谷氨酰胺转胺酶在肉制品加工中的应用

介绍了谷氨酰胺转胺酶的分类、生产方法及作用特点,并且系统地阐述了其在肉制品加工中的应用.     

转谷氨酰胺酶在肉制品中的应用

从转谷氨酰胺酶所催化的生化反应入手,依据此酶对肌肉蛋白质作用的特点,阐述了转谷氨酰胺酶对改善肉制品质构、提高产品率、拓宽原料来源及开发新产品的重要作用,并且对转谷氨酰胺酶作用产物的生物利用性进行了探讨。     

微波消解-分光光度法测定肉制品中磷酸盐

为建立用微波消解技术进行样品前处理,磷钼蓝分光光度法测定肉制品中磷酸盐含量的方法;采用微波消解仪,在肉制品中加入硝酸密闭消解,消解液用磷钼蓝分光光度法在660hm波长处测定样品中磷的含量。结果是微波消解技术可将样品消解完全,采用磷钼蓝分光光度法测定体系中磷酸盐（以磷酸根计）的含量在0～150μg（25ml比色管）时,磷酸盐的含量与吸光度呈线性关系,相关系数0．9999;用本法测定了国家标准物质茶叶与小麦粉等,测定值与标准参考值基本一致,对实际样品的加标平均回收率在97．0％～105．5％之间。该法操作简单,试剂用量少、重现性好,用微波消解技术大大缩短了样品前处理时间,适于肉制品中磷酸盐含量的测定。     

复合磷酸盐在肉品加工中的应用

磷酸盐广泛应用于肉品加工，对肉品品质的改良起着重要的作用，可以提高肉制品的保水性、凝胶强度、嫩度及出品率。     

低盐肉制品加工技术研究进展

阐述了近些年来国内外低盐肉制品加工技术现状,从低盐加工的必要性、肉制品减盐途径及减盐工艺3个方面论述了肉制品的低盐加工研究进展,就研发当中出现的问题提出了建议,并对该技术在未来的研究方向作了展望。     

食盐对肉制品风味影响及降盐技术研究进展

食盐中的主要成分为NaCl,是食品领域中最常用的一种食品添加剂,食盐可以有效促进风味物质的产生。脂肪氧化以及蛋白质降解过程中产生的小分子物质是肉制品风味物质的主要来源,食盐对肉制品的风味有着重要影响,但食盐摄入过多会对人体健康造成不利影响,因此具备良好风味的低盐肉制品研究已经成为当前的研究热点。文章主要从食盐对肉制品风味的影响以及低钠盐技术在肉制品加工中的应用两个方面进行阐述,以期对食盐在肉制品风味品质中所起的作用及低钠盐肉制品开发提供一定理论参考。     

Simultaneous application of transglutaminase and high pressure to improve functional properties of chicken meat gels

Low-fat protein gels obtained by pressure are softer than those processed by conventional heat treatment. In this study, microbial transglutaminase (MTGase) (0.3%) was added to chicken batters in order to investigate the combined effect of pressure and enzyme on the functional properties of gels. Batters of meat with egg proteins were treated at 500 MPa for 30 min at 40 °C and then heated at 75 °C for 5 min to inactivate the enzyme. Treated samples showed, under confocal microscopy, a more compact and homogeneous microstructure and exhibited a notable increase in hardness and chewiness as compared to controls that were pressurized but contained no MTGase. They were also harder, more chewy and springy but had a similar cohesiveness and cutting force to those obtained by heat alone.     

Synergistic action of transglutaminase and high pressure on chicken meat and egg gels in absence of phosphates

The effects of simultaneous application of microbial transglutaminase (MTGase) and high pressure (HP) (500, 700 and 900 MPa/40 °C/30 min), only pressure under the same conditions or heat (75 °C/30 min) were investigated on chicken batters with the addition of egg components and without phosphates. MTGase gels (700 and 900 MPa) showed marked increases in textural parameters compared to gels without enzyme (NE) or those obtained by heat. The addition of enzyme did not show differences between gels obtained at 700–900 MPa; however, gels obtained at 500 MPa were darker and more reddish than those obtained by heat. MTGase gels were more homogeneous and compact. Thermal analysis revealed that pressure levels above 700 MPa caused as much denaturing as did heat. The microstructure and texture of MTGase gels suggest that a higher amount and heterogeneity of crosslinks was produced when meat and egg proteins were treated in the presence of MTGase under specific conditions of pressure.     

