畜禽肌肉脂质脂肪酸组成及其影响因素的研究

本试验是为了探索畜禽肌肉脂肪酸组成与肌肉部位、年龄和动物种间的关系,对猪、羊、兔和鸡等４种畜禽的肌肉脂肪酸组成进行比较研究,其结果表明。①不同肌肉９部位肌肉脂３质脂肪酸组成有明显差异,尤其是多价不饱和脂肪酸组成;②肌肉脂质多价不饱和脂肪酸悄受年龄的影响,同时也不受个体差异的影响,较为稳定;③猪和羊肉脂肪酸中,Ｃ１８：１占支配地位,而兔肉和鸡肉中则Ｃ１８：１／Ｃ１８：２占支配地位。从多价不饱和脂肪酸     

黑豚肌肉的蛋白质组成及肌原纤维蛋白质的冷藏稳定性研究

本研究对黑豚肌肉的蛋白质质组成进行分离测定,结果如下：非蛋白氮为４７５ｍｇ／１００ｇ湿肉,肌浆蛋白质为５．２６％,肌原纤维蛋白质为８．５３％,总基质蛋白质为１．０１％,碱溶性基质蛋白质为０．６４％,碱不溶性基质蛋白质０．４８５％,酸溶笥基质蛋白质为０．４５０％,溶胀因子为４２。     

水牛乳蛋白质的组成

分析了摩拉水牛（M）、尼里-拉菲水牛（N）、一代杂交水牛（F1）、二代杂交水牛（F2）和高代杂交水牛（Fh）5个品代水牛的乳蛋白主要组分的相对百分比含量．同时分析了总氨基酸组成及钙、磷含量。结果表明，水牛乳蛋白的主要组分有：α-乳清蛋白（α-LA）、β-乳球蛋白（β-LG）、免疫球蛋白轻链（IgG—L）和重链（IgG—H）、αs1-酪蛋白（αs1-CN）、αs2-酪蛋白（αs2-CN），β-酪蛋白（β-CN）、κ-酪蛋白（κ—CN）、血清白蛋白（SA）和乳铁蛋白（LF）等；CN在水牛乳蛋白中占优势，与荷斯坦牛乳相比，水牛乳中CN的质量分数稍低，而且各品代水牛乳中的CN有显著性差异（P〈0．05）；乳清蛋白中β-LG含量最高；杂交水牛乳蛋白高于纯种摩拉水牛和尼里一拉菲水牛，差异显著（P〈0．05）：各品代水牛乳的氨基酸比例比较接近；不同品代水牛乳中钙、磷含量没有显著性差异。     

屠宰日龄对伊拉兔胴体和肉质量的影响

对伊拉兔在60、70、80 日龄屠宰的胴体和肉质量进行比较研究,结果表明：宰前活质量、热胴体质量、冷却胴体质量、参考胴体质量、屠宰率、肾周脂肪质量/参考胴体质量、可解剖脂肪质量/参考胴体质量均随日龄的增加而明显增大（P＜0.05）;胴体的滴水损失随日龄增大而明显减少（P＜0.05）;pH24 h值随日龄增加有下降趋势;股二头肌L*、a*值在70 日龄和80 日龄组间无显著差异（P＞0.05）,背最长肌L*、a*值在各日龄组间无显著差异（P＞0.05）;背最长肌系水力和剪切力在70 日龄和80 日龄组间无显著差异（P＞0.05）,且均大于60 日龄;背最长肌的蒸煮损失随日龄增加而明显减小（P＜0.05）;背最长肌和后腿肌的粗蛋白、粗灰分含量在各日龄组间无显著差异（P＞0.05）,粗脂肪含量随日龄增大而明显增加（P＜0.05）,而水分含量有一定减小。伊拉兔在60 日龄屠宰生长潜力未充分发挥,70 日龄屠宰效益好,80 日龄屠宰改善了胴体和肉的品质。     

高白鲑肌肉蛋白质组双向电泳技术体系的优化

为建立高白鲑肌肉蛋白质双向电泳分析方法,通过固相p H梯度胶条等电聚焦和SDS-PAGE垂直电泳对蛋白质进行分离,分别考察了蛋白质样品制备方法、上样量、IPG胶条p H值、等电聚焦程序、助凝剂剂量、SDS-PAGE凝胶浓度及染色方法等影响的因素。结果显示,采用丙酮沉淀法制备蛋白质样品,上样量90μg,IPG胶条pH值5～8,一向胶聚焦时间400 V 16 h+1 000 V 2 h,平衡时间15 min,0.05 m L过硫酸铵及2μL TEMED,10%(体积分数)二向分离胶和硝酸银染色时,获得蛋白质分离效果好,分辨率高及横纹少的高白鲑肌肉蛋白质二维电泳图谱,为高白鲑肌肉蛋白质组学的进一步研究奠定了基础。     

