Recent Progress of Hyperspectral Imaging on Quality and Safety Inspection of Fruits and Vegetables: A Review

Objective quality assessment and efficacious safety surveillance for agricultural and food products are inseparable from innovative techniques. Hyperspectral imaging (HSI), a rapid, nondestructive, and chemical‐free method, is now emerging as a powerful analytical tool for product inspection by simultaneously offering spatial information and spectral signals from one object. This paper focuses on recent advances and applications of HSI in detecting, classifying, and visualizing quality and safety attributes of fruits and vegetables. First, the basic principles and major instrumental components of HSI are presented. Commonly used methods for image processing, spectral pretreatment, and modeling are summarized. More importantly, morphological calibrations that are essential for nonflat objects as well as feature wavebands extraction for model simplification are provided. Second, in spite of the physical and visual attributes (size, shape, weight, color, and surface defects), applications from the last decade are reviewed specifically categorized into textural characteristics inspection, biochemical components detection, and safety features assessment. Finally, technical challenges and future trends of HSI are discussed.     

Applications of Hyperspectral Imaging in Chicken Meat Safety and Quality Detection and Evaluation: A Review

Currently, the issue of food safety and quality is a great public concern. In order to satisfy the demands of consumers and obtain superior food qualities, non-destructive and fast methods are required for quality evaluation. As one of these methods, hyperspectral imaging (HSI) technique has emerged as a smart and promising analytical tool for quality evaluation purposes and has attracted much interest in non-destructive analysis of different food products. With the main advantage of combining both spectroscopy technique and imaging technique, HSI technique shows a convinced attitude to detect and evaluate chicken meat quality objectively. Moreover, developing a quality evaluation system based on HSI technology would bring economic benefits to the chicken meat industry. Therefore, in recent years, many studies have been conducted on using HSI technology for the safety and quality detection and evaluation of chicken meat. The aim of this review is thus to give a detailed overview about HSI and focus on the recently developed methods exerted in HSI technology developed for microbiological spoilage detection and quality classification of chicken meat. Moreover, the usefulness of HSI technique for detecting fecal contamination and bone fragments of chicken carcasses are presented. Finally, some viewpoints on its future research and applicability in the modern poultry industry are proposed.     

A Review of Hyperspectral Imaging for Chicken Meat Safety and Quality Evaluation: Application,Hardware, and Software

Food quality and safety issues have received widespread attention around the world. Traditional analytical methods are cumbersome, time consuming, and disruptive. Consumers and businesses are in desperate need of a fast, nondestructive test to evaluate the safety and quality of food. Chicken is an important food source for the human diet and has a high consumption rate. Its quality and safety issues are especially important. The hyperspectral imaging (HSI) technique combines the main characteristics of the spectroscopy technique and the imaging technique to achieve fast, nondestructive testing and demonstrates great potential for evaluating the food safety and quality of chicken. For the past few years, there have been many studies on the HSI technique for the detection and evaluation of chicken meat safety and quality. Therefore, the purpose of this article is to provide a detailed overview of the HSI technique for microbiological safety detection and quality attribute assessments of chicken meat. In addition, the hardware and software used in the HSI systems are also summarized and compared. Finally, some opinions on the focus of future research and its applications in the modern poultry industry are presented.     

Fourier Transform Infrared and Raman and Hyperspectral Imaging Techniques for Quality Determinations of Powdery Foods: A Review

Fourier transform infrared (FT‐IR) and Raman and hyperspectral imaging (HSI) techniques have emerged as reliable analytical methods for effectively characterizing and quantifying quality attributes of different categories of powdery food products (such as milk powder, tea powder, cocoa powder, coffee powder, soybean flour, wheat flour, and chili powder). In addition to the ability for gaining rapid information about food chemical components (such as moisture, protein, and starch), and classifying food quality into different grades, such techniques have also been implemented to determine trace impurities in pure foods and other properties of particulate foods and ingredients with avoidance of extensive sample preparation. Developments of corresponding quality evaluation systems based on FT‐IR, Raman, and HSI data that measure food quality parameters and ensure product authentication, would bring about technical and economic benefits to the food industry by enhancing consumer confidence in the quality of its products. Accordingly, a comprehensive review of the mushrooming spectroscopy‐based FT‐IR, Raman, and HSI literature is carried out in this article. The spectral data collected, the chemometric methods used, and the main findings of recent research studies on quality assessments of powdered materials are discussed and summarized. Providing a review in such a flourishing research field is relevant as a signpost for future study. The conclusion details the promise of how such noninvasive and powerful analytical techniques can be used for rapid and accurate determinations of powder quality attributes in both academical and industrial settings.     

