利用扇贝壳制备胶原螯合钙的研究

为了有效利用废弃扇贝壳,提高贝类加工废弃物的附加值,采用双酶法水解猪皮制得胶原多肽,并利用灰化的扇贝壳制备胶原螯合钙。优化的胶原螯合钙制备条件是:pH8,胶原多肽与氯化钙的比为0.3g∶7mL,反应时间50min。经95%乙醇沉淀得到胶原螯合钙产品。用红外光谱法对胶原螯合钙进行表征,结果表明胶原多肽的氨基和羧基都参与了与Ca2+的配位,找到Ca-N伸缩振动峰,说明经酶水解得到的胶原多肽成功螯合了贝壳中的钙离子,使该产品既具有胶原多肽增加骨胶原韧性的作用又具有补钙的特性。     

重整反应器扇形管变形机理研究

为研究重整反应器扇形管的变形机理,采用正交各向异性板模型简化其结构,并进行力学分析。为验证模型的合理性,从试验、理论计算及有限元模拟3方面对开孔板料进行分析比较,分别建立小段扇形管有限元完整模型和正交各向异性板简化模型进行分析,再加以试验验证,结果显示用正交各向异性板简化扇形管是可行的。通过对整段扇形管建立有限元模型,对其进行静力和线性屈曲分析,得到扇形管破坏的主要原因是外压载荷作用时的屈曲变形。     

虾夷扇贝内脏多糖SVP-12的分离纯化及性质研究

采用蛋白酶水解提取法提取虾夷扇贝内脏粗多糖。采用2步蛋白酶-sevag法脱除粗多糖中的蛋白质。粗多糖先后经Sephacryl-S 200凝胶过滤层析柱和DEAE-52阴离子交换层析柱分离得到多糖组分SVP-12。SVP-12经高效液相色谱鉴定为均一的多糖,其分子质量约为170 ku,其中多糖含量为72.05%,蛋白含量为2.74%,硫酸根含量为12.57%,氨基己糖含量为8.46%。气相色谱法检测结果表明,SVP-12含有鼠李糖、岩藻糖、阿拉伯糖、木糖、甘露糖、半乳糖、葡萄糖,其摩尔比例约为1.65∶2.54∶4.05∶5.60∶1.48∶4.90∶1.00。     

有益细菌A18在海湾扇贝(Argopecten irradians)育苗中的应用

在海湾扇贝D形幼虫期施用10^3,10^4,10^5CFU／ml三个浓度的有益细菌A18。经该菌处理后，扇贝幼苗的变态率与各个发育期的成活率均比加氯霉素组和未加任何处理的对照组高。其中以10^4CFU/ml处理的扇贝幼苗的变态率和成活率最高。对实验扇贝幼菌水体细菌总数和弧菌数分析发现，经10^5,10^4CFU/ml A18菌处理水体的细菌总数和弧菌数均比相应的对照组低。在扇贝育苗水体加入10^6,10^7,10^8CFU／ml的有益细菌A18，检测高浓度A18对扇贝幼苗的毒害作用，当该菌浓度在10^6CFU/ml时，经48小时扇贝幼苗成活率79％，高于对照组的68.5%；当浓度达10^7,10^8CFU/ml时，处理48小时后的扇贝幼苗死亡率分别为95.6%和100％。     

灭菌处理对扇贝沙司挥发性成分和游离氨基酸的影响

为了研究灭菌前后扇贝沙司中挥发性成分和游离氨基酸的变化,利用SPME-GC-MS法和HPLC法,对灭菌前后扇贝沙司中的挥发性成分和游离氨基酸进行分离鉴定。结果表明:灭菌前后分别鉴定出挥发性成分为16种和27种,其中共有10种相同的挥发性成分;游离氨基酸分别为16种和17种,灭菌后检测出甲硫氨酸。灭菌后的扇贝沙司中的挥发性成分显著多于灭菌前,游离氨基酸的含量差异不显著。因此灭菌过程对扇贝沙司的挥发性成分具有一定的保留和增香作用,改善了扇贝沙司的营养结构。     

Nucleation of amino acid‐rich crystals on the surface of dried scallop (Chlamys farreri) during storage: formation mechanism and influence of environmental relative humidity

Formation of crystals on the surface of dried scallop (Chlamys farreri) adductor muscle is often observed during storage. The composition of these white crystals was determined, and the effect of relative humidity (RH) during storage on their formation was also studied. The white crystals were determined as the crystal of free amino acids, mainly composed of taurine (Tau) and glycine (Gly). The main polymorphic form of glycine in the crystals was further confirmed as the γ‐form. Besides free amino acids, another major part of the crystal composition was ions, such as Na⁺, NH₄⁺, K⁺, PO₄^3? and Cl^?. The presence of various free amino acids and Na⁺ and K⁺ might contribute to the crystallisation of γ‐glycine. RH particularly at 65% and above significantly increased the amount of crystals. RH of 43% and below was recommended to prevent the formation of amino acid‐rich crystals on dried scallops during storage.     

