基于决策树雪花牛肉大理石花纹分级模型

为建立雪花牛肉大理石花纹等级评价方法,根据不同等级雪花牛肉大理石花纹图像特征及人工评级的标准,确定了影响大理石花纹的等级主要因素。本研究提出影响大理石花纹等级的几何参数特征、几何分布参数特征和统计参数特征。其中几何参数特征主要反映大理石花纹面积、周长等;几何分布特征主要反映大理石花纹图像中脂肪颗粒沉积的密度,根据脂肪颗粒沉积情况可分为大颗粒脂肪、中颗粒脂肪、小颗粒脂肪等;统计参数特征主要反映大理石花纹丰富程度以及大理石花纹分布均匀性。利用相关性分析提取影响雪花牛肉大理石花纹等级的特征参数。建立基于C4.5和CART算法的决策树模型,结果表明：对于C4.5算法建立的决策树分级模型,三级和五级大理石花纹分级预测精度分别为91.80%、92.31%,而该模型针对四级样本建立的模型无效,其结果多数误判为三级;对于CART算法建立的决策树模型同样存在这样的问题,即三级和五级大理石花纹分级预测精度高,而对四级样本分级无效。     

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。     

基于计算机视觉的牛肉质量分级研究进展

牛肉品质分级对于肉牛产业具有重要意义,为克服人工评级的弊端,客观、无损的自动分级技术成为研究热点。本文综述了国内外利用计算机视觉对牛肉大理石纹、生理成熟度、肉色和脂肪色这些指标进行分级预测的研究进展情况,讨论了研究过程中诸如图像分割、特征提取方面存在的困难,最后指出了计算机视觉技术在牛肉品质分级应用过程中存在的问题以及可能的发展方向。     

牛肉颜色的RGB特征

作为一个重要的食用品质,牛肉的颜色既是牛肉分级评定时的一个指标,同时又是自动分级时与脂肪区别的一个重要特征。本文从统计和理论的角度,结合我国现在使用的一种牛肉颜色等级图,对牛肉颜色的RGB特征进行了分析,得出了牛肉颜色的规律,为进一步自动分级算法设计提供保证。     

猪骨骼肌组织学特性与猪肉嫩度关系的研究

目的:研究背最长肌和腰大肌的肌纤维直径、肌纤维密度及肌内脂肪百分面积对肌肉嫩度等的影响力或贡献力;方法:对6个杂交组合猪(N=36)的骨骼肌组织形态特征进行二维显微图像重建和与肌肉嫩度的数学关系拟合(n=36×2或×3);结果:腰大肌的肌纤维直径和密度分别比背最长肌细且密,但肌内脂肪百分面积普遍小于背最长肌.肌纤维直径对肌肉嫩度的影响力最大(r=0.966,P<0.01),直径越粗肌肉嫩度越差.肌纤维密度随直径而变化,肌纤维直径越粗,单位面积肌纤维密度越低,且与肌肉嫩度呈显著性相关(r=0.905,P<0.05),肌纤维密度越大肌肉嫩度越好,但贡献力小于肌纤维直径.肌内脂肪百分面积仪占与肌肉总面积的3%左右,本实验数据证实其不足以影响猪肉嫩度;结论:骨骼肌嫩度受肌纤维直径和密度影响较大,一定范围内肌内脂肪可能更多地影响猪肉的风味,而不是嫩度.     

近红外技术在牛肉质量分级体系中的应用研究进展

牛肉等级评价体系旨在使市场形成以质论价、优质优价的优良市场机制,并引导肉牛产业的健康发展.世界主要发达国家都有较完善的牛肉等级评价体系,我国牛肉等级评价体系起步较晚,牛肉自动分级技术处于探索和研究阶段.近红外技术作为一种快速、在线的检测技术,在牛肉质量检测方面得到了广泛的研究.本文对国内外主要的牛肉质量分级标准体系进行了概述,指出了目前国内外的牛肉质量分级技术体系存在的问题,综述了国内外的近红外技术在牛肉质量分级体系中应用现状和研究进展,总之近红外技术在牛肉质量分级技术体系中具有很大的潜力.     

不同相对湿度对牛肉解冻效率及解冻后品质的影响

以新鲜牛肉为对照,探究低温条件(5℃)下,不同相对湿度(relative humidity,RH)(50%、75%、98%)解冻对牛肉解冻时间、保水性、pH值、色泽、嫩度、蛋白溶解度及丙二醛含量的影响。结果表明:与新鲜牛肉相比,解冻会降低牛肉保水性、嫩度、色泽方面的品质,促进蛋白变性与脂肪氧化的发生;随着解冻RH的增加,解冻效率明显提高,解冻汁液损失率降低,蛋白溶解度增加,蒸煮损失和pH值在不同解冻RH样品间变化不明显;同时,高RH能够改善牛肉解冻后的色泽和嫩度品质,缓解脂肪氧化,而RH 75%解冻的样品优于RH 98%解冻样品。因此,在一定范围内提高解冻RH更有利于提高解冻效率,降低解冻过程对牛肉保水性的影响,保持色泽、嫩度品质,缓解肌肉蛋白变性和脂肪氧化,改善解冻牛肉品质。     

关于浅圆仓扦样均匀性问题的探讨

浅圆仓的扦样工作在粮库日常质量管理中有着十分重要的意义.扦取的样品具有代表性,整仓粮食质量才能得到很好地把控,浅圆仓由于其装粮线高的特点导致入库粮食自动分级严重,如何避免库存粮食自动分级导致的粮堆内粮食质量分布不均匀,并让扦取的综合样品具有代表性,是浅圆仓库存粮食质量管理工作中的关键环节.     

