Quality Assessment of Poultry Egg Based on Visible–Near Infrared Spectroscopy and Radial Basis Function Networks

In this research the possibility of a non-destructive prediction of two main quality parameters of poultry egg using principle component analysis and radial basis function network by the transmission visible–near infrared spectroscopy method was investigated. The studied parameters include Haugh unit and air cell height as a function of a 5-week storage duration at room (25°C and 40% relative humidity) and refrigerator (5°C and 75% relative humidity) conditions. The spectra were interpreted and a radial basis function network model was developed for both storage conditions at wavelength ranges of 300–1100 nm. The developed models yielded a good prediction accuracy of Haugh unit for intact egg (R² value 0.745 and 0.76) as well as air cell height (R² value 0.835 and 0.844) for room and refrigerator conditions, respectively. Results of the experiment showed the developed model can be used in the prediction of egg freshness indices satisfactorily.     

Prediction of Egg Freshness and Albumen Quality Using Visible/Near Infrared Spectroscopy

Important changes occur in egg during storage leading to loss of quality. Prediction of these changes is critical in order to monitor egg quality and freshness. The aim of this research was to evaluate application of visible (VIS) and near infrared (NIR) spectroscopy as a rapid and non-destructive technique for egg quality assessment. Three hundred and sixty intact white-shelled eggs freshly laid by the same flock of hens fed with a standard feed were obtained. They were put under controlled conditions of temperature and humidity (T = 18 °C and RH = 55%) for 16 days of storage. Forty eggs were analyzed at day 0, 2, 4, 6, 8, 10, 12, 14, and 16. Transmission spectral data was obtained in the range from 350 to 2,500 nm. The non-destructive spectral data was compared to egg sample’s Haugh unit (HU) and albumen pH in terms of quality and to the number of storage days in terms of freshness. A partial least squares predictive model was developed and used to link the destructive assessment methods and the number of storage days with the spectral data. The correlation coefficient between the measured and predicted values of HU, albumen pH, and number of storage days were up to 0.94, R ² was up to 0.90 and the root mean square error values for the validation were 5.05, 0.06, and 1.65, respectively. These results showed that VIS/NIR transmission spectroscopy is a good tool for assessment of egg freshness and albumen pH and can be used as a non-destructive method for the prediction of HU, albumen pH, and number of storage days. In addition, the relevant information about these parameters was in the VIS and NIR ranging from 411 to 1,729 nm.     

Visible transmission spectroscopy for the assessment of egg freshness

The objective of this research was to investigate the feasibility of visible transmission spectroscopy for the non‐destructive assessment of the freshness of an individual egg. A total of 600 intact white‐shelled eggs of the same flock (Lohmann, 40 weeks of age) were measured. To obtain a considerable variation in freshness, groups consisting of 60 eggs were stored (18 °C, 55% RH) for 0, 2, 4, 6, 8, 10, 12, 14, 16 and 18 days. The non‐destructive spectral measurements were compared with the two most widely used destructive freshness parameters, namely Haugh units and albumen pH. A partial least squares (PLS1) model was built in order to predict Haugh units and pH of the albumen based on the transmission spectra. The correlation coefficients between the predicted value and the measured value were 0.842 and 0.867 for Haugh unit and pH of the albumen, respectively. These results show that the light transmission spectrum of an egg provides quantitative information about egg freshness. Relevant information concerning egg freshness is restricted to the interval between 570 and 750 nm. Furthermore, the models obtained for both destructive parameters were strikingly similar, indicating that Haugh unit and pH have the same physico‐chemical background. Copyright © 2006 Society of Chemical Industry     

贮藏温度变化对壳蛋新鲜度的影响

该文以新鲜罗曼粉壳蛋为研究对象,研究4个贮藏温度变化处理组壳蛋新鲜度指标的变化,分别于0、10、20、30 d检测所有实验组壳蛋失重率、气室高度、哈夫单位、蛋黄指数、浓稀蛋白比和蛋清pH。结果表明,贮藏10～30 d,处理组2、处理组3、处理组4的失重率显著升高(P<0.05),而气室高度和浓稀蛋白比显著降低(P<0.05),除对照组外,所有处理组壳蛋pH呈现先升高后下降的趋势,处理组3和处理组4的蛋黄指数下降趋势更为明显。对照组和处理组1壳蛋的哈夫单位、蛋黄指数和浓稀蛋白比显著高于(P<0.05)处理组3和处理组4。在贮藏10～20 d时,处理组2的壳蛋pH显著高于(P<0.05)对照组和处理组1。因此,如果前10 d常温贮藏温度≥20℃时,引起壳蛋失重率的增加和哈夫单位的下降,与低温(4℃)贮藏相比,采用贮藏温度变化(常温-低温)贮藏壳蛋更容易引起壳蛋新鲜度指标的下降。     