序贯提取-高效液相色谱-电感耦合等离子体质谱法测定栉孔扇贝裙边中砷组分

目的 建立序贯提取-高效液相色谱-电感耦合等离子体质谱法(high performance liquid chromatography-inductively coupled plasma mass spectrometry, HPLC-ICP-MS)测定栉孔扇贝(Chlamys farreri)裙边中砷组分。方法 以超纯水、甲醇及二氯甲烷-甲醇溶液为提取液, 采用序贯涡旋提取法, 提取扇贝裙边中砷, 并划分为水提取砷、非水提取砷及未提取砷3种组分。采用HPLC-ICP-MS砷形态检测法定性定量分析6类水提取已知砷：中砷酸、亚砷酸、一甲基胂、二甲基胂、砷甜菜碱、砷胆碱6类,; 采用ICP-MS总砷检测法定量分析总砷、水提取未知砷、非水提取砷及未提取砷。结果 市售栉孔扇贝裙边中总砷含量高, 水提取已知砷、水提取未知砷、非水提砷及未提取砷分别约占24.5%、26.8%、25.4%及23.3%, 无机砷含量符合国家限量要求。优化条件下, 6种砷形态在0~100 μg/kg范围内线性关系良好, 检出限为0.014~2.366 μg/kg, 定量限为0.050~3.090 μg/kg, 加标回收率在78.1%~116.2%之间, 相对标准偏差(relative standard deviations, RSDs)在1.1%~10.1%之间。结论 本研究建立的砷组分分析方法精密度高、灵敏度高、砷提取效率高, 适用于扇贝裙边中砷组分的分析, 可为扇贝裙边的安全性评价提供理论依据。     

Heat treatment of scallop adductor muscle using superheated steam

ABSTRACT:  Scallop ( Patinopecten yessoensis ) adductor muscles were heated using superheated steam (150 and 200 °C), boiling (98 °C), and normal steaming (95 °C). The amounts of amino acids, water-soluble peptides, and nucleotides, expressed as extractive nitrogen in scallop products, are very important elements of quality and taste. After 15-min heating of scallop muscles with normal steaming and boiling, respective losses of 50% and 64% of the extractive nitrogen were observed. However, most extractive nitrogen (> 86%) remained in the scallop muscles treated with superheated steam at 150 and 200 °C. Protective effects of superheated steam against elution loss of nitrogen compounds were also observed in amino acid analyses of the heated products. The scallop-muscle surface temperature during treatment with superheated steam increased more quickly than that with normal steaming and boiling. The rapid water loss and the surface protein denaturation engendered formation of a 30-μm-thick film covering the surface, which prevented extractive nitrogen loss from internal tissues. Superheated steam treatment at 200 °C caused browning, surface shrinkage, and 47% weight loss. In marked contrast, the appearance and the weight loss of sample treated at 150 °C were almost the same as those of normal steaming and boiling-treated samples. These results suggested that superheated steaming at 150 °C is an optimal heat treatment of scallop adductor muscles.     

扇贝酱发酵工艺研究

以扇贝裙边为原料,首先分析了扇贝裙边的营养成分,并从酱油曲精中分离纯化得到米曲霉作为菌种,然后研究了固态发酵法生产天然调味酱主要工艺。结果表明,新鲜扇贝裙边水分含量为86.06%(g/g),总氮含量为1.14%(g/g),氨基态氮含量为0.21%(g/g),最佳发酵工艺参数为扇贝裙边起始含水量40%左右,空气湿度60%~70%,加盐量8%~10%,主酵温度30℃2d,后酵温度60℃1d,再降至10℃以下后熟5~6d。制得的扇贝酱风味和体态最佳,产品中氨基态氮含量基本在0.64%(g/g)~0.69%(g/g)之间,值得的扇贝酱为淡黄色酱状物,入口细腻,香鲜浓郁,有典型的海鲜风味。     

基于等残留高度的自由曲面三轴数控加工刀具轨迹规划

提出了一种新的自由曲面三轴数控加工刀具轨迹规划方法,该方法首先将自由曲面进行离散,并沿曲面的法矢方向将离散曲面偏置一个刀具半径值,得到该曲面的偏距面,在偏距面上基于等残留高度来规划刀具轨迹。该方法已经在实际中得到很好的应用。