Nondestructive quality evaluation of agro-products using acoustic vibration methods—A review

ABSTRACT

Quality evaluation of agro-products is quite important because it is the basis for growers, distributers, and consumers. Various novel and emerging nondestructive methods were proposed for quality evaluation of agro-products. The acoustic vibration method is one of the major nondestructive methods for agro-products in pre- and postharvest research and industrial practice. Acoustic vibration characteristics of agro-products can be used for texture evaluation, prediction of optimum eating and harvest ripeness, ripeness classification and defect detection. Generally, there are three parts in the process of acoustic vibration method, including the excitation module, signal acquisition module, and signal-processing module. The impact method and forced method are two excitation methods in the excitation module, and there are contact and noncontact sensors for vibration measurement in the signal acquisition module. Noncontact measurement can meet the requirement of rapid and nondestructive measurement, especially for the on-line detection. However, increasing demand for accurate and cost-effective measurement remains a challenge in the agro-products industry. Comparison of acoustic vibration methods and traditional destructive methods was also discussed, which helps to give a more comprehensive assessment for the acoustic vibration method.     

生鲜肉品质安全无损伤检测技术研究进展

生鲜肉品质安全无损检测技术是肉品品质检测的关键技术,日益受到肉制品生产加工企业的重视。本文介绍了国内外肉品无损检测技术的研究情况,包括用于肉品外部品质检测的机器视觉和图像处理技术、用于肉品内外部多品质同时检测的光谱技术、用于胴体检测分级的超声波技术和X射线技术等。研究表明,以上技术可以对胴体和肉品的品质参数进行快速无损检测,但这些研究大部分停留在实验系统的开发阶段,没有大规模用于工业生产。文中指出,为满足工业生产无损检测的要求,需要将多种检测技术、检测手段进行融合和集成,利用多种信息对肉品品质安全进行无损检测,开发出用于工业生产的在线无损检测系统。     

On-line detection of eggshell crack based on acoustic resonance analysis

An on-line system based on acoustic resonance was developed for eggshell crack detection. The system employed digital signal processing (DSP) as core processor to collect and analyze the response signal of shell eggs. The effects of excitation point, speed of the conveying system, impact intensity and egg mass on the frequencies response signals were investigated. Based on previous experiments, differences between the signals of intact eggs and cracked eggs were analyzed. Five excited resonance frequency characteristics expressing the differences between intact and cracked eggs were explored as input vectors. A simple and robust calibration model was built to discriminate intact and cracked eggs, while meeting speed requirement of on-line measurement. The identification rates for intact and cracked eggs were 100% and 96.1% respectively. It is concluded that the system has significant potential in the on-line detection of cracked eggs.     

基于声振频带幅值特性香梨硬度无损检测研究

本文采用压电梁式传感器对香梨进行激励感测,分析了该装置采集的响应信号的稳定性,研究了频带幅值参数与香梨硬度的相关性,并采用频带幅值参数对其硬度进行主成分回归(PCR)分析,建立香梨硬度的检测模型。研究结果表明:香梨声振检测装置的时域和频域信号稳定,在320~880 Hz波段可提取8个频带幅值参数,它们与M-T检测硬度的相关系数最高仅为0.63,采用这些频带幅值PCR法构建的香梨硬度检测模型的校正集和验证集相关系数r_c与r_v分别为0.77和0.66,均方根误差RMSEC和RMSEV分别为1.23和1.59,对香梨硬度的检测敏感度仅为51.56%,模型检测性能较低、稳定性较差;引入香梨质量对模型修正,r_c和r_v分别升高到0.81和0.72,RMSEC和RMSEV分别降低为1.13和1.44,模型的检测性能和稳定性得到明显提高,对香梨硬度变化的敏感度提高至58.28%,与M-T检测法敏感度的差异仅为6.21%,可以适用于香梨硬度的无损检测。     

果汁中农药残留和棒曲霉素及其去除方法的研究进展

农药残留和棒曲霉素是影响果汁质量的重要因素．原料果的品质及加工工艺均会影响其含量。农药残留和棒曲霉素快速准确的检测及采用合理的加工工艺对果汁生产非常重要。就果汁中农药残留和棒曲霉素的种类和来源进行了综述．回顾了近年来常用的检测方法和去除方法，并报告了一些相关研究工作的进展。     

