect of fat on identification. Only about one-third of the panel could identify correctly all four meats by memory of the flavors. There was an increase in the total number of correct identifications made by comparison of the unknown roasted meat samples with known standards but this was not significantly greater than the total correct responses by memory of the flavor alone. Beef and lamb, but not pork and veal, were identified significantly less often when lean ground roasts were tested than when normal ground roasts (containing fat) were used. Texture, color, mouth feel, and other factors may be important in the identification of meat. Beef, lamb and pork fat, as well as these fats after extraction with chloroform: methanol, were added to lean veal prior to roasting. Addition of beef fat did not increase recognition of veal as beef. Pork fat contained a factor increasing identification of veal as pork, but this factor was water-soluble and could be removed. Lamb fat contained a component, or a fat-soluble component, that significantly increased the identification of veal as lamb.     

新型兔肉脯加工技术

采用新配方、新工艺和微波杀菌新技术研制具有高蛋白、低脂肪、营养丰富、口味独特新型兔肉脯休闲食品,并对其营养成分进行测定,结果显示:新型兔肉脯蛋白质含量34.54%、氨基酸总量32.64%均高于牛肉脯、鸡肉脯和猪肉脯;脂肪含量为7.2%,均低于其他三种肉脯。     

不同种类原料肉对婴幼儿肉泥理化性质和体外消化特性的影响

为研究不同种类原料肉对婴幼儿肉泥的影响,本实验以3 种婴幼儿肉泥（牛肉泥、猪肉泥、鸡肉泥）为研究对象,对其营养成分、流变特性及消化情况的差异性进行分析。结果表明：婴幼儿肉泥是一种高蛋白、低脂肪、高水分食品。不同种类肉泥的营养成分含量存在显著性差异（P＜0.05）。其中牛肉泥蛋白质量分数最高（（11.01±0.53）%）,猪肉泥脂肪质量分数最高（（6.19±0.42）%）,鸡肉泥水分质量分数最高（（81.15±0.26）%）。流变学分析结果表明,婴幼儿肉泥呈现出剪切稀化特点,具有弹性成分占主体的弱凝胶特征。表观黏度和储能模量（G’）都呈现出牛肉泥＞猪肉泥＞鸡肉泥。经过胃蛋白酶和胰蛋白酶两步消化后,猪肉泥的消化率高于其他两种肉泥,肉泥的粒径分布范围由最初4.3～550.0 μm范围缩小至1.2～118.0 μm。牛肉泥消化后的中值粒径最小,为（8.15±0.94）μm,猪肉泥和鸡肉泥的粒径无显著差异。总体来说,不同种类原料肉加工而成的婴幼儿肉泥在理化性质和体外消化特性方面存在较大差异。     

青海八眉猪与甘肃黑猪肉品质及营养成分比较

通过分析比较青海八眉猪和甘肃黑猪肉质性状、营养成分、氨基酸、脂肪酸、肌苷酸等含量差异,为研究青海八眉猪肉提供数据支撑,并为其资源保护提供一定依据。以10头青海八眉猪和10头甘肃黑猪为研究对象,采用国标法对其背最长肌的各个指标进行了系统比较分析。结果表明:八眉猪肉的失水率、熟肉率显著高于甘肃黑猪肉(P<0.05),大理石纹、肉色、脂肪色、pH在2个品种肉质上差异不显著(P>0.05);八眉猪肌肉中粗脂肪含量显著低于甘肃黑猪(P<0.05),蛋白、水分含量显著高于甘肃黑猪(P<0.05),粗灰分含量差异不显著。相对于甘肃黑猪肌肉中的7种脂肪酸,青海八眉猪肌肉含有14种脂肪酸,且饱和脂肪酸和多不饱和脂肪酸含量显著高于甘肃黑猪(P<0.05),不饱和脂肪酸及单不饱和脂肪酸显著低于甘肃黑猪(P<0.05);甘肃黑猪肌肉氨基酸总量(20.23 g/100 g)高于青海八眉猪(19.14 g/100 g),八眉猪肌肉鲜味氨基酸含量(8.76 g/100 g)高于甘肃黑猪(7.84 g/100 g)。八眉猪肌肉肌苷酸含量为2.44 mg/g,显著高于甘肃黑猪肌肉肌苷酸含量2.05 mg/g(P<0.05);八眉猪肌肉肌酐、次黄嘌呤含量依次为0.55、0.13 mg/g,均显著低于甘肃黑猪的0.81、0.55 mg/g(P<0.05)。由此说明,相比于甘肃黑猪,青海八眉猪肌肉氨基酸比例更合理,脂肪酸更丰富,肌苷酸含量更高,高蛋白、低脂肪,肉质更鲜美。     

The effects of hot water pasteurizing treatments on the appearances of pork and beef