蛋白质组成对苔麸面条品质影响及其作用机制

为改进苔麸面条品质,通过重组面粉法改变谷蛋白与醇溶蛋白含量,探究蛋白质组成对苔麸面条品质的影响,并对作用机制进行研究。结果表明：在谷蛋白∶醇溶蛋白含量为2.0∶1.0时,苔麸面条吸水率最高、蒸煮损失最低、亮度最高、硬度最大、面条品质最佳;蛋白质组成显著影响面团热稳定性、蛋白二级结构、麦谷蛋白大聚体含量、二硫键含量和面团微观结构的完整性;通过改变蛋白质组成可以提高面团热变性温度、降低焓值,提高β-折叠、麦谷蛋白大聚体和二硫键含量,从而形成连续且致密的结构,进而改善苔麸面条品质。综上,蛋白质组成能够显著影响苔麸面条品质。     

蛋白质组成对啤酒浑浊和泡沫稳定性的影响

在中型(50L)和小型(700—800mL)酿酒试验中，利用免疫化学技术包括酶联免疫吸附法(ELISA)，对通过麦芽性状来预测啤酒质量的方法进行了研究报道。该方法主要在啤酒泡沫蛋白和利用硅胶提取的蛋白质中加入多克隆抗体和单克隆抗体，通过抗原抗体间的反应和免疫印迹进行鉴别，研究发现ELISA法可以鉴定不同的麦芽蛋白质。随着免疫化学技术的发展，该方法可为酿造者选择高质量的麦芽，以提高啤酒泡沫的稳定性和降低浑浊形成的机率提供依据。     

蚱蜢蛋白质的提取、组成及分类研究

对蚱蜢蛋白质进行了氨基酸组成分析、分类提取研究并采用单因素实验法和正交实验法对提取条件进行优化设计.结果表明,提取蛋白较优的条件为：固液比（w/v）1∶1 5、pH值7.6、盐浓度1.0%、提取时间6h,蛋白质提取率为8.9%.以重量法、茚三酮比色法分别测定了各类型蛋白质的含量.其中,水溶性蛋白质含量为43.4%,酸溶性蛋白质含量为1.8%,碱溶性蛋白质含量为1.9%,醇溶性蛋白质含量为3.0%.     

发酵对蛋白质组成、结构与功能特性及风味影响的研究进展

发酵作为最古老的食品加工技术之一,不仅可对食品进行加工和处理,也可调节其内部结构及成分,从而优化食品质量。伴随着科学技术的进步,发酵工艺对食品中蛋白质影响的研究也逐步深入。文章总结了发酵对蛋白质组成成分、结构、功能特性的影响,进一步探究其在营养风味方面的影响,并对发酵影响蛋白质变化的机理及相应检测指标的测定方法进行简单表述。旨在阐明发酵过程中蛋白质的变化,为进一步提高食品发酵工艺提供新的思路和理论指导。     

饲养因素对兔肉脂肪酸组成影响的研究进展

兔肉除了其\     

伊拉兔肉肌内脂肪酸组成及温度对其脂肪氧化的研究

研究了伊拉肉兔后腿肉的肌内脂肪含量,并分析测定了其脂肪酸组成,同时研究了兔腿肉在常温(15±0.5)℃和低温(4±0.5)℃贮藏条件下的脂肪氧化稳定性。结果表明,兔腿肉肌内脂肪主要含有19种脂肪酸,其中棕榈酸(16∶0)、硬脂酸(18∶0)、油酸(18∶1)、亚油酸(18∶2)的总含量占脂类总脂肪酸含量的71.06%左右。伊拉兔肉肌内脂肪中主要是不饱和脂肪酸,尤以多不饱和脂肪酸居多。在常温(15±0.5)℃和低温(4±0.5)℃贮藏条件下,兔腿肉POV、TBA值的差异极显著(p<0.01)。常温条件下,第5d兔肉出现异味并逐渐变成臭味,而低温条件下,第7d才开始出现轻微异味,低温冷藏对保证肉品质量有重要意义。      

留兰香茎叶粉对肉兔生长性能和屠宰性状的影响

在肉兔饲料里用5%、10%和15%留兰香茎叶粉替代相应苜蓿草粉探讨留兰香茎叶粉对肉兔生长性能和屠宰性状的影响。结果表明:与对照组相比,5%留兰香茎叶粉组和10%留兰香茎叶粉组平均日采食量、平均日增重有改善向好的趋势(P>0.05),15%留兰香茎叶粉组平均日增重显著降低(P<0.05),3个组全净膛重、半净膛重、全净膛率和半净膛率均有提高的趋势(P>0.05)。添加10%留兰香茎叶粉替代苜宿草粉效果较好。     

Effects of tomato pomace supplementation on carcass characteristics and meat quality of fattening rabbits

