Determination of microbial transglutaminase in meat and meat products

Transglutaminase is an enzyme that can be used to cross-link pieces of meat, fish or meat products. The resulting product gives the optical impression of an intact chunk of meat. The usage of transglutaminase as a food additive is permitted in some countries. However, its utilisation has to be declared to ensure transparency for consumers. This paper describes two orthogonal analytical methods suited for the detection of technological relevant transglutaminase concentrations (around 25?mg pure enzyme in 1?kg of product) in meat and meat products. The mass spectrometry-based approach relies on a previous digestion with Achromobacter lyticus protease and LC-MS/MS separation and detection. Sufficient selectivity was obtained by monitoring four different peptides. The orthogonal (complementary and independent), ELISA-based approach relies on two commercially available bacterial transglutaminase-specific antibodies, combined to a sandwich ELISA. The two methods were tested by analysing some 60 samples obtained from the market.     

Application of microbial transglutaminase in meat foods: A review

Microbial transglutaminase (MTG) is an enzyme isolated from a variant of Streptomyces mobaraensis that forms covalent cross-links between protein molecules. Studies are being conducted since last two decades on utilization of MTG in meat foods to improve their characteristics, such as gelation, water-binding, emulsion stability, purge loss, cooking loss, etc. MTG is one of the important topics of interest in meat processing industry due to its advantages in practical utilization and commercial exploitation. This review will discuss about the overall applications of MTG in manipulating the functional properties of meat and meat products by means of various processes such as restructuring, value addition, etc.     

Enzyme-assisted extraction for the HPLC determination of ochratoxin A in pork and dry-cured ham

The extraction of ochratoxin A from meat products is generally carried out using chlorinated organic solvents, such as chloroform or methyl chloride, acidified with hydrochloric or o-phosphoric acid. In this study, an innovative method was developed to extract ochratoxin A from pork and dry-cured ham samples. The method was based on an enzyme-assisted extraction with pancreatin in phosphate buffer pH 7.5. Pancreatin hydrolyses the proteins, so that ochratoxin A, kept in the ionised form, is easily extracted by the aqueous solution. After purification through an immunoaffinity column, ochratoxin A is determined by HPLC with fluorescence detection. The average recovery values were higher than 90.0% and the relative standard deviations were below 5.5%. The limits of detection and of quantification were 0.06 and 0.12?µg?kg^?1, respectively. A comparison between the new enzyme-assisted extraction and an established chloroform method was carried out on six naturally contaminated samples of pork and on 40 samples of dry-cured ham. Significantly higher (p?<?0.001) values of ochratoxin A were obtained on dry-cured ham samples by the enzyme-assisted method.     

肉及肉制品质量属性评价方法及其面临问题

研究者和生产者一直试图通过育种、饲料组分功效量化、饲养方案优化、加工工艺调整和贮藏条件改善等来提升肉及肉制品的产量和品质,而肉及肉制品的质量属性检测分析是衡量肉及肉制品营养价值、安全性、生产能力和市场接受性的重要途经,也是研究者和生产者开展生产和产品市场定位等的重要依据之一。目前肉及肉制品质量属性的检测方法,主要包括通过凯氏定氮法测定蛋白质含量、采用色谱法测定胆固醇含量、色谱法对脂肪酸组分的测定分析和色谱法测定氨基酸组分等对常规营养属性的分析、采用味觉识别系统、质谱分析技术、颜色分析系统对味觉、风味和颜色等感官品质进行的分析等。肉及肉制品质量属性评价方法的完善和改进不仅能够促进肉制品加工产业的发展,还能够更好的促进消费,鉴于此,本文对肉及肉制品质量属性评价方法及其创新进展进行了概述,对肉及肉制品质量安全属性评价方法目前面临的挑战进行了分析,以期为肉制品产业发展和科研提供参考。     

Determination of polycyclic aromatic hydrocarbons (PAHs) in commonly consumed Nigerian smoked/grilled fish and meat

Smoking and/or grilling, when carried out with traditional methods involving direct contact with wood combustion fumes, is responsible for high contamination levels with carcinogenic polycyclic aromatic hydrocarbons (PAHs). The aim of this work was to investigate the PAH content of different smoked or grilled meat and fish products commonly consumed in Nigeria. A rapid method involving microwave-assisted saponification and simultaneous extraction followed by solid-phase extraction (SPE), high-performance liquid chromatography (HPLC) separation and spectrofluorometric detection was employed. Samples that were smoked or grilled using traditional systems, which use a wood fire, were heavily contaminated with benzo[a]pyrene (BaP) at levels ranging from 2.4 to 31.2 µg kg^?1 wet weight. Considerably lower contamination levels were found in samples smoked or grilled in the laboratory using a charcoal fire (BaP from 0.7 to 2.8 µg kg^?1 wet weight). The health risk associated with a daily consumption of 100 g of these products was also evaluated using the margin of exposure (MOE) approach. MOE values lower than 10,000 were obtained for all smoked/grilled commercial samples, indicating a potential concern for consumer health.     