贮藏温度-时间变化对壳蛋新鲜度影响研究

该文以新鲜罗曼粉壳蛋为研究对象,研究5个贮藏温度-时间变化组壳蛋新鲜度指标变化,分别于0、10、20、30 d检测所有实验组壳蛋失重率、气室高度、哈夫单位、蛋黄指数、浓稀蛋白比、蛋清pH。结果表明,贮藏期间壳蛋失重率、气室高度和蛋清pH显著升高（P<0.05）,哈夫单位、蛋黄指数和浓稀蛋白比显著下降（P<0.05）。贮藏20 d时,处理组5壳蛋哈夫单位和蛋黄指数显著高于（P<0.05）对照组1、处理组1、处理组2和处理组3,而失重率、气室高度、蛋清pH较低（P<0.05）。贮藏30 d时,处理组5壳蛋失重率和气室高度显著低于对照组1、处理组1和处理组3（P<0.05）,蛋黄指数显著高于对照组1、处理组2、处理组3、处理组4（P<0.05）。除失重率、哈夫单位外,对照组2与处理组5壳蛋新鲜度指标整体差别不大。因此,除了壳蛋自身品质外,需要尽可能延长低温（4 ℃）贮藏时间,延缓壳蛋新鲜度指标劣变。     

Egg Freshness on-Line Estimation Using Machine Vision and Dynamic Weighing

This paper proposed a non-destructive method for online estimation of egg freshness based on machine vision and dynamic weighing. The machine vision system and the dynamic weighing system were developed for the measurement of egg external physical characteristic and weight. Digital signal processing was employed to denoise, analyze, and extract the effective feature information from the images and vibration signals. Then, the method of multiple linear regressions was used to build model for Haugh unit prediction using the parameters of long axis, minor axis, and weight. The performance of the predictive model using six variables was achieved, with R (correlation coefficient) of 0.8653 and RMSEP (root mean square error of prediction) of 3.7454 in prediction set. The speed of the system reaches four eggs per second for every measurement. Good consistence confirmed that the proposed method has a significant potential application in online estimation of the egg freshness.     

鸡蛋新鲜度指标与贮藏天数相关性研究

目的 分析鸡蛋新鲜度指标与贮藏天数的相关性, 确定新鲜度指标数值显著变化的时间, 建立新鲜度与贮藏时间相关性模型。方法 2 d为一个时间点, 设立12个实验组, 每组5枚鸡蛋, 按照标准中鸡蛋新鲜度评定指标重复3次测定鸡蛋相对密度、气室高度、哈夫单位、蛋黄指数、pH值、失重率。根据Pearson相关系数评价贮藏天数与鸡蛋新鲜度各指标之间的相关程度, Duncan法评价贮藏天数与鸡蛋新鲜度各指标之间的差异显著程度。结果 鸡蛋新鲜度各指标与贮藏天数之间显著相关(P<0.05), 各新鲜度指标数值出现显著变化的时间各不相同, 各天数之间的鸡蛋失重量、失重率差异显著(P<0.05)。结论 本研究所建立的鸡蛋新鲜度与贮藏时间的相关性模型, 可作为鸡蛋新鲜度评价模型。     

A market study on the quality characteristics of eggs from different housing systems

To study the differences among commercial eggs from four housing systems i.e. cage, barn, free range and organic, 41 physical and chemical parameters were evaluated on 28 fresh egg samples from the Italian market. The univariate statistic analysis evidenced that organic eggs had the highest whipping capacity and foam consistency but the lowest freshness (the highest air cell height) and albumen quality (the lowest Haugh Unit); cage eggs presented instead the lowest whipping capacity and the highest shell resistance to breaking. The multivariate technique discriminant partial least-squares regression was unable to correctly classify the eggs from the four housing systems but successfully differentiated cage eggs from alternative (organic + barn + free range) eggs. The variables with the most discriminant power were shell breaking resistance, overrun, protein content, and shell thickness.     

