高效谷氨酰胺转胺酶在火腿肠加工中的应用研究

在火腿肠加工中添加一定量的微生物谷氨酰胺转胺酶,采用质构仪分析测定其组织凝胶破断强度.实验结果表明,将庞博牌TG酶加入火腿肠中,55℃下酶作用55min,再经过蒸煮等工艺,火腿肠的破断强度比对照组显著提高,产品的粘弹性得到了显著改善.同时在工艺不变的情况下,减少火腿肠中肉的添加量,增加淀粉的比例,当加入量增加3%时,与原配方相比,产品的质地和感官指标不变,成本降低.     

高效谷氨酰胺转胺酶在火腿肠加工中的应用研究

在火腿肠加工中添加一定量的微生物谷氨酰胺转胺酶,采用质构仪分析测定其组织凝胶破断强度.实验结果表明,将谷氨酰胺转胺酶加入火腿肠中,55℃下酶作用55min,再经过蒸煮等工艺,火腿肠的破断强度比对照组显著提高,产品的粘弹性得到r显著改善.同时在工艺不变的情况下,调整火腿肠和淀粉等辅料的比例,当谷氨酰胺转胺酶加入量增加3％时,与原配方相比,产品的质地和感官指标不变,成本降低.     

转谷氨酰胺酶改善PSE 猪肉西式香肠质构特性的研究

探讨转谷氨酰胺酶(transglutaminase,TG)及处理工艺对PSE 猪肉香肠质构特性的影响。测定在不同TG 质量分数、TG 处理时间、加热方式的条件下PSE 肉和正常肉(red,firm and non-exudative,RFN)肉糜蒸煮损失、凝胶强度和色度指标。结果表明：添加0.3% 的TG 可显著提高香肠的凝胶强度,但蒸煮损失也会增加;4℃条件下TG 处理的时间以2h 为宜;在20℃热水中升温加热比在75℃热水中直接加热所形成的凝胶强度大、蒸煮损失小;TG 质量分数和处理时间对凝胶色泽无显著影响,加热方式对凝胶的亮度(L*)和红度(a*)有显著影响。TG 处理可促进猪肉蛋白质的交联,改善PSE 猪肉西式香肠的质构品质。     

麻辣蒸煮香肠品质和感官特性研究

将麻辣粉(粉碎粒度200目,辣椒粉∶麻椒粉为2∶1)添加到蒸煮香肠中,考察其对香肠品质和质构特性的影响。以精肉、肥膘、麻辣粉和淀粉添加量为实验因素,以香肠的蒸煮损失、颜色和感官特性等指标为目标值,确定麻辣香肠的最佳配方为麻辣粉1.5%,精肉80%,肥膘15%,淀粉5%。研究结果表明:在优化的配方条件下,麻辣香肠的乳化稳定性和出品率均显著提高(p0.05)。随着麻辣粉添加比例的增加,香肠的pH、弹性和色差L值显著下降,色差a*值、b*值显著上升(p0.05),硬度、咀嚼性和凝胶性显著上升。研究可以为高膳食纤维、低脂麻辣香肠的生产提供理论依据。     

TG酶协同超高压处理对鸡肉糜制品品质的影响

为了提高鸡肉糜制品的品质,优化加工工艺,把TG酶添加到肉糜制品中,然后经超高压处理,经过二段加热形成凝胶,测定其质构特性和保水率。结果表明,酶活度、压强和保压时间对鸡肉糜凝胶的质构特性（硬度、咀嚼性）和保水率影响显著（P＜0.05）。通过Box-Behnken试验设计所得结果和二次多项回归方程确
立了最优的工艺条件,即：酶活度1.95 U/g、压强450 MPa、保压时间22 min。此条件下验证实验得到凝胶保水率可达到（90.1±0.5）%。酶活度与压强和保压时间交互作用显著（P＜0.05）,而压强与保压时间交互作用不显著（P＞0.05）。研究表明,TG酶和超高压结合能够促进鸡肉糜形成良好的凝胶,在鸡肉糜加工中具有广泛的应用前景。     

紫甘蓝花色香肠的研制

将紫甘蓝浓缩汁添加到肉馅中,研制成紫色的新型花色香肠制品.通过测定香肠的感官、理化和微生物指标,确定了紫甘蓝花色香肠的最佳配方和加工工艺条件.     

胡萝卜花色香肠的研制

将胡萝卜浓缩汁添加到肉馅中,研制成橙色的新型花色香肠制品.通过测定香肠的感官、理化和微生物指标.确定了胡萝卜花色香肠的最佳配方和加工工艺条件.     

