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1.
基于计算机视觉的鸡蛋新鲜度无损检测 总被引：6，自引：1，他引：5
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。 相似文献
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3.
选取仙居地区450~500日龄阶梯式笼养、山林地散养、草地散养鸡蛋各20枚,比较和分析鸡蛋感官品质和营养成分。从鸡蛋重量来看,山林地散养鸡蛋显著高于笼养和草地散养鸡蛋;从蛋黄颜色、哈氏单位、蛋壳强度来看,草地散养鸡蛋显著高于笼养和山林地散养鸡蛋;从营养成分胆固醇和低密度脂蛋白胆固醇含量来看,笼养鸡蛋最高,山林地散养鸡蛋最低;从不饱和脂肪酸含量、ω3系列含量和ω6/ω3比值来看,草地散养鸡蛋和山林地散养鸡蛋均好于笼养鸡蛋,且草地散养鸡蛋最优。结果表明,草地散养鸡蛋品质优于笼养鸡蛋,尤其是消费者偏好的蛋黄颜色、哈氏单位以及对人体起保健作用的不饱和脂肪酸和ω3系列脂肪酸含量;山林地散养鸡蛋品质略逊色于草地散养鸡蛋,但其蛋品质和营养成分整体均优于笼养鸡蛋。 相似文献
4.
鸡蛋贮藏过程中品质变化的动力学模型 总被引：5，自引：1，他引：4
为研究鸡蛋贮藏过程中品质变化与贮藏期的相关性,采用动力学研究方法建立鸡蛋贮藏的预测模型。结果表明鸡蛋质量和蛋黄系数随着贮藏时间的延长而降低,气室高度随贮藏时间的延长而增加。一级化学反应动力学模型和Arrhenius方程对鸡蛋质量、蛋黄系数和气室高度变化具有较高的拟合精度。动力学反应速率常数表明贮藏温度越高,鸡蛋品质下降越明显。由预测模型所获得贮藏期预测值与实际值相对误差在10%以内,该模型可预测鸡蛋质量、蛋黄系数和气室高度在5～35℃范围内的变化情况和鸡蛋的贮藏期,为鸡蛋的贮藏和销售提供参考。 相似文献
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基于介电特性与蛋黄指数回归模型的鸡蛋新鲜度无损检测 总被引：1，自引：1，他引：0
为了更准确、快速的实现鸡蛋新鲜度品质指标蛋黄指数的无损检测,基于介电特性建立了鸡蛋新鲜度无损检测模型,获取鸡蛋的蛋黄指数信息。试验以不同新鲜度鸡蛋为研究对象,采用平行极板法测量不同新鲜度鸡蛋在温度为20℃,相对湿度为72%~89%,频率为1~200 k Hz下的介电特性参数,分析鸡蛋介电特性的变化规律,并建立鸡蛋介电特性与蛋黄指数之间的数学模型。分析了鸡蛋介电特性随测量信号频率及新鲜度指标蛋黄指数的变化曲线,发现其介电参数随频率及蛋黄指数的增大而减小。构建了蛋黄指数与相对介电常数的拟合方程,鸡蛋样品的实际蛋黄指数与模型预测的蛋黄指数间的决定系数R2为0.9115,蛋黄指数的误差为±4.2%,试验结果表明:利用拟合方程预测检验鸡蛋蛋黄指数取得了较好的预测效果,为无损检测鸡蛋新鲜度提供了一种新的可行方法。 相似文献
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利用高压静电场保鲜鸡蛋试验 总被引：2，自引：0，他引：2
为探讨高压静电场对鸡蛋贮藏保鲜的影响,该试验利用30、60、90 kV/m不同高压静电场分别对鸡蛋进行30和60 min的预处理,然后置于13℃左右的室温条件下贮藏,定期测定鸡蛋的哈夫单位、蛋黄指数、挥发性盐基氮和感官性状的变化等指标,研究高压静电场对其贮藏保鲜效果的影响。试验结果表明：高压静电场处理能很好地保持鸡蛋内部的含水量;有效地降低了哈夫单位、蛋黄指数与挥发性盐基氮的变化速率;贮藏保鲜效果明显好于对照。该试验30 kV/m、60 min剂量和60 kV/m、30 min剂量的处理,保鲜效果最好。 相似文献
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提高蛋清粉起泡性能的工艺 总被引：6，自引：0，他引：6
在实际生产中,蛋清中常会混入蛋黄,这些少量脂质的存在会降低蛋清粉起泡性。为减少混入的蛋黄中脂类物质对蛋清粉起泡性的影响,该试验采用脂肪酶水解脂类来提高蛋清粉起泡性能。试验考察了酶添加量、pH值、水解时间、水解温度对蛋清粉起泡性能的影响,确定了脂肪酶水解脂类的较适条件为酶添加量5000U/g,pH值8.0,水解时间6h,水解温度42℃。与原工艺相比,蛋清粉起泡力由36.67%提高到88.42%,泡沫稳定性从26.58提高到32.02。研究所确定的较佳工艺对高起泡性蛋清粉的生产具有指导意义。 相似文献
8.