Advances in Feature Selection Methods for Hyperspectral Image Processing in Food Industry Applications: A Review

There is an increased interest in the applications of hyperspectral imaging (HSI) for assessing food quality, safety, and authenticity. HSI provides abundance of spatial and spectral information from foods by combining both spectroscopy and imaging, resulting in hundreds of contiguous wavebands for each spatial position of food samples, also known as the curse of dimensionality. It is desirable to employ feature selection algorithms for decreasing computation burden and increasing predicting accuracy, which are especially relevant in the development of online applications. Recently, a variety of feature selection algorithms have been proposed that can be categorized into three groups based on the searching strategy namely complete search, heuristic search and random search. This review mainly introduced the fundamental of each algorithm, illustrated its applications in hyperspectral data analysis in the food field, and discussed the advantages and disadvantages of these algorithms. It is hoped that this review should provide a guideline for feature selections and data processing in the future development of hyperspectral imaging technique in foods.     

高光谱成像技术在动物源性食品微生物污染快速检测中的应用进展

高光谱成像(hyperspectral imaging,HSI)技术作为一种无损、快速、准确的检测技术在动物源性食品微生物污染检测方面得到了广泛应用.该技术集图像与光谱技术的优势于一体,可同时检测实验样品的物理特征与化学特征.本文系统地综述HSI原理,及其在动物源性食品微生物(菌落总数、腐败菌、致病菌)污染无损检测方面...     

Cold Plasma for Effective Fungal and Mycotoxin Control in Foods: Mechanisms,Inactivation Effects,and Applications

Cold plasma treatment is a promising intervention in food processing to boost product safety and extend the shelf‐life. The activated chemical species of cold plasma can act rapidly against micro‐organisms at ambient temperatures without leaving any known chemical residues. This review presents an overview of the action of cold plasma against molds and mycotoxins, the underlying mechanisms, and applications for ensuring food safety and quality. The cold plasma species act on multiple sites of a fungal cell resulting in loss of function and structure, and ultimately cell death. Likewise, the species cause chemical breakdown of mycotoxins through various pathways resulting in degradation products that are known to be less toxic. We argue that the preliminary reports from cold plasma research point at good potential of plasma for shelf‐life extension and quality retention of foods. Some of the notable food sectors which could benefit from antimycotic and antimycotoxin efficacy of cold plasma include, the fresh produce, food grains, nuts, spices, herbs, dried meat and fish industries.     

Emerging nondestructive approaches for meat quality and safety evaluation—A review

Meat is one of the most consumed agro-products because it contains proteins, minerals, and essential vitamins, all of which play critical roles in the human diet and health. Meat is a perishable food product because of its high moisture content, and as such there are concerns about its quality, stability, and safety. There are two widely used methods for monitoring meat quality attributes: subjective sensory evaluation and chemical/instrumentation tests. However, these methods are labor-intensive, time-consuming, and destructive. To overcome the shortfalls of these conventional approaches, several researchers have developed fast and nondestructive techniques. Recently, electronic nose (e-nose), computer vision (CV), spectroscopy, hyperspectral imaging (HSI), and multispectral imaging (MSI) technologies have been explored as nondestructive methods in meat quality and safety evaluation. However, most of the studies on the application of these novel technologies are still in the preliminary stages and are carried out in isolation, often without comprehensive information on the most suitable approach. This lack of cohesive information on the strength and shortcomings of each technique could impact their application and commercialization for the detection of important meat attributes such as pH, marbling, or microbial spoilage. Here, we provide a comprehensive review of recent nondestructive technologies (e-nose, CV, spectroscopy, HSI, and MSI), as well as their applications and limitations in the detection and evaluation of meat quality and safety issues, such as contamination, adulteration, and quality classification. A discussion is also included on the challenges and future outlooks of the respective technologies and their various applications.     