TG酶协同超高压处理对鸡胸肉中肌原纤维蛋白凝胶品质的影响

为了提高鸡胸肉中肌原纤维蛋白凝胶的品质,优化加工工艺,把TGaes添加到鸡胸肉肌原纤维蛋白溶液中,经超高压处理,再经过二段加热形成凝胶,测定其凝胶强度和保水性。结果表明,p H、酶的添加量和压力水平对肌原纤维蛋白凝胶的凝胶强度和保水性影响显著(p0.05),保压时间对凝胶强度有明显影响(p0.05),但对凝胶的保水性影响不显著(p0.05)。通过Box-Behnken实验所得的结果和二次多项回归方程确立了最优的工艺条件,即:p H5.9,TGase的添加量为0.5%,压力432MPa,保压时间15min,此条件下肌原纤维蛋白凝胶强度为(255.26±5.31)g,保水性为(95.23%±1.87%)。p H与酶的添加量、压力水平和保压时间交互作用显著(p0.05),其他因素交互作用不显著(p0.05)。研究表明,TGase和超高压结合能够促进肌原纤维蛋白形成良好的凝胶,在鸡肉制品加工中具有广泛的应用前景。     

酶解生产微胶囊胡萝卜速溶粉工艺研究

胡萝卜在我国大部分省市均有种植,其β-胡萝卜素、维生素、矿物质含量丰富。本文利用微胶囊技术将经酶解处理的胡萝卜加工成一种速溶产品。利用液态果胶酶PectinexUltraSP-L和PectinexSMASHXXL酶解胡萝卜浆,提高了胡萝卜汁的产量。结果表明,果胶酶PectinexUltraSP-L最佳用量(以胡萝卜浆重量计)为0.09ml/kg胡萝卜浆液,PectinexSMASHXXL最佳用量0.18ml/kg胡萝卜浆液,最佳温度50℃,酶解时间2h,酶处理后出汁率能提高到82.8%。加入15%玉米油,3%乳化剂,3%酪朊酸钠和40%糊精微胶囊化后喷雾干燥得到胡萝卜速溶粉。该产品既能直接加水冲调饮用,也能作用一种成分加入到其它配方食品中,应用范围得到了进一步的扩大。     

芹菜花色香肠的研制

将芹菜浓缩汁添加到肉馅中,研制成绿色的新型花色香肠制品.通过测定香肠的感官、理化和微生物指标,确定芹菜花色香肠的最佳配方和加工工艺条件.     

添加牛血浆蛋白和MTG酶对乳化肠凝胶特性的影响

研究了牛血浆蛋白（BPP）和谷氨酰胺转胺酶（MTG）添加量对乳化肠产率、凝胶破裂强度和硬度、色泽的影响。结果表明,添加牛血浆蛋白和MTG酶对乳化肠产率、总压出汁液、凝胶强度和硬度有显著影响,但牛血浆蛋白处理组与MTG酶处理组有一定差异。添加牛血浆蛋白处理组乳化肠的L＊、a＊和b＊值显著高于MTG处理组。结论指出,牛血浆蛋白作为一种天然蛋白添加剂用来代替MTG,不仅能降低加工成本,还可以改善肉制品的品质。     

Differentiation in improvements of gel strength in chicken and beef sausages induced by transglutaminase

This research investigated the improvement in the texture of chicken and beef sausages induced by using microbial transglutaminase (MTG). The ε-(γ-glutamyl)lysine (G-L) content and the extractability of myofibrillar proteins from these sausages were also investigated. Treatment with MTG significantly affected the breaking strength score in both meat types, especially for beef cooked at 80°C (p<0.001). The protein concentration of both meat types treated with MTG and extracted in water-soluble protein solution (WSP) was slightly decreased; compared with a significant decrease (p<0.003) in samples extracted in Guba-Straub-ATP solution (GS-ATP). The variation in protein extractability of both meat types could lead to some considerations of the mechanisms and the high affinity reaction between MTG and myosin heavy chain (MHC). SDS-PAGE analysis revealed significant changes in the density of the bands after adding MTG, especially for the beef samples. The G-L content in the presence of MTG was double that in control samples of both meat types. The amount of crosslinking in chicken and beef meat was different and found to be reasonable. Collectively, this suggests that the binding ability of myofibrillar proteins with MTG is strong and dominated by MHC. There was a unique reaction among MHC proteins with MTG molecules considered as a very advantageous reaction. This leads us to suggest that the functional properties of MTG make it a beneficial protein-binding agent, positively helping the functionality of proteins to improve the texture and gelation of meat products that are treated mechanically, such as sausages. Some variation in gel improvement level between chicken and beef sausages was observed; this resulted from the variation in meat proteins in response to MTG, as well as to the original glutamyl and lysine contents.     

