西瓜子破壳力学特性的影响因素

目的：对西瓜子破壳载荷的影响因素进行研究，为其破壳加工工艺提供理论依据；方法：设计西瓜子挤压破壳试验，对影响西瓜子破壳载荷的不同因素：加载位置、加载速率、西瓜子宽度和含水率进行研究，求出回归方程并进行方差分析；结果：加载位置应位于西瓜子最大宽度两侧；西瓜子的含水率是影响破壳载荷的显著因素，适当增加可以减小破壳载荷并降低能耗；根据西瓜子宽度设置挤压间隙，增大加载速率可提高生产效率，这2个因素都不影响破壳载荷。     

Challenges and solutions of optical-based nondestructive quality inspection for robotic fruit and vegetable grading systems: A technical review

BackgroundOptical techniques, including computer vision, spectral imaging, near-infrared technology and other emerging imaging and spectroscopy techniques, have been rapidly developing and widely applied in fruit and vegetable grading systems for nondestructive quality inspecting and grading over the past decades. However, automatic detection of quality and grading is still difficult due to some still existing challenges, which are the key of blocking their commercialization in robotic fruit and vegetable grading systems. The challenges include the following aspects: the influence of physical and biological variability, whole surface detection, discrimination between defects and stems/calyxes, unobvious defect detection, robustness of the features and algorithms, as well as rapid optical detection system development. These challenges can reduce the fruit or vegetable quality inspection accuracy, thus greatly reducing automatic level of the quality inspecting and grading machines.Scope and approachAs agricultural engineers with about eight years of technical experience in fruit grading systems, we believe the ultimate goal of each scientific research should seek its task in serving the engineering. So, we have made many attempts to solve the challenges and increase the automation of the grading machines.Key findings and conclusionsThe review gives a detailed summary about the challenges and solutions of optical-based nondestructive quality inspection for fruit or vegetable grading systems from the perspective of engineering. Particular attention has been paid to the techniques that can improve the automation degree of the grading robot in this review. The advantages and disadvantages of the solutions are compared and discussed. Additionally, the remaining engineering challenges and future trends are also discussed.     

不同品种西瓜、甜瓜中6种重金属富集能力的差异性分析

目的 中文为明确不同品种西瓜、甜瓜重金属富集能力的差异。方法 本文以不同品种西瓜、甜瓜果实及其对应根际土壤为试验材料,采用ICP-MS(电感耦合等离子体质谱仪)分析了试验材料中铬(Cr)、镍(Ni)、铜(Cu)、砷(As)、镉(Cd)、铅(Pb) 6种重金属元素的含量,进而通过富集系数,分别评估了西瓜、甜瓜6种重金属富集能力的差异,并采用聚类分析,以6种重金属为评判指标,开展了受试品种重金属富集能力强弱的分类与探讨。结果 结果表明：9个西瓜、10个甜瓜品种6种重金属含量变异系数范围分别是11.756%~18.943%、19.519%~48.110%,不同品种西瓜、甜瓜富集系数极大值与极小值比值范围分别为2.0～3.7、1.7～22.2;西瓜甜瓜富集能力较强的重金属种类有所不同,西瓜为Cd和Pb,甜瓜为Cd和As;9个西瓜、10个甜瓜品种6种重金属富集能力可分别聚为4类和3类,西瓜E212和甜瓜K11-4品种兼具6种重金属富集能力相对较弱的特点。结论 上述结果表明：西瓜、甜瓜6种重金属含量及富集能力品种间存在较大差异,西瓜E212和甜瓜K11-4品种适合作为6种重金属低富集品种,应用于污染区的栽培种植。     

果蔬品质安全近红外光谱无损检测研究进展

我国果蔬产量和销量均居世界首位, 生产和消费正由产量规模型向质量效益型转变, 对果蔬品质安全检测的要求与日俱增。当前, 果蔬采后品质分级、安全检测和货架期评价尚处于人工或简单机械的粗略检测阶段, 果蔬的内在组分和内部缺陷采用破坏性抽检, 货架期采用人工经验式, 效率低且成本高。近红外光谱检测技术具有无损伤、快速绿色、适于现场检测和在线分析等优势, 适于构建果蔬快速、高精度、智能化的检测系统。本文分析了果蔬产业的发展现状及关键技术需求, 阐述了近红外光谱技术的基本原理, 分别从果蔬内部光传输特性、内在组分检测、隐形缺陷判识、货架期评价4个方面论述了国内外近红外光谱技术在果蔬品质安全检测应用中的最新研究进展, 深入分析了近红外光谱技术在果蔬品质安全检测中的存在的问题, 并指出了解决思路和进一步研究的方向。     