猪肉瘦肉率和背膘厚度在线检测系统的研究

目的 建立猪肉瘦肉率和背膘厚度在线检测系统。方法 利用图像处理技术设计屠宰线上猪胴体无损等级评定系统, 实现对猪肉品质的在线分级。结果 针对猪肉的瘦肉率检测提出了一种依据直方图的检测方法, 针对猪肉胴体背膘厚度肋骨位置的检测提出了三种确定方法: 按照比例来确定, 按照轮廓拐点来确定, 直接数取肋骨的数量来确定。结论 本研究设计的猪胴体无损等级评定系统对于实时检测评估猪肉品质具有很大的潜力。     

水果病虫害无损检测技术研究进展

水果的病害和虫害是影响水果品质等级鉴定的重要因素。水果在生长、加工、贮藏、运输过程中容易受到病菌侵染和害虫侵蚀,这将造成水果品质降低,同时对食品安全也会造成不良影响。本文综述了X射线成像技术、计算机视觉技术、核磁共振技术、光谱技术、新兴传感器技术等无损检测技术在水果病虫害识别与检测中的应用进展,并分析各技术的优势和劣势,重点介绍了高光谱成像技术在水果病虫害识别与检测方面的应用进展,分析存在的问题、展望发展趋势,为后续研究提供参考。     

Critical assessment of methods for measurement of temperature profiles and heat load history in microwave heating processes—A review

Limitations of microwave processing due to inhomogeneities of power input and energy absorption have been widely described. Over- and underheated product areas influence reproducibility, product quality, and possibly safety. Although a broad range of methods is available for temperature measurement and evaluation of time/temperature effects, none of them is sufficiently able to detect temperature differences and thermally induced effects within the product caused by inhomogeneous heating. The purpose of this review is to critically assess different methods of temperature measurement for their suitability for different microwave applications, namely metallic temperature sensors, thermal imaging, pyrometer measurement, fiber optic sensors, microwave radiometry, magnetic resonance imaging, liquid crystal thermography, thermal paper, and biological and chemical time-temperature indicators. These methods are evaluated according to their advantages and limitations, method characteristics, and potential interference with the electric field. Special attention is given to spatial resolution, accuracy, handling, and purpose of measurement, that is, development work or online production control. Differences of methods and examples of practical application and failure in microwave-assisted food processing are discussed with a special focus on microwave pasteurization and microwave-assisted drying. Based on this assessment, it is suggested that infrared cameras for measuring temperature distribution at the product surface and partially inside the product in combination with a chemical time/temperature indicator (e.g., Maillard reaction, generating heat-induced color variations, depending on local energy absorption) appear to be the most appropriate system for future practical application in microwave food process control, microwave system development, and product design. Reliable detection of inhomogeneous heating is a prerequisite to counteracte inhomogeneity by a targeted adjustment of process and product parameters in microwave applications.     

Smart packaging: sensors for monitoring of food quality and safety

The development of chemical sensors and biosensors over several decades has been investigated resulting in novel and very interesting sensor devices with great promise for many areas of applications including food technology. The incorporation of such sensors into the food packaging technology has resulted what we call smart or intelligent packaging. These are truly integrated and interdisciplinary systems that invoke expertise from the fields of chemistry, biochemistry, physics and electronics as well as food science and technology. Smart packaging utilises chemical sensor or biosensor to monitor the quality & safety of food from the producers to the costumers. This technology can result in a variety of sensor designs that are suitable for monitoring of food quality and safety, such as freshness, pathogens, leakage, carbon dioxide, oxygen, pH, time or temperature. Thus, this technology is needed as on-line quality control and safety in term of consumers, authorities and food producers, and has great potential in the development of new sensing systems integrated in the food packaging, which are beyond the existing conventional technologies, like control of weight, volume, colour and appearance.     

