扇贝柱质构分析的测试条件

研究了扇贝柱质构分析(TPA)的测定方法.考察了TPA测定时扇贝柱适宜的预处理方法,比较了压缩程度、压缩速率对扇贝柱TPA特性参数硬度、弹性、凝聚性、咀嚼性和回复性的影响.研究结果表明,压缩程度对扇贝柱咀嚼性之外的TPA特性参数影响显著,压缩速率对其影响不显著.最终确定扇贝柱的适宜预处理条件为温度70℃,时间12 mi...     

扇贝过敏原荧光免疫层析检测方法的构建与应用

目的 构建一种简便、快速、可降低非特异性荧光干扰的时间分辨免疫层析检测方法,实现快速检测扇贝中原肌球蛋白(tropomyosin,TM)过敏原。方法 本研究采用双抗体夹心免疫层析法,以含有铕(Eu)纳米微粒的荧光微球作为标签偶联兔抗TM多克隆抗体,制备荧光探针并对其进行表征。以4 mg/mL兔多克隆抗体作为T线,羊抗兔免疫球蛋白G (immunoglobulin g,IgG)作为C线组装免疫层析试纸条。结果 本研究组建的试纸条视觉检出限为0.05μg/mL,仪器检出限为0.01μg/mL。试纸条除对虾蟹有交叉反应外,对其他10余种物种无明显交叉反应。加标样品批内和批间变异系数分别为3.71%～7.94%和12.09%～12.80%,在不含TM的4种食物基质中加入浓度由低到高的TM,检测结果与实际加标情况相符。结论 本检测方法准确性良好、灵敏度高、特异性强,可在多种食物基质中实现对扇贝TM的快速检测。     

热处理对扇贝闭壳肌肌动球蛋白生化性质的影响

肌动球蛋白是扇贝闭壳肌中的主要功能蛋白质,对贝类制品的品质起关键的作用。文中以虾夷扇贝(Patinopecten yessoensis)闭壳肌为原料,提取其肌动球蛋白,并考察了热处理温度和时间对肌动球蛋白的α-螺旋含量、表面疏水性、活性-SH含量和浊度的影响。结果表明:在热处理过程中,扇贝闭壳肌肌动球蛋白的α-螺旋发生解旋,肽链展开,疏水性氨基酸残基暴露,蛋白表面疏水性增强;同时热处理使活性-SH氧化生成二硫键,蛋白聚集,使得扇贝闭壳肌肌动球蛋白的浊度增加。加热温度越高,这些指标变化越快。由此推断,扇贝闭壳肌肌动球蛋白在热处理过程中伴随着肽链的解旋和蛋白的无规则聚集。     

扇贝裙边水解液制备海鲜酱的加工工艺

以扇贝裙边为主要原料,选用中性蛋白酶、木瓜蛋白酶和酸性蛋白酶对其进行酶解.然后将水解液浓缩,再配以各种辅料,研制一种营养丰富的新型海鲜酱.其调配比例为:水解液55%、白糖8%、料酒2%、食盐8%、味精0.5%、淀粉4%、老抽酱油4%、辣椒油4%、胡椒粉1.5%、麻油0.5%.     

扇贝面酱发酵工艺条件的研究

为开发我国的扇贝资源,提高贝类附加值,研究一种扇贝面酱的发酵工艺。以形态不规则的扇贝柱和面粉为实验材料,研究不同贝柱与面曲添加比例、不同蛋白酶添加量、不同酒醪添加量、不同食盐添加量和不同发酵温度对扇贝面酱氨基酸态氮含量和感官的影响。结果:采用三元一次正交回归实验设计,确定了扇贝面酱较优发酵工艺条件:贝柱56%、面曲28%、蛋白酶1300U/g、酒醪3%和食盐13%,混料后于40℃保温发酵12d。结论:采用米曲霉发酵不规则扇贝柱和面粉,制得一种营养丰富、配比合理、风味鲜美的扇贝面酱。     

Anatomical distribution of heavy metals in the scallop Pecten maximus

This paper studied the anatomical distribution of mercury (Hg), cadmium (Cd), lead (Pb), chromium (Cr), nickel (Ni), arsenic (As), silver (Ag), copper (Cu) and zinc (Zn) in the scallop Pecten maximus and the possible implications in terms of shellfish management. Six organs were analysed: mantle, gills, foot, digestive gland, kidney and gonad. On the basis of their anatomical distribution, two groups of metals were able to be distinguished: the first included Pb, Hg, Ni, Zn and Ag; and the second comprised the four other metals studied. The metals in the first group preferentially accumulated in the kidney (except for Pb), with generally much lower concentrations in the other organs. The metals in the second group accumulated mainly in the digestive gland. As and Cu were included in the second group, but they also had particular inter-organ distribution characteristics. Among the edible organs of the scallop only the adductor muscle contained important proportions of one metal, As (which is very likely accumulated as a non-toxic derivative). A selective evisceration of the metal rich non-edible organs may therefore be considered a reliable measure to be taken with a view to reduce the metal content of scallops used for human consumption. This could be especially relevant for Cd, which is accumulated in high concentrations in the digestive gland.     

