利用机器视觉与近红外光谱技术的皮蛋无损检测与分级

为了对优质蛋、次品蛋和劣质蛋这3种皮蛋进行检测及分级,该文应用机器视觉结合近红外光谱技术,研究利用皮蛋凝胶品质无损检测的分级方法。首先采集皮蛋透射光图像,提取18个图像颜色特征值,然后将所提取的18维特征利用主成分分析(principal component analysis,PCA)进行降维,对PCA降维后的3个主成分建立遗传算法优化支持向量机(genetic algorithm-support vector machine,GA-SVM)分级模型,把皮蛋样本分为两大类:可食用蛋(优质蛋与次品蛋)与不可食用蛋(劣质蛋),劣质蛋测试集识别率为100%。然后在机器视觉分类结果的基础上,利用近红外光谱技术获取可食用蛋(优质蛋与次品蛋)的原始光谱,并进行多元散射矫正(multiplicative scatter correction,MSC),利用竞争性自适应重加权算法(competitive adaptive reweighted sampling,CARS)降维提取特征波长,基于支持向量机(support vector machine,SVM)对特征波长变量建立分级模型,区分出优质蛋与次品蛋,优质蛋测试集识别率为96.49%,次品蛋识别率为94.12%。研究结果表明:基于机器视觉和近红外光谱进行皮蛋凝胶品质无损检测分级是可行的。     

基于图像处理-深度学习的孵前种鸭蛋外部品质在线无损检测

种鸭蛋的品质影响着孵化率和健雏率,挑选优质种鸭蛋孵化不仅可以减少孵化占用的资源,还可以及时将不适宜孵化的种鸭蛋筛选出另做它用,避免其孵化失败造成浪费。为了对不同外部品质的孵前种鸭蛋进行检测分级,该研究设计了一种基于图像处理和深度学习的种鸭蛋外部品质检测系统。在传送轨道上获取种鸭蛋的透射图像后,选取多张鸭蛋图像中的最大长轴计算形状特征,通过交错值衡量大小头相似度;在伽马变换平衡图像颜色后,使用HSV分割提取脏污特征图来计算脏污面积;采用自适应阈值分割和脏污特征图掩膜对图像样本数据进行预处理,搭建裂纹识别网络CrackNet来识别脏污鸭蛋的裂纹。结果表明,该检测系统可计算种鸭蛋的大小、蛋形指数、脏污面积和大小头相似度,检测表面裂纹,计算所得长轴和蛋形指数的均方误差仅0.220 2 mm²和0.000 058,CrackNet的裂纹识别准确率为98.03%,研究结果可为入孵前种鸭蛋的筛选工作提供技术支持。     

鸡蛋内部品质的光特性无损检测

无损检测鸡蛋内部品质是鸡蛋流通、加工中不可缺少的组成部分。为了提高鸡蛋内部品质光特性无损检测的精度,建立了鸡蛋的光学模型,找出了整蛋、内容物、蛋壳三者透射特性之间的关系。通过试验研究,得到了鸡蛋内部品质指标(哈氏单位)与整蛋透射率、蛋壳颜色、鸡蛋几何参数之间的相关关系。并对光特性无损检测的分级精度作了初步分析。     

结合LLE流形学习和支持向量机的猪肉颜色分级

猪肉颜色分级是肉品品质无损检测的重要内容。该文通过对猪肉彩色数字图像颜色规律的分析,结合猪肉红(R)、绿(G)、蓝(B)颜色分量及其亮度和饱和度值,构建了一个新的颜色维度。将采集的1070份猪肉图像样本进行专家分级和标记后,给出了猪肉颜色的特征表示,并利用支持向量机(SVM)进行了颜色分级。试验结果表明,随着训练集样本数的增加,分级准确率有所提高。当将所有样本作为训练集时,分级准确率高达96.5%。针对SVM分级后泛化能力不强的问题,采用流形学习LLE维数变换,使其泛化能力由37%提高近1倍。结果表明LLE可有效改善SVM的分级准确率。该方法可为猪肉品质无损检测的研究与应用提供参考。     