Analysis of texture and dynamics of water binding in enzymatically modified myofibrillar preparation obtained from washed mechanically recovered poultry meat

Experiments were conducted on a myofibrillar preparation, obtained from washed mechanically recovered poultry meat. An enzymatic preparation containing microbial transglutaminase (MTG) was added to samples of the myofibril isolate. The binding of water contained in the protein preparation with added MTG was assessed using low field nuclear magnetic resonance (NMR). Moreover, texture was analyzed in myofibril samples with the addition of transglutaminase pre-incubated for 0.5, 1.5, 3, 4.5 and 6 h. All measurements were taken at 7 ± 0.2 °C. Samples with added transglutaminase exhibited improved mechanical failure strength and better water binding capacity. The most dynamic increase of texture parameter values was observed in the interval from 1.5 to 3 h pre-incubation of the preparation with the added enzyme. Based on NMR (T ₁) testing it was established that the highest amount of water was bound by protein in the period from approximately 1 to 1.5 h pre-incubation. After that time free water content in the sample was again found to increase. This means that water was displaced from the system as a result of protein–protein interactions dominating over protein–water interactions. The above suggests that the enzymatic modification of the protein preparation contributed to the intensification of cross-linking between proteins in the preparation.     

Evaluation of red bean protein [Vigna angularis] isolate on rheological properties of pork myofibrillar protein gels induced by microbial transglutaminase

The effects of 1% red bean protein isolate (RBPI) on the gel properties of myofibrillar protein (MP) in various levels of microbial transglutaminase (MTG: 0%, 0.1%, 0.5%, & 1%) were evaluated. The cooking yield (CY) of the MP gels decreased with increasing MTG level, while the addition of RBPI improved the CY of the MP gels. Gel strength (GS) was also improved when RBPI was incorporated into the MP gels containing higher than 0.5% of MTG. The addition of MTG and RBPI was slightly changed the endothermic peak temperatures. Scanning electron microscopy (SEM) showed that the three‐dimensional structure of MP with RBPI alone or in combined with MTG was compacted as compared to the control. Based on the results, RBPI could be functioned as a substrate for MTG (0.5–1.0%) and a water binder of meat protein gel mediated by MTG.     

EFFECT OF SETTING CONDITIONS USING MICROBIAL TRANSGLUTAMINASE DURING OBTENTION OF BEEF GELS

Microbial transglutaminase (MTG) is a food additive widely used to improve the mechanical properties of beef, poultry and fish gels. The aim of this study was to determine the effect of incubation temperature on the mechanical properties of restructured beef gels treated with MTG. The restructured beef gels were obtained by adding 0.0% (untreated) or 0.3% MTG. Three incubation temperatures (40, 50 or 60C) for 30 min were used, followed by cooking at 90C for 15 min. Control samples without incubation were also prepared. Changes in the mechanical properties (texture profile analysis and puncture test), color attributes, expressible water and cooking loss were determined. Results indicated that the maximum mechanical properties can be obtained by incubating beef pastes at 50C for 30 min with minimal effect on color, expressible water and cooking loss when 0.3% of MTG is added.

PRACTICAL APPLICATIONS

Meat and poultry are considered nonsetting proteins, and consequently, an incubating treatment to allow optimal cross-linking has not been considered, and the products are usually obtained by direct cooking. Our results showed that beef gels containing 0.3% of microbial transglutaminase incubated at 50C showed higher mechanical properties than control gels without incubation. These results could be useful to improve the mechanical properties of beef gels.     

可得然胶预处理及其对低脂牛肉肠品质的影响

为了研究预处理方法对可得然胶粘度、凝胶强度的影响,探索经过预处理的可得然胶对低脂牛肉肠的保水性和质构特性的影响,本实验分别采用高速斩拌、酸碱中和的方法对可得然胶进行预处理,研究两种预处理方法对可得然胶粘度及凝胶强度的影响。并在低脂牛肉肠的加工中,分别添加0.1%、0.3%、0.5%和0.7%经高速斩拌与酸碱中和预处理的可得然胶,测定低脂牛肉肠蒸煮损失、保水性、质构特性以及感官等指标,探究高速斩拌、酸碱中和预处理所得可得然胶的应用效果。结果表明:高速斩拌和酸碱中和预处理均能显著提升可得然胶的凝胶强度和粘度（P<0.05）,其中,酸碱中和预处理可得然胶的粘度和凝胶强度更高,高速斩拌及碱溶的最适时间分别为5和15 min。随着高速斩拌、酸碱中和的可得然胶添加量的增加,低脂牛肉肠的蒸煮损失显著低于添加未处理可得然胶粉末的低脂牛肉肠（P<0.05）,而非压出水分、保水性、硬度、咀嚼性、感官评分等均显著高于添加未处理可得然胶粉末的低脂牛肉肠（P<0.05）,并且添加酸碱中和可得然胶的实验组效果更佳。因此,高速斩拌和酸碱中和预处理可以显著改善可得然胶的凝胶强度和粘度以及在低脂牛肉肠中的应用效果,并且酸碱中和预处理效果更佳。     