Portions of post- and pre-rigor pork and beef were treated by immersion in water of 75 or 85 °C for 5, 10, 15 or 20 s. The appearances of untreated and treated cut muscle, fat, membrane covered and cut bone surfaces, and the overall appearances of treated and untreated meat pieces, were assessed by a 5-member panel 2 hr and 24 hr after each treatment. At those times, CIE L(?)a(?)b(?) values were obtained for cut-muscle surfaces. The appearances of surfaces covered by membrane, of fat and cut bone surfaces of pre-rigor pork and beef, and of fat and cut bone surfaces of post-rigor pork, were not persistently degraded by any treatment. However, the appearances of fat and cut bone surfaces of post-rigor beef were persistently degraded by the harsher treatments, apparently because of pre-treatment staining of fat and changes in the bone marrow. Panel scores for the overall appearance and for the appearance of cut muscle surfaces were generally the same for each meat piece. All treatments caused patchy bleaching of cut muscle. The degraded appearances of pre- and post-rigor pork and post-rigor beef muscle persisted at 24 hr, but the appearances of beef muscle treated pre-rigor improved between 2 and 24 hr. Most treated muscle gave increased CIE L(?) values and decreased a(?) and b(?) values as compared with untreated portions from the same primal cut. However, CIE b(?) values for pre-rigor beef muscle were higher than for untreated muscle 2hr after treatment, but lower than for untreated muscle 24 hr after treatment. It appears that pasteurizing treatments cannot be applied to meat without some degradation of the appearances of cut muscle surfaces, which will persist in pork treated pre- or post-rigor and in beef treated post-rigor, but which will partially resolve during the storage of beef treated pre-rigor.     

Contribution of lean,fat, muscle color and degree of doneness to pork and beef species flavor

Flavor is an important contributor to consumer acceptability of meat, our objective was to characterize the impact of species-specific fat/lean sources, fat level, degree of doneness and muscle color are on pork and beef flavor. Three separate experiments were conducted. Patties were formulated differently for each experiment in order to evaluate the desired variables. Experiment. 1: Flavor from combination patties (same species lean/fat or combination of species lean/fat) was not impacted by degree of doneness (66 °C vs. 71 °C). Beef flavor was highest in samples made with beef lean, regardless of species fat type. Pork flavor was highest in samples made with pork lean and had higher flavor intensity scores. Experiment. 2: Beef flavor was not increased in all-beef patties formulated with higher fat levels. Pork patties formulated with higher fat content increased pork flavor. Experiment. 3: All-beef and all-pork patties formulated with light or dark lean did not impact flavor in either species.     

Determination of the Amount of trans-Octadecenoate and trans-9,trans-12-Octadecadienoate in Fresh Lean and Fatty Tissues of Pork and Beef

Longissimus muscle and subcutaneous fat from 17 pork and 6 beef carcasses were analyzed for trans-octadecenoates and trans-9,trans-12-octadecadienoate (linolelaidate) content by argentation thin layer chromatography and/or glass capillary gas liquid chromatography. No detectable amount of trans-9,trans-12-octadecadienoate was found in pork or beef. In pork the amount of trans-octadecenoates ranged from 0.0074 – 0.0077 g/100g of fresh Longissimus muscle and 0.1453 – 0.1549 of fresh subcutaneous fat. The content of trans-octadecenoates in beef ranged from 0.0782 – 0.0839 g/100g of fresh Longissimus muscle and 2.4280 – 2.7368 g/100g of fresh subcutaneous fat. The content of trans fatty acids contributed by pork and beef to the human diet is negligible relative to that derived from other dietary sources.     

Heat-Resistance of Escherichia Coli O157:H7 in Meat and Poultry as Affected by Product Composition

The effects of fat level and low fat formulation on survival of Escherichia coli O157:H7 isolate 204P heated in ground beef [7%, 10% and 20% fat], pork sausage [7%, 10%, and 30% fat], chicken (3% and 11% fat), and turkey (3% and 11% fat) were determined by D- and z-values. D-values for E. coli 0157:H7 in lowest fat products were lower than in traditional beef and pork products (P < 0.05). Overall, higher fat levels in all products resulted in higher D-values. D₆₀ values (min) ranged from 0.45–0.47 in beef, 0.37–0.55 in pork sausage, 0.38–0.55 in chicken and 0.55–0.58 in turkey. D₅₅ and D₅₀ values were respectively longer. Z-values ranged from 4.4–4.8°C. Product composition affected lethality of heat to E. coli O157:H7.     

Gamma Irradiation Effects on Thiamin and Riboflavin in Beef, Lamb, Pork, and Turkey

A study was made of the loss of thiamin and riboflavin due to gamma irradiation of beef, lamb and pork longissimus dorsi, turkey breast and leg muscles. Thiamin losses averaged 11%/kiloGray (kGy) and riboflavin losses 2.5%kGy above three kGy. The rate of loss of thiamin in beef was higher than that in lamb, pork and turkey leg, but not turkey breast. with losses of 16%/kGy in beef and 8%/kGy in lamb. The rate of thiamin loss was not related to sulfhydryl, protein, moisture, fat or water content, pH or reducing capacity by redox titration. Loss of riboflavin was not different among species. Any detriment from such slight losses would seem to be more than compensated by the advantage of controlling bacteriological contamination by irradiation processing.