电击晕对肉鸭屠宰品质的影响

以肉鸭胸肉和腿肉为研究对象,研究宰前电击晕对肉鸭屠宰品质的影响,以p H值(30 min和24 h)、肉色、加压失水率、蒸煮损失率和剪切力作为评价指标。研究结果表明:电击处理对肉鸭的胸肉影响较大,使胸肉的p H值降低(p0.05),L*值增大(p0.05),加压失水率(p0.05)和蒸煮损失率(p0.05)减小,剪切力值增加(p0.05);电击处理使腿肉的p H值降低(p0.05),对腿肉肉色、加压失水率、蒸煮损失率和剪切力值均无显著影响。     

不同电压击晕对獭兔生理信号及宰后兔肉品质的影响

本文研究了电击晕屠宰时,不同电压对獭兔致晕后生理参数(脑电波、心电波)、胴体质量、兔肉品质(蒸煮损失率、滴水损失率、剪切力)的影响。实验分为四组,以手砍脑干颈椎致晕法为对照组,其他三组分别用90、120、150V电压头部电击獭兔3s致晕,然后割动脉放血,取其股二头肌(biceps femoris)测定相关指标分析。结果发现,与对照组相比,电击后獭兔脑电波呈癫痫状,随电击电压的增大癫痫状脑电波振幅增大,其心电波主峰频率也比对照组加快。同时,电击致晕獭兔出现不同程度胴体瘀斑、骨折和出血等现象。随着击晕电压的增大,兔肉蒸煮损失率和滴水损失率均显著增大。同时电击晕处理能增大兔肉剪切力,降低兔肉嫩度。以上结果表明,与脱颈处死相比,电击致晕降低了兔肉品质,其随着电压强度的增加而更加明显。按照屠宰需要及考虑动物福利的原则,选用90V电压为獭兔适宜击晕电压。     

不同屠宰方式对新疆多浪羊肉品质的影响

以新疆多浪羊为研究对象,对比分析传统屠宰（对照）和3 个不同电压（90、127 V和220 V）击晕屠宰 （分别计作EST 90、EST 127、EST 220）对多浪羊肉品质的影响。结果表明：EST 90处理组成熟过程中pH值下降 速率最快,血液中的皮质醇浓度、肌酸激酶和乳酸脱氢酶活力最高,羊应激反应最剧烈,宰后1、7 d的蒸煮损失率 最高（P＜0.05）;EST 127处理组的持水力最好;电击晕对多浪羊肉嫩度有一定影响,宰后7 d各处理组嫩度显著 改善,而EST 127处理组表现最佳;EST 220处理组放血不充分,且胴体表皮有多处血斑形成;电击晕屠宰对多浪羊 肉色泽无显著影响（P＞0.05）。综合分析实验结果,EST 127处理组持水力与嫩度较优,羊应激反应较小,肉品质 相对较好,因此EST 127处理适合应用于多浪羊的屠宰加工。     

宰前电击晕对鸡肉品质影响的研究进展

以鸡肉为主的禽肉由于高蛋白、低脂肪、低胆固醇、低热量、营养价值高，深受消费者喜爱，近年来在我国成为仅次于猪肉的第二大消费肉类。随着肉鸡屠宰行业的不断发展，在国内动物福利越来越受到重视，肉鸡宰前处理越发受到关注。击晕作为保证动物福利的重要步骤，对降低肉鸡的应激、提升肉质有积极作用。电击晕方便、经济、所需空间小，是禽类流水线屠宰广泛使用的击晕方法，可以减少肉鸡胴体损伤和宰前应激程度、降低次品率、改善鸡肉品质、提升食用口感，探究适宜的电击晕参数成为多年来的研究重点。本文介绍动物的不同击晕方法，综述宰前电击晕对鸡肉品质影响的研究现状、影响电击晕效果的因素、国内外电击晕的标准化现状，分析电击晕的优势与应用，同时对未来的发展前景进行展望，旨在为后续研究和标准制定提供参考。     

