Production of Restructured Meat using Microbial Transglutaminase without Salt or Cooking

To produce restructured meat, microbial transglutaminase (MTGase) was evaluated for its ability to introduce covalent crosslinks between protein molecules. Pork muscle cubes were mixed with MTGase and held at 5°C for 2 hr for the enzyme reaction. Restructured products were analyzed for binding strength without cooking. MTGase treatment resulted in effective binding of meat pieces provided there was addition of salt (NaCl). To ensure proper binding without NaCl, some food proteins with MTGase were also investigated. Meat cubes in combination with MTGase and sodium caseinate showed acceptable bind, and sodium caseinate appeared to be a superior substrate for the crosslinking to meat proteins than soy protein, whey protein, or gelatin. These results suggest a useful method for producing restructured meat which can be distributed in the raw, chilled state.     

Characteristics of Sodium Caseinate- and Soy Protein Isolate-Stabilized Emulsion-Gels Formed by Microbial Transglutaminase

ABSTRACT:  Protein-stabilized emulsion gels were prepared via microbial transglutaminase (mTGase) catalysis, and their physicochemical characteristics were examined. Emulsion oil droplet size and interfacial protein load were measured. The sodium caseinate and soy protein isolate emulsion gels exhibited different microstructures and physical properties. The emulsion gels improved the storage stability of aroma compounds. Rheological measurements of the emulsion gels revealed interesting strength, gelation kinetics, and thermal sensitivity properties. The mTGase-induced emulsion gels comprised a fine network which led to less release of aroma compounds upon storage than did emulsions. These results suggest that emulsion gels may be used to improve the texture of food emulsions and to control release of food aromas.     

微生物转谷氨酰胺酶对大豆分离蛋白乳液凝胶性能的影响

研究了不同油相比例（φ=0.2~0.6）的微生物φ转谷氨酰胺酶（MTGase）诱导的大豆分离蛋白（SPI）乳液凝胶性能及微观结构,发现提高乳液中的油相比例,凝胶的弹性模量G’及凝胶持水性均有显著提高并存在一定相关性,乳液凝胶形成的凝胶网络机械强度更大,油滴在酶促乳液凝胶中充当了良好的＂活性填充剂＂。     

重组肉中常用黏合剂的研究进展

肉制品加工过程中会产生大量碎肉,多用于饲料等低值副产品,本身价值未得到高效利用。黏合剂主要以碎肉中的盐溶性蛋白（肌原纤维蛋白/肌球蛋白）为物质基础,以机械作用辅助肌球蛋白空间结构改变,促进蛋白质-蛋白质、蛋白质-水相互交联,形成均匀致密的三维凝胶网络结构,制成重组肉制品,提高产品的完整性。目前,常用的黏合剂包括亲水胶体、谷氨酰胺转氨酶、大豆分离蛋白、血浆蛋白和葡萄糖酸-δ-内酯等,它们依据自身特性在重组肉产品中发挥着重要作用。作者阐述了重组肉加工过程中常用黏合剂的应用原理,归纳比较了它们的研究现状,简要分析了温度、pH和浓度等因素对黏结性能的影响,为后续黏合剂研究提供理论依据。     

Using Salt and Microbial Transglutaminase as Binding Agents in Restructured Fish Products Resembling Hams

ABSTRACT: Restructured products were obtained from fish paste of silver carp ( Hypophthalmichthys molitrix ) by massaging and cooking in ham presses. Assayed were 3 levels of salt (0 as control, 1, or 2%) and 3 levels of microbial transglutaminase (MTGase). Changes on solubility of pastes, mechanical properties, WHC, and SDS-PAGE of the cooked product were evaluated. MTGase needed the addition of NaCl to improve the mechanical properties of these restructured products. Better textural properties were obtained with 2% NaCl. Adding 0.3% of MTGase and 1% NaCl obtained a low-salt, homogenous restructured meat block with 2773 g hardness, 29106 g/cm gel strength, 0.233 cohesiveness, and 11.6% extracted water.     