肉品质量无损检测技术研究进展

肉类和肉类食品品质与安全检测一直是肉类行业中关注的热点。本文综述了超声波、电磁特性、电子鼻与电子舌、计算机视觉、光谱分析等几种当前主要无损检测技术在肉品质量评价中的研究进展。其中,重点介绍了光谱分析中具有图谱合一、可同时获取样品内外部品质信息特性的高光谱成像技术及其在国内外肉品品质检测中的应用现状,提出了该技术在肉类品质检测研究方向的几点思考,并展望了无损检测技术在肉品品质检测中的研究前景,以期为后续研究提供参考。     

Nondestructive determination of pear internal quality indices by visible and near-infrared spectrometry

The relationships between the nondestructive visible and near-infrared (Vis-NIR) measurements and the internal quality indices of pear fruit were established, and the potential of Vis-NIR spectrometry technique was investigated for its ability to nondestructively measure soluble solids content (SSC) and firmness of intact pear fruit. Intact pear fruit were measured by diffuse reflectance Vis-NIR in 350–1800 nm range. In this study, calibration models relating Vis-NIR spectra to SSC and firmness were developed based on multi-linear regression (MLR), principal component regression (PCR) and partial least squares regression (PLSR) with respect to the logarithms of the reflectance reciprocal log(1/R), its first derivative D₁ log(1/R) and second derivative D₂ log(1/R). The best combination, based on the robust models and the prediction results, was PLSR method with respect to log(1/R) at equatorial position of pear fruit. The PLSR models for prediction samples resulted correlation coefficient (r_p) of 0.912 and 0.854, and root mean standard error of prediction (RMSEP) of 0.662°Brix and 1.232 N for SSC and firmness, respectively. The results indicate that Vis-NIR spectrometry technique could provide an accurate, reliable and nondestructive method for assessing the internal quality indices of intact pear fruit.     

禽蛋品质无损检测的研究现状及其展望

近年来,国内外已有不少学者对禽蛋品质的无损检测进行了研究,其中禽蛋蛋壳强度检测、禽蛋裂纹检测及禽蛋新鲜度检测为研究热点,而禽蛋微小裂纹、散黄蛋和双黄蛋的快速无损检测则是研究难点。本文通过论述机器视觉技术、光谱检测技术、声学技术、电子鼻技术以及称重-测距法等无损检测方法,依次分析国内外对禽蛋外观品质、禽蛋蛋壳强度、禽蛋裂纹和禽蛋新鲜度的研究现状,并对禽蛋品质无损检测的发展趋势进行了展望,以期为今后禽蛋品质无损检测的深入研究提供参考。      

食品微生物定量检测内部质量控制方法的应用

目的 加强实验室食品微生物定量检测的内部质量控制。方法 以蜂蜜中嗜渗酵母检测为例,根据内部质量控制技术要求,按照GB 14963-2011进行检测,采用空白对照、暴露实验、培养基质控、人员比对、加标回收、方法比对实验,对检测过程和结果进行质量控制。结果 空白对照和暴露实验结果有效,生长率为0.81,人员比对绝对差值0.11 log10(CFU/g),加标回收率73~93%,方法比对绝对差值0.21 log10(CFU/g)。结论 可用于食品微生物定量检测的内部质量控制。     

高光谱成像在水果内部品质无损检测中的研究进展

为了分析水果无损检测领域的研究趋势及热点前沿,为该领域的研究提供参考依据,基于文献计量软件CiteSpace,以2012年—2022年在CNKI（中国知网）及Web of Science核心数据库中发表的相关文献为主体,对该研究领域的发文量、作者、发文国家、机构、热点及前沿进行定量可视化研究。共纳入中文文献1322篇,外文文献3526篇,国内外文献的发文量总体均呈现上升趋势,国外的研究者合作团体更为庞大,中国和美国已成为全球该研究领域内最具影响力的国家。分析可知,研究热点是苹果,对水果的品质检测是研究前沿,光谱分析技术是该领域最常用的研究方法,国内外相关研究在热点领域具有一致性,但侧重点和研究进展略有不同,基于此,未来国内应加强研究团体之间的学术合作,关注该领域的研究前沿,结合计算机领域更新新的检测技术将会是新的研究方向。     