复合诱变法选育谷氨酰胺转胺酶高产菌株

为筛选谷氨酰胺转胺酶高产菌株,利用紫外-硫酸二乙酯复合诱变、一次筛选的方法诱变生产菌株茂源链霉菌（Streptoymyces mobaraensis）,结合高通量筛选技术筛选高产菌株。结果表明：复合诱变的方式较单独诱变的方式效率高。经过诱变的高产菌株由于酶的成熟加快或者蛋白表达量增加而提高了酶活力,最高可达7.02 U/mL,比野生菌株提高了54%。进一步研究高产菌株发现,高产菌株谷氨酰胺转胺酶的成熟加快,可提前24 h结束发酵;发酵液中酶原含量高,会降低发酵液中酶活性。     

Studies on the remedial effect of transglutaminase on protease anti‐felting treated wool

Oxidative protease treatment can improve anti‐felting of wool and also result in its loss of strength. In this study, one kind of microbial transglutaminase (MTG) was applied in the wet process of wool fabrics. The results indicated that transglutaminase could remediate wool damage following hydrogen peroxide and protease anti‐felting finishing, resulting in an increase in wool fabric strength and a decrease in alkali solubility. In addition, the evidence was provided that some cross‐linking through transglutaminase had occurred in the wool protein. The SEM showed that the scale structure became smoother after MTG treating. Analyzing of the thermal behavior revealed that the thermal stability of the MTG‐treated wool was enhanced. UV‐spectrum analysis suggested a decrease in protein extracted from the intercellular cements of the treated wool with MTG.     

Effect of the fungal protease EPg222 on proteolysis and texture in the dry fermented sausage ‘salchichón’

Proteolytic activity of the fungal protease EPg222 and its effect on the texture of the dry fermented sausage ‘salchichón’, which has a long ripening process, was assayed. Samples with enzyme added showed a significant reduction of myofibrillar protein concentration during the ripening period, compared with a control, and proteolytic activity of the enzyme led to a higher accumulation of non‐protein and ‐amino acid nitrogen. Analysis of volatile compounds in ripened dry fermented sausages revealed that only in EPg222 batches were branched compounds derived from amino acids catabolism detected that are associated with the flavour of dry cured meat products. The texture profile analysis showed reduction in hardness, gumminess and chewiness values in treated compared with control sausages. The effect of this enzyme could be of great interest in stimulating proteolysis, in flavour development and in reducing the hardness of dry fermented sausages produced by a long ripening process. Copyright © 2004 Society of Chemical Industry     

Effect of selected substances on the properties of frozen myofibril preparation obtained from mechanically recovered poultry meat

The experimental material was a myofibrillar preparation obtained from mechanically recovered poultry meat by the washing and separation of fat and connective tissues. Changes occurring during frozen storage were investigated in the preparation without and with the addition of the following substances: 2 g/kg carrageen, 2.5 g/kg sodium tripolyphosphate (TPP) mixture and 80 g/kg polydextrose, and 3 g/kg enzymatic preparation (ACTIVA WM) containing microbial transglutaminase (MTG). Samples with the addition of MTG were pre-incubated at the temperature of 7 ± 1 °C for 1, 3, 5, 24 h. All samples were stored at the temperature of approx. −23 °C for 2, 30, 60, 90 days. The smallest change in protein solubility was observed in samples with added TPP and polydextrose. Along with the extension of pre-incubation time of samples containing the enzyme a gradual decrease was found in the amount of soluble protein. Also the results of the investigations obtained using the DSC technique showed the most advantageous protective effect, i.e., causing the smallest decrease in enthalpy values of samples during freezer storage, in case of the addition of TPP and polydextrose mixture. Analysis of thermal drip volume from gels showed that carrageen was the most advantageous addition to the myofibrillar preparation. Moreover, a gradual increase was observed in the volume of thermal drip along with the extension of pre-incubation time of the protein isolate with enzymatic preparation. Results of gel texture testing indicated that the most advantageous effect on gel quality was found for ACTIVA applied in 3 and 5 h pre-incubation with the myofibrils. Assuming that among the analyzed properties the most important were thermal drip and gel texture, 3 g/kg MTG at pre-incubation time of 3 h was considered the most advantageous additive.