Recent Applications of Spectroscopic and Hyperspectral Imaging Techniques with Chemometric Analysis for Rapid Inspection of Microbial Spoilage in Muscle Foods

Muscle food is one of the most perishable food products because of its vulnerability to microbial spoilage, which can result in critical food safety problems. Traditional techniques for detection and evaluation of microbial spoilage in muscle foods are tedious, laborious, destructive, and time‐consuming. In recent years, spectroscopic and imaging technologies have shown great potentials for the assessment of food quality and safety due to their nondestructive, noninvasive, cost‐effective, and rapid responsive nature. This review focuses on the applications of several valuable spectroscopic techniques including visible and near‐infrared spectroscopy, Fourier transform infrared spectroscopy, fluorescence spectroscopy, Raman spectroscopy, and hyperspectral imaging for the rapid and nondestructive detection of microbial spoilage in common muscle foods such as meat, poultry, fish, and related products. Combined with chemometric analysis, such as spectral preprocessing and modeling methods, these potential technologies have been successfully developed for the determination of total viable count, aerobic plate count, Enterobacteriaceae, Pseudomonas, Escherichia coli, and lactic acid bacteria loads in muscle foods. Moreover, the advantages and disadvantages of these techniques are discussed and some perspectives about future trends are also presented.     

Analysis of proteins in food with electrophoretic and chromatographic methods

The efficiency of electrophoretic methods (gel electrophoresis, isoelectric focusing, twodimensional techniques) and of chromatographic methods (size exclusion and ion exchange chromatography, reversed phase HPLC) to analyze proteins in foods is reviewed. Several selected applications are discussed in detail. The large diversity of proteins in a particular food results in a unique electrophoretic or chromatographic pattern, that can be used for identification purposes, by means of the so called indicator proteins. The adaptability and resolving power of the methods assure their extended application to many protein containing foods. The uniqueness of the patterns obtained warranties differentiations of even closely related animal or plant foods as well as mixtures of them. The methods also allow quantitative determinations of mixtures of foods. Their ease of handling and good reproducibility and reliability favours their use in routine analyses. Numerous investigations on fish, meat and derived products, non-meat proteins in meat products, milk, cheese, cereals and products made of cereals, oilseed proteins, legumes, fruits and vegetables described in the literature are here presented.     

肉品中脂肪检测技术研究进展

脂肪是食品中重要的营养成分,可供给能量和必需脂肪酸,可作为脂溶性维生素载体.肉品中脂肪含量与脂肪酸种类及其组成直接影响肉品的质量和风味.本文介绍动物油脂的相关概念,重点论述肉品中脂肪的提取与检测方法,以及气相色谱法、高效液相色谱法、薄层色谱法和红外光谱法在脂肪酸分析检测中的应用现状.     

A rapid method for determination of the origin of meat and meat products based on the extracted fat spectra by using of Raman spectroscopy and chemometric method

Raman spectroscopy and the principal component analysis (PCA) were successfully applied to differentiate the origin of the meat and meat products based on their extracted fat samples in the present study. A total of 132 extracted fat samples that were obtained from different meat species (cattle, sheep, pig, fish, poultry, goat and buffalo) and their salami products were examined based on their Raman measurements. Then, the collected Raman data were analyzed with a four-stage PCA method. Seven meat species and their salami products were successfully differentiated from each other according to their origin. The results of this study showed that the Raman spectroscopy with a chemometric method can be used to detect the origin of the meat species in a very short analysis time (30 s) after fat extraction, without requiring complicated chromatographic, immunologic or genetic methods and instruments as well as trained personnel.     

Nondestructive Spectroscopic and Imaging Techniques for Quality Evaluation and Assessment of Fish and Fish Products

Nowadays, people have increasingly realized the importance of acquiring high quality and nutritional values of fish and fish products in their daily diet. Quality evaluation and assessment are always expected and conducted by using rapid and nondestructive methods in order to satisfy both producers and consumers. During the past two decades, spectroscopic and imaging techniques have been developed to nondestructively estimate and measure quality attributes of fish and fish products. Among these noninvasive methods, visible/near-infrared (VIS/NIR) spectroscopy, computer/machine vision, and hyperspectral imaging have been regarded as powerful and effective analytical tools for fish quality analysis and control. VIS/NIR spectroscopy has been widely applied to determine intrinsic quality characteristics of fish samples, such as moisture, protein, fat, and salt. Computer/machine vision on the other hand mainly focuses on the estimation of external features like color, weight, size, and surface defects. Recently, by incorporating both spectroscopy and imaging techniques in one system, hyperspectral imaging cannot only measure the contents of different quality attributes simultaneously, but also obtain the spatial distribution of such attributes when the quality of fish samples are evaluated and measured. This paper systematically reviews the research advances of these three nondestructive optical techniques in the application of fish quality evaluation and determination and discuss future trends in the developments of nondestructive technologies for further quality characterization in fish and fish products.     