涤纶工业长丝毛丝在线检测系统的研究

涤纶工业长丝毛丝在线检验工序一直制约着生产全流程智能制造的实现,为解决涤纶工业长丝毛丝检测问题,完善在线质量检测体系,提出一种借助机器视觉智能检测技术识别毛丝和数量统计的方法.以毛丝长度作为判断依据,基于LabVIEW图像处理技术,采用图像增强、二值化处理、数学形态学等方法获取毛丝图像,并提取长度信息.通过试验得到毛丝...     

Quantifying and predicting meat and meat products quality attributes using electromagnetic waves: An overview

The meat industry needs reliable meat quality information throughout the production process in order to guarantee high-quality meat products for consumers. Besides laboratory researches, food scientists often try to adapt their tools to industrial conditions and easy handling devices useable on-line and in slaughterhouses already exist. This paper overviews the recently developed approaches and latest research efforts related to assessing the quality of different meat products by electromagnetic waves and examines the potential for their deployment. The main meat quality traits that can be assessed using electromagnetic waves are sensory characteristics, chemical composition, physicochemical properties, health-protecting properties, nutritional characteristics and safety. A wide range of techniques, from low frequency, high frequency impedance measurement, microwaves, NMR, IR and UV light, to X-ray interaction, involves a wide range of physical interactions between the electromagnetic wave and the sample. Some of these techniques are now in a period of transition between experimental and applied utilization and several sensors and instruments are reviewed.     

Research advances in nondestructive determination of internal quality in watermelon/melon: A review

Watermelon/melon is a healthful and popular fruit in the world. The main indices of internal qualities of watermelons/melons are soluble solids content (SSC), firmness, internal defect, and maturity. Internal qualities of watermelons/melons were mostly assessed by human experience in the last decades. It was inconsistent, subjective, and slow. Research workers have paid attention to this issue and have done a lot of work on measuring the internal qualities of watermelons/melons nondestructively and rapidly. This review gives a comprehensive overview of the nondestructive determination techniques on internal quality assessment of watermelons/melons including acoustic technology, dynamic technology, electrical and magnetic technology, X-ray and computed tomography, and near infrared (NIR) spectroscopy. A comparison of these techniques indicates that on-line measurement by Vis/NIR spectroscopy will play an important role in the further study.     

On-line estimation of eggshell strength based on acoustic impulse response analysis

This paper proposes a nondestructive method for on-line estimation of eggshell strength based on acoustic resonance analysis. The system employed digital signal processing (DSP, TMS320F2812) as core processor to collect and analyze the response signal of eggshell. Fast Fourier Transform (FFT) and Discrete Cosine Transform (DCT) were used to transform the time domain signal into frequency domain signal for next analysis. Synergy interval partial least square (si-PLS) combined with multiple stepwise regression was used to establish a linear calibration model for eggshell strength measurement. The performance of the optimal model using 11 frequency variables was achieved, with R (correlation coefficient) of 0.776 and RMSEP (root mean square error of prediction) of 3.010 in prediction set. Good consistence confirmed that the acoustic resonance system has significant potential in on-line estimation of the eggshell strength.Industrial relevanceWith processing and handling procedure continues increasing in egg production, the possibility of the presence of eggshell crack sharply increases. In such case, it is essential to measure the strength of eggshell, so as to maintain the balance between eggshell strength and the handling load in the processing of egg collection, sorting and transportation. This work proposes a nondestructive method for on-line estimation of eggshell strength based on acoustic resonance analysis, and builds a robust calibration model to improve the prediction ability. The research data presents a potential way for on-line and non-destructive measurement of eggshell strength in egg industry.     

