软启动器在纸机打浆控制中的应用

介绍了软启动的控制原理与主要功能及其在纸机打浆控制中的应用.     

电机软启动器的应用

论述了对于鼠笼型三相异步电动机在智能控制中的几种启动方式及其优缺点。介绍了电子软启动器的应用。     

软启动器及其在打浆盘磨中的应用

介绍了三相异步电动机的几种常用启动方式,并针对造纸厂打浆车间盘磨主电机启动中存在的一些问题,提出了一种以可编程控制器(PLC)为核心,利用1台软启动器启动3台盘磨的电控系统。实际运行效果表明,该电控系统具有可靠性好、性能完善的优越性。     

软启动器在水箱拉丝机中的应用

介绍电子软启动器在不需调速的水箱拉丝机中的应用。软启动方式与传统启动方式几方面的对比结果表明 :用软启动器启动可降低对供电电网质量的影响 ,改善电机启动特性 ,减小启动对机械设备的冲击 ,降低设备运行和维护成本等 ,是今后发展的方向     

软启动器在井用潜水电泵中的应用

介绍了应用软起动器实现消除井用潜水泵起、停泵水锤的方法,以及软起动器的其它优点。     

几种软启动器的比较及其在盘磨中的应用

在对三相异步电动机的几种软启动器的分析比较之后，提出了一种以晶闸管软启动器为核心，利用一台软启动器启动三台盘磨电机的电控系统。实际应用效果证明了该系统的有效性。     

软启动器和变频器的时分多机复用技术及其应用

本文论述了时分多机复用的概念，并对其技术和应用加以具体说明，展现了该技术良好的应用前景。     

软启动器的谐波分析与抑制

软启动器作为一种集电动机软启动、软停车、轻载节能和多种保护功能于一体的新颖电动机控制装置,它不仅有效地解决了传统电动机启动过程中电流冲击和转矩冲击问题,而且可以根据不同工况设置其工作状态,有很强的灵活性和适用性。正因如此,软启动器得到了广泛的应用。然而由于软启动器采用晶闸管调压控制,不可避免地会产生高次谐波,对电机和电网的运行会产生很大的影响,需采取一定措施加以控制。本文分析了软启动器在工作过程中产生谐波的原因及危害,并在此基础上提出了抑制谐波的方法。     

电机软启动器的探讨

本文论述了对于鼠笼型三相异步电动机在智能控制中的几种起动方式及其优缺点。介绍了电子软启动器的应用。     

软启动器在大功率粉碎机上一拖三的应用

比较了粮食行业中大功率电动机的不同启动方式,介绍了软启动器在大功率粉碎机上一拖三的应用,实践证明:采用这种"一拖三"的方案既稳定、可靠、节能,又很好地降低了设备投资成本。     

干酪生产用发酵剂的筛选

概述了干酪的营养特点及生产用菌种所具备的特性,对本实验室现有的4种单一菌株和7种混合菌株的发酵性能和生化特性进行了研究,优选出了适于干酪加工的2株优良菌种L3（乳酸乳球菌）和L6（干酪乳杆菌：瑞士乳杆菌=1：1）。     

Preliminary observations on proteolysis in Manchego cheese made with a defined-strain starter culture and adjunct starter (Lactobacillus plantarum) or a commercial starter

Different authors have demonstrated the potential of adding lactobacilli as adjunct cultures to pasteurized milk used in cheese manufacture. The aim of this work was to observe the effect of the use of a defined-strain starter culture and the addition of an adjunct culture (Lactobacillus plantarum) to cheesemilk in order to determine their effect on the ripening of Manchego cheese. Manchego cheeses were manufactured using one of the following starter culture systems: a defined starter consisting of Lactococcus lactis ssp. lactis and Leuconostoc mesenteroides ssp. dextranicum; a defined starter, as described above, and Lb. plantarum, which were isolated from a good quality Manchego cheese made from raw milk, or a commercial starter comprised of two strains of Lc. lactis. The cheeses were sampled at 15, 45, 90 and 150 d of ripening. Principal component analysis of peak heights of reversed-phase HPLC chromatograms of 70% (v/v) ethanol-insoluble and -soluble fractions distributed the samples according to the starter used in their manufacture. Quantitative differences in several peptides were evident between the three cheeses. Cheeses made with the defined-strain starters received higher scores for the flavour quality and intensity and for overall impression than the cheeses made with the commercial starter.     

曲坯含水量对机压包包曲品质的动态影响

为了确定机压"包包曲"适宜的曲坯含水量,在其他条件不变的情况下,采用单因素实验设计方法,研究曲坯含水量分别为37%、38%、39%、40%对大曲培养过程中品质的影响.实验结果表明:曲坯含水量对机压"包包曲"培养过程中酸度、糖化力、发酵力、霉菌数、酵母数、芽孢杆菌数等均有不同程度的影响,对新曲的感官品质也有一定的影响:最适曲坯含水量为39%.     