Principles of Hyperspectral Microscope Imaging Techniques and Their Applications in Food Quality and Safety Detection: A Review

Hyperspectral imaging (HSI) techniques play an important role in the food industry for providing rapid, nondestructive, and chemical‐free detection method, whereas a microscope can provide detailed information about the microstructure of a food item. As an emerging imaging spectroscopy technique, hyperspectral microscope imaging (HMI) technique combines the advantages of HSI with microscopic imaging and has been gradually applied in the food industry. This review introduces the principles of different kinds of HMI techniques, such as fluorescence HMI, visible/near‐infrared HMI, Raman HMI, and infrared HMI. Moreover, detailed applications of HMI techniques are summarized, including evaluation of structures of nutrients, and detection of microorganisms and residues. On the other hand, some challenges and future trends in the applications of these techniques are also discussed. It is concluded that by integrating HSI with microscopy, HMI can not only provide both spectral and spatial information about food substances but also provide their chemical information at the molecular or cellular level. Therefore, HMI techniques have great potentials in nondestructive evaluation of structures of nutrients, and detection of microorganisms and residues for the food industry.     

Food Safety Challenges—A Pakistan's Perspective

Biological, chemical, and physical contamination of foods is a terrifying threat for the health and economic growth in developing societies. Rampantly available literature on foodborne illnesses especially diarrhea among children exclusively depicts the intensified disease burden associated with foodborne illness in the underdeveloped economies. Prevalence of many pathogens in several foods is commonplace in Pakistan. Precise estimates for foodborne illnesses in Pakistan are hard to make because of the absence of any monitoring, surveillance, and infection control. Poor processing and storage of milk, cereal grains, and nuts are a major cause of aflatoxin contamination and mold proliferation. Numerous studies manifest a multitude of foods to be contaminated with heavy metals. Escalating population growth limits the economic potential of the individual and the state through a tendency among the traders and manufacturers to intentionally debase food commodities offered for sale to make profit at the cost of their quality and safety. Therefore, a growing trend of adulteration in foods during the recent past, particularly adulteration of milk, poses a pressing challenge for the government. This review is a concerted attempt to elucidate the prevailing food safety scenario in Pakistan. Information derived from local and related international studies will be presented to clearly depict a picture of food safety in Pakistan. It is proposed that an extensive food safety infrastructure leading to a safer supply of foods needs to be devised, designed, and implemented.     

Recent Developments and Applications of Hyperspectral Imaging for Quality Evaluation of Agricultural Products: A Review

Food quality and safety is the foremost issue for consumers, retailers as well as regulatory authorities. Most quality parameters are assessed by traditional methods, which are time consuming, laborious, and associated with inconsistency and variability. Non-destructive methods have been developed to objectively measure quality attributes for various kinds of food. In recent years, hyperspectral imaging (HSI) has matured into one of the most powerful tools for quality evaluation of agricultural and food products. HSI allows characterization of a sample's chemical composition (spectroscopic component) and external features (imaging component) in each point of the image with full spectral information. In order to track the latest research developments of this technology, this paper gives a detailed overview of the theory and fundamentals behind this technology and discusses its applications in the field of quality evaluation of agricultural products. Additionally, future potentials of HSI are also reported.     

光谱技术在白酒质量控制中的研究进展

白酒质量控制中涉及检测样品成分复杂,采用传统检测方法存在效率较低和环境污染隐患等不足。因此,无损高效的光谱技术成为了分析白酒酿造过程中关键控制指标与质量监测控制的重要手段。本文综述了近红外光谱、拉曼光谱、荧光光谱和高光谱成像技术的特点,其中着重介绍光谱技术应用于酿酒原料关键物质组成、大曲理化指标、酒醅和白酒的无损检测,并讨论了光谱技术在白酒质量控制技术和提高白酒品质及安全性的重要意义。本文进一步提出,未来可扩展光谱技术在白酒检测中的应用范围,如在白酒酿造过程中建立其副产物（酒糟、黄水等）中理化指标的快速检测方法,或进行酱香型基酒三种典型体快速分类,将有益于白酒酿造行业的质量控制效果和提高经济效益。     