酶制剂在肉制品中的应用

概述了7种用于肉品加工的酶制剂的用法:(1)转谷氨酰胺酶对肉制品的修饰作用;(2)蛋白酶在动物血加工中的应用;(3)猪胰酶对鸡腿的嫰化和提高碎肉利用率的应用;(4)中性蛋白酶从骨头上回收残存肉;(5)酶法制造明胶;(6)酶法用肉来生产出调味浓缩物;(7)蛋白酶作为嫰化剂在宰前嫩化和肉类加工中的应用。     

Structuring processes for meat analogues

BackgroundAnimal-derived protein foods, such as meat, have a large impact on the environment. Meat analogues are products that replace meat in its functionality, i.e. have similar product properties and sensory attributes, which is achieved by the fibrous nature of those products.Scope and approachThe techniques used to make fibrous products that mimic muscle meats are outlined and categorized based on their approach. The bottom-up approach refers to assembly of structural elements that are combined. The top-down approach refers to structuring of biopolymer blends using an overall force field. The strengths and weaknesses of these approaches are discussed in terms of ingredient and equipment use, (achievable) product resemblance, robustness, scalability, and resource efficiency. To enlarge the theoretical framework, the techniques with the top-down strategy are further contextualized by relating to structure formation processes of materials with other applications, and the methods to analyse the fibrous structures are further outlined.Key findings and conclusionsTechniques that follow the bottom-up strategy have the potential to resemble the structure of meat most closely, by structuring the proteins hierarchically through assembly of individual structural components. The top-down strategy is better scalable, is more efficient in its use of resources, but can only create the desired structure on larger length scales. Significant progress has been made on the methods to analyse structured products from the last category. Most analysis methods focussed on the (micro)structural anisotropy of the fibrous products, however there is also a need for methods that allow in situ analysis of the evolution of the structure during processing.     

肉及肉制品真伪鉴别技术研究进展

近年, 肉制品掺杂掺假情况频繁发生, 主要掺假方式是在高价肉制品中掺入廉价的肉类原料, 且在商品标签中不注明成分, 严重损害消费者合法权益。本研究针对目前常见的肉制品真伪鉴别方法, 包括基于形态学、代谢学、蛋白质学和基因学这4大类真伪鉴别方法, 分别介绍各个方法的应用及优缺点, 为肉及肉制品真伪鉴别技术研究提供参考。     

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。     

Determination of PAHs in various smoked meat products and different samples by enzyme immunoassay

An enzyme immunoassay was used to determine benzo[a ]pyrene (BaP) in smoked meat products and other samples of food and environmental origin. The method used has a detection limit (3 σ) of 0.1 μg kg⁻¹ and a coefficient of variation less than 10%. The main aim of the study was to compare the possible influence of different smoking processes and packaging material on the amount of BaP deposited on smoked meat product, mainly different sausages. The lowest amount of BaP was found when smoke produced by steam in the indirect method smoking‐chamber was used. A slightly protective effect of polyamide casing was noted. © 1999 Society of Chemical Industry     

Identification of mechanically separated meat in meat products: a simplified analytical approach by ion chromatography with conductivity detection

Due to food safety concerns, the European Food Safety Authority asked for novel approaches for identifying mechanically separated meat (MSM) in meat products. In this work, a novel and simplified approach for MSM identification in meat products is presented. This approach is based on the calcium and magnesium determination by suppressed cation-exchange chromatography coupled to conductivity detection, after sample mineralisation. One hundred samples of meat products were analysed. The difference between calcium and magnesium concentration (MSM_index) was identified as the most significant parameter useful for discriminating the presence of MSM in the product. The approach was also validated by analysing simulated meat samples containing increasing percentages of MSM. Meat samples with MSM_index higher than 390 mg kg⁻¹ can be classified as MSM products, even if the MSM was obtained at high or low pressure. The protocol is applicable for MSM identification in meat products with MSM percentage higher than 25%.     

驴肉及其制品真伪鉴别技术研究进展

驴肉及其制品因具有极高的营养价值和独特的味道而深受人们喜爱。因其价格居高不下,市场上存在商贩掺假销售问题,极大侵犯了消费者的合法权益甚至危害身体健康,且扰乱了市场诚信。目前,中国尚未建立驴肉产品质量监督检测标准。因此,迫切需要建立一种简单、快速、准确的驴肉产品检测方法。近几年来,聚合酶链反应(polymerase chain reaction,PCR)及其衍生技术成为鉴别驴制品真伪的研究热点,新兴的DNA条形码和数字PCR技术也具有较大的应用潜力。本文综述了驴肉及其制品的形态、代谢物、蛋白质、核酸检测方法的研究进展,这些方法主要包括光谱法、色谱法、酶联免疫吸附法、PCR及其衍生技术等。     

