Selected Macro and Micro Minerals in Ground Beef and Longlssimus Muscle

Up to date values for nutrient composition of foods are required so nutritionally optimum diets can be determined. Selected minerals in longissimus muscle and ground beef from 20 beef carcasses were determined by inductively coupled plasma emission spectroscopy. Ground beef contained greater (P<0.003) amounts of Na, Ca, Fe, Mg and Zn than longissimus muscle. Longissimus muscle contained more (P<0.0073) K and P. The amount of Cu was the same (P<0.699). There were no detectable amounts of Mn observed Mean percentages on an “as is basis” for moisture (71.7 vs 65), protein (23.2 vs 18.8) fat (4.5 vs 16) and ash (0.6 vs 1.0) for longissimus muscle and ground beef, respectively, were different.     

Content of Zinc in Selected Muscles from Beef, Pork, and Lamb

Zinc concentration was measured in four muscles from beef, pork, and lamb: longissimus dorsi (LD), biceps femoris (BF), gluteus medius (GM), and triceps brachi (TB). Within a species, BF, GM, and LD had similar zinc concentrations but TB was significantly (P<0.01) higher in zinc. The means for the four muscles ranged from 39.8–53.5, 13.9–28.0, and 28.2–36.9 μg Zn/g wet weight for beef, pork, and lamb, respectively. The zinc concentration of muscle may relate to protein synthesis and the predominant type of energy metabolism occurring in the muscle. The mean zinc concentration of the four muscles between species was significantly (P< 0.01) different.     

Minerals in Pork Meat and Edible Offal

Pork meat contains important minerals, including iron and zinc, all of which are essential for good health throughout life. Edible offal is also a form of meat and in general possesses a higher content of minerals, than muscular tissue. The mineral levels in pork meat, and edible offal are variable. Major sources of variation in animal products are the proportion of lean to fat tissue, and the proportion of edible to inedible materials. The aim of this paper is to provide an overview of the existing scientific literature on the mineral levels in pork meat and edible offal.     

Thermal Gelation Properties of Protein Fractions from Pork and Chicken Breast Muscles

Thermal gelation properties of myosin, actin, myofibrils (MF), sarcoplasmic protein (SP) and connective tissue (CTS) from pork semimem-branosus and chicken breast (CB) were evaluated. Gels were prepared at pH 6.0, 2% NaCl and cooked to 70°C at 0.7°C/min. Pork myosin had a higher gel strength and a lower cooking loss than CB myosin at 7% protein. Actin from both species did not form a measurable gel. MF gels from pork and CB had the lowest cooking loss while CTS and SP had the highest cooking loss. Difference in gel strength between muscle and MF+SP+CTS at 7% protein was not consistent with that at 10% protein.     

Nutrient Content and Edible Yield of Selected Cuts of Cooked Pork

Analysis of lean-type pork cooked by standard methods showed that cooking to a final internal temperature of 77°C for fresh cuts, and 71°C for cured meats resulted in increased amounts of several essential nutrients. Edible yield was similar to that reported from earlier studies, while amounts of internal fat were somewhat lower. Levels of thiamin, riboflavin and niacin and of several minerals were found to be slightly higher than Handbook 8 values. Cobalamin and zinc from 100g of edible lean would provide approximately 10% and 20–35% of the respective recommended daily allowances. Iron contents were lower than previously reported for pork.     

单道扫描ICP-AES法同时测定食品中十一种常量及微量元素

本文研究了食品中十一种常量及微量元素(K、Na、Ca、Mg、P、Cu、Fe、Zn、Mn、Ni和St)单道扫描ICP-AES测定的方法。试验了仪器工作参数的选择,探讨了分析线的选择与背景校正,用表面活性剂解决雾化器喷雾堵塞问题,效果良好,并可维持一定的灵敏度,方法的RSD在3.1～10.1％之间,回收率在91～105％,基体元素对微量元素的测定基本无影响,对标准物质测定结果令人满意,方法适用于食品中上述元素的测定。     

Dietary Iron in Swine Rations Affects Nonheme Iron and TBARS in Pork Skeletal Muscles

Fifteen crossbred pigs (mean wt = 25 kg) were allocated to three groups and fed to market weight (mean wt = 103 kg) on corn-soy based diets containing either 62,131, or 209 ppm iron. After slaughter, the longissimus dorsi (LD) and rectus femoris (RF) muscles were dissected, cooked, and stored in oxygen-permeable bags for 12 days at 4°C. Cooking increased thiobarbituric acid reactive substances (TBARS) but did not affect nonheme iron (NHI) or α-tocopherol. NHI and TBARS increased continuously during storage while α-tocopherol decreased. NHI and TBARS were higher in cooked pork from pigs fed high-iron diets. Liver iron correlated with muscle iron (p<0.05).     