果实表面颜色计算机视觉分级技术研究

以计算机视觉自动检测果实表面着色度并进行分级为目的,建立了室内计算机视觉系统获取苹果果实的彩色图像,并将ＲＧＢ值转换成ＨＬＳ值;在分析苹果颜色特性的基础上,确定了用合适色相值下累计着色面积百分比进行颜色分级的方法。分级试验结果表明,用建立的准则和方法,计算机视觉分级与人工分级的一致度在８８％以上。     

鸭蛋整箱悬浮清洗机的机理分析与试验

为了整箱高效清洗鸭蛋,提出了一种悬浮清洗方法,并进行了悬浮清洗机的机理分析和试验研究。该方法是将鸭蛋整箱置于比重和鸭蛋比重相当的液体(如：泥浆、石灰浆等)中,使鸭蛋悬浮在液体中,再用柔性搅拌轴慢速搅拌悬浮的鸭蛋。其清洗机理是利用鸭蛋和搅拌轴之间,鸭蛋和液体之间,鸭蛋和容器内壁之间的摩擦作用,达到清洗的目的。试验结果表明,鸭蛋的清洗程度及鸭蛋的破损率与搅拌轴转速,清洗时间,清洗液比重,每次清洗鸭蛋的个数之间存在显著的相关性,按机理分析和试验得出的参数设计的清洗机能够实现鸭蛋整箱悬浮清洗。     

基于模糊彩色聚类方法的西红柿缺陷分割研究

缺陷的检测一直是应用计算机视觉技术进行水果自动分级的难点。在HSL颜色模型的基础上，提出了基于模糊颜色聚类的缺陷分割方法。将RGB颜色模型转化为HSL颜色模型；用三角隶属度函数定义H、S、L模糊集，进而构成模糊颜色集；在模糊颜色的基础上，定义模糊颜色相似度测度，分析两种模糊颜色的形似性。将该分割方法应用于西红柿的缺陷分割，试验表明：准确率达96%。     

农产品质量的计算机辅助检验与分级（第Ⅰ报）——烟叶外观品质特征的定量检验

应用计算机图象处理技术和色度学理论，研究了烟叶外观品质特征（颜色、叶形、叶面等）的提取、描述与定量检测方法，为开发烟叶外观品质的检验仪器与分级设备提供了理论依据     

农产品质量的计算机辅助检验与分级（第Ⅰ报）烟叶外观品质特征的定量检验

应用计算机图象处理技术和色度学理论，研究了烟叶外观品质特征（颜色、叶形、叶面等）的提取、描述与定量检测方法，为开发烟叶外观品质的检验仪器与分级设备提供了理论依据     

基于改进YOLOv5l的轻量化鸭蛋裂纹检测算法

鸭蛋裂纹检测技术对于禽蛋加工工厂实现智能化蛋品检测、分级具有重要意义。该研究针对鸭蛋裂纹检测流程复杂、计算量大、模型尺寸大等问题,提出了一种基于改进YOLOv5l(you only look once version5 large)的轻量裂纹检测算法,通过在黑暗条件下使用LED灯照射鸭蛋,根据裂纹蛋壳与完好蛋壳透光性不同产生的图像差异进行检测。通过在YOLOv5中引入Ghost＿conv模块,大大减少了模型的浮点计算量和参数量,并在模型的骨干网络中加入ECA(efficient channel attention)注意力机制以及使用多尺度特征融合方法 BIFPN(bi-directional feature pyramid network),增加模型对有效信息的关注度,以提高算法检测精度。同时使用CIoU与α-IoU损失函数融合后替代YOLOv5原始GIoU函数加速回归预测。利用自建的鸭蛋裂纹数据集验证改进后模型的性能,结果表明,本研究提出的改进YOLOv5l网络模型检测精准率为93.8%,与原始YOLOv5l模型相比,检测精度提高了6.3个百分点,参数量和浮点计算量分别减少了30.6...     

