不同质量等级的中国黄牛肉在成熟过程中的品质变化研究

选取优一级、优二级和普通级中国黄牛牛胴体的外脊,测定其在成熟0、1、3、7、14、21和30h的剪切力值、pH、解冻滴水损失、蒸煮损失和熟肉率。结果表明,等级和成熟时间对外脊剪切力值有显著影响(p<0.05),等级对解冻滴水损失、蒸煮损失和熟肉率有极显著影响(p<0.01)。在同一成熟时间,级别越高,剪切力值越小,解冻滴水损失和蒸煮损失越小,熟肉率越高;随着成熟时间的延长,牛肉的剪切力值显著降低,解冻滴水损失和蒸煮损失显著增大(p<0.01)。     

不同日粮水平和成熟时间对牛肉质量的影响

对3组未去势公牛分别采用不同日粮水平饲养并按照标准的屠宰工艺屠宰,对具有代表性的牛肉切块(背最长肌、腰大肌、半膜肌、臀中肌、臂三头肌、半腱肌)的质量的指标如滴水损失、pH值、颜色、蒸煮损失、剪切力进行了测定.结果表明,低日粮水平牛肉pH值偏高(P＜0.05),除腰大肌、臀中肌、臂三头肌的剪切力差异显著(P＜0.05)外,对其余各项指标的影响不显著;而成熟时间除了对牛肉的pH值无影响外,对其他各项指标均有显著影响(P＜0.05),随着成熟时间的延长,牛肉的滴水损失、蒸煮损失呈增加的趋势,而剪切力、颜色得分呈降低趋势.且牛胴体主要分割切块对成熟时间的反应不尽相同.     

不同剔骨工艺对牛肉煎制食用品质的影响研究

为研究不同剔骨工艺对牛肉煎制食用品质的影响,以西门达尔牛的外脊为原料,测定冷剔骨(L)、热剔骨成熟(R)及热剔骨速冻(RS)工艺条件下的肉色泽,pH,失水率,蒸煮损失,剪切力,硬度,嫩度,质地剖面分析(TPA),感官评定。研究结果表明:RS组牛肉的剪切力值和硬度值较其他两组小,但持水力较差,并且煎制后的多汁性与另两种差异显著(p0.05),食用品质差;R组牛肉的黏着性与另外两种工艺差异显著(p0.05),与L组牛肉的剪切力值差异不显著(p0.05)。由此判断,L组和R组牛肉较RS组牛肉更适宜作为煎制牛排原料。     

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。     

Curdlan协同Alcalase嫩化生鲜调理牛肉工艺优化

以新鲜牛肉为原料,分析不同浓度的Curdlan及Alcalase对生鲜调理牛肉剪切力、蒸煮损失及感官品质的影响,并研究该体系下肌浆蛋白质及肌原纤维蛋白质的分解情况,优化生鲜调理牛肉嫩化加工工艺。结果表明:体系中Curdlan对生鲜调理牛肉剪切力、蒸煮损失及感官品质均有显著的影响(P0.05),但是对牛肉中蛋白质无明显的分解作用;Alcalase对肌原纤维蛋白质及肌浆蛋白质有明显的分解作用。另外,不同的Curdlan及Alcalase添加量对生鲜调理牛肉的剪切力、蒸煮损失均有显著的影响(P0.05);并且Curdlan、Alcalase对生鲜调理牛肉感官品质有显著的促进作用;通过响应曲面试验二次回归法优化生鲜调理牛肉工艺,得到工艺条件为Curdlan添加量5.43 mg/g,Alcalase添加量4.29 U/g,腌制时间73.4 h,以该工艺进行验证实验后得到产品剪切力为(0.960±0.006)kg,蒸煮损失为(19.96±0.36)%,感官评分为92.81±0.75,与理论值相比,相对误差小于5%,该工艺准确可靠,可以用于生鲜调理牛肉的嫩化加工处理。     

热处理对牛肉剪切力值及蒸煮损失的影响

本试验研究了不同处理条件对牛背最长肌剪切力值（SF—V）及蒸煮损失的影响。结果显示165℃烘烤的牛肉样剪切力较高,蒸煮损失低;而85℃水浴加热的牛肉样剪切力较小,蒸煮损失较高。不同的预处理方法.对牛肉背最长肌的剪切力值的影响差异显著。     

