不同来源鳡鱼的肉质分析

通过分析鳡鱼的营养组成、质构特性、流变特性及热特性,研究了不同来源鳡鱼的肉质差别。结果表明,海鱼养殖与野生鳡鱼的营养品质与加工品质均很相似,但海鱼养殖的鳡鱼含C20∶5ω3达5.30%、C22∶6ω3达14.88%,ω3/ω6之比更合理。饲料养殖的鳡鱼蛋白质含量为18.87%,高于海鱼饲养的16.39%及野生鳡鱼的13.86%;灰分含量为1.15%,高于海鱼饲养的0.90%及野生鳡鱼的0.79%;粗脂肪含量为4.68%,仅为其它两种鱼的1/3左右;多不饱和脂肪酸含量介于海鱼饲养及野生鳡鱼之间,为31.79%。饲料养殖的鳡鱼弹性、凝胶强度和硬度均较大,硬度为9034.26N,是海鱼喂养与野生鳡鱼的2倍。流变特性曲线中,饲料喂养的鳡鱼分别在31.9~44.3℃和67.8~78.9℃有两次急剧变化,转变的起始温度低于海鱼喂养与野生鳡鱼,约为43~70℃。DSC结果表明,饲料喂养鳡鱼的起始变性温度为97.6℃,低于海鱼喂养与野生鳡鱼,分别为104.0℃和107.7℃,说明饲料喂养的鳡鱼较其他两种鳡鱼的热稳定性差。      

鱼类肉质评价及影响因素研究进展

目前,有关鱼类肉质的评价标准还未确立,对肉质进行全面评估的研究还未见报道.本文对鱼类肉质研究内容和方法的研究现状以及影响鱼类肉质的因素作一综述,以期为进一步研究和评价鱼类肉质提供一定参考.     

饵料中不同鱼饲比对黄鳝生长性能和肉质的影响

探索饵料中不同鱼饲比对黄鳝生长性能和肉质的影响。结果表明:当饵料中鱼饲比从T(4∶1)降到T(1∶2),黄鳝的生长性能未受到影响;当鱼饲比降至T(1∶4),黄鳝的相对增重率显著下降。与野生黄鳝相比,采用冰鲜鱼与膨化饲料投喂的黄鳝,其基本营养成分蛋白质和部分氨基酸含量略低于野生黄鳝,随着饵料中鱼饲比的不断降低,黄鳝肌肉蛋白质含量和部分氨基酸含量也有下降的趋势。     

不同贮藏条件下东海鲐鱼鱼肉质构变化研究

以鲜活鲐鱼为研究对象,在鱼体TVBN含量变化基础上,应用质构仪质地多面分析(TPA)试验法,采集不同贮藏温度下样品的质构特性。结果表明:鲐鱼TVBN值在贮藏期间不断升高,5℃和0℃贮藏组分别贮藏5 d和7 d后,肌肉TVBN含量超过国家标准限量(30 mg/100g);鲐鱼各质构参数(硬度、弹性、粘聚性及咀嚼度)随贮藏时间延长总体呈下降趋势;-55℃和-20℃冻藏样品质构特性变化相对缓慢,且-55℃保鲜效果优于-20℃贮藏。     

鳀鱼蛋白质自水解的条件优化

鳀鱼含有丰富的内源蛋白酶,可以将鳀鱼蛋白水解为小分子的肽和游离氨基酸等成分。采用正交试验和响应面分析法研究并优化鳀鱼中蛋白质成分被内源蛋白酶水解的工艺条件,得到最佳工艺条件：温度为57.05℃,加水量为80%,初始pH值为9.00。最佳工艺条件的验证结果表明,水解液中的氨基氮含量(0.4259g/100ml)和回归方程的预测值(0.4377g/100ml)具有较好的拟和性,水解液中的氨基氮含量比优化前的最大值(0.3814g/100ml)提高11.67%。     