咸蛋黄快速腌制过程中理化性质变化规律

该研究以新鲜蛋黄为原料,利用快速腌制模具,探究在咸蛋黄的上表面添加食盐单侧腌制过程中,食盐添加量和腌制时间对咸鸡蛋黄快速腌制过程中形貌特征和理化性质变化规律的影响。借助多种仪器分析手段对蛋黄腌制过程中形貌与物性的变化、水分及盐分的迁移规律进行了表征。低场核磁及成像结果表明：在腌制过程中,蛋黄中的水分不断向外迁移,含水率显著降低,当增加食盐的添加量和延长腌制时间,会加快水分的迁移速率;原子吸收结果表明：增加食盐添加盐量越多和腌制时间越长盐分迁移速率越快,质构、色差结果共同表明咸蛋黄腌制过程中,由于水分的向外迁移和盐分的向内渗入,使得蛋黄的蛋白质发生聚集使颜色加深;同时与市售整个腌制后分离的鸡蛋黄产品相比,当腌制时间为7d,添加盐量为3%;腌制时间为3d,添加盐量为5%时,所得的样品与市面的成品咸鸡蛋黄的感官品质及量化指标差异不显著（P<0.05）,为咸蛋黄单侧腌制技术提供理论的可行性。     

Enrichment of poultry products with omega3 fatty acids by dietary supplementation with the alga Nannochloropsis and mantur oil

Experiments were conducted to evaluate the efficiency of the microalga Nannochloropsis sp. (Nanno.), as a supplement to laying hens' diet, for the production of enriched eggs and meat with omega3 fatty acids (FA). Nanno. has a unique FA composition, namely, the occurrence of a high concentration of eicosapentaenoic acid (EPA; 20:5 omega3) and the absence of other omega3 FA. The effect of supplementing diets with Nanno. on omega3 FA levels in eggs, plasma, liver, and thigh muscle was compared to that of mantur oil, high in alpha-linolenic acid (LNA; 18:3 omega3). Nanno. is rich also in carotenoids, which may be useful for egg yolk pigmentation. The observed effect of Nanno. supplementation on yolk pigmentation was dose responsive, in both the rate of coloration and the color intensity. Addition of enzyme preparations (glucanase plus cellulase or glucanase plus pectinase) slightly elevated the yolk color score. The most prominent changes in the level of omega3 FA in egg yolk were evident when the diets were supplemented with 1% Nanno. or mantur lipid extracts. Levels of dietary algal meal (0.1-1.0%) had low and inconsistent effects on the level of yolk omega3 FA. Algal EPA is not accumulated in the liver or in the egg yolk; it is apparently converted and deposited as docosahexaenoic acid (DHA). LNA from mantur oil was partially converted to DHA, and both DHA and LNA were deposited in egg yolks and livers. It is suggested that the absence of DHA and EPA from thigh muscle is due to the small amount of dietary omega3 FA used in this work, compared to other studies, and to the possibility that in laying hens the egg yolk has a priority on dietary FA over that of muscles.     

Identification of antiadhesive fraction(s) in nonimmunized egg yolk powder: in vitro study

The presence of antiadhesive component(s) in the hen egg yolk against foodborne pathogens was anticipated from results of a previous animal study conducted by the authors. The previous work showed egg yolk powder without specific antibodies is effective in controlling Salmonella enteritidis,Salmonella typhimurium, and Escherichia coli O157:H7 colonization in laying hens. Therefore, this study was necessary to locate the activity and identify the effective component(s). In vitro experiments were conducted using confluent Caco-2 cell monolayers. S. enteritidis, S. typhimurium, and E. coli O157:H7 were investigated against the various extracted granule and plasma fractions in three different assays: adhesion elimination, adhesion prevention, and antimicrobial. This study revealed original findings and identified the protective yolk fraction against the foodborne pathogens as the granule component, high-density lipoproteins (HDL). The protective activity conveyed by HDL was confirmed to remain intact despite peptic and tryptic enzymatic digestion and to have antiadhesive but not antimicrobial effect.     