Variable selection for partial least squares analysis of soluble solids content in watermelon using near-infrared diffuse transmission technique

This work is focused on the variable selection in building the partial least squares (PLS) regression model of soluble solids content (SSC) that is used to evaluate quality grading of watermelon. The spectra were obtained by the near infrared (NIR) spectrometer with the device designed for on-line quality grading of watermelon and the spectra of 680–950 nm were adopted to analysis. The variable selection was based on Monte-Carlo uninformative variable elimination (MC-UVE) and genetic algorithm (GA). In comparison of the performances of the full-spectra (680–950 nm) PLS regression model and the feature wavelengths PLS regression model showed that the MC-UVE–GA–PLS model with baseline offset correction combined multiplicative scatter correction (MSC) pretreatment was much better and 14 variables in total were selected. The correlation coefficients between the predicted and actual SSC were 0.885 and 0.845, the root mean square errors were 0.562 °Brix and 0.574 °Brix for calibration and prediction set, respectively. This work can make a great contribution to the research of on-line quality grading for watermelon nondestructively.     

Combination of high-intensity pulsed electric fields with natural antimicrobials to inactivate pathogenic microorganisms and extend the shelf-life of melon and watermelon juices

The effect of high-intensity pulsed electric field (HIPEF) combined with citric acid (0.5-2.0%, w/v) or cinnamon bark oil (0.05-0.30%, w/v) against populations of Escherichia coli O157:H7, Salmonella Enteritidis and Listeria monocytogenes in melon and watermelon juices were evaluated. Microbiological shelf-life and sensory attributes were also determined. Populations of E. coli O157:H7, S. Enteritidis and L. monocytogenes were reduced by more than 5.0log(10)CFU/ml in HIPEF-processed melon (35kV/cm for 1709 micros at 193Hz and 4 micros pulse duration) and watermelon (35kV/cm for 1682 micros at 193Hz and 4 micros pulse duration) juices containing 2.0% and 1.5% of citric acid, respectively, or 0.2% of cinnamon bark oil. In addition, these treatments were also able to inactivate mesophilic, psychrophilic and, molds and yeasts populations, leading to a shelf-life of more than 91 days in both juices stored at 5 degrees C. Hence, the microbiological quality and safety of these fruit juices by combining HIPEF and citric acid or cinnamon bark oil were ensured. However, the taste and odor in those HIPEF-treated melon and watermelon juices containing antimicrobials were significantly affected. Therefore, further studies are needed to decrease the impact on the sensory attributes by using antimicrobials.     

高光谱成像技术在禽类产品品质无损检测中的研究进展

应用新兴的高光谱成像技术对禽类产品品质进行无损检测是当前的研究热点之一。本文介绍了该技术的基本原理,总结分析了国内外禽类产品品质高光谱图像无损检测的研究现状和存在问题,主要针对其在禽类产品表面污染物检出、禽类表面皮肤肿瘤检出及禽蛋种蛋孵化情况识别中的应用进行综述,提出了对该技术在禽类产品品质检测未来研究发展方向的几点思考,以期为相关研究提供参考。      

纳米技术在食用油脂质量与安全检测中的应用

食用油脂的质量与安全检测一直是食品分析领域的难点和热点问题。纳米技术在油脂分析中显示了良好的应用前景。该文概述了纳米技术在油脂质量与安全检测研究中的最新进展,并介绍了用于油脂检测的不同纳米材料。讨论了纳米技术在油脂检测中的发展趋向。     

质控图在乳粉中左旋肉碱检测内部质控中的应用

目的建立质量控制图评估实验室对乳粉中左旋肉碱检测的受控情况。方法以有证标准物质作为控制样品,依据GB 29989-2013《食品安全国家标准婴幼儿食品和乳品中左旋肉碱的测定》检测其中左旋肉碱的含量,选取均值图和极差图用作分析。结果统计了27组乳粉中左旋肉碱的检测结果,得出乳粉中左旋肉碱的平均值为16.80 mg/100 g,标准偏差为0.96 mg/100 g,极差的平均值为0.45 mg/100 g,极差的标准偏差为0.40mg/100g。结论质控图表明,实验室乳粉中左旋肉碱的检测方法受控。质量控制图操作简便,有助于实验室及时发现失控情况。但实验室要注意对控制数据的长期评估,以匹配实验室当前的检测情况。     

