库尔勒香梨粗皮果振动频谱特性的研究

为了实现库尔勒香梨粗皮果的无损判别与检测,采用脉冲激励法测试了香梨正常果和粗皮果的振动频谱特性,分析了两种品质香梨响应主频率的差异显著性,并通过对两品质香梨石细胞含量的统计测量以及对果皮和果肉显微结构观察,探讨了粗皮果与正常果的响应主频率产生差异的本质原因。结果表明,正常果和粗皮果的响应主频率分别为(687.5±13.1)Hz和(775±19.4)Hz,存在显著差异(p<0.05)。粗皮果具有较高的响应主频率,其本质原因是其果表皮层致密、木质化细胞数量较多、含水率较低且其果肉中有大量分布的石细胞(团)和较多的木质纤维。      

喷雾干燥法制备打瓜籽蛋白粉的研究

为得到优质的打瓜籽蛋白粉,采用喷雾干燥法,以蛋白粉的集粉率和分散系数(PDI)为指标,探讨了进料温度、进风温度、进料流量和雾化压力对喷雾干燥效果的影响。通过均匀实验,得到打瓜籽蛋白粉制备的最佳工艺参数:进料温度20℃,进风温度180℃,进料流量300 m L/h,雾化压力140 k Pa,此时打瓜籽蛋白粉的集粉率为50.43%,PDI为80.1%,所得蛋白粉为粉末状,奶白色,无异味,无结块,功能性质良好。      

采用夹持果梗方法的水果检测分级机设计

采用夹持水果果梗的方法,设计一套能够适应当前水果在线检测分级需求的水果检测分级机,主要包括水果果梗夹持装置、输送装置、旋转装置以及分级卸果装置。其中果梗夹持装置是本设计的核心部件,它不仅能够独立完成果梗的夹持功能,还能够在其他辅助装置的配合下完成水果的输送、旋转及卸果功能。该果梗夹持装置实现了水果夹持部分与水果的共同旋转,有效避免了水果与机械装置之间的摩擦,使得整个水果检测分级机对水果的机械损伤大大降低,能够很好地满足水果在线检测分级的需求,具有较高参考价值和应用前景。     

在高中学区食堂建立HACCP的效果分析

目的 通过在高中学区建立HACCP体系并对其效果进行分析,为在其他学生食堂开展HACCP体系提供依据和经验.方法 采取问卷调查、实验室检测、资料比较等方法开展卫生学调查,对该学区食堂实施HACCP体系的效果进行分析.结果 从业人员经5次培训后卫生知识知晓合格率达到了98.46%,食品加工环节的菌落总数检测值显著下降(P <0.05)大肠菌群合格率显著提高(P<0.01)餐具消毒合格率在实施前后均为100%,操作间空气质童的差异无统计学意义.结论 在高中学区食堂建立HACCP体系的效果明显,食品加工操作更规范化、流程化,突出了控制食品安全的重点.     

荨麻总黄酮提取工艺

采用荧光分光光度法,以槲皮素为标准,荨麻中总黄酮为指标,通过单因素和正交试验,系统研究食药两用植物荨麻黄酮类化合物提取工艺。结果表明:黄酮类化合物的最佳工艺条件为乙醇浓度70%,提取时间2 h,料液比1 g∶60 mL,提取温度60℃。     

大豆醇溶性磷脂制备中浸提温度对产品指标的影响

考察了大豆醇溶性磷脂制备中,浸提温度对醇溶性磷脂产品酸值、过氧化值、磷含量及氮含量的影响。结果显示,采用95%乙醇作为浸提溶剂时,其浸提温度不宜太高,浸提温度最好控制在40℃,结合氮气驱氧,能较好地控制大豆醇溶性磷脂的品质指标。     

Synthesis of highly active and stable Pd/C catalysts toward HCOOH dehydrogenation by a simple NH3 adsorption method

Pd catalysts supported on activated carbon (Pd/C–NH₃) toward HCOOH dehydrogenation were prepared by a simple adsorption method using ammonia (NH₃) and Ar as the working gas. The results show that the TOF_initial of Pd/C–NH₃ was 459.8 h⁻¹ at 50 °C. When the reaction was carried out for 4 h, the HCOOH dehydrogenation ratio over Pd/C–NH₃ was about 81.2%, which was 1.15 and 1.13 times, respectively, as that of the as-prepared Pd/C catalyst without any treatment (Pd/C–As) and the Pd/C catalyst purchased from Sigma-Aldrich (Pd/C-CM). The total amount of H₂ and CO₂ produced by using Pd/C–NH₃ to decompose HCOOH in the third cycle was 99.4% of the gas produced by the first reaction cycle, and 1.80 and 12.60 times, respectively, as that of Pd/C–As and Pd/C-CM. The characterization results indicated that the Pd active species in Pd/C–NH₃ migrated to the outer surface of the carbon support during the reaction, and the pore volume of the carbon support became larger, which were beneficial to the reaction. These factors made Pd/C–NH₃ exhibit excellent HCOOH dehydrogenation activity and stability. NH₃ adsorption is a simple and effective method for preparing high-performance Pd/C HCOOH dehydrogenation catalysts, and has important guiding significance for the preparation of other carbon supported noble metal catalysts.     

Air pollution policy in Europe: Quantifying the interaction with greenhouse gases and climate change policies

This paper uses the computable general equilibrium model WorldScan to analyse interactions between EU's air pollution and climate change policies. Covering the entire world and seven EU countries, WorldScan simulates economic growth in a neo-classical recursive dynamic framework, including emissions and abatement of greenhouse gases (CO₂, N₂O and CH₄) and air pollutants (SO₂, NO_x, NH₃ and PM_2.5). Abatement includes the possibility of using end-of-pipe control options that remove pollutants without affecting the emission-producing activity itself. This paper analyses several variants of EU's air pollution policies for the year 2020. Air pollution policy will depend on end-of-pipe controls for not more than two thirds, thus also at least one third of the required emission reduction will come from changes in the use of energy through efficiency improvements, fuel switching and other structural changes in the economy. Greenhouse gas emissions thereby decrease, which renders climate change policies less costly. Our results show that carbon prices will fall, and may even drop to zero when the EU agrees on a more stringent air pollution policy.     

分子蒸馏及其在食品工业中的应用

分子蒸馏是一种在高真空下进行液一液分离操作的连续蒸馏过程。介绍了分子蒸馏技术的基本原理、装置及在食品工业中的应用，最后提出国内分子蒸馏技术工业化应用存在的问题及解决方法。     

超声法提取中药制剂中醇溶性成分的研究

以超声时间、提取温度、乙醇浓度和固液比为因素,每因素进行3水平的正交实验,用紫外分光光度法测定中药制剂——促生长散中厚朴酚的含量和以其作为综合评价指标。结果发现提取实验中影响因素最大的是乙醇浓度,最佳提取条件为:超声时间60(20,20,20)min,超声温度35℃,乙醇浓度65%,固液比1:10。