基于计算机视觉的鸡蛋新鲜度无损检测

对鸡蛋的新鲜度、贮藏期进行无损检测,在鸡蛋生产、流通、加工领域具有重要意义。该文进行了鸡蛋新鲜度（哈夫值）常规指标在一定温度条件下随贮藏时间变化的试验,采用高分辨率的工业化数字摄像头,以冷光源背向照明方式（照度为10 000 Lx）获取数字图像,并提取了鸡蛋的图像特征蛋黄指数和气室指数。建立了鸡蛋新鲜度与蛋黄指数、贮藏时间与鸡蛋新鲜度、贮藏时间与蛋黄指数和气室指数的关系模型。得知鸡蛋新鲜度与蛋黄指数呈线性相关性,经检验实测值与预测值平均相对误差为6%;贮藏时间与鸡蛋新鲜度以及贮藏时间与鸡蛋蛋黄指数、鸡蛋气室指数均具有二次函数关系,经检验实测值与预测值绝对误差不超过2 d。结果表明基于计算机视觉技术、采用背向照明方式采集的鸡蛋的透射图像得到鸡蛋的蛋黄和气室的图像信息,可以预测鸡蛋的新鲜度和贮藏期。     

Development of yellow pigmentation in squid (Loligo peali) as a result of lipid oxidation

The impact of lipid oxidation on yellow pigment formation in squid lipids and proteins was studied. When the squid microsomes were oxidized with iron and ascorbate, thiobarbituric acid reactive substance were observed to increase simultaneously with b values (yellowness) and pyrrole compounds concomitantly with a decrease in free amines. Oxidized microsomes were not able to change the solubility, sulfhydryl content, or color of salt-soluble squid myofibrillar proteins. Aldehydic lipid oxidation products were able to decrease solubility and sulfhydryl content of salt-soluble squid myofibrillar proteins but had no impact on color. Aldehydic lipid oxidation products increased b values (yellowness) and pyrrole compounds and decreased free amines in both squid phospholipid and egg yolk lecithin liposomes. The ability of aldehydic lipid oxidation products to change the physical and chemical properties of egg yolk lecithin liposomes increased with increasing level of unsaturation and when the carbon number was increased from 6 to 7. These data suggest that off-color formation in squid muscle could be due to nonenzymatic browning reactions occurring between aldehydic lipid oxidation products and the amines on phospholipids headgroups.     

Antimicrobial potential of egg yolk ovoinhibitor, a multidomain Kazal-like inhibitor of chicken egg

Chicken egg ovoinhibitor is a multidomain Kazal-type serine protease inhibitor with unknown function. Comparison of expression between different tissues indicated that ovoinhibitor is highly expressed in the magnum and liver followed by the uterus, which secrete egg white, egg yolk, and eggshell precursors, respectively. The results also revealed that ovoinhibitor expression is increased in the liver during sexual maturation followed by a subsequent decrease in mature hens. Ovoinhibitor was purified from the egg yolk plasma from nonfertilized eggs using two consecutive affinity chromatographies and gel filtration. Purified egg yolk ovoinhibitor was shown to inhibit trypsin and subtilisin. It was shown that purified egg yolk ovoinhibitor exhibited antimicrobial activities against Bacillus thuringiensis . The results suggest that this anti-protease plays a significant role in antibacterial egg defense against Bacillus spp., preventing contamination of table eggs (nonfertilized eggs) and protecting the chick embryo (fertilized eggs).     

Recovery of Salmonella from shell eggs.