宰前碳酸水处理对猪肉品质的影响

试验通过对生猪宰前禁食期间饮用不同时间的碳酸水,研究碳酸水处理对宰后猪肉品质的影响。结果表明:通过宰前禁食期间碳酸水处理,对猪宰后不同时间测定的pH值都具有显著影响(P<0.05),且宰前饮用120min碳酸水时最终pH值有所偏高;禁食期间饮用碳酸水对宰后猪肉的色泽和持水力、剪切力值无显著影响(P>0.05),但对宰后猪肉的蒸煮损失均有显著影响(P<0.05),其试验组相比宰前饮用60min碳酸水时宰后猪肉的蒸煮损失最小,因此,宰前禁食期间饮用60min碳酸水时,猪肉品质最佳。     

香茅草调理牛肉烤肠的研究

试验以牛肉和香茅草为原材料,通过单因素试验对牛肉烤肠中香茅草的添加量进行筛选,并采用正交试验对发色条件和热处理条件进行优化。试验结果表明:香茅草不同添加量对牛肉烤肠的香味、质地以及总体接受度具有显著性影响(p0.05),当香茅草的添加量为0.6%时,牛肉烤肠总体接受度评分最高。发色温度对牛肉烤肠的剪切力和总体接受度有显著影响(p0.05),发色时间对牛肉烤肠的剪切力、L*值和总体接受度均有显著影响(p0.05),蒸煮中心温度对总体接受度有显著影响(p0.05)。以L*值和总体接受度为预测条件,最佳发色和热处理条件为60℃条件下发色40min,蒸煮至中心温度72℃。     

大理石花纹评分与淮南猪背最长肌感官特性的关系研究

通过研究不同大理石花纹猪肉的感官特性,进一步阐明大理石花纹与猪肉感官特性的内在联系。根据第5~6根肋骨背最长肌横切面的大理石花纹分布程度,进行感官评分;以肉色相近且含有不同大理石花纹的淮南猪背最长肌腰段为原料,各大理石花纹等级随机选择10条,测定它们的肉色、肌内脂肪含量、剪切力、多汁性和风味等。结果表明:大理石花纹分为3级,1级、2级和3级的肌内脂肪含量范围分别是<2%、2%~4%和﹥4%。随着大理石花纹等级的增加,L*值、b*值和肌内脂肪含量明显增加(P<0.01),剪切力值明显降低(P<0.01)。大理石花纹等级3与等级1、等级2之间的风味和多汁性存在显著性差异(P<0.05)。因此,大理石花纹评分越高,则肌内脂肪含量越高,剪切力值越低。多汁性和风味随着大理石花纹评分的增加而得到改善。     

宰后不同时间冷冻和冻结速率对牛肉食用品质的影响

采用均匀实验设计,以宰后时间和冻结速率为考察因素,以牛背最长肌为原料,探讨宰后放置不同时间进行冷冻和不同冻结速率对解冻后牛肉食用品质的影响规律。结果表明,宰后时间和冻结速率对冻结肉样的蒸煮损失、p H、a*值和剪切力值均有显著影响(p0.05),但对肉样的L*值、b*值影响不显著(p0.05)。当保持冻结速率一定时,肉样解冻后的蒸煮损失和p H均随着宰后时间的增加而增加,a*值和剪切力随宰后时间的延长而降低,宰后时间对肉样的解冻汁液流失无显著影响(p0.05);当保持宰后时间一定时,冻结肉样的解冻汁液流失、蒸煮损失、p H、a*值和剪切力值均随着冻结速率的增大而降低。     

不同注水量对猪肉食用品质的影响

通过研究不同注水量(0、10%、20%、30%、40%)对猪肉色泽、pH、剪切力、滴水损失、蒸煮损失、压榨损失、离心损失、贮藏损失、拿破率的影响,比较分析正常猪肉与不同比例注水猪肉食用品质的差异。结果表明:随着注水量的增加,L*、b*、滴水损失、蒸煮损失、压榨损失、离心损失、贮藏损失显著增大(p<0.05),a*、剪切力随着注水量的增加显著减小(p<0.05);当注水量小于20%时,注水猪肉的L*、压榨损失、贮藏损失、离心损失与正常猪肉差异显著(p<0.05),而当注水量大于等于20%时,注水猪肉的L*、a*、压榨损失、贮藏损失、离心损失、剪切力值、蒸煮损失、滴水损失均与正常猪肉存在显著性差异(p<0.05)。与正常猪肉相比,注水后的猪肉亮度增加,保水性变差,嫩度有所增加。相关性分析表明,注水后肉块保水性的变化影响色泽的改变,同时也会影响嫩度的变化。     

