复合磷酸盐、谷氨酰胺转氨酶、大豆分离蛋白对新型鸭肉火腿保水特性和感官品质的影响

为研究复合磷酸盐、谷氨酰胺转氨酶、大豆分离蛋白对新型鸭肉火腿保水特性和感官品质的影响,通过单因素和L9（34）正交试验,以蒸煮损失、低场核磁共振自旋-自弛豫时间（T2）和感官品质为参考指标,确定最适添加量。结果表明：单独添加复合磷酸盐或大豆分离蛋白可以显著改善新型鸭肉火腿的蒸煮损失（P＜0.05）,添加大于0.5%的谷氨酰胺转氨酶会显著降低鸭肉火腿的保水性（P＜0.05）。通过正交试验优化得出的最佳添加量为：复合磷酸盐0.3%、谷氨酰胺转氨酶0.4%、大豆分离蛋白4%。应用此工艺,能够明显改善鸭肉火腿的保水特性和感官品质。     

无磷酸盐贡丸品质改良剂

旨在研究一种无磷酸盐贡丸品质改良剂.实验中采用蒸煮损失,质构仪分析及感官评定作为测定指标,探究微生物谷氨酰胺转胺酶(MTG)、卡拉胶、柠檬酸钠三因素对贡丸品质的影响.实验结果表明,MTG可显著提高贡丸的硬度、咀嚼性及弹性,但是增加了蒸煮损失;卡拉胶则可显著降低贡丸的蒸煮损失;柠檬酸钠对弹性、内聚性影响不明显,但是降低了硬度及咀嚼性.通过正交实验测定MTG、柠檬酸钠、卡拉胶在贡丸中的最佳用量分别为0.1%、1%和0.4%(w/w),可替代磷酸盐在贡丸中的使用,改善贡丸品质.     

正交实验优化西式火腿食用品质

为了研究低温腌制过程中西式火腿最佳的食用品质优化工艺,通过四因素三水平L9(34)正交实验考察脂肪酶、转谷氨酰胺酶、复合磷酸盐、风味蛋白酶四种对西式火腿食用品质影响较大的因素对产品压力损失、色差和质构特性的影响。并对产品的组织状态、色泽、风味、口感进行感官评定。结果表明:最优工艺为脂肪酶添加量0.9%、TG酶添加量0.1%、复合磷酸盐添加量0.4%、风味蛋白酶添加量0.01%。该组合能显著提高西式火腿的质构特性,并有令人满意的感官品质。该研究得出的优化组合为西式火腿的生产提供了理论参考。     

利用生物技术研制低脂白羽鸡肉丸

目的:利用复合磷酸盐、大豆分离蛋白、复配亲水胶和转谷氨酰胺酶研制新型低脂白羽鸡肉丸产品,并分析其质构与感官品质。方法:以硬度和感官为指标,利用单因素试验和响应面法筛选、优化配方,并进行感官评定。结果:白羽鸡肉丸的最佳制作工艺是:大豆分离蛋白1.58%(体积分数,下同),转谷氨酰胺酶0.59%,复配亲水胶0.26%,复合磷酸盐0.26%。在降低脂肪的同时,产品感官品质得以提高。结论:利用生物技术研制的新型低脂白羽鸡肉丸具有低脂、健康、风味佳的特点。     

速冻披萨饼坯品质改良剂的筛选

以速冻披萨饼坯为研究对象,通过单因素实验和正交实验,考察魔芋粉、大豆卵磷脂、山梨糖醇、甘油对产品胶粘性、硬度、内聚性、弹性、感官弹性和咀嚼性的影响。通过显著性差异分析和正交分析得到复合品质改良剂在基础配方中的最佳配比为魔芋粉0.60%、大豆卵磷脂1.20%、山梨糖醇0.04%、甘油1.00%。     

转谷氨酰胺酶及非肉蛋白对生煎调理鸭肉饼物性及感官的影响

为探究非肉蛋白和转谷氨酰胺酶（glutamine transaminase,TG）的添加量对鸭肉饼物性及感官的影响,以鸭胸肉为原料,通过单因素试验考察大豆分离蛋白、卵清蛋白、酪蛋白酸钠和TG添加量以及反应时间对生煎调理鸭肉饼质构和感官品质的影响,并利用响应面法优化工艺条件。结果表明：3 种蛋白和TG的添加量以及反应时间对鸭肉饼的硬度及感官均影响显著（P＜0.05）,3 种蛋白的添加比例为大豆分离蛋白、卵清蛋白、酪蛋白酸钠质量比5∶4∶2;加工生煎调理鸭肉饼的最佳工艺参数为TG添加量1.25%、反应时间155 min、反应温度4 ℃、复合蛋白添加量2.25%,所得产品硬度1 723.37 g、弹性0.83、咀嚼性1 683 g、胶着性2 036.40 g、黏聚性1.18、回复性0.49、感官评分41.23 分,产品硬度适宜,感官评价较好。     