谷氨酰胺转氨酶对大豆分离蛋白塑料拉伸性能的影响

研究了微生物谷氨酰氨转胺酶对大豆分离蛋白塑料拉伸性能的影响,发现在50℃时转氨酶对大豆分离蛋白催化聚合反应60 min,形成的高分子聚合物使大豆分离蛋白的抗拉强度和杨氏模量分别由未经处理时的9.2 MPa和265.4 MPa增加到14.7 MPa和390.1 MPa,同时增加了蛋白质的变性温度和热焓值。在酶处理90 min时,由于转氨酶变性失去活性及大豆分离蛋白的部分变性,蛋白质塑料的拉伸性能反而下降。对大豆分离蛋白的预热处理降低了转氨酶的催化聚合反应,且变性后的大豆分离蛋白制备的塑料拉伸性能大大降低。     

响应面优化转谷氨酰胺酶改性大豆分离蛋白工艺

为获得适于添加到冷饮食品中的大豆分离蛋白,利用转谷氨酰胺酶(TG)对其进行改性,提高其乳化性。采用响应面试验设计,以酶添加量、酶解时间、酶解温度为试验因素,以乳化活力指数为响应值,建立数学模型,对酶解条件进行优化。结果表明,最佳酶解条件为TG酶的添加量0.93×10-4g、温度46℃、时间1.2h。在此条件下,乳化活力指数的预测值为1.9623m2/g,验证实验所得乳化活力指数为1.9658m2/g。所得回归模型拟合情况良好,达到设计要求,本实验得到的改性大豆分离蛋白的乳化性显著高于未改性的大豆分离蛋白。     

Sensory, Instrumental Texture Profile and Cooking Properties of Restructured Beef Steaks Made with Various Binders

Restructured steaks made with various binders were evaluated using subjective and objective texture profile analysis of the following treatments: intact ribeye muscle, calcium alginate, salt/tripolyphosphate, crude myosin extract, whey protein, wheat gluten, soy protein isolate, surimi and no additives. Steaks made with calcium alginate or crude myosin extracts had superior binding. Steaks with 1.5% surimi had similar textural properties to those with calcium alginate or crude myosin extract. Whey, wheat gluten or soy isolate protein in restructured steaks detrimentally affected product flavor. Calcium alginate, crude myosin extract and surimi could be potential binders in the manufacture of restructured steaks without deterimental effects on quality.     

转谷氨酰胺酶的特性及其聚合大豆蛋白的研究

转谷氨酰胺酶作为一种生物催化剂,可以催化蛋白质赖氨酸上ε-氨基和谷氨酰胺上γ-羟酰胺基之间的交联反应,在蛋白质分子间或分子内形成ε-(γ-谷氨酰胺基)赖氨酸(G-L)键。此催化过程具有反应条件温和、底物选择性好的特点,交联聚合后蛋白的功能特性,如凝胶性、热稳定性和保水性等会得到明显改善,因此,其广泛应用于动植物蛋白的改性中。本文介绍了不同来源转谷氨酰胺酶的特性和其在不同食品体系中的作用,并对转谷氨酰胺酶催化大豆蛋白聚合的研究进行了综述。     

谷氨酰胺转移酶对大豆分离蛋白成膜性能的影响

研究了谷氨酰胺转移酶（TGase）对大豆蛋白膜特性的影响。研究表明：在成膜溶液中加入TGase（4U／g）可以使膜的抗拉强度增加16．79，6，表面疏水性增加39．2％，同时也明显降低了膜的断裂伸长率、水分含量、总可溶性物质量及透光率，但是对水蒸气转移速率几无影响。扫描电镜（SEM）显示，酶法交联膜的表面比对照膜略为粗糙，断面却更为均匀致密。SDS-PAGE分析表明，TGase催化SPI产生了共价交联。     

Assessment of Cross-Linking in Combined Cross-Linked Soy Protein Isolate Gels by Microbial Transglutaminase and Maillard Reaction

