苏尼特羊肌肉胶原蛋白发育性变化与嫩度的研究

选择自然放牧的3个不同月龄苏尼特羊2个不同部位的肌肉,用比色法测定胶原蛋白的含量,用高效液相色谱仪测定吡啶诺林(Pyr)的含量,用质构仪测定剪切值。结果表明,随着月龄的增加,总胶原蛋白、吡啶诺林的含量都呈增加的趋势,月龄之间差异显著(P<0.05)。而胶原蛋白的溶解度随月龄的增加呈下降的趋势,且月龄之间差异显著(P<0.05)。相关分析结果显示,肌肉的剪切值与总胶原、吡啶诺林呈极显著正相关(P<0.01),胶原溶解度与剪切值呈极显著负相关(P<0.01)。苏尼特羊肉胶原蛋白特性在生长发育过程中有显著的变化,非还原性交联吡啶诺林的含量是影响肌肉嫩度的主要内在因素,不同部位、生长月龄对胶原蛋白含量及交联特性有显著影响。      

苏尼特羊肌肉胶原蛋白发育性变化与嫩度的研究

选择自然放牧的3个不同月龄苏尼特羊2个不同部位的肌肉,用比色法测定胶原蛋白的含量,用高效液相色谱仪测定吡啶诺林(Pyr)的含量,用质构仪测定剪切值.结果表明,随着月龄的增加,总胶原蛋白、吡啶诺林的含量都呈增加的趋势,月龄之间差异显著(P<0.05).而胶原蛋白的溶解度随月龄的增加呈下降的趋势,且月龄之间差异显著(P<0.05).相关分析结果显示,肌肉的剪切值与总胶原、吡啶诺林呈极显著正相关(P<0.01),胶原溶解度与剪切值呈极显著负相关(P<0.01).苏尼特羊肉胶原蛋白特性在生长发育过程中有显著的变化,非还原性交联吡啶诺林的含量是影响肌肉嫩度的主要内在因素,不同部位、生长月龄对胶原蛋白含量及交联特性有显著影响.     

苏尼特羊骨骼肌总胶原蛋白含量的测定

本试验通过对不同月龄苏尼特羊的不同部位的肌肉总胶原蛋白含量的测定与分析,其结果表明,随着月龄的增加,总胶原蛋白的含量呈增加的趋势,相关分析表明,同一月龄不同部位肌肉中总胶原蛋白含量依次为:斜方肌>股二头肌>背最长肌>半腱肌,1、2月龄间总胶原蛋白含量在半腱肌和背最长肌之间没有显著性差异(P>0.05),其他月龄差异均显著(P<0.01),这些结果表明,通过测定肌肉总胶原蛋白的含量可以较客观的评价肉的嫩度。     

不同月龄乌珠穆沁羊肌纤维类型与肉品质的变化分析

本研究分别选取1、3、6、9、12、18月龄的乌珠穆沁羊不同部位的股二头肌,测定并比较它们的肌纤维类型以及肉质指标,探讨肌纤维类型与宰后动物肌肉品质的变化关系。结果表明:股二头肌中I型肌纤维随着月龄的增加百分比呈下降的趋势(P<0.05),IIa型肌纤维百分比含量在1月~9月龄之间百分比含量逐步增加(P>0.05),IIb型肌纤维百分比含量在6月~18月龄之间差异均显著(P<0.05)。肌纤维百分比与y值呈显著负相关(P<0.05),与L值、r值、剪切力和熟肉率呈负相关(P<0.05)。     