谷氨酰胺转胺酶和脂肪酶的使用量对中式香肠品质的影响

研究谷氨酰胺转胺酶和脂肪酶的复合使用在低温腌制过程中对中式香肠食用品质和质构特性的影响。通过对中式香肠的质构特性、加压损失、颜色的测定,发现谷氨酰胺转胺酶的加入能够提高中式香肠的胶黏强度,并且在一定的条件下还能降低加压损失,提高保水性,而脂肪酶的加入能改善中式香肠的硬度和咀嚼性等特性。当谷氨酰胺转胺酶用量为0.2%,脂肪酶为0.75%时,能显著提高中式香肠制品的硬度、凝聚性、胶凝强度和咀嚼性等质构特性,产品的感官品质比对照组更令人满意。     

响应面法优化复合食品添加剂对猪肉蒸煮出品率工艺研究

为了提高猪肉的蒸煮出品率,首先将三聚磷酸钠∶焦磷酸钠∶六偏磷酸钠按4∶3∶2比例复配成复合磷酸盐添加剂。以猪肉蒸煮出品率为评价指标,在单因素工艺试验的基础上,应用响应面分析法对复合磷酸盐、谷氨酰胺转胺酶、大豆分离蛋白、卡拉胶添加量进行优化,结果表明,最佳添加量为复合磷酸盐0.36%、TG酶0.60%、卡拉胶0.20%、大豆分离蛋白0.41%,在此条件下,猪肉蒸煮出品率可达到89.5311%。验证试验猪肉蒸煮出品率为(89.1±0.4)%,表明实验结果与软件优化结果相符。     

三种改性方式对大豆分离蛋白功能性的影响

本文主要研究了氮气改性和谷氨酰胺转胺酶改性以及氮气、谷氨酰胺转胺酶复合改性等3种改性方式对大豆分离蛋白功能性的影响,为大豆分离蛋白在不同食品类产品中应用提供理论依据,结果表明：①要求溶解性较高并且乳化性、乳化稳定性显著提高者,需要选择氮气单独改性处理。②要求常温黏度、高温黏度、凝胶性、吸油性最佳、吸水性、保水性显著提高者,需选择MTG单独改性处理。③要求吸水性、保水性最佳而且常温黏度、高温黏度、凝胶性较显著提高者,需选择复合改性处理。     

大豆分离蛋白的复合改性及其对某些功能性的影响

利用中性蛋白酶和微生物谷氨酰胺转胺酶(MTG)对大豆分离蛋白进行复合改性,通过单因素实验和正交实验研究,获得改性SPI最佳凝胶性的反应条件为:添加中性蛋白酶0.003%,水解20min;添加MTG0.5%,作用2.0h。获得最佳溶解性的反应条件为:添加中性蛋白酶0.005%,水解30min;添加MTG0.3%,作用1.0h。正交实验结果表明,双酶复合改性的最佳处理组合为添加中性蛋白酶0.005%,水解30min;添加MTG0.5%,作用1.0h,得到产品凝胶性为4226cp,比对照提高了36.3%,溶解性为70.1%,比对照降低了5.8%。     

The levels of zinc, copper, manganese, selenium, chromium, nickel, cobalt, and aluminium in the meat, liver and kidney of swedish pigs and cattle

Summary The levels of zinc, copper, manganese, selenium, chromium, nickel, cobalt, and aluminium were determined in samples of meat, liver and kidney from pigs and cattle from Swedish slaughterhouses. The results have been compared with those reported from other investigations carried out in recent years. For zinc, copper, manganese and selenium, the mean levels found in the different tissues were very similar to those reported in previous studies. The mean levels of chromium and nickel were found to be in the range <0.010–0.015 mg/kg, regardless of the type of tissue. Cobalt levels ranged from 0.001 to 0.043 mg/kg, the highest levels being in the liver samples. The mean levels of aluminium were between 0.024 and 0.068 mg/kg. Tissues from cattle contained approximately twice as much aluminium as tissues from pigs. Analytical quality assurance was carried out by analysing standard reference materials. A great effort was made to minimize and check contamination. This may partly explain the fact that the levels of chromium, nickel, and aluminium found in the present study are among the lowest reported.