大气滑动弧放电对沙门氏菌的灭活机制及在鸡蛋保鲜中的应用

为了保持鸡蛋的新鲜度、延长其保质期,本研究提出了一种可在室温和大气环境中进行灭菌处理的新型冷杀菌技术,即滑动弧放电技术。首先,将配制好的沙门氏菌液均匀接种在鸡蛋表面,然后使鸡蛋以一定的自旋速率通过等离子体放电区域进行灭菌处理,从鸡蛋表面取得菌样后进行灭活机制研究,并将灭菌处理后的鸡蛋在37℃条件下进行贮藏,通过测定质量损失率和哈夫单位来评价大气放电技术对鸡蛋品质的影响。扫描电子显微镜观察和细胞外蛋白质质量浓度检测结果表明,大气滑动弧放电技术可对沙门氏菌产生有效的刻蚀作用,导致细胞膜破碎和胞内蛋白质泄漏。同时,鸡蛋品质检测表明,滑动弧放电处理组无论作用时间长短,鸡蛋质量损失率增大的程度均比对照组明显,但哈夫单位的降低程度小于对照组,说明大气滑动弧放电可在一定程度保持鸡蛋的新鲜度。     

基于CUVE-PLS-DA的鸡蛋新鲜度在线检测分级

针对目前鸡蛋新鲜度检测技术方法存在劳动强度大、检测精度低、分级效率不足等缺陷,本研究在4 800 枚/h的禽蛋传输机上搭建了可见-近红外透射光谱（501～1 000 nm）在线检测装置,动态采集鸡蛋透射光谱数据,并建立光谱信息与鸡蛋哈夫值等级的偏最小二乘判别模型。采用3∶1原则对鸡蛋样本进行随机划分,其中校正集169 个,验证集57 个,通过比较多种光谱预处理方法以及两种特征波长选择方法,得出标准正态变换预处理方法和多模式共识方法能够有效地提高模型的正确率、运算效率和预测能力,优化模型后的校正集和验证集准确率分别为92.31%、91.23%。结果表明本实验建立的可见-近红外光谱透射光谱检测方法能够对鸡蛋的新鲜度进行无损、智能、在线检测分级。     

基于电子鼻的鸡蛋新鲜度检测

鸡蛋新鲜度检测十分重要,为实现无损检测鸡蛋新鲜度,该文利用电子鼻技术,通过挥发物的检测来尝试对20℃、70%RH贮藏条件下的鸡蛋新鲜度进行预测。并测量鸡蛋的理化指标(哈夫单位和蛋黄指数)作为新鲜度的衡量标准。通过线性判别分析对储藏不同天数的鸡蛋进行分类分析,发现线性判别分析能较好地区分不同储藏天数的鸡蛋,判别函数的总贡献率为75.70%;利用多元线性回归和BP神经网络分析法建立电子鼻响应信号和鸡蛋理化指标之间的关系模型,所建多元线性回归模型的相关系数达0.84以上,相对误差在8.00%左右;所建BP神经网络模型的相关系数达0.84以上,相对误差在9.00%左右。说明电子鼻技术对鸡蛋新鲜度具有一定的预测能力,该研究可为鸡蛋新鲜度的无损检测提供参考。     

Prediction of Poultry Egg Freshness Using Ultrasound

A non-destructive ultrasound based method was used to develop a model for poultry egg freshness assessment. The proposed model can predict the Haugh unit, albumen thickness, air-cell height, and a number of other egg quality parameters by computing the ultrasound phase velocity within the egg material. For this purpose, the effect of the storage time on the ultrasound phase velocity within the poultry eggs together with the peak values of the transmitted ultrasound signals in the time and frequency domains were considered as indicators of egg freshness. Tests were conducted on eggs that were stored for five weeks in different storage conditions. The computed parameters were used to develop different models to predict the number of storage days for the egg samples. The results showed that the amplitude of the main peaks of the ultrasound signal in the time domain increased by the number of storage days. Moreover, there was a significant difference between the mean values of the phase velocities obtained at different times during the storage period. Comparing the results obtained for the eggs kept at the room temperature to those refrigerated showed that these variations were more significant for the eggs kept at room temperature.     