The aim of this study was to determine how a feeding plan characterized by different levels of tomato pomace (TP) supplementation influences the carcass characteristics, the chemical, physical and sensorial characteristics of rabbit meat. 144 weaned crossbred rabbits were divided into three groups of 48 each. The first group was fed a basal diet without TP, while the other two groups were fed the basal diet after replacing part of the diet with TP at 3% and 6%, respectively. There was a significant difference between the experimental groups in terms of live and carcass weights. The meat of rabbits fed on a 6% TP diet exhibited higher yellowness (b*) and Chroma values when compared to others. The saturated fatty acid content in the longissimus dorsi muscle and perirenal fat decreased significantly with increasing TP inclusion, while polyunsaturated fatty acids increased. Furthermore, our results indicate that a diet integrated with 6% TP could influence positively the overall preference of cooked meat.     

Evaluation of pre-rigor injection of beef with proteases on cooked meat volatile profile after 1day and 21days post-mortem storage

This research was carried out to determine the effects of pre-rigor injection of beef semimembranosus muscle with nine proteases from plant and microbial sources, on the volatile profile of cooked beef after 1 day and 21 days post-mortem (PM) storage using Solid-phase microextraction gas chromatography mass spectrometry analysis. A total of 23 aldehydes, 5 ketones, 3 furans, 8 nitrogen and sulphur compounds, 4 alkanes, 7 alcohols and 6 terpenes were detected. Eleven volatile compounds characteristic of ginger flavour were detected in zingibain-treated meat. Benzaldehyde significantly increased (p<0.05) only in kiwifruit juice (KJ), fungal 31 protease and Asparagus protease (ASP) treated samples from 1day to 21days PM storage. A significant increase (p<0.05) in 3-methylbutanal was observed in KJ, bacterial and fungal protease treated samples at 21days PM storage. Treatments with bromelain, papain, ASP, actinidin, and KJ (except KJ 21days) proteases resulted in flavour profiles closer to that of the control beef sample.     

Effects of protein posttranslational modifications on meat quality: A review

Meat quality plays an important role in the purchase decision of consumers, affecting producers and retailers. The formation mechanisms determining meat quality are intricate, as several endogenous and exogenous factors contribute during antemortem and postmortem periods. Abundant research has been performed on meat quality; however, unexpected variation in meat quality remains an issue in the meat industry. Protein posttranslational modifications (PTMs) regulate structures and functions of proteins in living tissues, and recent reports confirmed their importance in meat quality. The objective of this review was to provide a summary of the research on the effects of PTMs on meat quality. The effects of four common PTMs, namely, protein phosphorylation, acetylation, S-nitrosylation, and ubiquitination, on meat quality were discussed, with emphasis on the effects of protein phosphorylation on meat tenderness, color, and water holding capacity. The mechanisms and factors that may affect the function of protein phosphorylation are also discussed. The current research confirms that meat quality traits are regulated by multiple PTMs. Cross talk between different PTMs and interactions of PTMs with postmortem biochemical processes need to be explored to improve our understanding on factors affecting meat quality.     

日龄对麻鸭肌内脂肪、肉质及挥发性风味的影响

通过测定不同日龄麻鸭的肌内脂肪含量,蒸煮损失、剪切力、失水率、肉色等肉品质指标,研究日龄对肌内脂肪和鸭肉品质的影响,同时采用顶空固相微萃取气质联用技术分析不同日龄麻鸭的挥发性风味成分。结果表明,不同日龄麻鸭肌内脂肪含量差异显著(p<0.05),且随日龄的增加而增加。日龄对蒸煮损失、剪切力、失水率和b*(黄度)有显著影响(p<0.05),随着日龄增加,蒸煮损失减小,剪切力变大,b*(黄度)变大。在不同日龄麻鸭挥发性成分的研究中发现,45日龄、180日龄、360日龄分别检测出28种、35种、33种挥发性物质,其中醇类、醛类和酮类是主要成分。不同日龄麻鸭的特征性风味物质种类基本相同,含量有显著差异,这可能是造成不同日龄鸭肉风味差异的主要原因。      

Changes in meat quality characteristics of bovine meat during the first 6 days post mortem

The development of some quality parameters in bovine meat during the first 6 days of post mortem ageing was studied in two commercial groups (heifer and bull). In the first day bull meat is harder and springier. Meat pH falls during the first 24 h post mortem in both groups, reaching values around 5.5, and it did not change during the next 5 days. Water-holding capacity (expressed as percentage of expelled water) increased in heifer meat. Instrumental texture measures (texture profile analysis, TPA) showed a decrease in hardness, springiness and chewiness in bull raw meat. Sensory analysis showed that assessors perceived a decrease in hardness and in springiness in bull meat and a decrease in juiciness and in chewiness (number of chewings before swallowing) in heifer meat. Ageing showed no effect on assessors’ pleasantness either in heifers’ or in bulls’ meat. During the first 3 days, heifer meat was juicier. Heifers’ meat produced a greater pleasantness on the sixth day. Both meats were not very different for most quality parameters studied in this work.     