杏采后的品质变化及保鲜技术的研究进展

我国鲜杏产量很大,但是采后易腐烂变质,造成了很大的经济损失。介绍了杏采后品质的变化,并探讨了杏果采后的贮藏保鲜技术如涂膜保鲜、冷藏保鲜、气调保鲜、钙处理等。微观多糖纳米结构研究表明,杏采后质地变化是由多糖链降解引起,冷藏和气调技术可有效维持杏的抗氧化等特性。通过延缓杏果实内生化反应和多糖链降解可有效延长采后杏的货架期。     

Influence of physical and biological variability and solution methods in fruit and vegetable quality nondestructive inspection by using imaging and near-infrared spectroscopy techniques: A review

Over the past decades, imaging and spectroscopy techniques have been rapidly developing and widely applied in nondestructive fruit and vegetable quality assessment. The physical properties (including size, shape, color, position, and temperature) and biological properties (including cultivar, season, maturity level and geographical origin) of fruits and vegetables vary from one to another. A great variety of physical and biological properties of agricultural products influence the optical propagation properties and interaction behaviors with incident light, thus decreasing the quality inspection accuracy. Many attempts have been made in image correction and spectral compensation methods to improve the inspection accuracy. This paper gives a detailed summary about influence of physical and biological variability, as well as the correction and compensation methods for eliminating or reducing the effects in fruit and vegetable quality nondestructive inspection by using imaging and spectroscopy techniques. The advantages and disadvantages of the solution methods are discussed and summarized. Additionally, the future challenges and potential trends are also reported.     

我国国家标准和行业标准中黄曲霉毒素测定方法综述

黄曲霉毒素广泛存在于自然界中,能够污染多种农作物和食品,对人类的健康造成极其严重的危害。目前,尚无绝对有效的措施避免黄曲霉毒素的污染,因此,制定相应的标准并进一步规范和加强对黄曲霉毒素的检测和监控显得尤为重要。截至到2015年1月,我国现行的针对黄曲霉毒素的国家标准和行业标准共有21个,其中有11个标准在2010~2015年发布实施。本文全面综述了21个标准中采纳的7种测定方法及其特点,其中高效液相色谱法是目前广泛使用的最权威的确证定量测定方法,而免疫层析法则是最简便的快速筛查定性检测方法。在此基础上,本文进一步讨论了标准的制修订现状,并展望了黄曲霉毒素检测技术的发展趋势。      

Recent advances in rapid and nondestructive determination of fat content and fatty acids composition of muscle foods

Conventional methods for determining fat content and fatty acids (FAs) composition are generally based on the solvent extraction and gas chromatography techniques, respectively, which are time consuming, laborious, destructive to samples and require use of hazard solvents. These disadvantages make them impossible for large-scale detection or being applied to the production line of meat factories. In this context, the great necessity of developing rapid and nondestructive techniques for fat and FAs analyses has been highlighted. Measurement techniques based on near-infrared spectroscopy, Raman spectroscopy, nuclear magnetic resonance and hyperspectral imaging have provided interesting and promising results for fat and FAs prediction in varieties of foods. Thus, the goal of this article is to give an overview of the current research progress in application of the four important techniques for fat and FAs analyses of muscle foods, which consist of pork, beef, lamb, chicken meat, fish and fish oil. The measurement techniques are described in terms of their working principles, features, and application advantages. Research advances for these techniques for specific food are summarized in detail and the factors influencing their modeling results are discussed. Perspectives on the current situation, future trends and challenges associated with the measurement techniques are also discussed.     

提高双歧杆菌制品质量的研究进展

双歧杆菌是人体重要的有益菌群．双歧杆菌微生态制品在食品工业和医疗上有很好的发展潜力。因其不耐氧和不耐胃酸等生理特性，给生产、保存和应用带来许多难题。本文从优良菌株的选育、发酵丁艺的优化以及提高活菌的存活力三个方面概述了改进双歧杆菌微生态制品质量的方法。     

食品及其包装材料中双酚A的检测研究进展

双酚A(BPA)是世界上使用最广泛的一类有机化工原料之一,人们几乎每天都在接触和使用该化合物及其制品。由于其具有类雌激素特性,引起人们对其影响身体健康可能性的关注,特别是食品及食品包装材料中双酚A的危害成为争论的焦点。本文综述了双酚A的残留现状,以及食品及其包装材料中双酚A检测方法的研究进展,着重介绍了液相色谱法、气相色谱法、免疫分析法、光谱分析法、电化学分析法、传感器法等检测方法的应用情况,并对检测方法的发展进行了展望。