超临界二氧化碳扇贝阻尼密封动力稳定性研究

为研究超临界二氧化碳(Supercritical Carbon Dioxide, SCO₂)扇贝阻尼密封在不同工况下动力稳定性,建立SCO₂扇贝阻尼密封数值计算模型,分析进口压力、温度及转速对SCO₂扇贝阻尼密封动力特性及泄漏特性的影响。结果表明：直接复合刚度随涡动频率增加由正变负;交叉复合刚度随进口温度、压力增加而减小,随转速增加而增大;SCO₂扇贝阻尼密封的有效阻尼随进口温度、转速增加而减小,随进口压力增加而增大,进口压力为8.1 MPa时有效阻尼约为7.7 MPa时的1.7～2.9倍;扇贝阻尼密封直接复合刚度、有效阻尼整体上大于迷宫密封,稳定性高于迷宫密封,但泄漏量略高于迷宫密封。     

Elongation and Contraction of Scallop Sarcoplasmic Reticulum (SR): ATP Stabilizes Ca2+-ATPase Crystalline Array Elongation of SR Vesicles

The Ca²⁺-ATPase is an integral transmembrane Ca²⁺ pump of the sarcoplasmic reticulum (SR). Crystallization of the cytoplasmic surface ATPase molecules of isolated scallop SR vesicles was studied at various calcium concentrations by negative stain electron microscopy. In the absence of ATP, round SR vesicles displaying an assembly of small crystalline patches of ATPase molecules were observed at 18 µM [Ca²⁺]. These partly transformed into tightly elongated vesicles containing ATPase crystalline arrays at low [Ca²⁺] (≤1.3 µM). The arrays were classified as ‘’tetramer’’, “two-rail” (like a railroad) and ‘’monomer’’. Their crystallinity was low, and they were unstable. In the presence of ATP (5 mM) at a low [Ca²⁺] of ~0.002 µM, “two-rail” arrays of high crystallinity appeared more frequently in the tightly elongated vesicles and the distinct tetramer arrays disappeared. During prolonged (~2.5 h) incubation, ATP was consumed and tetramer arrays reappeared. A specific ATPase inhibitor, thapsigargin, prevented both crystal formation and vesicle elongation in the presence of ATP. Together with the second part of this study, these data suggest that the ATPase forms tetramer units and longer tetramer crystalline arrays to elongate SR vesicles, and that the arrays transform into more stable “two-rail” forms in the presence of ATP at low [Ca²⁺].     

循环周期对Sn3.0Ag0.5Cu/Cu钎焊接头界面化合物的影响

基于自制多场耦合装置,利用准原位观察方法,研究了Sn3.0Ag0.5Cu/Cu焊点在30~125℃热循环过程中不同循环周期下界面金属间化合物微观形貌和生长变化规律。结果表明:随着循环周期的延长,同一位置处的界面化合物的平均厚度是逐渐增加的,且呈抛物线规律。单个扇贝状的Cu6Sn5在纵向方向上先降低后逐渐变大;在横向方向上,随着循环周期的增加,平均宽度一致增加。当热循环周期达到600时,界面金属间化合物的形貌扇贝状转变成层状。     

Effects of Various Geometric Features on the Performance of a 7:1 Pressure Ratio Deeply Scalloped and Split Radial Turbine in a Gas Turbine Engine

A 2 MW gas turbine engine has been developed for the distributed power market.This engine features a 7:1 pressure ratio radial inflow turbine.In this paper,influences of various geometry features are investigated including turbine tip and backface clearances.In addition to the clearances,the effects of the inducer deep scallop and exducer rounded trailing edge are investigated.Finally,geometric features associated with a split rotor(separate inducer and exducer)are studied.These geometry features are investigated numerically using CFD.Part of the numerical results is also compared to experimental data acquired during engine test to validate the CFD results.