声发射技术在家具质量检测中的应用

本文探讨了声发射技术应用于家具质量检测的适用性和实用性。首先,介绍了声发射检测技术的概念、基本原理、应用领域、源定位方法和信号处理技术,然后归纳总结了其应用特点,并结合其特点初步探索了其在名贵传统家具的无损鉴定及建立家具质量量化检测体系等方面的应用。     

鱼油品质光谱检测技术的研究进展

鱼油制品具有丰富的营养功能,深受消费者喜欢。常规检测鱼油品质方法,由于操作困难、破坏性强、试剂污染等缺点,不能满足快速无损、高效无污染的检测要求。光谱检测技术(如近红外光谱技术和核磁共振技术),伴随着化学计量学的发展,突破了常规检测方法局限性,是鱼油品质检测技术的发展趋势。在大量文献的基础上,综述目前光谱检测技术在鱼油品质的应用情况,特别分析光谱方法、化学计量学和仪器设备,指出现阶段利用光谱技术检测鱼油品质存在的主要问题,并对今后的研究方向进行展望。     

快速蒸发电离质谱法在食品质量安全快速检测中的应用

快速蒸发电离质谱技术(rapid evaporation ionization mass spectrometry, REIMS)是环境电离-质谱技术迅速发展的最新成果, 也是近几年质谱检测领域的热点。通过电离切割组织或其他生物样品产生的含丰富特定区域生物特征的气溶胶, 借助高分辨率质谱对其进行原位、在线、实时、快速分析。随后进行计算机数据建模与可视化, 实现目标物质的快速检测。本文综述了REIMS技术的发展概况、主要结构组成、检测原理、采用的常规数据处理方法及其在食品检测领域中的具体应用, 包括肉品掺假鉴别、风味物质检测、品种鉴别、干果真实性评估、果汁风味物质鉴别等。主要通过对当前快速蒸发电离质谱技术在不同食品检测领域的应用研究进展进行综述, 以期为食品安全快速检测等相关研究领域科研工作者提供一定的思路与参考。     

化学计量学方法在果蔬领域的应用

果蔬富含维生素、矿物质和膳食纤维等营养物质,是人们补充营养必不可少的食品之一。但果蔬在加工储存过程中存在农药残留、营养成分损失、品质下降等一系列问题,如何保证果蔬的食用安全和食用品质一直是果蔬研究领域的焦点。测定果蔬的营养理化指标是评价果蔬品质的有效手段,然而过多的指标通常会产生大量繁杂冗余的数据,需要专门的工具对数据进行分析处理。化学计量学方法是进行数据处理的有效手段,近年来在果蔬生产加工方面已得到广泛应用。本文综述了主成分分析、偏最小二乘和人工神经网络等化学计量学方法在果蔬品质差异评价、果蔬农药残留检测、果蔬理化分析、果蔬保鲜效果优劣及果蔬生产工艺优化等方面的应用,讨论了各种方法的优缺点,为化学计量学方法在果蔬领域中的应用提供参考。     

梨果实近红外光谱无损检测技术研究进展

梨果实容易发生果肉褐变,即使外观完好,也有可能内部发生劣变。近红外光谱(NIRS)分析技术以其快速、无损、多组分同时测定等优势,近年来在梨果实无损检测应用的研究中取得重要进展。本文介绍了NIRS检测技术的原理与方法,综述了国内外应用NIRS无损检测技术在梨糖度、酸度、硬度等内部品质、褐变和损伤等内部缺陷方面及便携式检测的研究进展,并对其存在的问题及应用前景进行了展望。     

基于网络拓扑的生鲜食品供应链管理的无线传感器网络设计

基于ZigBee标准无线传感器网络(WSN),开发设计了一套实时生鲜食品供应链监控系统,并改进了综合传感器的可配置架构和网络交换方案。从性能方面对192个终端设备的树型拓扑无线传感器网络系统和80个终端设备的星型拓扑无线传感器网络系统进行了实现和评价。测试结果表明,数据通信的成功率在99%以上,理论分析和实际测量的结果表明,终端设备的功能及寿命足以满足供应链监控的应用。     

粮仓中小麦的声学检测方法研究进展

小麦的贮藏品质关系到粮食的数量安全和质量安全,对小麦品质的声学检测技术的应用研究进行了综述,首先对农产品的声学特性的概念进行了简述,然后从以下几个方面综述了声学检测技术的研究进展:通过采集并分析小麦粉调制面团过程中的声学特性测定不同小麦粉的品质;或采集并分析小麦籽粒在特定装置中的声音信号来达到测定小麦品质的目的;或通过声学方法测定粮食的密度或采集分析粮仓中害虫的声信号来监测粮仓中小麦的贮藏状态。