冻融次数对牦牛肉胶原蛋白特性及品质的影响

为探究冻融次数对牦牛肉胶原蛋白特性和品质的影响。以牦牛肉为研究对象,分析不同冻融次数下牦牛肉剪切力、pH、解冻损失、蒸煮损失、色差、质构、胶原蛋白含量及溶解性、酶活性及微观结构的变化规律。结果表明,随着冻融次数的增加,牦牛肉剪切力下降了59.72%,牦牛肉胶原蛋白溶解性、β-半乳糖苷酶和β-半乳糖醛酶活力、解冻损失、蒸煮损失和b^*值显著上升(P<0.05),胶原蛋白含量、剪切力、pH、L^*值、a^*值以及质构显著下降(P<0.05)。相关性分析表明:剪切力与L^*值、a^*值、pH、胶原蛋白含量和溶解性、质构指标呈显著正相关(P<0.01),与解冻损失、蒸煮损失、b^*值、β-半乳糖苷酶活性和β-葡糖醛酸酶活性呈极显著负相关(P<0.001);pH与胶原蛋白特性呈极显著正相关(P<0.001);胶原蛋白特性与质构指标呈极显著正相关(P<0.001)。牦牛肉组织结构随冻融次数增加表现为破坏严重,肌纤维边界模糊。综上,冻融次数增加,...     

不同生长月龄下有机山黑猪背最长肌肉营养成分和食用品质的分析比较研究

以有机山黑猪为研究对象,分析其在不同生长月龄下的背最长肌肉营养成分及食用品质,以最终确定其最佳屠宰月龄。结果表明:月龄对水分、肌内脂肪、pH值、肉色、嫩度、滴水损失率、熟肉率均有显著(P<0.05)或极显著(P<0.01)影响;随着月龄的不断增长,山黑猪背最长肌肉水分含量逐渐降低,在7月龄最高为74.55%;蛋白质含量差异不显著(P>0.05),在8月龄最高为19.56%,其平均值为18.63%;肌内脂肪含量呈现递增趋势,有极显著(P<0.01)的影响,在10月龄最高为5.24%;有机山黑猪宰杀后45min,在4个不同生长月龄下肌肉亮度L1*平均值为44.26、肌肉红度a1*平均值为7.49,嫩度(剪切力)平均值为57.05N。结果表明:有机山黑猪肉色红润富有光泽、蛋白质及矿物质含量丰富、肌内脂肪含量适中且分布均匀等,具有肉质优良的宝贵特性,最终确定最佳屠宰月龄为8月龄。     

贮藏温度对马肉不同部位嫩度变化的影响

研究不同贮藏温度对马肉不同部位嫩度变化的影响。将宰后马肉的臀肌、肩肌和背最长肌在15、4、-18℃3种不同的温度条件下贮藏24h后,分析测定其水分、脂肪、胶原蛋白和剪切力等指标的变化情况,并对上述指标进行相关性分析。结果显示:臀肌和肩肌的剪切力值均与水分含量呈极显著负相关(p0.01),臀肌的剪切力值与胶原蛋白含量呈显著负相关(p0.05)。肩肌剪切力值与总胶原蛋白含量呈极显著负相关(p0.01),与不溶性胶原蛋白含量呈负相关。背最长肌剪切力值与总胶原蛋白含量呈负相关,与不溶性胶原蛋白含量呈显著负相关(p0.05)。在15、4、-18℃下,3个部位的剪切力值与蒸煮损失呈负相关,与脂肪含量、系水力呈正相关。肩肌和背最长肌的剪切力值与pH呈负相关,而臀肌相反。15、4、-18℃下马肉3个部位肌肉的各项指标不能统一达到相对最佳点。     