计算机视觉在牛肉自动分级技术中的应用

国外计算机视觉牛肉自动分级技术较为成熟,国内的研究也取得了一定的成果。鉴于国内牛肉分级意义重大,本文概述了我国牛肉质量等级标准和国内外研究现状,并针对利用计算机视觉技术对牛肉自动分级,从完善标准、调整工艺、设计成像条件和计算方法等多个方面提出所遇到的问题,并指出牛肉自动分级技术的研究方向。     

清真屠宰工艺对牛肉品质的影响机制研究

通过检测分析清真屠宰后牛肉排酸后的pH值、压力失水率、肌肉色泽、大理石花纹、嫩度、微生物等指标,同时与普通非清真屠宰牛肉品质的检测结果做对比,分析评价清真屠宰工艺对牛肉品质的影响。结果显示,与普通非清真屠宰牛肉相比,清真屠宰牛肉在排酸成熟后pH值偏高(P0.05),色泽L*值a*值升高(P0.05),b*值降低(P0.05),剪切力偏低(P0.05),压力失水率偏低(P0.05)。微生物检测结果中,细菌总数较低(P0.05),大肠杆菌检出率较低,沙门氏菌检出率无明显变化,两者差异显著。与非清真屠宰牛肉相比,清真屠宰牛肉的色泽、嫩度和系水力较好,微生物污染程度得到改善,表明清真屠宰工艺能显著改善牛肉品质和食用卫生质量。     

基于图像的牛肉大理石纹理自动评级方法研究

研究一种基于图像处理技术的牛肉大理石花纹自动等级评定方法。通过图像重采样、单阈值分割、形态学腐蚀及膨胀等方法分割出大理石花纹,再提取图像的特征参数组,并用多元回归分析的方法构造牛肉大理石花纹评级模型,并用VC++实现了自动评级软件。通过对多个牛肉图像的检测,表明此评级计算模型具有良好的准确性和鲁棒性。     

牛眼肌区域大理石花纹评级特征的研究

针对我国牛肉分级制度中的大理石花纹等级评定特征不确定的问题,提出用几何、粒度及形状参数来表征花纹几何、形状及分布特点的方法。选择对牛肉大理石花纹等级评定起主要作用的特征参数,对中国、美国及日本3个国家的牛肉等级图进行深入地研究,找寻3个国家牛肉大理石花纹分级标准的侧重点。对选取的参数数据进行相关性分析,剔除原特征集中相关性较强的特征,应用主成分分析法对影响大理石花纹等级的参数进行线性组合,选取适合的主成分建立大理石花纹的等级预测模型。     

The relationship of physiological maturity and marbling judged according to Korean grading system to meat quality traits of Hanwoo beef females

Fifty seven carcasses from Hanwoo beef females were randomly selected by official meat graders and were sorted into three levels of maturity and marbling. Carcass data was collected for back fat thickness, longissimus area, carcass weight, meat colour, fat colour, marbling score, yield and quality grades. Mature carcasses had more yellow fat, coarser texture, a larger longissimus muscle area and lower quality grades and marbling scores (P<0.05). Carcasses with a higher marbling score had thicker fat and a higher quality grade. Carcasses with low marbling had a higher yield grade and a coarser texture (P<0.05). Higher marbling scores corresponded with lower cook and drip loss values for longissimus steaks. As the maturity of carcass was increased, the redness and lightness of meat and the yellowness of fat all tended to increase. Tenderness, flavour and overall acceptability scores for the older maturity group were lower than for younger and intermediate groups. Marbling was significantly (P<0.01) correlated with quality grade, crude fat content, cook and drip losses, and Warner-Bratzler shear force. The maturity level was also significantly (P<0.01) correlated with quality grade, fat colour, texture score, number of calves produced and milk teeth, meat redness and yellowness, fat yellowness, and Warner-Bratzler shear force. Results indicate that a low marbling group and older maturity group based on Korean grading system could negatively influence carcass traits and beef qualities of Hanwoo beef female.     

Ether-Extractable Fat in Longissimus Muscles From Beef Carcasses with the Same Marbling Scores but Different Yield Grades

Ether-extractable fat in beef longissimus muscles–completely trimmed of all subcutaneous fat, epimysium and peripheral muscles–from 383 heifer and steer carcasses of A and B maturity was compared to determine whether the fat content of muscle was the same when marbling was held constant but yield grade of carcasses differed. Yield grade was a significant source of variation in intramuscular fat content of trimmed steaks within marbling scores (P < 0.001); as yield grade increased, total fat content of the ribeye muscle increased very slightly, even though marbling score was held constant. These data indicated that marbling score alone did not account for all of the variation in the fat content of totally-trimmed beef longissimus steaks.     