屠宰应激对宰后猪肉保水性的影响

本文研究了电击晕和二氧化碳致晕对杜大长三元杂交猪和三门峡黑猪的应激效应及宰后肌肉保水性的影响。结果表明:与电击晕相比,二氧化碳致晕使得杜长大三元杂交猪和三门峡黑猪血液中的乳酸(LAC)、乳酸脱氢酶(LDH)、肌酸激酶(CK)、肌酐(CRE)、皮质醇(COR)含量显著降低(P0.05);且杜长大三元杂交猪和三门峡黑猪宰后p H45min值较高,差异显著(P0.05),宰后24 h汁液损失率(降低1.17%和0.59%)、蒸煮损失率(降低3.09%和3.56%)及解冻损失率(降低0.55%和0.29%)显著降低(P0.05);剪切力显著降低0.71 kg及0.66 kg(P0.05)。此外,杜长大三元杂交猪的抗应激能力较差,其宰后肌肉保水性显著低于三门峡黑猪(P0.05)。LF-NMR研究表明,二氧化碳致晕能够显著降低解冻后肌肉中的自由水含量(降低32.24%和28.92%),抑制了不易流动水向自由水的"态变"。因此,在实际生产中采用二氧化碳致晕能降低生猪屠宰应激,提高肌肉保水性。     

不同屠宰方式对蒙古羊应激及羊肉食用品质的影响

以内蒙古蒙古羊为研究对象,对比分析抹脖子屠宰、掏心式屠宰及电击晕屠宰对蒙古羊应激及羊肉食用品质的影响,利用生化分析仪等仪器对蒙古羊血液指标及食用品质进行测定。结果表明：经电击晕后屠宰,肉羊血液中乳酸含量、皮质醇含量、乳酸脱氢酶活性及肌酸激酶活性显著低于其他2 种方式,肉羊在屠宰过程中应激反应也最小;相比于抹脖子及掏心式屠宰2 组,电击晕组羊肉的蒸煮损失率较低,而嫩度高于抹脖子组,且与掏心组差异不显著,红度值（a*）高于上述2 组,且电击晕组羊肉的硫代巴比妥酸反应物值最低;营养方面,电击晕及掏心式屠宰可提高羊肉中不饱和脂肪酸的含量。因此,从肉羊屠宰食用品质及经济效益等方面比较,电击晕屠宰方式可以减小肉羊应激反应,提高肉羊屠宰企业的经济效益,符合动物福利屠宰要求。     

生猪宰前不同静养时间和屠宰方式对背长肌肌肉pH值和滴水损失的影响

两个不同的屠宰场分别随机选取50头待宰的商品猪分为两组,分别进行屠宰前禁食6h和12h处理,测定背最长肌pH值和滴水损失率.结果表明,6h和12h不同的静养时间对肌肉滴水损失率没有显著差异,但是升高了屠宰后24h肌肉pH值,表明宰前较长时间的静养有利于提高肌肉品质性能.另外对电击致晕屠宰和活体屠宰方式相比,前者滴水损失率明显低于后者,表明电击致晕的屠宰方式对提升肉品质量来讲是一种更适宜推广的方式.     

不同电压电击昏对猪肉品质的影响

30头品种、年龄、性别相同的杂交猪(体重120 kg±5 kg)随机分成3组,每组10头,分别用215、150、100V的电压在头部进行电击昏后屠宰.取背长肌测定各项肉质指标.结果显示:宰后45 min采用215 V电压电击昏组的猪肉pH值与150 V电压组差异显著(P<0.05),其它时间点差异不显著;215 V电压组与100 V电压组相比在45 min、1.5、2.5、24 h差异显著(P<0.05).150 V电压组与100 V电压组相比在1.5、2.5 h差异显著(P<0.05).击昏电压对宰后背长肌的色泽(L*和a*值)、滴水损失、蒸煮损失、嫩度、没有显著影响(P<0.05);宰后24 h 215 V组的细胞间空隙面积明显高于其它两个组.生产操作中建议击昏电压采用150 V电压.     