Effect of Postmortem Storage on Titin and Nebulin in Pork and Poultry Light and Dark Muscles

Purified myofibrils were prepared from samples of chicken breast and thigh muscles and from light and dark portions of pork semitendinosus muscle at death and after storage at 4° and 22°C for 1, 3, and 7 days postmortem. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used to examine the effect of postmortem storage of muscle on titin and nebulin. Results indicated that titin and nebulin were more rapidly degraded in light than in dark chicken muscle. In contrast, titin and nebulin were more rapidly degraded in dark than in light pork muscle.     

Yield and Comparison of Nutritive and Energy Values: Selected Variety Pork Products

Eight raw and cooked pork products were compared for yield and physiologic energy values, nutrient composition and protein quality. Cracklings were not cooked. Cooking resulted in some significant changes (wet basis) in parameter values. Knuckles and ham hocks had similar parameter values. All products, except skin, had a cooking loss. Skin had a 15.3 g/kg gain, apparently due to an exceptional moisture increase. The fat composition showed a very low ratio of polyunsaturated to total saturated fats. There were no differences between the calculated PERs of each raw and cooked product. These data indicated that the chemical score and the PER values of these products were generally directly proportional to the total quantity of essential amino acids present.     

Effect of Animal Age on the Tenderness of Selected Beef Muscles

The tenderness of 12 beef muscles from animals of 8 different age groups (ranging from 1 to about 60 months old) which were treated to minimize pre-rigor myofibrillar shortening, have been assessed using objective and subjective methods. The mean tenderness of these 12 muscles significantly (p<0.001) decreased with age. The rate of increase in the toughness of individual muscles with animal age was related to their connective tissue strength. Psoas major muscles were almost unaffected by increasing animal age whereas high connective tissue strength muscles, such as the Biceps femoris, trebled in toughness. A comparison of the different muscles revealed that one of the least representative was the often used M. longissimus dorsi.     

Mineral Composition of Selected Bovine, Porcine and Avian Muscles, and Meat Products

THE MINERAL CONTENT of young and old avian muscles, in mature bovine and porcine tissues destined for processing, and in selected meat products and additives was determined. Inter- and intra-species variations in mineral composition were found among all the muscle tissues investigated. Muscle-to-muscle variation was found to be highly significant for all but one of the minerals analyzed in the avian (K) and bovine (P) muscle tissues and all but three (Fe, Ca, P) in the porcine tissues. The mineral content of three major meat products and four meat additives are reported. The least variability in tissue mineral content was found when the data was expressed on a dry weight, fat free basis.     

OCC回用过程中胶黏物的定量分析及浮选控制

以废纸为原料生产挂面纸板会给造纸厂带来许多问题.如果不进行适当控制,就会引起产品质量下降,并影响纸机正常运行.为解决废纸造纸带来的诸多问题,科研工作者进行了广泛的研究并开发出了许多新技术方法,如纤维分级、磨浆前用酶处理回收纤维、表面施胶和Condebelt干燥等.近来,许多造纸生产者已经意识到了废纸回用中控制胶黏物的重要性.因此,有必要确立胶黏物定量分析的标准方法,以此来评价胶黏物对产品质量和纸机运行状况的影响,并测定造纸过程中不同部位的胶黏物含量.     

Thermal Gelation of Pork, Beef, Fish, Chicken and Turkey Muscles as Affected by Heating Rate and pH

Effects of heating rate (3°C or 0.7°C/min) and pH (5.5, 6.0, 6.5, or 7.0) on thermal gelation properties of different muscle systems were evaluated (10% protein, 2% NaCl) using pork, beef, fish, and chicken and turkey (breast and thigh) muscles. Results indicated that, at pH 6.5 and 7.0, force required to rupture the gel (Pf), force required to move plunger through the gel (Fp), and viscosity index (Ni), using a slow heating rate, were higher than with rapid heating. All muscles (except breast muscles with the slow heating rate) yielded higher (P<0.05) gel strength (Fp, Pf) at pH 6.0 than at the other pHs.     