Defining and characterizing the “nutty” attribute across food categories

The term “nutty” has been used to describe a vast array of foods including many foods outside the realm of nuts. However, it is not clear if “nutty” is a single term or if it takes various forms, depending on the type of product. The objective of this study was to determine whether a single nutty term could be used to describe nuttiness in all food products or if additional terms were needed. More than 200 products with potential nutty flavor, including nuts, nut spreads, grains/cereals, seeds, beans/legumes, oils, cheeses, fish, and beverages, were studied. Five “nutty” concepts were found and described with terms, definitions, and references with intensity ratings: overall nutty, nutty-beany, nutty-buttery, nutty-grain-like, and nutty-woody. Four of those attributes, excluding overall nutty, were single concept attributes that described subgroups of nuttiness. Specific terms, such as peanut or almond, that describe a certain type of nut but are separate from the “nutty” character were excluded intentionally because they do not describe nutty, they describe an overall concept flavor beyond nutty. A second panel of trained assessors was used to review the lexicon. This panel used this lexicon to describe a set of 10 products (nuts, grains, beans, seeds, cheeses) and determine if any additional attributes were needed to describe nuttiness. All of the products displayed varying intensities of the nutty attributes and the panel found no additional terms for the “nutty” component were needed. The development and verification of the lexicon has real-world application because it can assist in product development and quality assurance when describing foods with a “nutty” attribute. These terms can be applied across all food categories and is not exclusive to characterizing nuts.     

高光谱成像在鱼肉品质无损检测中的研究进展

高光谱成像（hyperspectral imaging,HSI）技术作为一种无损、快速、准确的绿色分析技术在水产品品质检测方面得到了广泛应用。集图像与光谱技术优势于一体,HSI技术可同时检测实验样品的物理和几何特征（颜色、大小、形状和质地等）,还可以提供内部组成成分的化学和分子信息（水分、脂肪、蛋白及其他氢键物质）。本文主要综述了HSI技术在鱼肉品质快速检测方面的最新研究进展,主要涉及到鱼肉的化学组成、物理属性、微生物污染以及新鲜度等四大方面。同时对HSI技术在鱼肉检测中的应用研究进行了展望,以期开发适用于不同检测要求的在线HSI设备。     

Recent Advances in Data Mining Techniques and Their Applications in Hyperspectral Image Processing for the Food Industry

Hyperspectral imaging (HSI) facilitates better characterization of intrinsic and extrinsic properties of foods by integrating traditional spectral and image techniques, in which careful and sophisticated data processing plays an important role. In the past decade, much progress has been made on applying various algorithms to deal with hyperspectral images. This review first introduces the general procedure of hyperspectral data analysis and then illustrates the most typically and commonly used algorithms for denoising, feature selection, model establishment, and evaluation, as well as their applications for assessing food quality, safety, and authenticity. Finally, brief summaries for regression and classification methods are presented. This article will provide a guideline for data mining in the future development of HSI in the food field.     

Phytosterol Oxidation Products: Their Formation,Occurrence, and Biological Effects

Phytosterols or plant sterols are integral natural components of plant cell membranes that are abundant in vegetable oils, nuts, seeds, and grains; as well as added components in various functional foods. Due to their chemical structure, phytosterols are susceptible to oxidation under certain conditions giving rise to a family of compounds known as phytosterol oxidation products (POPs). The following review gives an in-depth account on the formation and occurrence of POPs in foodstuffs. The metabolism and biological effects of these oxides is also discussed in detail.     