Effects of vitamin E supplementation on performance and meat quality traits of Morkaraman male lambs

This research was carried out to determine the effects of vitamin E supplementation on meat quality traits of approximate 8 months of age Morkaraman male lambs. The lambs were divided into two groups-control (CG, n=7) and experimental (VG, n=6)-at the beginning of fattening period. The diet given to the CG and VG consisted of concentrate and grass hay. In addition, the VG received a supplement of 45 mg vitamin E per lamb in a day during a 75-day fattening period. At the end of the study, average daily weight gain and feed conversion efficiency values as to feed basis were found to be 208 g and 6.3 for CG and 223 g and 6.0 for VG groups, respectively. Vitamin E supplementation resulted in 8.8% improvement in feed conversion efficiency. In the same way, vitamin E supplementation resulted in 6.7% increase in daily weight gain. Slaughter and carcass characteristics of lambs were also determined, but fattening performance, slaughter and carcass characteristics were not significantly different between groups. The effects of vitamin E on meat characteristics, meat colour (L*, a* and b*), thiobarbituric acid reactive substances content (TBARS), drip loss and pH were determined using m. longissimus dorsi (LD) muscles obtained from CG and VG. Though the effect of vitamin E supplementation on most of the meat quality traits was not statistically significant (P>0.05), L* and a* values in LD muscle from VG were preserved for a period of 12 days of maturation. In addition, a* (redness) tended to increase slightly. TBARS values in samples from CG were found to be higher than those of vitamin E treatment group. In this study, it was also concluded that drip loss was relatively preserved by vitamin E supplementation. In conclusion, vitamin E supplementation of Morkaraman male lambs at an inclusion rate over the amount of nutritional recommendations, significantly reduced lipid oxidation, drip loss and tended to maintain meat redness.     

Influence of dietary conjugated linoleic acids (CLA) and age at slaughtering on meat quality and intramuscular collagen in rabbits

To assess the effects of dietary conjugated linoleic acids (CLA) on meat composition and intramuscular collagen (IMC), 144 New Zealand White rabbits, half males half females, 55 days old (1.8 kg LW), were assigned to three weight- and sex- balanced groups and given the following dietary supplements: 0.5% sunflower oil, (C); 0.25% sunflower oil plus 0.25% CLA (T1); and 0.5% CLA (T2). The CLA was prepared from sunflower oil and contained 65% CLA isomers, half cis-9, trans-11 and half trans-10, cis-12. Six males and six females from each group (total 36) were slaughtered at 76, 90 and 104 days of age (corresponding to 2.5, 2.8, and 3.1 kg BW, respectively). The lean fraction was higher and the water content significantly higher in the meat of T2 compared to C and T1 for all ages combined. At the third slaughtering (104 days) the meat fat content was significantly lower in group T2. For all ages combined, IMC content, IMC hydroxylysylpyridinoline (HLP) concentration (index of collagen cross-linking) and IMC maturity (HLP/IMC) were significantly lower in the intermediate supplementation group (T1) compared to C and T2, and were also lower in animals slaughtered at 90 days. CLA supplementation has limited effects on the chemical composition of rabbit meat, with positive effects on meat texture and tenderness after supplementation up to 35 days at 0.25%, and a significant decrease in fat content only at high slaughter weight and high supplementation level (0.5%).     

添加含磷与非磷保水剂对牦牛肉肉糜蛋白质氧化的影响

以添加复合磷酸盐、乳酸钠和柠檬酸三钠作为保水剂制作牦牛肉肉糜,以不添加任何保水剂处理的为对照,通过测定牦牛肉肉糜色度值、表面疏水性、总巯基含量和羰基含量,探讨三种保水剂的抗蛋白氧化性,并比较三者抗蛋白氧化性的差异。实验结果表明:在4℃冷藏条件下,7 d贮藏期间,保水剂确实可以延缓肉糜的蛋白氧化,保水剂的种类显著影响牦牛肉肉糜中蛋白质的氧化程度(p<0.05);其中柠檬酸三钠对肉色的改善效果最佳,在第7 d时比其它组的色度值都低为1.26;复合磷酸盐对降低蛋白质表面疏水性的效果最好,在第7 d时表面疏水性为108.70 nmol/mg,仅比第1 d增加了12.73%;乳酸钠对保护蛋白质巯基和减少羰基生成的效果最好,在第7 d时与其它组相比巯基值最大为94.94 nmol/mg,羰基值最小为25.25 nmol/mg。本研究为减少肉制品中蛋白质氧化提供了新途径。