国际科技资讯

正巴西研究宰前电击晕和二氧化碳致晕对猪肉品质的影响对家畜进行屠宰时预先进行击晕处理是为保障家畜在被屠宰时处于无意识的状态,不会对疼痛产生反应,以此确保动物福利的实施。在巴西,对家畜进行击晕的方式主要有电击晕和二氧化碳(90%)致晕2种。击晕不仅是出于动物福利的考虑,还会对肉制品的品质产生不可逆的影响,如肉制品的颜     

不同击晕电压对猪肉胴体性能与冷却肉品质的影响

探讨不同的击昏电压对猪肉胴体品质与冷却肉品质的影响.采用原料猪种为三元杂交猪,试验猪只均重在105±2.37kg.结果显示,击晕电压高于200V时.猪只宰后45min的胴体温度显著高于其他处理组(P<0.05).击晕电压在280V时的蒸煮损失显著高于其他处理组;感官评价小组的肉色评分范围在3.2±0.4～4.2±0.75,其中280V的肉色评分最大(4.2±0.75).击晕电压在200V时冷却肉的亮度显著低于其它处理组(P<0.05),其它各组间差异不显著(P>0.05).随着击晕电压的升高,冷却肉的红度也随着升高.初步确定150V可以作为最佳的击晕电压.     

不同品种乳鸽胸肌肉品质及主要营养成分比较研究

为更好地建立乳鸽肉质评价标准,同时为培育良好肉质乳鸽新品种提供借鉴,取美国白羽王鸽、美国银羽王鸽、欧洲肉鸽、泰森鸽及苏威肉鸽胸肌肉,测定肉的食用品质（肉色、pH值、失水率和剪切力）和营养成分（水分、蛋白质、脂肪、肌苷酸、氨基酸和脂肪酸）含量,并进行比较分析。结果表明：不同品种乳鸽胸肌肉亮度值（L*）、红度值（a*）和黄度值（b*）均差异显著（P＜0.05）,pH值、剪切力、失水率差异不显著（P＞0.05）,有色羽的银羽王鸽和泰森鸽L*、a*、b*均低于白羽的白羽王鸽、欧洲肉鸽及苏威肉鸽,苏威肉鸽肉色与欧洲肉鸽接近,相较于其他品种偏亮、偏红、偏黄;不同品种乳鸽胸肌肉的水分、蛋白质和脂肪含量差异均不显著（P＞0.05）;泰森鸽胸肌肉肌苷酸含量显著低于白羽王鸽、欧洲肉鸽和苏威肉鸽（P＜0.05）;不同品种乳鸽胸肌肉必需氨基酸和鲜味氨基酸含量差异不显著（P＞0.05）,相较于白羽的白羽王鸽、欧洲肉鸽及苏威肉鸽,有色羽的银羽王鸽、泰森鸽必需氨基酸含量偏低,鲜味氨基酸含量偏高;银羽王鸽胸肌肉饱和脂肪酸含量显著低于白羽王鸽、欧洲肉鸽及苏威肉鸽（P＜0.05）,泰森鸽略高于银羽王鸽。相较于白羽的白羽王鸽、欧洲肉鸽及苏威肉鸽,有色羽的银羽王鸽和泰森鸽肉色深、鲜味氨基酸和不饱和脂肪酸含量较高,但肌苷酸和必需氨基酸含量较低。无论是食用品质还是主要营养成分,苏威肉鸽均与欧洲肉鸽较为接近。     