饲料中添加适宜水平铁对建鲤肉质、鱼糜稳定性及组织蛋白酶B/L的影响

探讨饲料中添加适量铁对建鲤肉质、鱼糜品质及其肌肉中组织蛋白酶B/L的影响。以添加适宜水平铁的饲料饲喂90 d的建鲤（适宜组,铁实测质量分数146.1 mg/kg）为研究对象,同时以未添加铁组（缺乏组,铁实测质量分数53.9 mg/kg）作为对照。采样后测定鱼肉品质指标及肌肉中组织蛋白酶B/L活性,并采用免疫组化法进行蛋白表达定量;而后将2组鱼肉加工为鱼糜,并测定其稳定性指标。结果表明,与缺乏组相比,适宜组肌原纤维耐折力、断裂指数分别稍有上升及下降,但差异不显著（P>0.05）;剪切力极显著增加31.80%（P<0.01）,可溶胶原蛋白含量、不溶胶原蛋白含量和总胶原蛋白含量均分别极显著增加305.45%、180.98%、219.35%（P<0.01）。适宜组鱼肉pH及失水率略呈下降趋势,差异无统计学意义（P>0.05）。适宜组组织蛋白酶B/L活性分别极显著（P<0.01）及显著（0.01相似文献   

贮藏温度对马肉不同部位嫩度变化的影响

研究不同贮藏温度对马肉不同部位嫩度变化的影响。将宰后马肉的臀肌、肩肌和背最长肌在15、4、-18℃3种不同的温度条件下贮藏24h后,分析测定其水分、脂肪、胶原蛋白和剪切力等指标的变化情况,并对上述指标进行相关性分析。结果显示:臀肌和肩肌的剪切力值均与水分含量呈极显著负相关（p<0.01）,臀肌的剪切力值与胶原蛋白含量呈显著负相关（p<0.05）。肩肌剪切力值与总胶原蛋白含量呈极显著负相关（p<0.01）,与不溶性胶原蛋白含量呈负相关。背最长肌剪切力值与总胶原蛋白含量呈负相关,与不溶性胶原蛋白含量呈显著负相关（p<0.05）。在15、4、-18℃下,3个部位的剪切力值与蒸煮损失呈负相关,与脂肪含量、系水力呈正相关。肩肌和背最长肌的剪切力值与pH呈负相关,而臀肌相反。15、4、-18℃下马肉3个部位肌肉的各项指标不能统一达到相对最佳点。      

巴寒杂交一代肉羊一磷酸腺苷激活蛋白激酶活性与肉品质的关系研究

选取巴寒杂交一代肉羊5月龄、6月龄、8月龄和12月龄不同部位骨骼肌,分别测定它们的一磷酸腺苷激活蛋白激酶(AMP-activated protein kinase,AMPK)活性、糖酵解指标和肉质指标,研究不同月龄不同部位三者的差异,以探讨AMPK与宰后肌肉品质的相关性.结果表明:AMPK活性随着月龄的增加呈下降的趋势(p＜0.05),不同部位间背最长肌AMPK活性显著大于股二头肌和臂三头肌(p＜0.05);AMPK活性与pH24值呈极显著负相关(p＜0.01)、与肌糖元含量呈极显著正相关(p＜0.01),与L*值呈显著负相关(p＜0.05),与熟肉率呈显著正相关(p＜0.5).实验表明AMPK活性与pH24值、肌糖元含量、L*值和熟肉率具有显著相关性,AMPK可能通过调节糖酵解进程进而影响肉品质.     

超高压处理对牛肉主要理化品质的影响

探讨超高压处理(不同压力和保压时间)对牛肉主要理化品质的影响。牛半腱肌肉经200～600MPa压力分别处理10min和20min,分析胶原蛋白含量和溶解性等特性以及牛肉蒸煮损失和嫩度在超高压处理过程中的变化。结果表明：随着压力的升高,牛半腱肌肉的剪切力均呈下降趋势,保压时间为20min时剪切力下降更显著。当压力达600MPa,牛肉剪切力分别降至39.59N(保压10min)和31.36N(保压20min)。总胶原蛋白、可溶性胶原蛋白的含量和胶原蛋白的溶解性随着处理压力的升高而增加。胶原蛋白特性变化与肉品质之间存在显著相关性。     

Relevance of collagen solubility and gelatinolytic proteinase activity for texture softening in chilled grass carp (Ctenopharyngodon idellus) fillets