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Gehalt an Zink, Kupfer, Mangan, Selen, Chrom, Nickel, Kobalt und Aluminium in Fleisch, Leber und Nieren von schwedischen Schweinen und Rindvieh

Zusammenfassung Es wurde der Gehalt an Zink, Kupfer, Mangan, Selen, Chrom, Nickel, Kobalt und Aluminium in Fleisch, Leber und Nieren vom Schwein und Rind aus schwedischen Schlachthäusern bestimmt. Diese Ergebnisse wurden mit denen anderer Untersuchungen verglichen. Die Durchschnittswerte für Zink, Kupfer, Mangan und Selen in verschiedenen Geweben waren ungefähr die gleichen wie in früheren Untersuchungen; die für Chrom und Nickel lagen alle im Intervall <0,010 bis zu 0,015 mg/kg, unabhängig von der Art der Gewebe, und die für Kobalt zwischen 0,001 und 0,043 mg/kg, mit den höchsten Werten in der Leber. Für Aluminium ergaben sich Durchschnittswerte zwischen 0,024 und 0,068 mg/kg, wobei die Gewebe vom Rind ungefahr doppelt so viel Aluminium enthalten wie die Gewebe vom Schwein. Die analytische Qualitätskontrolle wurde mit Referenzmaterial durchgeführt. Viel Arbeit wurde zur Minimierung und Kontrolle der Kontamination aufgewendet. Das kann zu einem Teil erklären, daß die Werte von Chrom, Nickel und Aluminium unserer Untersuchung zu den niedrigsten bisher veröffentlichten Werten gehören.

     

The levels of zinc, copper, manganese, selenium, chromium, nickel, cobalt, and aluminium in the meat, liver and kidney of swedish pigs and cattle

The levels of zinc, copper, manganese, selenium, chromium, nickel, cobalt, and aluminium were determined in samples of meat, liver and kidney from pigs and cattle from Swedish slaughterhouses. The results have been compared with those reported from other investigations carried out in recent years. For zinc, copper, manganese and selenium, the mean levels found in the different tissues were very similar to those reported in previous studies. The mean levels of chromium and nickel were found to be in the range less than 0.010-0.015 mg/kg, regardless of the type of tissue. Cobalt levels ranged from 0.001 to 0.043 mg/kg, the highest levels being in the liver samples. The mean levels of aluminium were between 0.024 and 0.068 mg/kg. Tissues from cattle contained approximately twice as much aluminium as tissues from pigs. Analytical quality assurance was carried out by analysing standard reference materials. A great effort was made to minimize and check contamination. This may partly explain the fact that the levels of chromium, nickel, and aluminium found in the present study are among the lowest reported.     

Water-, oil-, and soil-repellent treatment of textiles,artificial leather,and leather

Several products are on the market to realize water-, oil-, and soil-repellent properties on textiles or textile-related materials. To make an adequate and fast rating of repellent properties of finished textiles, different drop tests according to AATCC and ISO standards are commonly used. For evaluation of the repellent properties of solid substrates against different liquids often contact angle measurements are performed. The aim of the work presented here is to determine and evaluate the repellent effects gained by the application of three different finishing agents on three different substrates, such as polyester fabric, artificial leather, and leather. The main questions are at that point: It is possible to gain similar repellent effects with the same finishing product applied on different substrates? Do the different testing methods lead to comparable results? Is there a relation to the repellency against everyday consumer products as red wine, ice tea, or coffee? This article should help the reader to evaluate different testing methods and the influence on common substrates.     

卷烟中锂、铬、镍、铜、砷、硒、钼、镉、铊和铅含量分析

采用微波消解-电感耦合等离子体质谱法测定了41个牌号烤烟型卷烟和雪茄烟样品烟丝中的锂、铬、镍、铜、砷、硒、钼、镉、铊和铅含量,并按照类型和价位对卷烟中这10种有害元素含量进行了统计分析。结果发现:①卷烟中锂和铜的含量较高,铊的含量很低,铬、镍、镉、铅、砷、硒和钼7种元素的平均含量为0.55～4.42μg/g;②雪茄烟中铬、镍、砷、钼、镉、铊和铅的含量一般高于烤烟型卷烟,而硒元素的含量则相反,但差别较小;烤烟型卷烟中锂和铜的含量与雪茄烟没有显著差异;③高档卷烟中的锂、镍、镉、铊和铬含量较低,而砷、铅的含量较高;不同价位卷烟的铜、硒和钼含量差异不显著。     