肉制品绿色制造——低钠干腌肉制品研究进展

干腌肉制品因其具有独特的色泽、风味和口感等感官特性而深受广大消费者的喜爱。然而传统干腌肉制品的钠盐（氯化钠）含量过高,人体摄入过高的钠盐会对健康产生不良影响。本文讨论了食盐对干腌肉制品风味、质构和微生物安全的影响,概述了低钠干腌肉制品的相关研究动态,并对低钠干腌肉制品绿色制造的未来研究（如低钠复合盐）提出展望。     

Texturisation and modification of vegetable proteins for food applications using microbial transglutaminase

Microbial transglutaminase (MTG) isolated from Streptomyces mobaraensis has been available on a commercial scale for several years. MTG generates inter- and intramolecular cross-links between γ-carboxylamide groups of glutamine residues and ɛ-amino groups of lysine residues in proteins. Due to its great potential to improve various functional properties of proteins, MTG is mainly used to enhance texture, stability, and water binding. Application of MTG for the production of plant protein-based foodstuffs such as tofu, noodles, bread and bakery products, is still limited to raw materials from soybean and wheat. However, with the increasing demand for vegetarian foods, the utilisation of novel proteins as functional ingredients, e.g. from peas, lupins, sesame, and sunflower, seems promising. To open new horizons for MTG application, this review aims at demonstrating the actual potential of MTG in processing foodstuffs based on vegetable proteins. Particular focus was laid on novel plant protein sources suitable for cross-linking with MTG. Furthermore, strategies for improving texture and nutritive value of the proteins are discussed.     

Analysis of soyabean proteins in meat products: a review

The use of soyabean proteins as meat extenders has spread significantly due to the interesting nutritional and functional properties that are present in soyabean proteins. Together with these, health and economical reasons are the major causes for the addition of soyabean proteins to meat products. Nevertheless, despite the good properties associated to soyabean proteins, there are many countries in which the addition of these proteins is forbidden or in which the addition of soyabean proteins is allowed up to a certain extent. Thus, the need of analytical methods enabling the detection of added soyabean proteins in meat products is obvious. Microscopic, electrophoretic, immunologic, and chromatographic methods are the most widely used for this purpose. However, the detection of soyabean proteins in meat products presents difficulties related to the composition (meat species, meat quality, soyabean protein source, presence of other non-meat proteins, etc.) and the processing of the meat products, and, although these analytical methods have tried to overcome all these difficulties, there is still not a method enabling quantitative assessment of soyabean proteins in all kinds of meat products.     

Production of low-salt restructured fish products from Mexican flounder (Cyclopsetta chittendeni) using microbial transglutaminase or whey protein concentrate as binders

Mexican flounder (Cyclopsetta chittendenni) is an abundant fish specie usually caught as shrimp by-catch in the north of the Gulf of Mexico, but due to its small size is mostly discarded after dying during catching and handling operations. The objective of this work was to determine the feasibility of obtaining low-salt restructured fish products using flounder flesh as raw material. Two levels of salt (10 and 20 g/kg) were tested and microbial transglutaminasa (MTGase) (3 g/kg) or whey protein concentrate (WPC) (10 g/kg) were used as binders. Changes in mechanical properties (texture profile analysis and puncture test), expressible water and colour attributes were measured. Good gels from Mexican flounder were obtained at both salt levels. The use of MTGase improved the mechanical properties at both salt levels. However, WPC improved the mechanical properties of gels obtained only with 20 g salt/kg. The restructured fish products showed a light greyish colour adequate for commercialization.     

低盐肉制品降盐与品质改良加工技术研究进展

肉制品是人类重要的营养物质来源,在肉制品加工过程中食盐是常见且必需的调味料。传统加工肉制品普遍含盐量过高,过量的摄入食盐也已经被证实能引发一系列的心脑血管疾病,因此开发低盐肉制品势在必行。但是,直接减少食盐添加量会对产品风味、口感、质构和保质期产生不利影响。因此,需要通过添加风味提升物、品质改良剂等物质并辅助以品质改良加工技术来优化产品品质。本文论述了国内外低盐肉制品的研究现状,阐述了降盐技术(食盐替代物、改变食盐形态等)和品质改良加工技术(腌制技术、超声波技术、超高压技术等)在肉制品中应用研究进展,指出其研发中存在的主要问题,并对其未来的发展前景进行展望,为低盐肉制品研发提供理论借鉴和参考。     