谷物中DON、ZEA毒素的净化、检测、 毒性与生物脱毒技术的研究

禾谷镰刀菌在侵染谷物过程中所产生的次生代谢产物——单端孢霉烯族毒素[脱氧雪腐镰刀菌烯醇(deoxynivalenol, DON)、雪腐镰刀菌烯醇(nivalenol, NIV)]以及玉米赤霉烯酮(zearalenone, ZEA)是世界上粮食安全的一个重大问题。毒素经固液萃取技术提取后, 需要通过净化处理才能进行检测与分析。目前有多种净化技术用于毒素的净化, 如免疫亲和柱、多功能净化柱等固相萃取柱等, 以及广泛使用且简便经济的QuEChERS前处理技术。本文还介绍了禾谷镰刀菌毒素中DON、ZEA的检测方法、产毒条件、毒性以及生物脱毒技术等方面的研究进展, 旨在开发与应用更安全、高效、经济的生物脱毒技术进行毒素的防御与去除, 以提供安全、优质的粮食与食品。     

Barcode High Resolution Melting analysis for forensic uses in nuts: A case study on allergenic hazelnuts (Corylus avellana)

Tree nuts are nutritionally important foods, being rich sources of vitamins, minerals, healthy fats and proteins and having cardio protective effects. Despite their healthy attributes, some tree nuts are also known for triggering adverse immune responses to individuals. Thus, an ongoing challenge in molecular biology is to develop rapid, accurate and reliable techniques to identify organisms and their processed foods, particularly those which could be contaminated with allergenic compounds. Lately, in addition to different chemical and immunological methods used, DNA based methods were also applied for this purpose. We describe here a novel, specific and highly sensitive High Resolution Melting analysis based method, using chloroplast barcoding regions (Bar-HRM) in order to a) obtain barcoding information for the major tree nut species (we have also included peanuts and sesame in our study) and b) to quantitatively identify one such allergenic tree nut species, like hazelnut in processed foods. The results show that the proposed method i) is capable of distinguishing among different tree nut species, ii) can be applied to processed tree nut products such as biscuits and iii) can detect a ratio of 0.01% of hazelnut in biscuits. In conclusion, it is demonstrated that BAR-HRM is suitable for the rapid, closed-tube and accurate screening of large numbers of tree nuts and/or of their processed foods and for the identification of allergenic tree nut species contained in processed foods.     

Advanced applications of chemo-responsive dyes based odor imaging technology for fast sensing food quality and safety: A review

Public attention to foodquality and safety has been increased significantly. Therefore, appropriate analytical tools are needed to analyze and sense the food quality and safety. Volatile organic compounds (VOCs) are important indicators for the quality and safety of food products. Odor imaging technology based on chemo-responsive dyes is one of the most promising methods for analysis of food products. This article reviews the sensing and imaging fundamentals of odor imaging technology based on chemo-responsive dyes. The aim is to give detailed outlines about the theory and principles of using odor imaging technology for VOCs detection, and to focus primarily on its applications in the field of quality and safety evaluation of food products, as well as its future applicability in modern food industries and research. The literatures presented in this review clearly demonstrated that imaging technology based on chemo-responsive dyes has the exciting effect to inspect such as quality assessment of cereal , wine and vinegar flavored foods , poultry meat, aquatic products, fruits and vegetables, and tea. It has the potential for the rapid, reliable, and inline assessment of food safety and quality by providing odor-image-basedmonitoring tool. Practical Application : The literatures presented in this review clearly demonstrated that imaging technology based on chemo-responsive dyes has the exciting effect to inspect such as quality assessment of cereal , wine and vinegar flavored foods, poultry meat, aquatic products, fruits and vegetables, and tea.     

Recent Advances in Wavelength Selection Techniques for Hyperspectral Image Processing in the Food Industry

During the past decade, hyperspectral imaging (HSI) has been rapidly developing and widely applied in the food industry by virtue of the use of chemometric techniques in which wavelength selection methods play an important role. This paper is a review of such variable selection methods and their limitations, describing the basic taxonomy of the methods and their respective advantages and disadvantages. Special attention is paid to recent developments in wavelength selection techniques for HSI in the field of food quality and safety evaluations. Typical and commonly used methods in HSI, such as partial least squares regression, stepwise regression and spectrum analysis, are described in detail. Some sophisticated methods, such as successive projections algorithm, uninformative variable elimination, simulated annealing, artificial neural network and genetic algorithm methods, are also discussed. Finally, new methods not currently used but that could have substantial impact on the field are presented. In short, this review provides an overview of wavelength selection methods in food-related areas and offers a thoughtful perspective on future potentials and challenges in the development of HSI systems.