POTENTIAL USES OF MECHANICALLY DEBONED BULLFROG (RANA CATESBEIANA) MEAT TO PARTIALLY REPLACE LEAN PORK TO PRODUCE EMULSIFIED MEATBALLS

ABSTRACT

The objective of this study was to evaluate the qualities of emulsified meatballs where part of the lean pork was substituted with mechanically deboned bullfrog (Rana catesbeiana) meat (MDBM) during manufacturing and subsequently stored at 4C. Meatballs were manufactured by adding 0, 7.5, 15, 22.5 or 30% MDBM. The meatballs had higher moisture, lower protein and fat contents, darker color, lower water‐holding capacity, higher cooking loss and softer texture as the MDBM usage level increased. The thiobarbituric acid and volatile basic nitrogen values of the products significantly (P < 0.05) increased, and the shear values, springiness and fracturability decreased as the MDBM usage level increased (P < 0.05). The products containing 7.5% MDBM had higher acceptable sensory characteristics than those samples containing more MDBM. In conclusion, emulsified meatballs that had 7.5% mechanically deboned bullfrog meat, substituted with equal quantities of the lean pork, were acceptable based on their physicochemical and sensory qualities.

PRACTICAL APPLICATIONS

Many animal by‐products which are produced during processing are edible and valuable. How to utilize these by‐products has become a great issue for the industry. In this study, high‐quality proteins which were obtained from mechanically deboned bullfrog meat (MDBM) resulted in emulsified meatballs with acceptable qualities. More specifically, this information could make MDBM a possible material to substitute for part of the added lean meat in many emulsion‐type meat products and increase products marketability because of lower raw ingredients' cost. This finding may be useful for both marine and domestic animal industries to make better use of this by‐product. Lastly, this information can be used to enhance the potential reduction of animal wastes, which might pollute the environment.

     

Use of independent component analysis to improve signal‐to‐noise ratio in multi‐probe fluorescence microscopy

In conventional multi‐probe fluorescence microscopy, narrow bandwidth filters on detectors are used to avoid bleed‐through artefacts between probes. The limited bandwidth reduces the signal‐to‐noise ratio of the detection, often severely compromising one or more channels. Herein, we describe a process of using independent component analysis to discriminate the position of different probes using only a dichroic mirror to differentiate the signals directed to the detectors. Independent component analysis was particularly effective in samples where the spatial overlap between the probes is minimal, a very common case in cellular microscopy. This imaging scheme collects nearly all of the emitted light, significantly improving the image signal‐to‐noise ratio. In this study, we focused on the detection of two fluorescence probes used in vivo, NAD(P)H and ANEPPS. The optimal dichroic mirror cutoff frequency was determined with simulations using the probes spectral emissions. A quality factor, defined as the cross‐channel contrast‐to‐noise ratio, was optimized to maximize signals while maintaining spatial discrimination between the probes after independent component analysis post‐processing. Simulations indicate that a ～3 fold increase in signal‐to‐noise ratio using the independent component analysis approach can be achieved over the conventional narrow‐band filtering approach without loss of spatial discrimination. We confirmed this predicted performance from experimental imaging of NAD(P)H and ANEPPS in mouse skeletal muscle, in vivo. For many multi‐probe studies, the increased sensitivity of this ‘full bandwidth’ approach will lead to improved image quality and/or reduced excitation power requirements.     

三维有限元分析隧道开挖收敛损失与纵剖面 变形曲线关系研究

采用实验室研发的三维有限元程序,运用隧道收敛-约束法的分析模式,针对岩体弹性参数、初始应力与隧道径向位移等影响因素,探讨有支撑与无支撑情况下的隧道开挖收敛损失与纵剖面变形曲线关系.采用纵剖面变形曲线的研究结果,并与三维有限元数值计算结果相比较,探讨收敛损失的影响.由隧道收敛-约束法理论分析结果与三维有限元数值计算结果可知:(1) 确立隧道开挖收敛损失与纵剖面变形曲线的关系;(2) 隧道纵剖面变形曲线的归一化处理方式,可消除岩体参数、初始应力和隧道收敛的位置等因素影响;(3) 在弹性条件下,隧道开挖面产生的前期位移量约为最终位移量的25%～36%;(4) 由二维纵剖面变形曲线的分布,可计算并获得隧道开挖收敛损失值、了解隧道开挖工作面效应的三维影响,进而能计算分析岩体结构的应力与位移等变化量.     

THE EFFECT OF TRINITROPHENYL NUCLEOTIDE DERIVATIVES ON THE ADENOSINE TRIPHOSPHATASE ACTIVITIES IN MAIZE TONOPLAST VESICLES

The effects of trinitrophenyl (TNP) derivatives of adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP) on the coupled activities of the tonoplast ATPase in corn roots were investigated. The addition of TNP-ATP at micromolar concentrations (0.5–0.25 mM) significantly decreased both the ATP hydrolytic activity and the coupled proton pumping activity. The presence of TNP-ATP resulted in an increased Km for ATP and a reced maximum enzyme velocity. Unlike TNP-ATP that strongly inhibited proton transport at low concentration, TNP-ADP inhibited this activity only slightly. TNP-AMP stimulated proton transport at low concentrations. ADP and AMP inhibited the initial rate of proton transport in a different manner. The concentrations required to inhibit half of the initial rate of proton transport activity for ADP and AMP were 80 μM and 2 mM, respectively. The results suggest that tonoplast vesicles may contain at least two kinds of nucleotide binding sites.     

50—100KVA可調稳压器

本文介绍了一种结构简单、易于实现的大功率可调稳压器,在这种稳压器的控制线路中,采用了二级磁放大器推动直流电动机来进行电压自动调整。文中介绍了高效率的磁放大器线路及调整系统的设计方法。经过实际运转,输出电压波动为±1.5伏,工作可靠,不需要进行特别维护。