蛇皮组织结构的研究

本文介绍了用生物显微镜对菜花蛇皮、大王蛇皮组织切片进行的观察结果；根据这几种蛇皮微观组织结构特点，提出了在蛇皮制革加工过程中应注意的问题和工艺技术理论依据。     

Evolution of the localisation and composition of phenolics in grape skin between veraison and maturity in relation to water availability and some climatic conditions

BACKGROUND: Several studies have investigated the composition of phenolics in grape skin during grape maturation under various conditions of light exposure, water stress, nitrogen supply and mineral nutrition, but their localisation during berry development is not well known. In this study the composition and localisation of proanthocyanidins were monitored for three years on four plots known to induce a distinctive behaviour of the vine (Cabernet Franc). The composition of phenolics was determined by spectrophotometry; also, in one year, proanthocyanidins were determined by high‐performance liquid chromatography. Further information was obtained histochemically by means of toluidine blue O staining and image analysis. RESULTS: The results indicated that clear differences in phenolic quantification existed between the biochemical and histochemical approaches; the proportion of cells without phenolics was not linked with the quantity determined by the analytical methods used. The histochemical method showed the evolution of the localisation and typology of cells with and without phenolics during ripening. The number of cells without any phenolic compounds appeared to be very dependent on the mesoclimatic conditions and only slightly dependent on the site water status. CONCLUSION: Clear differences in phenolic quantification existed between the biochemical and histochemical approaches; the proportion of cells with phenolics was not linked with the quantity determined by biochemistry. The histochemical method showed an evolution of the localisation and typology of cells with and without phenolics in which mesoclimatic conditions were the most influential factor. Finally, the study showed some advantages of the histochemical approach: it gives information about the anatomy of the tissue as well as the nature and distribution of some of the large macromolecules and allows reconstruction of the three‐dimensional plant structure. Copyright © 2011 Society of Chemical Industry     

沙河板鸭加工中的危害分析与关键工艺控制

通过对沙河板鸭加工过程中各个环节可能造成的危害进行分析,确定了活鸭验收与检疫、热烫去毛、宰后检验、腌制、脱水干制5个关键控制工艺点,并制定了HACCP工作表,确定了关键限值、监控措施和纠偏措施。该体系的建立将使板鸭加工过程中的各种潜在危害降到最低水平,对提高板鸭的安全性和产品质量有积极作用。     

Rehydration kinetics at 5 and 15 °C of dry salted meat

The surface of meat products during intermittent drying is successively subjected to dehydration and rehydration processes. The aim of this paper was to study the rehydration kinetics at two temperatures (5 and 15 °C) of salted ground pork, (2% or 4% NaCl) dried to different water contents, (10%, 20% and 35%) using Peleg and Weibull’s models. Surface structure of dried samples was analyzed with electron microscopy and related to rehydration kinetics. The equilibrium water content decreased with temperature and increased with NaCl, but was not affected by the initial water content. The rehydration rate at the beginning decreased with water content and was significantly higher at 5 °C than at 15 °C, but it was not significantly affected by NaCl content. However, the equilibrium water decreased with temperature and tended to increase with NaCl content, but was not affected by the initial water content. High level of dehydration resulted in a more damaged and porous meat matrix. This microstructure may contribute to accelerating the rehydration process.     

罗非鱼皮胶原肽的制备及抗氧化活性研究

采用酶法从罗非鱼皮中制取胶原肽,选用动物蛋白水解酶,当酶的添加量为0.5%,61℃,pH 6.7下水解3 h时,蛋白质的回收率为92.97%,水解度为9.37%.水解产物90%以上相对分子质量低于10 kD的胶原肽.胶原肽对由Fe^2＋引发的卵磷脂脂质体过氧化有一定抑制作用,同时对·OH具备一定的清除作用.     

低盐咸蛋的腌制工艺及其品质研究

提出一种两段腌制法制备低盐咸蛋的方法,分别对两段法腌制过程中咸蛋蛋白和蛋黄的水分含量、盐分含量进行实时检测,考察腌制结束时蛋黄的出油率,并且对咸蛋品质进行综合感官评定。结果表明,先使用19%盐水再换用3.5%盐水的两段法腌制工艺,咸蛋产品中蛋白盐分含量为3.64%,比传统法腌制产品蛋白盐分含量降低51.21%,口感适宜;蛋黄含盐量为0.94%,略低于传统法腌制的1.23%;蛋黄脂质渗出率为67.73%,与传统法腌制的69.22%基本相当。该腌制工艺不仅可解决传统咸蛋蛋白盐分过高、口感过咸的问题,同时也可保证蛋黄松沙出油,从而获得高品质的低盐咸蛋。     

喷雾干燥入口温度对大目金枪鱼皮明胶乳化特性的影响

研究不同喷雾干燥入口温度（130、160、190 ℃）对大目金枪鱼皮明胶乳化特性的影响。通过乳析指数和乳液微观结构评价乳化效果,通过表面疏水性和凝胶强度评价不同乳液界面与连续相的差异,通过明胶分子质量分布和红外光谱初步分析喷雾干燥入口温度影响明胶乳化特性的机制。结果表明,随着喷雾干燥入口温度的升高,明胶的高分子质量亚基被过度破坏,降低了三螺旋结构的完整性,从而导致更多的亲水性氨基酸被暴露,进而降低了凝胶强度（851.29～676.65 g）和表面疏水性（218.81～82.96）,表面疏水性的降低不利于明胶在油-水界面的吸附及网络结构的形成,明胶凝胶强度的降低表明乳液连续相中网络结构变得松散,最终表现为明胶乳液的液滴粒径和乳析指数增大,乳液稳定性降低。由此可见,当前研究的喷雾干燥入口温度（130、160、190 ℃）与乳液稳定性呈负相关,利用喷雾干燥制备乳化型鱼皮明胶,入口温度不宜过高,130 ℃时效果更佳。     

牛皮胶原蛋白切向超滤工艺参数的优化

如何获得高纯度胶原是实现动物皮胶原高值转化利用的关键。本文研究了将切向超滤技术用于牛皮胶原蛋白的纯化处理,考察了透膜压、切向流量、胶原蛋白浓度和透析倍数对超滤过程的影响。结果表明,对截留量为50kDa的聚醚砜膜优化得到的最佳超滤参数为：透膜压为0．102～0．118MPa,切向流速为57．6L／h,胶原浓度为2mg／mL,透析倍数为6．67,采用该工艺条件可获得较高纯度胶原。     

机车应用蒙皮预应力焊接技术

通过对蒙皮焊接工艺的讨论,针对产生蒙皮波浪变形的原因及影响因素,利用计算分析对其中主要技术参数进行量化处理,并对机车侧墙蒙皮采用了预应力控制薄钢板焊接变形的新的工艺方法进行分析。     

基于感应加热技术的轴承拆装器的计算机仿真研究

在研究感应加热基本理论的基础上,通过MATLAB及ANSYS有限元分析软件,对所设计的轴承内环感应拆装器进行了计算机仿真研究.通过对感应加热过程中拆装器内电磁场的计算机模拟,得出了磁场的分布规律,证明了涡流集肤效应的存在,为感应加热装置的设计奠定了基础.