致昏电压对兔肉品质的影响研究

采用100、75、65、55V和人工致昏(对照组)的宰杀方式,研究其对兔肉品质的影响,结果表明:不同致昏电压对兔肉pH值的影响差异不显著(p>0.05),只有75V致昏组与100V致昏组间宰后1h的背最长肌pH值差异显著(p<0.05);宰后1h,不同致昏电压对兔背最长肌的肉色亮度L*值、红度a*值、黄度b*值和后腿肉的L*值、a*值的影响差异不显著(p>0.05);宰后24h,75V致昏组的肌肉颜色鲜红,而人工致昏组和100V致昏组的肌肉颜色较苍白;100V致昏组的滴水损失最大,为3.738%,而75V致昏组的最小,为2.420%;蒸煮损失最大的为100V致昏组,最小的为55V致昏组,其次是75V组;肌肉嫩度最好的是75V致昏组,最差的是人工致昏组。     

宰前运输、休息、禁食和致晕方式对鲜肉品质影响的研究进展

屠宰前畜禽在经历装卸、运输与休息、入栏、禁食以及宰前致晕等过程中,要面临许多应激原的刺激,如饥饿、颠簸、拥挤等客观因素,以及由此导致的惊恐、紧张等心理因素。宰前处理程序带来的应激大部分对肉质的形成是不利的,但是运输前的禁食、供水以及宰前休息等可能对肉质有一定的改善作用。电击晕、CO2致晕,二者都是机械化屠宰经常采用的工序,国内对于CO2致晕的应用与研究均较少。本文综述了近年来国内外有关宰前运输、休息、禁食及致晕方式对鲜肉品质影响的最新研究成果,旨在为优质肉的生产及相关科学研究提供参考。     

Animal welfare at markets and during transport and slaughter

This review highlights some recent developments in our understanding of stress and physical injuries that occur before and during transport to slaughter, during handling at livestock markets, and at the time animals are put-up for slaughter within abattoirs. Stress in pigs during transfer to the stunning point within the abattoir has important effects on meat quality, and there is growing evidence that strenuous exercise or CO(2) stunning can contribute to oxidative rancidity in pigs, poultry and fish. In the EU, putting cattle through a crush in order to check that their eartag numbers correspond to their passport numbers is imposing additional stress, and there are reports that it is leading to greater hide contamination with Escherichia coli O157. Recent developments in stunning and slaughter include a better understanding of the causes of variation in captive bolt gun performance, the effectiveness of poll instead of frontal shooting in water buffalo, the prevalence of false aneurysms in carotid arteries during shechita and halal slaughter, and the stress effects of CO(2) stunning in fish. Stunning pigs with 90% CO(2) leads to less PSE meat than 80% CO(2). There have been concerns about the physical activity that cattle show following electrical stunning with an electrically induced cardiac arrest, and with electrical stunning using DC waveforms in broiler chickens. There is also growing concern about the hygiene problems that exist in wet markets, where animals are slaughtered alongside meat that is on display to customers.     

氯化钠腌制对鸽肉品质特性的影响

以新疆塔里木肉鸽为原料,设计单因素试验,控制腌制液中氯化钠添加量分别为0%、3%、5%、7%、9%,采用湿法腌制,对腌制后鸽肉的水分含量、水分活度（water activity,aw）、含盐量、硫代巴比妥酸反应物（thiobarbituric acid reactive substances,TBARs）值、挥发性盐基氮（total volatile basic nitrogen,TVB-N）含量、pH值等指标进行测定并结合感官评定,探究不同添加量氯化钠腌制对鸽肉品质特性的影响。结果表明：随着氯化钠添加量的增加,鸽肉的水分含量、aw、TBARs值、TVB-N含量、pH值逐渐降低;鸽肉盐含量与氯化钠添加量呈正相关。综合分析各种指标,最终确定腌制液中氯化钠添加量为5%,腌制后的鸽肉表面富有光泽且肉质紧致有弹性,品质较优。     

Effects of electrical and mechanical stunning methods on meat quality in ostriches