热处理对皮蛋生产周期和品质的影响 总被引：4，自引：1，他引：3
为了缩短皮蛋制作周期,保持品质,研究了热处理对锌铜混合盐腌制皮蛋品质的影响。对腌制15、20和25 d的皮蛋进行不同温度（35、42、49℃）,不同时长（14、22、30 h）的热处理,对其进行L9（34）正交试验。以皮蛋的含水率,蛋黄硬化率,游离碱度,色度来探讨热处理条件（热处理温度、热处理时长和热处理时机）对皮蛋品质的影响。结果表明,不同的热处理均可降低皮蛋的含水率,加快蛋黄的凝固,提高蛋黄硬化率,降低皮蛋内容物的游离碱度,促进蛋清蛋黄的转色,提高皮蛋的口感和风味。对蛋黄硬化率和皮蛋内容物游离碱度加权得到综合评分并进行方差分析,表明对于热效果的影响程度大小依次是热处理时机、热处理温度、热处理时长,最佳热处理工艺条件是腌制20 d后在42℃的温度下热处理22 h,不仅品质好,并且将生产天数减少至21 d,比传统生产周期缩短了40%～50%。 相似文献
9.
欧姆加热对米饭蒸煮过程能耗及其品质的影响 总被引：1，自引：1，他引：0
电饭煲蒸煮米饭存在电热转化效率低、温度不易控制等不足。该研究设计了一种加热速率和保温温度自动可控的欧姆加热试验系统,并研究了浸泡时间和水米比对水米混合物的电导率、欧姆蒸煮加热速率、能耗以及米饭品质（膨胀率、吸水率、物性值和颜色）的影响,并与电饭煲蒸煮米饭的能耗和品质进行比较。结果表明：浸泡能够增大水米混合物电导率,水米比越小电导率增加越快,有效提高欧姆加热蒸煮米饭加热速率;浸泡还有利于减少米饭蒸煮能耗（P<0.05）,促进米饭软化;因此大米浸泡处理30 min后采用欧姆加热蒸煮米饭可行。欧姆蒸煮加热速率越快,米饭硬度上升（P<0.05）,而黏性和弹性则略有减小（P<0.05）,加热速率在3～9 ℃/min范围内为宜;水米比可取1.25∶1～1.50∶1 mL/g。蒸煮相同质量的大米,欧姆加热所需能耗仅为电饭煲蒸煮的20%～25%;相较于电饭煲蒸煮,欧姆加热蒸煮米饭硬度最大可减小21%,且膨胀率和吸水率较大（P<0.05）、亮度L*值较小（P<0.05）。研究结果可为研发基于欧姆加热的快速高效米饭自动蒸煮装置提供技术支撑。 相似文献
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生物超弱光子辐射在禽蛋新鲜度评价中的应用 总被引：1，自引：0，他引：1
为了探索生物超弱光子辐射在禽蛋新鲜度评价和检测方面的应用,研究了25℃和40℃储存温度下鸡蛋超弱光子辐射中自发发光和延迟发光的基本规律。结果表明,在25℃的储存温度下,随着储存时间的延长鸡蛋的自发发光缓慢增长,延迟发光初始光强缓慢降低;在40℃高温下自发发光迅速增长,而延迟发光初始光强迅速下降,鸡蛋的延迟发光服从双曲线弛豫。由延迟发光积分强度和单位时间内的自发发光构建鸡蛋的状态参量,研究发现,在25℃和40℃储存温度下鸡蛋状态参量的变化与哈夫单位的变化呈现良好的线性关系,表明鸡蛋状态参量可以作为鸡蛋新鲜度评价的定量指标。 相似文献
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Conjugated linoleic acids alter the fatty acid composition and physical properties of egg yolk and albumen 总被引：2，自引：0，他引：2
Watkins BA Feng S Strom AK DeVitt AA Yu L Li Y 《Journal of agricultural and food chemistry》2003,51(23):6870-6876
Effects of dietary conjugated linoleic acids (CLAs) and docosahexaenoic acid (DHA) on the fatty acid composition of different egg compartments after storage were studied. Four dietary treatments [supplemented with safflower oil (SAFF, control group), DHA, CLAs plus DHA (CAD), and CLAs alone] were administered to Single Comb White Leghorn (SCWL) laying hens. Eggs from the different treatment groups were collected and stored for 10 weeks at 4 degrees C before analysis. Fatty acids from the yolk (yolk granules and plasma), egg albumen, and vitelline membrane were analyzed by gas chromatography. The yolk of eggs from hens given CLAs had significantly higher amounts of saturated fatty acids, typically 16:0 and 18:0, but lower amounts of polyunsaturated fatty acids (PUFAs) compared to eggs from the control group (SAFF). CLA content was highest in the yolk and present in both neutral and polar lipids, with the greatest concentrations in neutral lipids. DHA was incorporated mainly into yolk polar lipids. Lipids in yolk plasma and granules contained similar amounts of CLAs. The fatty acid compositions of vitelline membrane and egg albumen mirrored that of the egg yolk. CLA supplementation resulted in hard and rubbery yolks when compared to hard-cooked eggs from the control group. This study showed that feeding CLAs to hens led to accumulation of the isomers in polar and neutral lipids of the egg yolk and that these isomers migrated into egg albumen. Because the sensory properties of hard-cooked eggs were negatively affected by the enrichment of a mixture of CLA isomers in this study, further research should be conducted to evaluate how the different isomers alter the properties of egg yolk and albumen so that the quality of designed eggs containing CLAs and DHA can be improved. 相似文献
12.