优质鸡肉质性状相互关系的研究

本试验研究了优质鸡胸肌和腿肌肌肉性状间的相互关系,并对肉质性状进行了主成分分析。结果表明,肌肉IMF与pH1、pH2、肌纤维密度呈正相关,而与烹饪损失、肌肉剪切力、肌纤维直径呈负相关。肌肉pH与烹饪损失、剪切力、肌纤维直径呈负相关,而与肌纤维密度呈极显著正相关。滴水损失与烹饪损失、肌纤维密度呈负相关,而与剪切力、肌纤维直径呈正相关。肌肉烹饪损失、剪切力与肌纤维直径呈正相关,而与肌纤维密度呈显著负相关。另外,主成分分析表明,胸肌肉质性状可以用4个主成分因子进行表示,腿肌肉质性状可以用2个主成分因子进行表示。     

不同冻藏条件对鸡胸肉品质特性的影响

为研究不同冻藏条件对鸡胸肉品质特性的影响,本实验以新鲜鸡胸肉为原料,于-16、-26和-36 ℃分别冻藏1、2、3、4、5、6个月,分析比较不同冻藏温度和时间对鸡胸肉的系水力、色泽、蛋白质变性程度、嫩度、脂肪酸败及新鲜度的影响情况。结果表明,随着冻藏温度的升高及冻藏时间的延长,pH呈现先降低后升高的趋势,鸡胸肉的解冻损失率、蒸煮损失率、剪切力以及b*值也逐渐增加,L*值、总蛋白及肌原纤维蛋白溶解度显著降低(p<0.05),但对肌浆蛋白的溶解度无显著影响(p<0.05);a*值则在冻藏前1个月显著增加(p<0.05),但随后逐渐降低,且随着冻藏温度升高而减小(p<0.05)。衡量系水力指标的解冻损失和蒸煮损失结果,衡量色差的L*、a*和b*值以及衡量蛋白变性指标的三大蛋白溶解度和TBARS值与TVB-N值均表明,鸡胸肉在冻藏温度为-36~-26 ℃及冻藏时间为5个月内能有效维持较好的鸡胸肉食用品质。此外,各指标间的相关性分析表明,不同冻藏条件下解冻损失率、蒸煮损失率、剪切力、TVB-N值、TBARS值、a*值、b*值、蛋白溶解度与新鲜鸡胸肉呈现显著的差异(p<0.05),而pH、L*值与新鲜鸡胸肉差异不明显(p>0.05)。本文为快速发展的冷冻禽肉的加工及贮藏环境提供了理论依据。     

EFFECTS OF PHYSIOLOGICAL MATURITY OF BEEF AND MARBLING OF RIB STEAKS ON EATING QUALITY

SUMMARY— Selected characteristics of beef rib steaks representing three physiological maturity levels and two marbling levels were investigated. Paired steaks at the 1lth thoracic vertebra were used to obtain cooking time and losses, palatability scores, Warner-Bratzter shear values, and selected histological data. In addition, steaks from the left 7th and right 8th thoracic vertebrae positions were used to measure cooking time and losses, Warner-Bratzfer shear values, waterholding capacity, pH, color-difference, and total moisture. Ether extract was obtained for raw longissimus dorsi at the 12th thoracic vertebra. Maturity and marbling affected told moisture (P < 0.001), quantity of fat in raw muscle (histological measurement, P < 0.01). ether extract (P < 0.001). and dripping losses (7th and 8th thoracic vertebrae P < 0.001). Other factors were not affected significantly. Maturity and marbling, at levels represented, had little effect on palatability of the steaks, although generally, measurements for fat content were higher and those for moisture lower at the higher marbling level. Most correlation coefficients for overall acceptability and histological measurements were low. Tenderness had more influence on the overall acceptability of the meat than flavor or juiciness. Moderate to high relationships occurred between cooking time and both initial weight of steaks and cooking losses. Generally, waterholding capacity was not related to pH, total moisture, or cooking losses. Correlation coefficients for pH vs. shear value and pH vs. color-difference were low.     