The effect of electrical and captive needle air pressure stunning methods on some meat quality parameters was examined in ostriches under practical conditions. One hundred and fifteen ostriches were used in three experiments. The ostriches were stunned either electrically (head only) or by using a captive needle with air pressure. In the first experiment the ostriches were stunned at 90 V (～effectively 52 V), 200 V and by captive needle using air pressure. In the second experiment voltages of 175 and 200 V were applied and a captive needle stunning method using air pressure. In the third experiment the birds were stunned at 175 V with a short stun/stick interval. Experiments 2 and 3 were performed in a different slaughterhouse from experiment 1. Meat quality was assessed by measuring the pH, temperature and colour at 45 min and 18 h post mortem and by determining water binding capacity and haemorrhage score at 18 h post mortem in the big drum, tender loin and triangular filet muscles. The measured stunning parameters in the first experiment were 204±96 mA (～52 V) during 11±1 s and 556±85 mA (～200 V) during 6±0 s. The stun/stick interval was 136±38 s. The rigor mortis value in the tender loin and both pH(1) and pH(2) in the big drum, tender loin and triangular filet muscles were (p<0.05) lower when stunned with air pressure compared with electrical stunning. Moreover internal light scattering remained higher. The measured currents in the second experiment were 561±226 mA (～173 V) during 6±2 s and 518±120 mA (～200 V) during 6 s. The stun/stick interval was 39±12 s. The pH at 45 min and 18 h differed (p<0.05) in the tender loin and triangular filet muscles as did the temperature at 45 min in the three muscles between the different stunning groups. The stunning in the third experiment was carried out with 548±180 mA during 6±2 s. The stun/stick interval was 5±2 s. After the short stun/stick interval the pH(2) was lower (p<0.05) for the tender loin and triangular filet muscles and the wetness of the filter paper of the big drum was (p<0.05) lower compared with the other groups. Our experiments showed that stunning methods affected several meat quality parameters. Using a high electrical stunning current, captive needle stunning or a short stun/stick interval may positively affect some parameters. More research is necessary to examine effects of pre slaughter handling on meat quality.     

The assessment of pre-slaughter and slaughter treatments of livestock by measurement of plasma constituents-A review of recent work

The measurement of plasma constituents in a blood sample can provide information on the stress status of the animal. The interpretation of results obtained for constituents of blood samples collected at exsanguination must consider the effect of the slaughter process on the constituent. Both electrical and mechanical stunning methods can cause dramatic increases in catecholamine levels and minor increases in glucose levels. Thus, there are difficulties in the interpretation of catecholamine and, to a lesser extent, glucose, values in blood samples collected post-stunning. Cortisol levels appear to be unaffected by stunning methods and measurement of this constituent in post-slaughter blood samples has been used to assist in the evaluation of transport and abattoir treatments. Beta-hydroxybutyrate concentrations may assist in evaluating nutritional stress prior to slaughter while the limited evidence available suggests that beta-endorphin measurements will be of value in assessing pain and other stressors prior to slaughter. Adreno-corticotrophic hormone, calcium and magnesium, free fatty acids, glucose, lactate and thyroid hormones have all been used on occasions to assist in the evaluation of stress status. In some cases it was not possible to demonstrate a clear relationship between plasma constituents that indicate stress, and stress-related meat quality defects.     

Head current during and blood splashes after electrical stunning in relation to characteristics of the pig's body

In order to evaluate electrical stunning in relation to the incidence of blood splashes, meat quality and carcass quality parameters, 2035 pigs, heterozygous for the halothane gene, were observed during slaughter at a commercial slaughterhouse. The head current during electrical stunning is significantly higher (P<0.01) in gilts with a lower live weight (P<0.0001) or cold carcass weight (P<0.0001) and a higher lean meat percentage (P<0.0001). Also the incidence of blood splashes in the ham is significantly higher in gilts (P<0.0001) with a higher lean meat percentage (P=0.0028; odds ratio=1.11), a lower live weight (P=0.003; odds ratio=0.98) and a lower type number (P=0.0074; odds ratio=0.64). For barrows, no significant parameters were revealed. These results suggest that the variability in incidence of blood splashes can be explained by the variability of current density depending both on sex and body characteristics. Thus, electrical stunning can be improved by providing an energy level, based on the body characteristics of the pig.