ABSTRACT:  Soy protein isolate (SPI) gels were produced using single cross-linking agents (SCLA) of microbial transglutaminase (MTG) via incubation for 5 or 24 h (SCLA-MTG). When powdered SCLA-MTG gels were heated for 2 h with ribose (R2) (2 g/100 mL), dark brown gels were formed, and these were designated as combined cross-linking agent (CCLA) gels: MTG5(R2) and MTG24(R2). The results showed that the levels of Maillard-derived browning and cross-links of MTG5(R2) and MTG24(R2) gels were significantly ( P  < 0.05) lower than a control gel produced without MTG (SCLA-R2) even though the percentage of ribose remaining after heating of these gels was similar, indicating that a similar amount of ribose was consumed during heating. ɛ-(γ-glutamyl)lysine bonds formed during incubation of SPI with MTG may have reduced the free amino group of SPI to take part in the Maillard reaction; nevertheless, ribose took part in the Maillard reaction and initiated the Maillard cross-linkings within the CCLA gels.     

转谷氨酰胺酶改善大豆组织蛋白肉丸品质

为了获得高品质的肉丸制品,以添加大豆组织蛋白的肉丸为研究对象,采用转谷氨酰胺酶对其进行酶解改性.通过单因素试验和响应面优化试验,研究不同酶解条件对大豆组织蛋白肉丸品质的影响.结果表明:三因素对肉丸品质的影响主次顺序依次为酶添加量＞反应温度＞反应时间,最佳工艺条件为酶添加量0.3％、反应温度53℃、反应时间122min,在此条件下,产品的感官评分为22.5,比未改性产品的感官评分提高了0.8.综上所述,转谷氨酰胺酶能显著改善大豆组织蛋白肉丸的品质,具有较高的开发利用价值.     

大豆蛋白在调理肉制品中的应用

本文主要介绍了大豆蛋白的分类、功能特性以及在调理肉制品中的应用,并对大豆蛋白在调理肉制品的作用和使用方法进行简要描述。     

HPLC检测火腿肠中大豆分离蛋白的方法研究

利用高效液相色谱(HPLC)法测定火腿肠中大豆分离蛋白的含量。色谱条件为:Xb ridgeBEH300 C4色谱柱;蒸发光散射检测器;梯度洗脱;流动相A:0.05%三氟乙酸-HPLC级水溶液,B:0.05%三氟乙酸四氢呋喃溶液;流速1.0 mL/min;检测波长254 nm;柱温30℃;进样量20μL。大豆分离蛋白在1%～9%含量范围内与特征峰面积呈良好的线性关系,回归方程为Y=2 923.1 X-970.85,相关系数R=0.994 2,平均回收率为99.30%,RSD为2.04%。HPLC法准确度、精密度、稳定性、重现性良好,为火腿肠中大豆分离蛋白的定量检测提供了可选择的方法。     

谷氨酰胺转氨酶对大豆蛋白／PVA 复合薄膜性能的影响

以大豆蛋白和聚乙烯醇（ PVA）为主要原料,以抗张强度、断裂伸长率、透光率、吸水率为评价指标,通过单因素试验和正交试验,研究了谷氨酰胺转氨酶（简称TG）对大豆蛋白/PVA复合薄膜性能的影响。试验结果表明：当反应pH为5．0,反应温度为55℃,TG添加质量分数为0．20‰时得到性能最佳的复合薄膜;在最佳条件下,薄膜的抗张强度、断裂伸长率、透光率和吸水率分别为8．06 MPa,89．97％,30．8％和46．43％。     

Plasma Protein and Soy Fiber Content Effect on Bologna Sausage Properties as Influenced by Fat Level

The effects of plasma protein (PP) and soy fiber (SF) content on the properties (binding properties, color, and texture) of bologna sausages as influenced by fat level (F) were assessed by response surface methodology (RSM). Higher soy fiber and plasma protein contents favored the formation of harder, chewier structures with improved fat and water binding properties. Fat reduction decreased textural properties and increased weight loss. Cooking loss was affected (P < 0.05) by interactions between PP and F and chewiness was affected (P < 0.05) by interactions between SF and F. Plasma protein influenced binding and textural properties more than soy fiber and was, therefore, thought best to limit the effect of fat reduction.     