肌内结缔组织热特性及其影响因素研究进展

肌内结缔组织是肌肉的重要组成部分,与肌纤维共同影响肉品的感官品质。该文对结缔组织与肉品嫩度、多汁性、风味等感官品质指标的关系进行总结,并聚焦于结缔组织主要成分胶原蛋白,总结其在加热过程中变性、收缩和溶解等热特性的影响因素,分析其热特性和结缔组织蛋白聚糖降解的关系,以及其热特性与原料肉内源酶降解体系的关系,探讨结缔组织影响肉品品质的可能机制,以期为改变结缔组织的热特性,提高肉品的感官品质指明研究方向。     

环境热应激对畜禽养殖及肉质影响的研究进展

热应激是畜禽养殖加工业的主要环境应激源之一,国内外研究者发现,当环境温湿度超出畜禽耐受范围时,养殖动物会出现精神萎靡、采食量降低等热应激反应,此时体内出现的激素水平改变、血液蛋白水平改变、抗氧化能力降低等一系列生理生化及病理变化,将导致畜禽体质量降低、肉质变差或死亡,造成不可挽回的经济损失。畜牧业是肉类食品的重要来源,是人们饮食结构中的重要蛋白来源途径,热应激带来的肉品质下降在造成经济损失的同时,还会产生食品营养及安全等问题。本文对上述研究进行梳理,从畜禽热应激的定义、畜禽热应激行为反应机制、畜禽热应激生理反应机制、畜禽热应激对肉品质的影响及热应激缓解管理措施等方面进行综述,为畜禽热应激反应的判别及缓解策略提供参考。     

饲料中苏氨酸含量对建鲤肉质及组织蛋白酶B、L的影响

该试验测定了饲料中3组苏氨酸含量,即7. 4 g/kg(缺乏组)、15. 7 g/kg(适宜组)、25. 2 g/kg(过量组),对建鲤肉质及组织蛋白酶B、L的影响。通过利用显微镜图像分析各处理组肌纤维特征、鱼肉品质指标,荧光合成肽底物法测定组织蛋白酶B(cathepsin B,CTS B)、组织蛋白酶L(Cathepsin L,CTS L)的活性,免疫组化法测定蛋白表达量,研究发现,饲喂90 d后,适宜组的肌纤维密度最高,肌纤维平均直径(22. 12μm)最小;肌原纤维耐折力(0. 116 3μm)相对较高,而其断裂指数(A_(540)=59. 70)最低;剪切力(0. 168 4 kg·f)最高,失水率(21. 02%)最低,p H值(6. 91)最低;组织蛋白酶B、L的酶活性及表达量最低。综上,饲料中添加适宜水平苏氨酸能够改善鱼肉肌纤维特性及硬度品质,为通过营养素水平调节而提高建鲤鱼肉品质提供一定理论依据。     

鱼明胶提取及其品质影响因素

明胶是一种由哺乳动物胶原蛋白热水解而得到的天然大分子物质,由于其独特的凝胶性质和合理的价格使其在食品、医药行业得以广泛的应用,但出于疾病安全及宗教信仰等问题,哺乳动物明胶的应用受到质疑与排斥,现急需一种新型来源的明胶以取代,目前研究最深入的是鱼明胶。鱼明胶的品质受多种因素影响而限制其应用,该文对影响鱼明胶产量和品质的原因进行了综述,并总结了近年来与鱼明胶传统提取法相结合以获得符合市场需求的更佳品性的明胶的新技术新手段,以期为相关科研工作者进一步提高鱼明胶产量和品质、扩大鱼明胶的应用前景提供参考和理论依据。     

影响肉质嫩度的因素及改良办法

一道菜肴质地是否细嫩,其主料往往是我们关注的焦点。拿酱爆牛肉来说,若成菜后牛肉口感老韧,那么该菜就谈不上成功,而爆炒腰花如果自己吃着都觉得老,那就说明你做的菜整体失败。因此,事厨者要想让做出来的菜肴肉质细嫩,就必须先了解影响肌肉嫩度的因素,然后去合理地运用某些改良肉质的方法     