微生物谷氨酰胺转胺酶的应用进展

谷氨酰胺转胺酶是一种催化酰基转移反应的转移酶,它可使酪蛋白、肌球蛋白、谷蛋白和乳球蛋白等分子之间产生交联,改变蛋白质的功能性质,简述了谷氨酰胺转胺酶在食品应用的一些最新进展。     

Physical properties of acid milk gels: Acidification rate significantly interacts with cross-linking and heat treatment of milk

Rheological properties and microstructure of acid milk gels largely depend on the pre-treatment of the milk, including heating and enzymatic modification of the gel-forming proteins. It was the aim of our study to investigate the impact of the acidification rate on gels which were produced from milk reconstituted from powder containing casein cross-linked by microbial transglutaminase (mTGase), and on gels which were produced from cross-linked raw milk. 3–7% Glucono-δ-lactone (GDL) was used as acidulant. Gel stiffness was determined by dynamic small-deformation rheometry and penetration experiments, and forced syneresis and gel permeability served as indicators for gel microstructure.     

Easy determination of the addition of soybean proteins to heat-processed meat products prepared with turkey meat or pork-turkey meat blends that could also contain milk proteins

The addition of non-meat proteins to processed meat products is limited by regulations. Therefore, this work has investigated the determination of added soybean proteins in commercial heat-processed meat products prepared with turkey meat or pork-turkey meat blends that could also contain milk proteins. The method consisted of extracting proteins from the meat products in a Tris-HCl buffer (pH 8) and analysing the extract by high-performance liquid chromatography with a linear gradient water-acetonitrile containing 0.05% (v/v) TFA. This method enabled the detection and quantitation of up to 0.08 and 0.28% (w/w), respectively, of soybean proteins (related to 6 g initial product) in these products. Satisfactory precision and recovery data were established. Accuracy was evaluated by a comparison of soybean protein contents determined by the proposed method and the existing AOAC official method based on an enzyme-linked immunosorbent assay (ELISA) from which no statistically significant differences were observed.     

Desorption isotherms of salted minced pork using K-lactate as a substitute for NaCl

The aim of this study was to obtain and compare water desorption isotherms of ground meat containing NaCl (0.107 kg NaCl/kg raw-meat dry matter) and/or K-lactate as NaCl substitute at two different levels of molar substitution (30% and 100%). A thin layer of salted ground meat was dried and sampled at pre-determined times. The moisture content of the samples and their water activities (a_w) were measured at 5 °C and 25 °C. Results showed that ground meat with NaCl and/or different K-lactate contents had a similar water desorption isotherm for a_w ranging from 0.7 to 1.0. Below 0.7, the water equilibrium content fell with small decreases in a_w faster for meat with NaCl than for meat with K-lactate. K-lactate could reduce the excessive hardening at the surface of salted meat products. Experimental desorption isotherms were compared to those estimated using two approaches of the Ross equation. Models provided a good fit for the experimental data.     

谷氨酰胺转胺酶改性大豆分离蛋白在低能量肉制品中应用的研究

利用谷氨酰胺转胺酶(MTG)对大豆分离蛋白(SPI)进行改性,并将改性SPI应用于低能量肉制品中。实验表明:除常温黏度外,改性SPI的其他功能性明显优于市售肉用SPI;改性SPI在低能量肉制品中适宜的添加量为5%,改性SPI使产品的固体脂肪乳化稳定性、得率分别比肉用SPI提高了14%和7%,产品的感官指标也明显好于肉用SPI。     

肉制品磷酸盐含量调查与限量研究

系统调研国内外肉与肉制品磷酸盐限量标准,对8大类1015个肉制品样品的磷酸盐含量进行测定,研究肉制品中磷酸盐残留限量.结果表明:与国际食品法典委员会(CAC)标准相比,我国肉制品中磷酸盐最大使用限量偏高,残留限量缺乏标准;常见肉制品中磷酸盐含量的范围为0.62～16.2g/kg,中位值为6.09g/kg,平均值为6.43g/kg,中位值低于平均值,不同种类的常见肉制品中磷酸盐含量存在显著差异(P＜0.05),不同种类的副产物肉制品中磷酸盐含量差异不显著(P＞0.05);最大残留限量因产品种类不同各有差别.