Screening for tetracycline residues in food products of animal origin in the State of Kuwait using Charm II radio-immunoassay and LC/MS/MS methods

This study surveyed tetracycline residues in foods marketed in Kuwait using various techniques to determine their prevalence above the threshold level. A total of 1517 locally produced and imported food samples of animal origin were collected for analyses, comprising dairy products, eggs and tissue samples (meat, poultry and fish) to give a representative picture of the current use and/or misuse of the drug in Kuwait. Screening was carried out using the Charm II test for tetracycline residues. Positive and suspect positive samples were confirmed by LC/MS/MS. Negative and positive controls, in triplicate, were applied to each method and showed 80–100% agreement. The results showed that 100% of tested eggs, meat, fish, ice cream and cheese were within the limit, while 5% of poultry and 18% of milk samples were above the permitted limit.     

拉曼光谱技术在肉类掺假检测方面的应用研究进展

随着人们对高品质肉要求的提高,对快速、可靠的肉类掺假鉴别需求也不断增加。拉曼光谱技术是基于非弹性散射原理建立起来的分子结构表征技术,该技术能检测出官能团分子的化学结构,经过几十年的发展已广泛应用于食品检测,具有快速、无损、无污染、简单、可重复等优点,在肉品掺假检测方面取得了较好研究结果,应用潜力巨大。本文对近年来拉曼光谱技术在肉类掺假检测方面的研究进展和最新研究成果进行综述,并讨论其存在的问题及发展前景。     

介电谱方法在食品领域中的研究进展

本文评述了近年来食品领域的介电加热技术以及介电谱方法应用于各类食品体系（主要包括水果/蔬菜、食用油、肉鱼、奶及奶制品、蛋、蜂蜜和酒类等）的研究进展。综述了介电加热在食品加工中的优势/局限性,以及介电谱方法在各类食品体系的品质检测及贮藏加工过程的质量监测的可行性,重点介绍介电谱技术分别在各类食品质量检测中的优势差异性,以期该技术能被有效地利用。最后,还对介电谱方法在食品相关领域中的发展趋势进行了评述性展望。     

Incidence and control of Listeria monocytogenes in foods in Denmark

The Danish regulatory policy on Listeria monocytogenes in foods is based on the principles of HACCP and was developed using a health risk assessment approach. The Danish policy focuses examinations and criteria for L. monocytogenes in ready-to-eat foods and is based on a combination of inspection and product-testing. Based on current epidemiological information from several countries, a concentration of L. monocytogenes not exceeding 100 cfu/g of food at the time of consumption, seems to be of low risk to the consumers. In Denmark, ready-to-eat foods have been placed into six categories where absence of L. monocytogenes in 25 g is required in foods heat treated in the final package and in heat-treated as well as preserved, non heat-treated foods which can support growth within the shelf life. This level is necessary in foods capable of supporting growth, in order not to exceed 100 L. monocytogenes per g at the point of consumption. In heat-treated and preserved foods, which are not supportive of growth within the shelf-life and for raw, ready to eat foods, a level below 10 L. monocytogenes per g is regarded acceptable. A level between 10 and 100 L. monocytogenes per g is not satisfactory and a level above 100/g is not acceptable. Data on the qualitative and quantitative occurrence of L. monocytogenes in foods in Denmark are presented and discussed. In 1997 and 1998, greater than 15,000 samples from different categories of food were examined (semi-quantitatively) for the presence of L. monocytogenes. A significant difference could be seen in the number of samples containing more than 100 L. monocytogenes per g, between different categories of foods (1997, P = 0.001; 1998, P = 0.016). In 1997, preserved meat products and preserved fish products and to a lesser extent vegetables and meat or vegetable mayonnaise were more likely to contain high numbers (i.e. above 100 cfu/g) of L. monocytogenes than other food categories. In 1998, preserved meat products, but also heat-treated meat products, vegetables and meat or vegetable mayonnaise had the highest frequency of samples with > 100 L. monocytogenes per g. In a survey performed in 1994 and 1995, 1.3% of ready-to-eat food samples (heat-treated meat products, preserved meat and fish products) were found to be contaminated with L. monocytogenes at a level above 100 cfu/g. The samples included in this survey were primarily products produced by authorized companies and were comprised mainly of vacuum packed products or products packed in modified atmosphere and with long shelf lives, typically above several weeks. The corresponding percentages of positive samples primarily processed in the retail outlets (heat-treated meat products, preserved meat and fish products) in 1997 and 1998 were 0.3% and 0.6%, respectively. The results suggest that ready-to-eat meat and fish products with extended shelf-lives produced by authorized companies are more likely to contain high numbers (> 100 cfu/g) of L. monocytogenes than products processed in the retail sector which often have a shorter shelf life.     