荞麦红曲酒的酿造

采用红曲霉固态培养荞麦制曲,液态发酵产洒的方法酿造荞麦红曲酒。固态培养5d的荞麦红曲加水转入液态发酵,添加少量酿酒活性干酵母以及大米根霉糖化液有助于发酵过程,并且使成品酒风味更好。     

The design of a three strain starter system for Cheddar cheese manufacture exploiting bacteriocin-induced starter lysis

A three strain starter system was developed for increasing the level of starter cell lysis during cheese manufacture and ripening. The composition of this starter combination includes a bacteriocin (lactococcin A, B and M) producer which causes the lysis of a second strain (sensitive to bacteriocin activity) during cheese manufacture, and a third strain resistant to bacteriocin activity. The latter strain plays an essential role in ensuring acid production during cheese manufacture. Cheeses manufactured at pilot-scale (450 L vats), with the three strain starter combination were assessed for levels of the intracellular enzyme, lactate dehydrogenase, released into the cheese matrix during ripening. Experimental cheeses, manufactured with the bacteriocin-producing adjunct, exhibited higher levels of free amino acids and greater release of intracellular LDH than control cheeses manufactured in its absence. Cheese was subject to sensory analysis which revealed that experimental cheese showed a decrease in bitterness over cheeses manufactured without the bacteriocin-producing adjunct. Thus, this three strain system offers manufacturers a reliable starter system exhibiting increased lysis with concomitant improvements in cheese flavour.     

Genetically modified starter and protective cultures

Modern approaches towards starter and protective culture improvement rely on advances in molecular biology. For most microorganisms used for food production, gene technological methods have been well developed. By recombinant DNA technology, ‘tailor-made’ starter and protective cultures may be constructed so as to combine technically desirable features. A single strain which normally would fail to accomplish a given ‘wtask’ may now be improved so as to meet a set of requirements necessary for a specific production or preservation process (e.g. wholesomeness, no off-flavour production, overproduction of bacteriocins or particular enzymes). In addition, undesirable properties (e.g. mycotoxin or antibiotic production by cheese moulds) may be eliminated by techniques such as ‘gene disruption’.     

Growth characteristics of meat starter cultures

The Australian Code of Practice for manufacture of dry and semi-dry sausage (salami) states that fermentation temperatures must not exceed 25°C and that a pH of 5·2 must be achieved in the product within 48 h. In order to select the most appropriate starter cultures for fermentation, Lactobacillus plantarum, Pediococcus pentosaceus and Staphylococcus carnosus were characterised with respect to growth and acid production determined at constant pH (4·7, 5·5 and 6·3). L. plantarum and P. pentosaceus showed similar characteristics over the pH range studied while S. carnosus was sensitive to lower pH. Also, P. pentosaceus showed greater psychrotrophic growth without pH control than L. plantarum or S. carnosus. Salami made with P. pentosaceus maintained higher viable numbers in the product over 8 days than did L. plantarum. Growth of S. carnosus in salami could not be detected in the presence of the more pH-tolerant organisms. The growth of L. plantarum and P. pentosaceus did not prevent the development of high levels of non-starter flora, a factor that can be important in determining salami quality. However, the more psychrotrophic P. pentosaceus ensured a greater dominance of starter over non-starter flora.     

Defined multi-species semi-liquid ready-to-use sourdough starter

This paper aimed at setting up a protocol for the manufacture of a defined multi-species semi-liquid ready-to-use sourdough starter consisting of lactic acid bacteria (LAB) selected on the basis of their capacity of rapid acidification and adaptation to several technological factors. Preliminarily, 56 strains of sourdough LAB were screened based on the acidification kinetics during sourdough fermentation. The influence of temperature (25-37 degrees C), NaCl (2%, w/w, of wheat flour), initial cell number (10(7)-10(9) cfu g(-1)), dough yield (150-180), substrate for cell cultivation (mMRS or SDB media) and phase of cell growth (exponential or stationary phases) on the kinetics of acidification was also determined. Lactobacillus casei DPPMA27, Weissella confusa DPPMA20 and Lactobacillus fructivorans DPPMA8 were selected and used to produce a defined multi-species semi-liquid sourdough starter. Fermentation was carried out in a 2l batch fermentation bioreactor (12 h at 37 degrees C), under controlled pH, by cultivating cells in a medium made of water (60%), flour and other nutrients (40%). The semi-liquid sourdough starter was stored for 30 days under different conditions and used for dough fermentation (dough yield 160). The microbial composition, acidifying activity and fermentation end-products were kept constant during 21 days of storage. The findings of this study may be useful to increase the use of sourdough in bakery industries.     

肉制品发酵剂的研究进展

发酵剂以其具有独特的生理功能,被广泛应用于肉制品中。本文综述了肉制品发酵剂的起源,研究进展及常见的肉制品发酵剂,并对未来的研究作了展望。     

马奶酒发酵剂用菌种的筛选研究

采用乳酸菌联合酵母的发酵方法,制备一种新型马奶酒并为工业化生产马奶酒提供新型发酵剂。通过考察8%酵母菌（F1）、6%酵母菌联合2%嗜酸乳杆菌（F2）、6%酵母菌联合2%瑞士乳杆菌（F3）、6%酵母菌联合1%嗜酸乳杆菌及1%瑞士乳杆菌（F4）以上四种发酵菌种配比,以酒精度、酸度、感官品质为考察指标,开发适合马奶酒工业化生产的优良发酵剂。结果表明,当采用6%酵母菌联合1%嗜酸乳杆菌及1%瑞士乳杆菌（F4）的发酵方式时,马奶酒酒精度为1.39%vol,马奶酒酸度为90 °T,感官评分为91分,且马奶酒香醇可口、组织均匀,适于大众饮用;因此6%酵母菌联合1%嗜酸乳杆菌及1%瑞士乳杆菌,可作为工业化生产马奶酒所用的发酵剂。