Prediction models for residue transfer into eggs are being developed. Recent results indicate that the developing egg yolk serves as an important storage depot for chemical residues. The current study was conducted to visualize incorporation and potential compartmentalization of drug residues in developing egg yolks. To this end, the drug magnevist was injected into hens to evaluate drug transfer into either early- or late-developing yolks. High-resolution magnetic resonance images (MRI) of drug residues in eggs were acquired using a 1.5 T Siemens Magnetom clinical scanner. A 10-cm circular surface coil was used for receiving the magnetic resonance signal. The eggs were positioned inside the coil cavity for an improved signal to noise ratio (SNR). Gradient-echo images were used to locate the centers of the eggs and to prescribe the position of the high-resolution image slab. The images were recorded using an inversion time (T1) weighted magnetization-prepared, rapid acquisition, gradient-recalled-echo (MPRAGE) pulse sequence. The sequence parameters used were as follows: repetition time (TR) equals 12 ms, echo time (TE) equals 5 ms, field of view (FOV) equals 200, TI = 10 ms, 1.25-mm slice thickness, and a matrix of 200 x 256. Following dosing, images of drug residues in eggs indicate that drugs can be incorporated and compartmentalized into ring structures within individual developing egg yolks. These results have significant human food safety implications because even after only a single dose, sequestered drug residues may be stored and later released to contaminate eggs for days to weeks after dosing. 相似文献
13.
Limsuwan S Priess B Tansakul N Nau H Kietzmann M Hamscher G 《Journal of agricultural and food chemistry》2007,55(15):6401-6405
The penetration of propoxur and phoxim from eggshell into whole egg was investigated in vitro by spraying eggs directly and in vivo after application of the compounds in henhouses. Although mean concentrations of the compounds on eggshells were up to 23000 microg kg(-1), mean residue concentrations in whole eggs were far below the current maximum residue levels (50 microg kg(-1) for propoxur and 60 microg kg(-1) for phoxim). These results provide the first evidence that propoxur and phoxim do not penetrate from eggshell into whole egg under experimental and field conditions. Subsequently, residue carry-over after egg cracking in households and during a worst-case situation in an egg-cracking plant was investigated. However, when eggs were cracked manually, a negligible contamination of whole egg values occurred. If, in an automated process, eggshells accidentally come into close contact with whole egg, very high residue levels of propoxur and phoxim may be generated time dependently. These results suggest that eggshell contact with whole egg during egg cracking must be avoided to prevent pesticide carry-over. 相似文献
14.