不同加工方式对鱼肉组织质地影响的研究进展

鱼类是一种风味独特、营养丰富并且平衡性很好的水产品,深受消费者喜爱。质构与食品的外观、风味、营养一起构成食品的4大品质要素。与畜肉相比,鱼肉的组织更加柔软细嫩,这主要和鱼肉的化学组成有关,随着人们生活水平的提高和食品加工业的发展,鱼肉的组织质地越来越引起人们的重视。本文介绍了几种质构参数,并从物理因素、化学因素和鱼体死后变化3方面分析了影响鱼肉组织质地的各种因素,其中主要介绍了鱼肉肌肉组织的蛋白质组成及其对质构的影响;重点综述了在水产品加工过程中不同加工方式如加热、冷冻、盐渍、烟熏等对鱼肉组织质地的影响,以期为质构分析在产品品质评定中的应用及即食产品的开发和生产提供一定的理论参考,进而更好地满足消费者的需要。     

肌肉酶对宰后鱼肉品质影响的研究进展

鱼肉在贮藏过程中物理、化学和生化性质都会发生改变。大量研究表明,鱼肉性质的变化与其肌肉中许多内源性酶类密切相关。本文综述了几种与肉的品质或肉的成熟有关的肌肉酶的结构特点、作用机理以及对鱼肉品质的影响;并就肌肉酶的发展趋势进行了展望。      

腌制鱼类中内源性酶类对制品品质影响的研究进展

鱼类腌制品在加工过程中产生一系列的品质变化(主要是风味和质构的变化),内源性酶类是引起这些变化的主要原因之一。与产品质构密切相关的酶类主要是一些降解蛋白质的内源性蛋白酶类(溶酶体组织蛋白酶、钙激活蛋白酶、基质金属蛋白酶),与产品风味密切相关的酶类主要是氨肽酶和降解脂肪的一些酶类(脂肪水解酶类、脂肪氧合酶)。本文对腌制鱼类产品中对组织蛋白降解和脂肪降解、氧化的主要内源性酶类特性和国内外研究现状进行了综述,以期为进一步革新传统腌制鱼类产品加工技术和提高产品品质提供一定的参考。      

Correlated changes in skeletal muscle connective tissue and flesh texture during starvation and re‐feeding in brown trout (Salmo trutta) reared in seawater

Quantitative and qualitative changes to muscle and collagen were analysed following starvation and re‐feeding of brown trout (Salmo trutta) reared in seawater. Fish were submitted to starvation for 2 months followed by re‐feeding for 1 month and compared with a control group continuously fed. Classical effects of starvation on growth and morphometrics traits were observed with only a partial recovery of these parameters after 1 month of re‐feeding. Muscle composition of starved fish was significantly affected (lower dry matter content and higher post‐mortem pH) compared with control fish and was partially recovered in re‐fed fish compared with continuously fed fish. Muscle structure and composition were affected with thinner muscle fibre and higher connective tissue content for the starved fish but similar thickness of myosepta compared with the control group. No difference was observed after 1 month of re‐feeding. Characteristics of the connective tissue were significantly affected by starvation (more high weight molecular collagen form, higher thermal stability of skin collagen). These differences remained significant after the re‐feeding period. Starved fish showed also higher mechanical resistance of the raw flesh compared with the control group, but no difference in rheological measurements was observed after 1 month of re‐feeding. The changes in texture and their relationships with muscle composition, muscle structure and collagen characteristics are discussed. Copyright © 2004 Society of Chemical Industry     

甘薯块根质构特性的研究进展

甘薯是重要的粮食、饲料及食品工业原料作物,质构特性是甘薯品质的重要组成部分,是评估其质量优劣的重要指标,它直接影响块根食用品质以及产后加工途径、技术及其利用价值.质构特性是近年来甘薯研究的一个热点.本文对甘薯块根质构测定及评价方法、影响质构特性变化的各种因素作用等多个方面研究结果进行较为系统的综述,对甘薯质构研究中存在...     