Destructive and non-destructive analytical techniques for authentication and composition analyses of foodstuffs

Compliance with the European legislation on the labeling of fishery products requires standardization and validation of authentication methods. This work presents several protein- and DNA-based speciation techniques; it then examines the potential of trace elements, stable isotope ratios analyses and ¹H, ²H and ¹³C nuclear magnetic resonance (NMR) spectroscopy to identify the origin and production method; and finally introduces some NMR spectroscopic and imaging analyses to estimate, in a fast and non-destructive manner, fat, water and salt content in foods. This may permit the classification of alive fish depending on their fat content, and the on-line optimization of processing conditions.     

Aliphatic secondary amines in meat and fish products and their analysis by high pressure liquid chromatography

A simple and reliable high pressure liquid chromatographic method for aliphatic secondary amines in foods has been developed. The method, which involves rapid extraction, derivatisation with dinitroflurobenzene and one-step liquid chromatographic analysis, allows dimethylamine to be determined without interference by the completing agent, whereas only a slight increase in the response of dimethylamine is caused by large amounts of trimethylamine. The presence of free secondary amines in a number of Italian meat and fish products and their formation as a consequence of some preservation techniques have been investigated. The results are discussed.     

Documentation of fatty acid profiles in lamb meat and lamb-based infant foods

Lamb meat, when used in the weaning diet of children, is presumed to have a lower allergenicity than other forms of red meat. In children with atopic dermatitis and multiple food hypersensitivities, consumption of lamb meat has also resulted in significant clinical improvements in the severity of the eczematous lesions. Lamb meat is also of special interest in infant nutrition because it provides a somewhat unique fatty acid (FA) profile that mirrors what is thought to be optimal for neonatal growth and development. However, very little is known about how the processing of fresh meat (FM) into prepared infant foods influences its FA composition. In this study, we compared the FA profile of FM from suckling lambs with those of homogenized (HO) and lyophilized (LIO) baby foods prepared primarily with lamb meat. The results show that the content of total omega-3 polyunsaturated FAs was the highest in FM (more than 3-fold) compared to commercial baby food, due to largely higher contents of α-linolenic acid (1.5-fold higher), eicosapentaenoic acid (6-fold higher), and docosahexaenoic acid (10-fold higher). Furthermore, arachidonic acid was more than 6-fold higher in FM compared to LIO and HO. Results from this study suggest the possibility of enhancing the FA profile of commercial baby food based on meat by using lamb meat, but care should be taken during processing so that important FAs are not lost. PRACTICAL APPLICATION: In this article, we have documented that meat from the suckling lamb is an interesting and potentially important source of omega-3-FAs, especially some of the long-chain polyunsaturated FAs (LC-PUFAs) that are essential for optimal neonatal growth and development. These results may have special implications to the infant food industry, in that products made using meat from suckling lambs may provide not only exceptional amounts of these FAs, but also other limiting essential nutrients such as iron. This may be especially important in regions of the world, such as Italy, where use of lamb meat as a weaning food is common during infancy.     

生肉新鲜度评定方法研究进展

简单介绍了一些传统的肉品新鲜度评价方法,以及目前国内外利用电子鼻、光谱法、计算机视觉技术评价肉品新鲜度的新进展。最后指出多种技术的融合在肉品新鲜度评定中的应用,对肉质和货架寿命监控具有深远的影响。     

香辛料中植物化学物对肉制品品质及健康功效影响研究进展

香辛料是肉类食品加工过程中常用的一种辅料,其在改善食品风味、抑菌防腐以及延长食品保质期方面的能力得到了广泛的认可。香辛料中的植物化学物种类丰富,在食品加工以及贮藏过程中,可能与肉制品中的营养成分以及风味成分发生相互作用,从而改善食品的营养品质以及风味特性。同时,大多数香辛料中的植物化学物具有一定的抗氧化、抗炎等作用,能够改善食品的生物活性,对人体起到一定的食疗保健作用。本文主要对香辛料中植物化学物对肉制品营养品质、感官品质、防腐保鲜以及健康功效的影响进行了总结,以期为后续探究香辛料中植物化学物在食品体系中的应用及相关作用机理提供参考。     