Proximate Analyses, Selected Vitamins and Minerals and Cholesterol Content of Mechanically deboned and Hand-deboned Broiler Parts

Samples of commercial mechanically deboned broiler product derived from necks, with and without skin, backs and rib cages, separately and combined into blended mixture were analyzed. Moisture content ranged from 62.7–73.4%, fat from 13.2–25.2%, protein from 10.3–11.9% and ash from 0.74–0.94%. Vitamin analyses (mg/100g wet weight) included: thiamin 0.051–0.068, riboflavin 0.128–0.211, niacin 2.50–3.39, vitamin B₆ 0.094–0.149, and pantothenic acid 0.581–0.700. Cholesterol content was 94.2–129.1 mg/100g wet weight. Mineral content (mg/100g) was K 123–151, Na 48–62, Ca 53–91, Mg 13–15, Zn 1.13–1.78, Fe 1.45–1.86, Mn 0.019–0.026, and Cu 0.029–0.034. One batch each of necks with and without skin, and backs was hand deboned and analyzed. Calcium and cholesterol contents were 350 and 14% higher, respectively, in mechanically deboned products as compared to the hand-deboned counterparts. There were differences in vitamin levels due to source of material, but not due to method of deboning.     

Utilization of Surimi-like Products from Pork with Sex-odor in Restructured, Precooked Pork Roast

Surimi-like materials from boar and sow muscle and Alaskan pollack fish surimi were evaluated as binders for sow muscle chunks in restructured roasts. Boar surimi-like material tended to have lower mi-crobial counts and less lipid oxidation than unwashed counterparts. Increasing salt content increased lipid oxidation (P<0.05), degraded color and improved (P<0.05) textural integrity. The surimi-like boar material had equal or better binding properties than fish surimi at a 5% level and did not consistently result in detectable boar odor. Roasts without binder were comparable or better in textural and microbial characteristics than those with binders. Restructured, precooked, pork roasts were successfully produced with 0.2% NaCI.     

东坡肉与井冈东坡猪肉石

<正>东坡肉是中华民族一道独特的传统喜宴佳肴。它美味可口、做工严谨、用料考究。倘若要制作一道脆嫩爽滑、色味俱佳的东坡肉,必须严格遵循以下几道操作工序:1.取料。一定要选取没有骨头的猪肚边的五花肉,将其切成正方或长方形的肉块,放入锅内焖熟取出。     

Effect of Heat Treatment and Selected Antimicrobials on the Shelf-life and Safety of Cooked, Vacuum-Packaged, Refrigerated Pork Chops

The shelf-life of refrigerated (2–4°C) pork chops inoculated with Clostridium sporogenes PA3679 and Staphylococcus aureus Z88 was examined in products sliced from loins cooked to 66°C (150°F), dipped in 5% polyphosphate blend, 2.5% potassium sorbate or 2% acetic acid solutions, vacuum-packaged and stored at 2–4°C. The effect of a second in-the-bag cooking step to 66°C (150°F) after vacuum packaging was also studied. Pork chops not reheated after packaging showed incipient spoilage after 15 days at 2–4°C, depending on surface treatment. The second cooking increased the shelf-life of refrigerated product to more than 60 days and reduced counts of inoculated cultures to undetectable levels. However, on exposure of the chops to simulated mishandling (24–25°C), clostridial growth was detected in all samples except those dipped in polyphosphate or acetic acid solutions.     

Effect of High Pressure during heat Treatment on the Wamer-Bratzler Shear Force Values of Selected Beef Muscles

The effect on the Warner-Bratzler shear values of post-rigor beef muscles of heat treatments ranging from 40 to 80°C with or without concurrent pressure treatment at 150 MPa have been investigated. For muscles in a stretched condition, a decrease in shear values attributed to changes in the connective tissue was found to occur at a higher temperature in the pressure treated samples than in those not pressure treated. For muscles in a contracted condition, a steep increase in shear values with increase in cooking temperature (attributed to myofibrillar toughening) was prevented by pressure treatment. Instead, a decrease in shear values attributed to changes in connective tissue as found in stretched muscle, was then evident.