Chemical and Histological Characterization of Raw Muscle from Soft and Hard Crabs of Snow Crab Chionoecetes opilio

ABSTRACT: Chemical analysis showed soft snow crab muscle to have a higher water content and a lower protein content than hard crab muscle. Histological observations revealed frequent occurrences of disintegrated regions in muscle fibers and pericellular connective tissue of soft snow crab muscle tissue. Salinity of the free body fluid recovered from the meropodites of the soft snow crab was significantly higher than that of the hard snow crab. Sensory evaluation revealed differences in texture and taste between soft and hard crabs, which corresponded well to their compositional and histological differences.     

Effects of natural trypsin inhibitor from soybean on texture deterioration of the bay scallop (Argopecten irradians) during cold storage and its mechanism

In this study, the inhibitory effects of natural trypsin inhibitor from soybean (SBTI) on texture deterioration of adductor muscle of scallop (AMS) during cold storage and its mechanism were revealed by determining the changes of structural proteins of AMS in situ and in vitro, respectively. Results indicated that the endogenous proteolysis resulted in the disintegration of connective tissue proteins, the degradation of myosin and actin, as well as the reduction of α-helix, the increase of β-sheet and amino acid side chains, and the exposure of tryptophan residues of isolated myofibrillar proteins (MPs). These changes in structural proteins contribute to the texture deterioration of AMS as reflected in a significant decrease in hardness, chewiness, adhesiveness and springiness, but a significant increase in cohesiveness. SBTI significantly inhibited the conformational changes of structural proteins caused by endogenous proteolysis, improved the MP gel-forming ability and consequently retarded the texture deterioration of AMS.     

Relevance of trimethylamine oxide demethylase activity and haemoglobin content to formaldehyde production and texture deterioration in frozen stored minced fish muscle

Minces were prepared from white muscle or fillets of gadoid and non-gadoid fish species. After the addition of blood, kidney or formaldehyde the minces were stored frozen for 6 months at ?8 and ?30°C. Blood and kidney of the gadoid species contained trimethylamine oxide demethylase (TMAOase), whereas in the tissues of the other species no activity of this enzyme could be detected. The formation of dimethylamine (and formaldehyde) was correlated with the TMAOase activity of the added tissues. The concentration of haemoglobin in the minces had no influence on the dimethylamine and formaldehyde production during frozen storage. The formaldehyde production was accompanied by an increase in the firmness of the texture as measured by mechanical and sensory tests.     

米制粉方式及影响因素研究进展

我国是稻谷生产大国。近年来,随着饮食结构的不断升级,米制食品消费量剧增,拥有广阔的前景。这些米制食品大多由大米粉制成,而大米粉在制粉时不同的制粉方式对大米粉的品质影响很大,它能够决定制得米粉的品质及其加工适用性。目前,常用的制粉方式主要有三种：干法制粉、湿法制粉和半干法制粉。因此,本文通过对三种制粉方式的研究现状进行综述介绍,并且论述了影响制粉工艺的主要因素,以期为米制粉产业提供一定的参考。     

草鱼鱼肉肠质构性质的影响因素研究

研究了鸡蛋清、玉米淀粉、植物油对草鱼鱼肉肠白度、凝胶破裂强度、凝胶强度和弹性的影响,发现向鱼肉肠中添加适量的鸡蛋清、玉米淀粉和植物油都能增加产品的白度、凝胶强度和弹性,而添加15%的玉米淀粉可以使鱼肉肠的弹性和凝胶强度增加约1倍。以鱼肉肠凝胶强度为质构指标,确定制备鱼肉肠的辅料添加量为:15%的玉米淀粉,3%的鸡蛋清,1%的植物油。