阻抗法检测鸡蛋新鲜度

鸡蛋在贮存过程中会发生一系列物理化学变化。在实际生活中,多以感官来衡量鸡蛋的新鲜度。本实验通过设立不同贮存条件,对不同温度(4、25℃)、不同相对湿度(75%、85%、98%)组合下的6组不同条件贮存过程中鸡蛋的哈夫单位、蛋黄指数、pH值以及相对应的阻抗进行检测。结果表明,在不同条件贮存过程中鸡蛋新鲜度指标哈夫单位、蛋黄指数、pH值与阻抗之间表现出了较好的相关性,建立标准曲线,通过阻抗值的大小对应标准曲线可计算鸡蛋新鲜度。阻抗法检测鸡蛋新鲜度具有操木作简便、快速、结果准确等优点,可为蛋品企业鸡蛋的保存提供一定的理论依据。     

不同处理对鸡蛋保鲜效果的研究

采用加热、钙制剂涂膜以及二者复合对鸡蛋处理,然后将其在30℃高温下放置40d;以新鲜度中的哈夫单位和感官评定等为指标,研究加热处理、钙制剂涂膜处理以及二者复合处理对其保藏效果的影响。实验结果表明：加热处理的最佳条件是温度50℃、加热时间20min,此时保鲜效果好;复合涂膜组的哈夫单位变化低干加热处理组、钙制剂涂膜组和空白对照组,保鲜效果最好。此外复合涂膜组蛋清透明度、表面色泽、光亮度等一些感官指标均好于加热处理组、钙制剂涂膜组和空白组。3种方法处理的鸡蛋在30℃下贮藏40d,其哈夫单位仍具有比较大的值,保留在A级水平上。     

Assessment of egg freshness by prediction of Haugh unit and albumen pH using an artificial neural network

Eggs are a good source of high quality protein and knowing their quality (physical and chemical properties) during storage is of great importance. Thus, the aim of this research was to design a computer vision system to assess egg freshness during storage time. To this end, 210 intact eggs were collected and stored for 30 days under room conditions (25?±?2 °C and 20?±?3%). After imaging, every other day, some internal and external quality characteristics including yolk height, yolk and albumen pH, yolk and albumen density and Haugh unit (HU) were measured as destructive parameters and area index (D) egg weight as non-destructive parameters. Based on Pearson correlation coefficients, area index were significantly correlated with all destructive variables (p?<?0.05). In order to predict egg freshness, artificial neural network was trained by Levenberg–Marquardt, scaled conjugate gradient, Bayesian regulation, resilient and radial basis algorithms. The best result of artificial neural network for HU and albumen pH prediction was achieved by the Levenberg–Marquardt algorithm with the correlation coefficient of 0.93 and 0.87, respectively.     

贮藏期鸡蛋新鲜度指标与S-卵白蛋白含量的相关关系

为了系统地研究鸡蛋新鲜度变化与S-卵白蛋白含量之间的关系,明确贮藏期间各鸡蛋品质参数对S-卵白蛋白形成的影响程度,本实验选取当日产新鲜海兰褐壳鸡蛋为研究对象,考察了鸡蛋哈夫值、蛋黄指数、pH值等指标与S-卵白蛋白含量的相关性,分析了各鸡蛋品质参数与S-卵白蛋白含量的灰色关联度,并以S-卵白蛋白含量为自变量建立了等价蛋龄预测模型。结果表明：鸡蛋哈夫值与S-卵白蛋白含量之间存在极显著负相关关系（R＝－0.913,P＜0.01）,其中S-卵白蛋白含量与蛋质量之间存在极显著负相关关系（R＝－0.367,P＜0.01）,与浓蛋白高度存在极显著负相关关系（R＝－0.905,P＜0.01）;蛋黄指数与S-卵白蛋白含量之间存在极显著负相关关系（R＝－0.900,P＜0.01）;pH值与S-卵白蛋白含量间存在极显著正相关关系（R＝0.648,P＜0.01）;此外,各品质因素与S-卵白蛋白含量的综合灰色关联度均大于0.6,且pH值是影响S-卵白蛋白含量变化的主导因素（灰色关联度为0.742）。建立的多项式回归等价蛋龄预测模型的决定系数为R2＝0.986 81（P＜0.01）,模型可靠性高。     

基于机器视觉的鸡蛋品质无损检测方法

目的以蛋品质量评价指标—哈夫单位值为检测标准,建立一种基于机器视觉的鸡蛋品质无损检测方法。方法通过摄像头捕捉到鸡蛋图像信息,利用MATLAB对鸡蛋图像的G分量以及I分量进行特征参数提取,并计算出与鸡蛋新鲜度相关的4个特征参数:蛋黄面积比、气室面积比、气室高度比与气室直径比,将其作为自变量,通过高精度游标卡尺实测每个鸡蛋样本哈夫值作为因变量,分别建立一元回归模型,寻找特征参数与哈夫值的关系,并根据哈夫值对鸡蛋新鲜度进行分级。结果实验表明,所测4个特征参数中,蛋黄面积比与哈夫值存在较强的相关性,相关系数为0.78,拟合优度为0.62,蛋黄面积比越小,鸡蛋哈夫值越大,说明鸡蛋越新鲜。结论基于机器视觉的鸡蛋品质无损检测方法不仅具有较强的应用价值,还可以为鸡蛋品质智能分级提供技术支撑。     