Lin F Wu J Abdelnabi MA Ottinger MA Giusti MM 《Journal of agricultural and food chemistry》2004,52(8):2397-2403
Soy isoflavones have been associated with several beneficial effects of soy in human diets. However, most soy is consumed by livestock in the Western countries. It is possible that isoflavones could be transferred and/or accumulated into animal products, which could become additional sources of dietary isoflavones for humans. Our objectives were to determine whether dietary isoflavone genistein could be transferred and/or accumulated into the eggs of Japanese quail (Coturnix japonica) and how the supplementation dosage and glycosylation of the isoflavone would affect this transfer. Adult reproductive female Japanese quail were randomly assigned to treatment groups that received encapsulated 50 or 100 mg genistein or 80 mg genistin per day (four quail per treatment) for 5 days. A control group (two quail) received placebo capsules. Eggs were collected prior to treatment and then daily for 15 days. The egg, separated into yolk and white, and pulverized quail diet were extracted in 80% methanol for 2 h and either centrifuged or filtered before evaporation of the solvent. The extracts were redissolved in 16% acetonitrile for high-performance liquid chromatography (HPLC) analyses. Genistein and genistein metabolites were detected in the egg yolks of treated quail. Trace concentrations of genistein were detected in the control group, due to the presence of genistein derivatives in the diet. Neither genistein nor its metabolites were found in egg white. Levels of genistein in the eggs increased significantly from the 3rd day of supplementation and reached the maximum about 2 days after the supplementation stopped. The higher dose of genistein supplementation resulted in higher genistein concentrations in egg yolks. Glycosylation decreased the transfer and accumulation of genistein into the egg yolks. 相似文献
15.
Bourin M Gautron J Berges M Attucci S Le Blay G Labas V Nys Y Rehault-Godbert S 《Journal of agricultural and food chemistry》2011,59(23):12368-12374
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). 相似文献
16.
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. 相似文献
17.
Gas chromatographic determination of cholesterol in egg products 总被引：2，自引：0，他引：2
J D Beyer F X Milani M J Dutelle R L Bradley 《Journal of the Association of Official Analytical Chemists》1989,72(5):746-748
A method has been developed for quantification of cholesterol in fresh egg yolks, spray-dried egg yolks, fresh whole eggs, and spray-dried whole eggs. The method uses saponification followed by petroleum ether extraction of cholesterol. Separation of organic and aqueous layers is enhanced by sodium chloride. Petroleum ether extracts are dried under nitrogen and redissolved in chloroform-methanol (2 + 1) for injection into a gas chromatograph. Cholesterol is separated and quantitated on a high temperature capillary column coated with 5% diphenyl and 95% dimethyl polysilicone crosslinked gum. The method was compared with the current AOAC method 17.017-17.022, and results indicated no significant difference (alpha = 0.05). However, the proposed method allowed separation and analysis of 16 samples in 7 h while the current AOAC method allowed separation and analysis of only 4 samples in 9 h. 相似文献
18.
Adding supplements to hen feed can increase egg nutritional value. Astaxanthin, tocotrienols, and tocopherols are potent antioxidants that provide health benefits to humans. We hypothesized that the addition of these nutrients to hen feed would result in an increased nutrient content in egg yolk with minimum changes in functional properties. Laying hens (Hy-Line W-36 breed) were fed four diets with different supplementation levels of palm toco concentrate and algae biomass containing astaxanthin for 8 weeks. Egg yolks were analyzed for physical, chemical, and functional properties. The feed with the highest nutrient concentration was also studied for stability of these antioxidants using the Arrhenius approach. No significant differences were observed in functional properties except for emulsification capacity and sensory characteristics among eggs from different diet treatments. Changes in egg yolk color reached the maximum values at day 8. Incorporation of tocopherols and tocotrienols increased until day 8, astaxanthin incorporation increased until day 10, and all decreased thereafter. Feed nutrients resulted in a dose-response relationship of these compounds in the egg yolk. The transfer efficiency ranged from 0 to 9.9% for tocotrienols and tocopherols and from 7.6 to 14.9% for astaxanthin at their peak values. Results of the Arrhenius accelerated stability study showed significant differences in the shelf life of various nutrients, and these results can be used to properly formulate and store the feed materials. 相似文献
19.
Recovery of Salmonella from shell eggs. 总被引：1，自引：0，他引：1
P Stephenson F B Satchell G Allen W H Andrews 《Journal of the Association of Official Analytical Chemists》1991,74(5):821-826
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. 相似文献
20.
Laying hens were fed a control diet alone or with 0.06 g of atorvastatin, a synthetic 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, per 100 g of diet for 20 days. Compared to controls, egg yolks from treated hens contained greater amounts of amino acids and reduced levels of total fatty acids and cholesterol. In contrast, egg albumen amino acid contents were unaffected by dietary treatments. In a residue study, seven hens each received a single oral dose of approximately 20 microCi of [(14)C]atorvastatin. Approximately 71% of the radioactivity was recovered in the excreta and liver, whereas virtually no radioactivity was detected in kidney, heart, muscle, bile, plasma, or egg albumen at 15 days postdosing. Yolk radioactivity peaked at 4 days postdosing in six of the seven birds and was absent in eggs laid after day 10. Reminiscent of that of certain antibiotic drugs, the atorvastatin egg residue pattern appeared to coincide with the physiological pattern of daily yolk accretion within the ovary. 相似文献