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...     

干贝多糖的蛋白质脱除方式对抗氧化活性的影响

为比较蛋白质脱除方式对干贝多糖的组成、结构和抗氧化活性的影响,对热水辅助超声法提取的干贝柱多糖采用碱酶法、稀碱法、三氯乙酸(TCA)法、D-葡萄糖酸-δ-内酯(GDL)法4种方式脱蛋白质,并比较脱蛋白质后4组多糖的多糖质量分数、单糖组成、氨基酸组成、三螺旋结构、微观结构及体外抗氧化活性.结果表明:TCA组多糖的质量分数...     

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。     

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⁺].     

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.     

扇贝裙边酱发酵工艺及营养成分分析的研究

为了降低扇贝酱产品成本,增加贝类产品的附加值,以扇贝裙边为主要原料,经米曲霉和豆粕制曲,扇贝裙边与豆曲的质量比为4∶1,加入中性蛋白酶2000U/g,添加12%食盐,在40℃恒温培养箱中发酵8d后以1%接种量接种耐盐四联球菌,在30℃恒温培养箱中发酵7d,25℃恒温培养箱中后熟30d,磨细后真空包装、灭菌制成扇贝裙边酱。对其营养成分、理化指标及游离氨基酸分析结果表明：蛋白质含量为20.04g/100g,脂肪含量为0.82g/100g,氨基酸态氮为1.76g/100g,19种游离氨基酸总量为9.82g/100g,游离的必需氨基酸总量为4.16g/100g。以上5个指标除脂肪含量外均显著高于由贝柱和豆粕、贝柱和面粉发酵生产的扇贝豆酱和扇贝面酱。该研究为降低扇贝酱产品成本提供了实验依据。     

海鲜酱油的研究与开发现状

介绍新型调味品的发展现状,开发与研究海鲜酱油的意义及市场前景,国内外以低值鱼、扇贝裙边为主要原料,经过科学的加工酿造的各种营养丰富、海鲜风味浓郁的海鲜酱油。     

海湾扇贝多肽对小鼠H22肝癌移植瘤的抑制机制研究

探讨海湾扇贝多肽(polypeptide from bay scallop,PBS)对小鼠H22肝癌移植瘤的抑瘤作用及机制。将50只KM小鼠随机分为正常对照组、H22肝癌模型组和PBS低、中、高剂量组共5组,按试验设计进行体内灌胃试验。结果显示,低、中、高剂量组的抑瘤率分别为28.16%、41.93%和84.00%,具有量效依赖趋势。与模型组相比,三剂量组小鼠血清中突变型p53、Survivin、8-iso-PGF2α和MDA的水平均有所降低,而IL-2、GSH-Px、SOD和TNF-α的水平均有所升高,且中剂量组较其他两组效果更明显;三剂量组小鼠肝脏组织提取液呈现相同变化趋势。肿瘤组织病理学观察也表明PBS有较好的抗肿瘤生物学效应。PBS对小鼠肝癌H22细胞具有明显的抑制作用。     

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.