香草牛奶冰淇淋工艺及其品质评价

结合几款传统冰淇淋特点,以奶粉、糖粉和水为主要原料,添加鸡蛋、生粉、香草粉、明胶等辅料,开发香草牛奶冰淇淋,着重探讨冰淇淋工艺及其品质评价。结果表明:水量1L,干基配比为全脂甜奶粉36.1%、鸡蛋23.8%、糖粉32.5%、生粉3.6%、香草粉0.9%、明胶3.1%时,香草牛奶冰淇淋的膨胀率和融化速率分别为88.3%和8.7%,感官评定92分。该工艺下制作的冰淇淋色泽均匀一致、香味宜人、滋味甜度适中、组织细腻,且形体无软塌、收缩或变形状态,品质优于传统冰淇淋,以冰淇淋膨胀率和融化速率为试验指标,辅以感官品质评价,取得良好效果。     

Enzymatic interesterification of palm and coconut stearin blends

Hard fractions of palm oil and coconut oil, blended in the ratios of 90:10, 85:15, 80:20 and 75:25, were interesterified for 8 h using Lipozyme TL IM. Major fatty acids in the blends were palmitic acid (41.7–48.4%) and oleic acid (26.2–30.8%). Medium‐chain fatty acids accounted for 4.5–13.1% of the blends. After interesterification (IE), slip melting point was found to decrease from 44.8–46.8 °C to 28.5–34.0 °C owing to reduction in solids content at all temperatures. At 37.5 °C, the blends containing 25% coconut stearins had 17.4–19% solids, which reduced to 0.4–1.5% on IE, and the slip melting point (28.6 and 28.8 °C) indicated their suitability as margarine base. The reduction in solid fat index of the interesterified fats is attributed to the decrease in high‐melting triacylglycerols in palm oil (GS₃ and GS₂U type) and increase in triolein (GU₃) content from 1 to 9.2%. Retention of tocopherols and β‐carotene during IE was 76 and 60.1%, respectively, in 75:25 palm stearin and coconut stearin blend.     

High resolution melting curve analysis with MATLAB-based program

High resolution melting curve analysis (HRM) is an emerging new method for interrogating and characterizing DNA samples. It has been used as a powerful tool for gene mutation and single-nucleotide polymorphism (SNP) detection with high throughput and low cost. Commercially available HRM analysis systems are mostly proprietary and expensive. It lacks the flexibility for the end users and researchers to incorporate new analysis algorithms into the existing system. This paper presents the development of a MATLAB-based open software program for high resolution melting curve analysis. Key analysis functions, such as to obtain the first derivative curve using Savitzky–Golay filter, to identify the melt region, subtraction of background fluorescence and curve normalization, are introduced, followed by case studies of HRM analysis using the developed software program.     

CPPS/PA1010/EMG合金的制备与性能表征

采用(乙烯/马来酸酐/甲基丙烯酸缩水甘油酯)三元共聚物(EMG)为增容剂,与PA1010和化学处理的PPS(CPPS)熔融共混制备了CPPS/PA1010/EMG合金。当EMG含量为9份时,制备的高刚性、高韧性合金在保持其它力学性能基本不变的情况下其冲击强度提高了4.5倍;并研究了该合金的熔融结晶行为和热降解行为。     

A plant for high-speed melting of basalt rocks

Aplant for fast basalt melting has been built as an alternative to the existing type of melting plant. The design incorporates the latest refractories and thermal insulation materials, together with the latest high-speed burners and comprehensive automation of all the processes. Translated from Novye Ogneupory, No. 4, pp. 103 – 105, April, 2009.     

桉叶素的纯化

对云南某香料公司生产的某批桉叶油进行了全组成分析,结果为桉叶素、柠檬烯、对聚伞花素、γ-萜品烯、月桂烯、α-蒎烯、β-蒎烯、α-水芹烯、芳樟醇、松油烯-4-醇、α-松油醇和未知成分的质量分数分别为86.98%、9.10%、0.89%、0.79%、0.57%、0.54%、0.27%、0.39%、0.16%、0.02%、0.03%和0.12%。物性分析表明,主要杂质与桉叶素具有相近的沸点和溶解性质,而熔点相差较大,因而确定采用管式熔融结晶技术对桉叶素进行纯化。40次实验结果表明,采用w(桉叶素)≈80%的桉叶油为原料,通过二次重结晶,即首先将原料在-20~-30℃结晶,缓慢发汗至0.5℃,得到w(桉叶素)≥95%的中间产品;再重结晶一次,可得w(桉叶素)≥99.5%的最终产品。实验结果再现性好。     

一种电子束熔炼炉用高真空插板阀

介绍了一种用于电子束熔炼炉加料系统的高真空插板阀.该型插板阀采用独特的充气气囊密封结构,通过一个气动控制回路巧妙实现了对气囊充气放气的操作,是一种工作可靠、满足低泄漏率密封要求的高真空环境插板阀.同时对该型插板阀常见故障进行了分析并给出了处理措施.     

Effects of isothermal treatment parameters on the microstructure of semisolid alloys

Cold-rolled 6061 aluminium alloys are used to prepare semisolid billets by recrystallisation and partial melting. The effects of isothermal treatment parameters on the microstructures were investigated. The results indicated that the high isothermal holding temperature increases the experimental liquid fraction, average grain size and shape factor. A long isothermal holding time also increases the experimental liquid fraction and improves the spheroidisation degree of solid grains, but the average grain size also increases. Moreover, when the isothermal holding time at high temperature is increased, the size of intragranular liquid droplets increases, but their quantity decreases. The optimal isothermal holding temperature and time during semisolid isothermal treatment were 635°C and 5?–?10?min, respectively.     

An investigation on selective laser melting of Al-Cu-Fe-Cr quasicrystal: From single layer to multilayers

In this study, the effects of processing parameters on the microstructure of Al-Cu-Fe-Cr quasicrystalline (QC) coatings fabricated by selective laser melting (SLM) are investigated. A qualitative analysis on the XRD patterns indicates that the phase composition for the SLM processed coating mainly consisted of Al-Cu-Fe-Cr quasicrystals and α-Al (CuFeCr) solid solution, and with increasing laser energy input or coating thickness, the volume fraction of QC i-Al₉₁Fe₄Cr₅ reduced and those of QC d-Al₆₅Cu₂₀Fe₁₀Cr₅ and crystalline θ-Al₂Cu increased. The formation of cracks during the coating building procedure from single layer to multilayers is also discussed. For the coatings with the same layer number, the pores and balling particles diminish as laser power increases, due to the growth of melting degree. At the early stage of fabrication, with increment of layer number (or coating thickness), pores and balling particles decrease considerably because the molten pool solidified more “slowly”. However, after the layer number increases continuously from 10 to 20, the porosity no longer decreases, and some big size pores, microcracks and fractures appear, especially for the sample obtained at lower laser power. A wavy-like pattern composed chiefly of Al and QC phases, is formed at the interfacial region between substrate and coating due to Marangoni effect.