Implant and biological type effects on beef carcass characteristics

Beef carcasses (n = 1574) were evaluated at Excel Corp. beef slaughtering facility, Friona, Texas, to determine the effects of implants (double Revalor and Ralgro/Revalor) and biological type (Continental European, Continental European × British and British) on carcass characteristics. No differences (P > 0.05) were found between implants for marbling score, USDA quality grade, adjusted preliminary yield grade, percentage kidney, pelvic and heart fat, or carcass weight. Carcasses from cattle implanted with double Revalor had a larger (P < 0.05) ribeye area and a lower USDA yield grade. No differences were found among breed types for marbling score, USDA quality grade, preliminary yield grade, ribeye area or USDA yield grade (P > 0.05). Steers classed as continental European had the lowest adjusted preliminary yield grade and percentage kidney, pelvic and heart fat, the heaviest carcasses and were most muscular as determined by the Excel muscle score (P < 0.05).     

我国牛胴体等级标准中部分指标的测定方法研究

本文对牛肉等级标准中所采用的生理成熟度、大理石花纹和眼肌面积三个指标的测定方法进行了研究。最终建立起了既能够方便地进行测定又能够保证其准确性的测定方法 ,为整个标准的实施打下了良好的基础。     

POSTMORTEM ENVIRONMENTAL FACTORS AFFECTING BEEF CARCASS LEAN MATURITY AND MARBLING EVALUATIONS

Postmortem environmental factors such as chill time before ribbing, evaluation time after ribbing, interstate shipment, ribeye condition and ribeye cover condition were related to beef carcass lean maturity and marbling evaluations. Also, effects of lighting type and intensity on the evaluation of beef quality factors were studied. Beef carcasses chilled 48 h or less before ribbing required additional chilling after ribbing (greater than 30 min) in order to optimize lean maturity and marbling scores. I n general, carcasses that are thoroughly chilled and have covered ribeye surfaces are likely to maintain or develop more youthful lean maturity evaluation scores during shipment. Carcasses that were less chilled at initial evaluations and had ribeye surfaces that remained substantially covered during transportation were more likely to increase in marbling scores during transportation. Carcasses chilled for only 24 h at initial evaluation and that had a “Small” or lower amount of marbling were more subject to change in marbling score during shipment than carcasses that were more thoroughly chilled or carcasses that had higher levels of marbling. Lean maturity evaluations were optimized when beef carcasses were evaluated under “high” incandescent (1937 lux) lighting, whereas marbling scores were optimized when beef carcasses were evaluated under “medium” incandescent (1076 lux) lighting.     

REALIMENTATION OF CULL BEEF COWS. I. LIVE PERFORMANCE, CARCASS TRAITS AND MUSCLE CHARACTERISTICS

The objective of this study was to determine whether culled beef cows fed a high-concentrate diet (FED) would have improved live performance, carcass traits and muscle characteristics compared with forage fed (CON) cows. In addition, ractopamine (RAC) supplementation was evaluated for added benefits over high concentrate alone. Live weight, average daily gain, hot carcass weight, ribeye area, marbling, quality grade and carcass fat measurements increased ( P ≤  0.05) by realimentation. As a percent of hot carcass weight, muscle yields did not differ ( P >  0.05). Lipid content increased ( P ≤  0.05) in 5 out of the 10 muscles from FED cows. Cows fed ractopamine showed some numeric improvements over feeding alone, but few statistical differences ( P >  0.05). This may result from variability associated with cull cows, and warrants investigation into the best dose/duration for ractopamine. However, realimentation by itself was able to improve cull cow quality.

PRACTICAL APPLICATION

The U.S. beef industry continues to explore new avenues to enhance undervalued sectors of the production system. Through realimentation, cull cow quality can be improved. The data presented herein demonstrate that feeding a high-concentrate diet to cull cows increases both live and carcass weights. In addition, high concentrate-fed cull cows display more marbling and whiter fat cover than those fed at maintenance level. Qualification for premium programs, heavier weights and overall higher quality may lead to increased value for this underutilized sector of the beef industry.     

Automatic segmentation of beef longissimus dorsi muscle and marbling by an adaptable algorithm

An algorithm for automatic segmentation of beef longissimus dorsi (LD) muscle and marbling has been developed. The algorithm used simple thresholding to remove the background and then used clustering and thresholding with contrast enhancement via a customised greyscale to remove marbling. It was possible to attain lean muscle free of obvious marbling or background pixels where specular reflection could be effectively mitigated. Features of the automatically derived LD muscle and marbling images were compared to corresponding features of LD muscle and marbling images derived with a segmentation method requiring manual completion. Very strong correlations (up to r = 1) were found between the colour features of both sets of LD muscle images. Strong correlations (up to r = 0.96) were found between the features of both sets of marbling images. The automatic segmentation method has shown its good ability to approximate colour and marbling features. The algorithm has adaptable parameters and can be retailored to suit different image acquisition environments.