The aim of the present study was to investigate the underlying mechanisms of softening texture in chilled grass carp filletsunderpinning collagen solubility, gelatinolytic proteinase activity and physicochemical parameters. Acid-soluble collagen (ASC) and heat soluble collagen (HSC) increased markedly, while a significant decline was detected in total collagen and insoluble collagen (ISC) during the first 3 days of storage, coinciding with a loss of shear force and water-holding capacity (WHC) (P < 0.05). Moreover, the activity of gelatinolytic proteinases was gradually activated and reached the peak at day 3 (P < 0.05). Pearson coefficient analysis showed that gelatinolytic proteinase activity revealed a significant correlation with collagen solubility. Total collagen, ASC, ISC and HSC were significantly correlated with shear force and WHC. Our study clarified that the increase of collagen solubility by gelatinolytic proteinases played an important role for texture softening in the early stage of chilled grass carp fillets.     

Tenderness of ovine semimembranosus: Is collagen concentration or solubility the critical factor?

The concentration and heat-dependent solubility of collagen were measured in the semimembranosus (36 animals) and, for comparison, the gluteus (108) muscles of sheep aged 4 months to 5 years. For both muscles, solubility declined with age but concentration remained unchanged. Compared to gluteus and other major ovine muscles, the semimembranosus had markedly insoluble collagen at a relatively low concentration. To assess the relative importance of collagen concentration and solubility on tenderness/texture for a muscle with this profile, the semimembranosus muscles contralateral to those used for collagen analysis were cooked to an endpoint of 75°C and assessed by sensory panel and Warner-Bratzler shear tests. The panel data showed that collagen concentration was the more important determinant of eating quality, whereas shear data were more clearly related to solubility. The implications of the sensory results are discussed for muscles that contain a different collagen profile.     

Effect of age and gender on the processing characteristics of buffalo meat

Comparison of processing characteristics of meat from young male, spent male and spent female buffaloes was made to find the suitability of the meat for developing ready to eat meat products. Intensively reared young male buffalo meat showed higher moisture, collagen solubility, sarcomere length, myofibrillar fragmentation index and water holding capacity than meat from the other animals. A higher pH, total meat pigments, salt soluble protein, emulsifying capacity and lower collagen solubility were observed in spent male buffalo meat. Spent female buffalo meat had higher fat, total collagen, muscle fibre diameter and shear force value. Sensory evaluation of pressure cooked meat chunks indicated a marked toughness in spent male and female buffalo meat samples. These results suggest that young male buffalo meat is more suitable for processing in chunks and spent male and female buffalo meat is more suitable for processing in smaller particles.     

Age of Farmed Atlantic Salmon at Seawater Transfer Affects Muscle Collagen Content and Solubility at Harvest

Salmon released to seawater as different smolt types differed significantly in the total collagen content and the solubility of the collagen present. A 11/2 smolt contained more total collagen than 1/2 and 1 smolt types. Less insoluble collagen and more of the pepsin soluble collagen was generally present in 11/2 smolt type as compared with both 1/2 and 1 types, with the exception of prerigor type 1 salmon. No differences between smolt types in acetic soluble collagen were present. Fish with the higher amount of collagen also had the lowest end pH. Although the bled body weight differed, no correlation between body weight and collagen content or its solubility was found. Fish with higher end pH had lower total collagen and pepsin soluble collagen (r = ‐0.77, P = 0.0001 and r = ‐0.51, P = 0.04, respectively, and more insoluble collagen (r = 0.72, P = 0.002).     

Organic Acids as Tenderizers of Collagen in Restructured Beef

Acetic, citric and lactic acid were incorporated into restructured beef steaks to determine their effect on collagen. These steaks were analyzed for collagen solubility, total collagen content, shear force behavior, sarcoplasmic and myofibrillar protein extractability, thermal stability and color. These results were compared to those obtained from control samples containing high collagen and low collagen. Results indicate that these acids increased collagen solubility, total collagen content and shear force values when compared with the control samples. No differences (P > 0.05) were found in sarcoplasmic protein extractability although myofibrillar protein extractability declined. Acid treatment decreased the thermal stability of collagen. The Hunter Color values of the uncooked and cooked acid-treated steaks differed (P 0.05) from the controls.     