AGING AND COOKING EFFECTS ON SENSORY TRAITS OF PORK FROM PIGS OF DIFFERENT BREED LINES

The effects of postmortem aging time (2, 9, and 16 days) and endpoint cooking temperature (60, 70, and 80C) on the eating characteristics of pork longissimus (LD) muscle were evaluated. Gilts (n=60) were from 4 different commercial hybrid genotypes (15 pigs/genotype) selected to produce a range of intramuscular fat. Results suggest that LD muscle from genotype 2, which was selected for its propensity to increase marbling had higher intramuscular fat content, tenderness and juiciness scores than that from the other genotypes (P < 0.05). Increasing aging time from 2 to 16 days increased sensory juiciness and tenderness, and decreased instrumental shear force and cooking loss (P < 0.05). Aging for nine days decreased shear force (P < 0.05) but had no effect on tenderness and juiciness scores and cooking loss when compared to 2 days aging. Increasing endpoint temperature increased cooking loss and shear force, and decreased tenderness (P < 0.05) and juiciness.     

碳酸氢钠对水煮牛肉片加工和冷藏性能的影响

研究碳酸氢钠对水煮牛肉片加工和冷藏性能的影响。添加碳酸氢钠(0.2%～0.8%)对牛肉片进行腌制,熟制后在4℃条件下分别冷藏0、2、4、6、8 d,测定水煮牛肉片在加工和冷藏期间蒸煮得率、色泽、pH值、剪切力、水分含量和硫代巴比妥酸反应物值的变化。结果表明：碳酸氢钠显著提高水煮牛肉片的蒸煮得率、pH值和水分含量(P<0.05),显著降低剪切力和红度值(a^*)(P<0.05);在冷藏期间,所有样品的水分含量均降低,亮度值和a^*减小,黄度值升高;但碳酸氢钠能抑制脂肪氧化,且随着添加量的增加,抑制效果显著提升,同时,碳酸氢钠对抑制水煮牛肉片a^*的下降有显著作用,添加碳酸氢钠水煮牛肉片的a*均大于对照组。因此,碳酸氢钠能提高水煮牛肉片的保水性、嫩度和抗氧化性。     

温度波动对冷却猪肉品质的影响

本文以宰后24 h猪背最长肌为研究对象,研究在4 ℃、0和4 ℃各2 h、4和8 ℃各2 h条件下冷藏0、24、48和72 h对pH、色差、冷藏损失率、蒸煮损失率、剪切力和水分分布状态的影响。结果表明,pH、b*值、冷藏损失率和蒸煮损失率随着冷藏时间的延长显著升高(p<0.05),剪切力显著降低(p<0.05);提高波动温度,pH、b*值、冷藏损失率和蒸煮损失率显著增加(p<0.05),剪切力显著降低(p<0.05)。低场核磁共振结果显示随着冷藏时间增加,T_2b、T₂₁和T₂₂的起始弛豫时间显著延长(p<0.05),P₂₁的峰面积比例降低,P₂₂的峰面积比例增加;降低波动温度,T_2b、T₂₁和T₂₂起始弛豫时间显著降低(p<0.05),P₂₁的峰面积比例升高,P₂₂的峰面积比例减少。综上所述,4、0和4 ℃各2 h冷藏保存有利于冷却肉品质的保持。     

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.     

Relationship of Fiber Type Composition to Marbling and Tenderness of Bovine Muscle

Beef carcasses (n = 65) were selected to range widely in marbling (moderately abundan: to practically devoid) and maturity (A, n = 25; B, n = 19; C, n = 6; D, n = 8; E, n = 7). Number, percent, area and mean diameter of β-red (βR), α-white (αW) and α-red (αR) muscle fibers were determined. Warner-Bratzler shear force values and taste panel tenderness ratings were also obtained. αW muscle fiber parameters were negatively correlated (P < 0.05) to marbling and tenderness ratings while αR and βR parameters were positively correlated (P < 0.05) to these quality attributes. The ratio of αW fiber area to βR and/or αR fiber area was correlated (P < 0.05) with marbling and tenderness. Regression analyses indicate that muscle fiber type composition is more highly related to marbling (marb) than it is to shear force value (SFV) or tenderness rating (TR) although all relationships were significant (P < 0.10). The relationship of these quality indicators to fiber type is greater within A maturity [marb, coefficient of determination (C.D.) = 65.09; SFV, C.D. = 65.09; SFV, C.D. = 28.85; TR, C.D. = 62.94] than for the entire population (murb, C.D. = 49.16; SFV, C.D. = 18.71; TR, C.D. = 30.47). It appears that the oxidative capacity of a muscle is related to marbling and tenderness and that muscle fiber type composition could possibly be used as a predictor of marbling potential.