肉制品中牛源性成分多重实时荧光PCR检测 方法的建立及初步应用

目的建立肉制品中牛源性成分的荧光PCR检测方法。方法根据牛特异性线粒体DNA片段,设计合成两对引物,以生、熟牛肉及超市牛肉加工品为材料,建立肉制品中牛源性成分的多重实时荧光PCR检测方法,并用该法与国标法同时对市售的25份肉制品同时进行检测,通过对其他种类的肉源DNA进行扩增验证方法的特异性;对含有不同比例牛肉成分的DNA样本进行检测确定检出限。结果该方法可成功检测出肉制品中的牛源性成分。在25份肉制品检测中,与国标法检测结果一致。该法的特异性为100%,灵敏度检测线为1%。结论本研究成功建立牛源性肉制品的检测方法,该方法快速简便,且具有较高的特异性和灵敏度,可用于市售肉制品中牛源性成分的鉴定。     

肉制品中动物源性成分DNA检测方法的研究进展

肉制品主要成分标识的真实性是全球重要的食品安全问题之一,特别是肉制品中动物源性成分的掺假和标识问题已引发全球关注。如何对肉制品中动物源性成分进行鉴定和标识已成为产品真实性鉴定的热点。基于DNA分子稳定性强的优点,DNA检测技术被广泛用于食品安全检测和监测诸多领域,体现出了灵敏度高、特异性强等优势。本文重点从动物源性检测的靶序列DNA选择和DNA分析技术研究2个方面,阐述了肉制品中动物源性成分定性、定量检测技术的研究和应用,并讨论动物源性成分定量分析的可能性,为我国实施动物源性成分量化监管提供思路。     

天然产物在肉制品护色保鲜中的应用

肉制品营养丰富、富含脂质,在加工和贮存期间,易感染微生物或发生氧化、褪色现象,影响其质量和安全性。研究表明,许多源于植物、动物、微生物的天然产物可以显著延长肉制品的保质期、减少脂类和蛋白质的氧化、抑制微生物生长,在肉制品防腐保鲜方面作用显著,在肉制品保鲜中的应用日益得到关注。本文简单介绍了近年来天然产物在肉制品保鲜护色方面的研究成果,期望为安全、高效的肉制品天然保鲜剂的研发提供思路。      

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.     

Lead and cadmium in meat and meat products consumed by the population in Tenerife Island, Spain

The aim of this study was to determine the levels of lead and cadmium in chicken, pork, beef, lamb and turkey samples (both meat and meat products), collected in the island of Tenerife (Spain). Lead and cadmium were measured by graphite furnace atomic absorption spectrometry (GFAAS). Mean concentrations of lead and cadmium were 6.94 and 1.68 µg kg^-1 in chicken meat, 5.00 and 5.49 µg kg^-1 in pork meat, 1.91 and 1.90 µg kg^-1 in beef meat and 1.35 and 1.22 µg kg^-1 in lamb meat samples, respectively. Lead was below the detection limit in turkey samples and mean cadmium concentration was 5.49 µg kg^-1. Mean concentrations of lead and cadmium in chicken meat product samples were 3.16 and 4.15 µg kg^-1, 4.89 and 6.50 µg kg^-1 in pork meat product, 6.72 and 4.76 µg kg^-1 in beef meat product and 9.12 and 5.98 µg kg^-1 in turkey meat product samples, respectively. The percentage contribution of the two considered metals to provisional tolerable weekly intake (PTWI) was calculated for meat and meat products. Statistically significant differences were found for lead content in meats between the chicken and pork groups and the turkey and beef groups, whereas for cadmium concentrations in meats, significant differences were observed between the turkey and chicken, beef and lamb groups. In meat products, no clear differences were observed for lead and cadmium between the various groups.     

近红外光谱技术结合化学计量学用于畜禽肉制品品质分析的研究进展

肉类作为人体摄入蛋白质的主要来源,随着人们生活水平的提高和对营养健康的追求,肉制品的需求量不断增大,与此同时,肉制品新鲜度、掺杂掺假等肉制品品质领域的质量问题较为多发。为改善传统肉类检测方法耗时费力的现状,肉品质量的检测方法也逐渐趋于多样化。近红外光谱技术目前已广泛应用于包括生物、医药、食品在内的诸多领域。近红外光谱技术与化学计量法结合可对样品进行定性和定量分析,具有快速、无损、高效的优势,适用于肉品及肉制品现场实时监测。在前期研究的基础上,本文综述了近年来近红外光谱技术在畜禽肉制品新鲜度、品种鉴别与掺假分析、产地溯源等方面的研究进展,以期为肉制品品质分析及质量控制提供理论指导。     

肉糜产品中掺杂低档肉类检验技术研究进展

文章综述了利用组织学和生物学来检验肉糜产品中掺杂低档肉制品的主要方法,分别是以DNA为基础的检测技术、以蛋白质为基础的检测技术、免疫学检测技术以及电泳联合检测技术,并探讨不同检验技术的原理、检验结果精确度及其优缺点。