Classification of Fresh and Frozen‐thawed Fish by Near‐infrared Spectroscopy

ABSTRACT: Frozen fish usually have a much lower market price than fresh fish; therefore, adulteration could occur. This article focuses on the use of near infrared (NIR) spectroscopy to detect whether fish has been frozen‐thawed because NIR spectroscopy has demonstrated the potential for addressing some authenticity issue in foods and is known to be a nondestructive rapid technique. Horse mackerel (n = 162) were evaluated as fresh and frozen‐thawed fish sample. Dry extract spectroscopy by infrared reflection (DESIR) of fresh and frozen‐thawed fish samples was performed on the meat juices then discriminated by principal component analysis (PCA) and multiple linear regressions (MLR). In DESIR spectra, the overall absorbance level was found to decrease in frozen‐thawed samples, indicating the different chemical composition of juice, amount of dry matter, particle size, and their scattering properties. The spectral changes that take place between fresh and frozen‐thawed samples are clearly seen in the 1920‐ to 2350‐nm region. The spectra are dominated by peaks attributed to proteins, in particular, peaks at 1510, 1700, 1738, 2056, 2176, 2298, and 2346 nm. It was found that fresh and frozen‐thawed fish could be separated 100% correctly by DESIR technique.     

植物基脂肪模拟物对肉制品质量影响及应用研究进展

为满足消费者对健康饮食的要求和未来食品供应的可持续性,植物基肉类替代品被广泛开发,具有广阔的市场发展前景。用植物基复合脂肪模拟物代替肉制品中的脂肪,可以减少食物中的脂肪,对消费者的健康有益。本文主要综述了各种胶体对植物基复合脂肪模拟物性质的影响,以便为其在肉制品行业中的应用提供更多的理论支持。多糖类胶体的添加可以提高脂肪模拟物的持水能力,增加肉制品的多汁感;蛋白类胶体可以提高脂肪模拟物的营养特性和弹性,增强咀嚼感和产品质地。此外,通过整理近年来国内外对植物基脂肪模拟物的研究,对植物基脂肪模拟物在肉制品的应用进行了分类和较全面的总结,并基于此阐述了植物基脂肪模拟物对肉制品质量的影响。在肉制品中添加植物基复合脂肪模拟物可以提高肉制品的保水性,在有效地模拟动物脂肪并且不影响产品感官特性的同时延长肉制品的保质期。最后,阐述了块状复合脂肪模拟物开发存在的一些问题和挑战以及潜在的解决方案,为植物替代肉类市场的预期扩张开辟了新的研究方向。     

Polycyclic aromatic hydrocarbons in grilled meat products—A review

Current efforts to detect and quantify carcinogenic polycyclic aromatic hydrocarbons (PAH) in the environment include analyses of foods. Grilled foods have been under scrutiny for almost 20 years. In this review reports concerning PAH contamination of grilled meat products are discussed. It is evident that the level of contamination varies considerably, primarily due to the extent of fat pyrolysis which has taken place. If proper precautions against fat pyrolysis are taken, and out-of-the-ordinary fuels such as crumpled paper or cones are not used, the PAH contamination is reduced substantially. Furthermore, if the relatively low consumption of grilled meat products is taken into consideration public concern over possible health risks due to grilling appears unwarranted.     

冷冻-解冻肌原纤维蛋白结构评价技术研究进展

肌肉类食品在加工和运输中常常经历冷冻-解冻的过程,严重破坏肌原纤维蛋白的结构与功能特性,进而降低肌肉食品的食用价值。因此,评价肌原纤维蛋白冷冻-解冻过程中结构特性的变化对于监测冻融肌肉食品的加工食用价值具有重要意义。本文针对现代检测技术在评价冻融肌原纤维蛋白结构特性方面的研究进展和应用情况进行了系统总结和分析,主要介绍了光谱学技术、显微镜技术、核磁共振技术、蛋白组学和分子动力学模拟等技术的研究应用现状。此外,比较了上述不同检测技术的优缺点,并对现代检测技术在评价肌原纤维蛋白品质特性方面的未来发展方向进行了展望,未来需进一步优化相关检测技术,使其操作更简单、更易实施,以期在冷冻肉品生产和加工工业化中推广应用并提供技术支持,旨在为提高冷冻肌肉食品品质提供科学参考。     

拉曼光谱技术在肉品加工与品质控制中的研究进展

拉曼光谱技术作为新型的光谱检测技术,在分析肉及肉制品结构和理化性质方面具有方便简单、快速无损、高效等优点,已迅速成为肉品研究领域中重要的检测技术之一。本文简述了拉曼光谱技术的原理,综述了拉曼光谱技术在肉品加工中的应用,其中包括肉品加工品质、食用品质以及安全品质等分析方面;进而阐述拉曼光谱技术与化学计量学相结合方式在肉品科学研究和工业生产中的优势,并对拉曼光谱技术在今后肉品领域中的发展进行总结和展望。