A preenrichment procedure and a direct selective enrichment procedure were compared for recovery of Salmonella artificially inoculated into liquid whole egg, egg yolk, and egg albumen. For liquid whole egg and egg yolk, the 2 procedures were comparable. With egg albumen, however, preenrichment in lactose broth gave significantly higher recoveries than did direct selective enrichment in either selenite cystine or tetrathlonate broths. The lactose preenrichment procedure was used to determine the survival of S. enteritidis in egg yolk and egg albumen over a period of 7 days. As shown by most probably number determinations, counts of S. enteritidis inoculated into egg albumen decreased by 3 log units, whereas those in egg yolk did not change significantly. It is recommended, therefore, that only the egg yolk be examined for this pathogen. In a comparison of 5 different preenrichment media (lactose broth, brain heart infusion broth, trypticase soy broth, buffered peptone water, and nutrient broth), lactose broth was somewhat less productive than the other 4 media for the recovery of Salmonella from egg yolks. Trypticase soy broth gave the highest recovery.     

Impact of a treatment with phospholipase A2 on the physicochemical properties of hen egg yolk

Changes in physicochemical properties of egg yolk were investigated after a treatment with phospholipase A 2 (PLA 2), where phospholipids are converted in lyso-phospholipids. Protein solubility and protein denaturation before and after modification by PLA 2 was monitored as well as the functionality of egg yolk by means of interfacial tension. Enzymatic treatment showed a significant impact on the properties of egg yolk with regard to protein solubility and denaturation behavior. To gain a closer insight, egg yolk was separated in its water-soluble fraction called plasma and the insoluble granules. Both fractions were separately modified by PLA 2. The granule fraction shows a higher protein solubility, and the plasma proteins show very high heat stability after modification by PLA 2. Hypotheses regarding related changes in the low-density lipoprotein (LDL) particles are discussed. Results suggest that significant differences in the functional properties of untreated and PLA 2-modified egg yolk do not primarily result from the existence of lyso-phospholipids but from structural changes in egg yolk granules and LDL particles.     

Ascorbic acid and ascorbic acid 6-palmitate induced oxidation in egg yolk dispersions

The oxidation in aqueous dispersions of egg yolk powder and the influence of addition of the proposed antioxidants ascorbic acid and ascorbic acid 6-palmitate indicate that both ascorbic acid and ascorbic acid 6-palmitate propagated the oxidation of egg yolk powder dispersions. Ascorbic acid 6-palmitate was found to be more prooxidative than ascorbic acid. Moreover, it was found that addition of ascorbic acid or ascorbic acid 6-palmitate gave rise to an increase in the amount of free iron Fe(II) in the egg yolk dispersions. It is proposed that ascorbic acid and ascorbic acid 6-palmitate react with the phosvitin-Fe(III) complex found in egg yolk and release Fe(II), which subsequently propagates lipid oxidation. It appears that less oxidation occurs in egg yolk dispersions exposed to high concentrations of peroxy radicals with added ascorbic acid than egg yolk dispersions with added ascorbic acid without exposure to peroxy radicals.     

Antioxidative stress activity of oligophosphopeptides derived from hen egg yolk phosvitin in Caco-2 cells

The protective effects of hen egg yolk phosvitin phosphopeptides (PPPs) against hydrogen peroxide (H2O2)-induced oxidative stress were evaluated in an in vitro assay using human intestinal epithelial cells. Caco-2 cells were stimulated with 1 mM H2O2 for 6 h, and the secretion of IL-8, a proinflammatory mediator, was determined by ELISA as a biomarker of oxidative stress. The inhibition of H2O2-induced IL-8 secretion from Caco-2 cells was observed by pretreatment for 2 h with PPPs, but not with phosvitin. PPPs also suppressed the formation of malondialdehyde in H2O2-treated Caco-2 cells. Furthermore, intracellular glutathione levels and glutathione reductase activity were elevated by the addition of PPPs. The protective effects of PPPs against H2O2-induced oxidative stress were almost the same as that of glutathione, and PPPs with a high content of phosphorus exhibited higher protective activity than PPPs without phosphorus; however, phosphoserine itself did not show any significant antioxidative stress activity. These findings suggest that oligophosphopeptides from hen egg yolk phosvitin possess novel antioxidative activity against oxidative stress in intestinal epithelial cells and that phosphorus and peptide structure seem to have a key role in the activity.