醇法大豆浓缩蛋白改性及在肉制品中的应用

采用醇法提取大豆浓缩蛋白具有明显优势,但此方法提取的大豆浓缩蛋白功能性不好,应用受限。本文介绍了通过物理、化学、酶法、基因工程等方法对醇法大豆浓缩蛋白进行改性,改性后醇法大豆浓缩蛋白的功能性明显提高。改性后的醇法大豆浓缩蛋白应用于肉制品中具有优良的持水持油性、乳化性以及凝胶性,可以提高肉制品的组织结构特性,并降低生产成本,且价格低廉,是一种性价比很高的大豆蛋白产品。     

Improvement of Gelling Properties of Lizardfish Mince as Influenced by Microbial Transglutaminase and Fish Freshness

ABSTRACT:  The effects of microbial transglutaminase (MTGase) at different levels (0 to 0.8 units/g sample) on the properties of gels from lizardfish ( Saurida undosquamis ) mince set at 25 °C for 2 h or 40 °C for 30 min prior to heating at 90 °C for 20 min were studied. Breaking force and deformation of gels increased with increasing MTGase amount added ( P < 0.05). At the same MTGase level used, gels with the prior setting at 40 °C for 30 min showed a higher breaking force compared with those subjected to prior setting at 25 °C for 2 h ( P < 0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoretic study revealed that myosin heavy chain (MHC) underwent polymerization to a higher extent in the presence of MTGase. Regardless of setting condition, microstructure of gel added with MTGase was finer with a smaller void compared with that of gel without MTGase. Therefore, setting temperature affected the property of gels added with MTGase. Gel properties of mince obtained from lizardfish stored in ice for different times (0 to 10 d) with and without MTGase at a level 0.6 units/g were determined. Irrespective of MTGase addition, breaking force and deformation of all gels decreased as the storage time of lizardfish increased ( P < 0.05). The addition of MTGase was able to increase both breaking force and deformation of the resulting gel produced from lizardfish kept in ice for all storage times used. Therefore, both freshness and MTGase addition had the direct impact on gel properties of lizardfish mince.     

以大豆蛋白微粒构建高蛋白食品体系的稳定性研究

本研究以大豆分离蛋白(SPI)为原料,在p H 3.0、p H 3.4和p H 3.8等低酸性p H条件下对其进剪切热处理,制备获得粒度分布在2～100μm的大豆蛋白微粒。当微粒制备的p H条件向SPI等电点(p H 4.5)靠近时,形成蛋白微粒的结构越致密,稳定性越高。在p H 3.8条件下制得微粒的内部蛋白含量达到34.22%,在p H 2.0～8.0范围内其粒径不发生明显改变,蛋白溶出率不超过13%。经过二次热处理(95℃、30 min),该微粒的粒径和形貌没有发生明显变化,其分散液的粘度明显低于SPI分散液,在12%的浓度下仍然不形成凝胶。微粒化过程可以封闭大豆蛋白的疏水基团和氢键结合位点,使蛋白分子间的相互作用减弱,导致粘度降低。该大豆蛋白微粒可应用于饮料、酸奶等高蛋白食品体系中,在保持其口感的同时增加其蛋白质含量。     

谷氨酰胺转氨酶对大豆蛋白游离伯胺含量的影响

利用了在硫基乙醇作用下,邻苯二甲醛(OPA)试剂与伯胺可以发生荧光反应,使用荧光分光光度计快速检测溶液中游离伯胺含量。应用此方法研究了加酶量、反应温度、反应时间、及反应pH对谷氨酰胺转氨酶(TGase)作用于大豆分离蛋白后对其游离伯胺含量的影响,并对主要影响因素利用响应面发进行优化,找出TGase反应条件的最佳组合。实验结果表明:加酶量20 U/g,反应温度为52℃,反应时间60 min,反应pH 7为TGase最佳反应条件,改性后每克大豆分离蛋白伯胺含量由0.059μmol减少为0.028μmol。