Effects of Carcass Maturity on Collagen Solubility and Palatability of Beef from Grain-Finished Steers

Samples from steers fed a high-energy diet for 185 days prior to slaughter were used to compare collagen solubility and palatability of beef from youthful and mature carcasses. Carcasses representing the two maturity classes were selected specifically to have similar levels of intramuscular and subcutaneous fat, but distinctly different maturity indicators. Under the conditions of this study, maturity class had no effect on sensory properties or shear force values of cooked rib steaks. Total collagen content of samples from the longissimus muscle was higher for mature carcasses, but maturity class means for percentage of soluble collagen were not different. The relationships of these findings to preslaughter feeding regimen and collagen metabolism are discussed.     

偏最小二乘回归法分析藏鸡胸肉质地特性

为揭示藏鸡肉独特的质地特性,探寻鸡胸肉质地特性与其化学成分和微观结构的关联性,本研究对5 种不同的鸡肉原料（藏鸡、与藏鸡同日龄或体质量接近的雪山草鸡、淘汰蛋鸡（对照）和白羽肉鸡（对照））进行剪切力、质地剖面分析（texture profile analysis,TPA）和应力松弛特性测定,并将上述质地特性分析结果和鸡肉的基本化学指标（水分质量分数、粗脂肪质量分数、粗蛋白质量分数、胶原蛋白质量分数、pH值）、组织学特征（肌纤维直径和密度）进行关联性分析,利用偏最小二乘回归（partial least squares regression,PLSR）法揭示影响鸡肉质地特征的显著因素。结果发现,利用PLSR能够将多个与肌肉质地特性相关的化学指标量化为鸡肉品质综合评价指标,其中剪切力的预测模型更适合预测鸡肉的质地特性。该模型的R2X为0.621,R2Y为0.739,模型拟合效果较好。Q2cum在0.6以上,说明该模型的可预测性能够被接受。载荷图显示剪切力与pH值、总胶原蛋白质量分数和肌纤维直径呈显著正相关（P＜0.05）,而与粗脂肪质量分数、可溶性胶原蛋白质量分数、胶原蛋白溶解性和肌纤维密度呈显著负相关（P＜0.05）。贡献度评价结果显示,胶原蛋白溶解性、肌纤维密度、可溶性胶原蛋白质量分数和肌纤维直径4 个指标均在模型中贡献显著。本研究可为从质地特性角度揭示藏鸡胸肉特有“咀嚼感”提供数据支持,并为丰富肉的力学特性研究提供一定的理论参考。     

离子强度对煮制前后猪肉胶原蛋白乳化特性的影响

为研究离子强度对煮制前后猪肉胶原蛋白乳化特性的影响,测定煮制前后不同NaCl浓度（0.0、0.2、0.4、0.6 mol/L）猪肉可溶性胶原蛋白和不溶性胶原蛋白的乳化特性,包括乳化活性指数（emulsification activity index,EAI）、乳化稳定性指数（emulsion stability index,ESI）、黏度及乳化液微观结构,同时测定猪肉胶原蛋白溶解度。结果表明：随着介质离子强度的提高,猪肉可溶性胶原蛋白溶解度降低,黏度增大,EAI先升高后降低,ESI先降低后升高;猪肉不溶性胶原蛋白溶解度升高,黏度增大,EAI、ESI均呈先升高后降低趋势。改变胶原蛋白的离子强度或对胶原蛋白进行热处理,均能使猪肉可溶性胶原蛋白和不溶性胶原蛋白的乳化特性发生显著变化。