Prediction modelling of storage time and quality measurements using visible-near infrared spectra of pasteurized shell eggs

A 12 week study was conducted on the egg albumen from both pasteurized and non-pasteurized shell eggs using visible-near infrared spectroscopy. Prediction models of the chemical changes detected in the spectra to the measurement of Haugh units (measure of interior egg quality) were calculated using principal component regression analysis. Additionally, the study sought to determine how pasteurization affects both shelf life and egg quality. 84 dozen eggs were involved in this study, with 12 dozen eggs scanned initially and biweekly for the remainder of the study. Eggs were stored at 4 °C throughout the study. Haugh unit measurements were conducted followed by the visible/near infrared spectra of the albumen. The changes in the spectra over the 12 week period were very subtle and consisted mainly of an approximately 10 % decrease in transmission across the 400–1,200 nm range. The 400–550 nm region can be used to distinguish between the spectra of control eggs and pasteurized eggs. The results suggest that spectral data can be used to confirm and/or predict the storage time of eggs. The correlation coefficients of the spectra models for storage time are 0.97 and 0.98 for the control (untreated) and pasteurized eggs, respectively. Correlation values for predicting Haugh units from the spectra of the samples resulted in less useful predictive models in this study, especially for pasteurized samples.     

鸡蛋内部品质与其呼吸强度的关系

贮藏期鸡蛋品质的变化与呼吸作用息息相关,为了进一步明确鸡蛋内部品质与其呼吸强度之间的关系,本研究选取同一品种的鸡蛋作为实验样本,利用呼吸测定仪测定鸡蛋的二氧化碳呼吸强度,通过SPSS 19.0软件分别分析鸡蛋哈夫单位、蛋白高度、pH值、黏度、蛋黄指数、蛋黄比例以及蛋黄色度与呼吸强度间的关系。结果表明：鸡蛋哈夫单位、蛋白高度及黏度与呼吸强度之间呈极显著正相关（P＜0.01）;pH值与呼吸强度之间呈极显著负相关（P＜0.01）;蛋黄指数、蛋黄色度与呼吸强度之间呈极显著正相关（P＜0.01）;而蛋黄比例与呼吸强度间相关性较小;此外,pH值与黏度、蛋黄指数、蛋黄色度间均存在极显著负相关（P＜0.01）;黏度与蛋黄指数、蛋黄色度之间呈极显著正相关（P＜0.01）;蛋黄比例与其他参数相关性较小。总之,在鸡蛋内部品质参数中,鸡蛋哈夫单位、蛋白高度、蛋黄指数、pH值、黏度及蛋黄色度对呼吸强度影响较大。     

Storage effects on dielectric properties of eggs from 10 to 1800 MHz

ABSTRACT:  The dielectric constant and loss factor of egg albumen and egg yolk over the frequency range from 10 to 1800 MHz were measured at 24 °C at weekly intervals during 5-wk storage at 15 °C. Moisture and ash contents of albumen and yolk, as well as Haugh unit and yolk index, were also measured. The dielectric constant and loss factor of albumen were higher than those of yolk. Linear relationships were evident between the log of frequency, below about 1000 MHz, and the log of loss factor of albumen as well as that of yolk. The dielectric constants of albumen and yolk at 10 MHz were lower than those of fresh albumen and yolk when eggs were stored at 15 °C for 1 wk. However, after 2 wk in storage these dielectric constants rose and remained at higher levels for the rest of the 5-wk period. At frequencies of 100 MHz and higher, the dielectric constant was essentially constant during the entire storage period. Storage had much less influence on the loss factor of either albumen or yolk. In general, the moisture content and ash content of albumen and yolk decreased slightly as eggs aged. The moisture content of yolk increased somewhat with storage, and there was a corresponding decrease in albumen moisture content. The freshness qualities, Haugh unit and yolk index, also decreased as eggs aged. No obvious correlation between dielectric properties and moisture content, ash content, Haugh unit, or yolk index was observed.