Polyphenols, Anthocyanins, Ascorbic Acid, and Radical Scavenging Activity of Rubus, Ribes, and Aronia

ABSTRACT: Total polyphenols, total anthocyanins, and reduced ascorbic acid were evaluated in berries belonging to the genera Rubus, Ribes, and Aronia by means of spectrophotometric and high-performance liquid chromatography (HPLC) techniques. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the fruit extracts was tested. Total polyphenols ranged from 140.6 to 888.5 mg/100 g fresh weight (FW), total anthocyanins ranged from 22.0 to 460.5 mg/100 g FW, and reduced ascorbic acid ranged from 12.4 to 153.8 mg/ 100 g FW. The average EC50 values for Aronia melanocarpa, Ribes nigrum, Ribes rubrum, Rubus fruticosus, and Rubus idaeus were 1.8, 2.8, 5.3, 6.4, and 8.2 mg FW, respectively. The results indicate that the fruits tested are good sources of natural antioxidants.     

Optimization of extraction conditions of total phenolics, antioxidant activities, and anthocyanin of oregano, thyme, terebinth, and pomegranate

The purpose of this study was to evaluate the total phenolic extracts and antioxidant activity and anthocyanins of varieties of the investigated plants. These plants include oregano, thyme, terebinth, and pomegranate. The optimum extraction conditions including temperature and solvent of the extraction process itself were investigated. Total phenolic and anthocyanin extracts were examined according to Folin-Ciocalteu assay and Rabino and Mancinelli method, respectively. The effect of different extracting solvents and temperatures on extracts of phenolic compounds and anthocyanins were studied. Plant samples were evaluated for their antioxidant chemical activity by 2, 2-diphenyl-1-picrylhydrazl assay, to determine their potential as a source of natural antioxidant. Results showed that all tested plants exhibited appreciable amounts of phenolic compounds. The methanolic extract (60 °C) of sour pomegranate peel contained the highest phenolic extract (4952.4 mg/100 g of dry weight). Terebinth green seed had the lowest phenolic extract (599.4 mg/100 g of dry weight). Anthocyanins ranged between 3.5 (terebinth red seed) and 0.2 mg/100 g of dry material (thyme). Significant effect of different extracting solvents and temperatures on total phenolics and anthocyanin extracts were found. The methanol and 60 °C of extraction conditions found to be the best for extracting phenolic compounds. The distilled water and 60 °C extraction conditions found to be the best for extracting anthocyanin.     

Simultaneous and Direct Determination of As, Bi, Pb, Sb, and Se and Co, Cr, Cu, Fe, and Mn in Milk by Electrothermal Atomic Absorption Spectrometry

Tungsten permanent modifier with coinjection of Pd(NO₃)₂ and W–Ru permanent modifiers are proposed for the direct and simultaneous determination of As, Bi, Pb, Sb, and Se (group 1) and Co, Cr, Cu, Fe, and Mn (group 2), respectively, in milk by graphite furnace atomic absorption spectrometry. The performance of modifiers was evaluated by means of thermal behavior of analytes, sensitivity, atomic signal profile, repeatability, graphite tube lifetime, and background intensity. An air-assisted pyrolysis step was necessary to quantitative elimination of the organic matter. After methods optimization, 14 commercial milk samples were analyzed. The found concentrations of As, Bi, Pb, Sb, Se, Co, and Cr were lower than their limit of detection (2.13, 2.21, 1.49, 1.63, 2.05, 1.0, and 1.2 μg L⁻¹, respectively). Concentrations of Cu, Fe, and Mn were in the 1.58–5.74 μg L⁻¹, 9.79–49.3 μg L⁻¹, and 2.25–4.08 μg L⁻¹ intervals, respectively. The limits of detection for Cu, Fe, and Mn were 1.7, 5.3, and 2.0 μg L⁻¹, respectively. The accuracy of methods was checked after analysis of two milk standard materials. Results for Cr, Cu, Fe, Mn, Pb, and Mn were in agreement with certified values of SRMs at the 95% confidence level. Accuracy was also evaluated by addition–recovery tests and recoveries in the 86–127% range were obtained for all elements. The use of pretreat platform of graphite tubes with W or W–Ru allowed enlarging the lifetime of atomizer in 750 heating cycles.