变温烘焙技术对丹桂乌龙茶香气品质的影响

采用L_(16)(4~5)正交设计探讨变温烘焙技术对丹桂乌龙茶香气感官品质及香气成分的影响。结果表明,处理13(A_4B_1C_4D_2E_3)丹桂乌龙茶香气品质最佳,变温烘焙较佳参数为120℃、20 min,90℃、130 min,120℃、30 min。烘焙后,丹桂乌龙茶中的醇类、醛类、碳氢化合物、含氮化合物含量相对较高;共检出香气成分64种,主要为反-橙花叔醇、α-合金欢烯、苯乙醛、吲哚、苯乙醇、2-甲基丁酸-2-苯乙酯、苯乙腈、二氢芳樟醇、苯甲醇、芳樟醇、苯乙烯等,约占香气总量的90%。极差分析表明,香气品质影响因子的主次顺序为:烘焙Ⅲ阶段温度、Ⅲ阶段时间Ⅰ阶段温度、Ⅰ阶段时间Ⅱ阶段温度,即3个烘焙阶段的影响顺序为ⅢⅠⅡ,该研究结果为深入研究丹桂乌龙茶的烘焙技术提供了理论依据与参考。     

A new lean no time test baking method with improved discriminating power

In response to customer concerns related to gluten strength in commercial baking, the Canadian Grain Commission assessed whether the Canadian Short Process (CSP) test bake method was generating useful data related to intrinsic strength of wheat varieties. Assessment of CSP loaf volume data for Canadian variety trials spanning 2003 to 2013 showed very little correlation with dough strength parameters as measured by farinograph and extensigraph. A lean no time (LNT) test baking method was developed that can better discriminate genotypes and provide objective indicators of the effect of intrinsic dough strength on baking quality. From early method development, through method validation and verification using diverse sets of samples targeting different Canadian wheat classes and grown in three different crop years, results showed the LNT method to be more discriminating and easily adopted by other laboratories. In 2015, the LNT method was adopted as the method of choice in future Canadian variety registration trials. The LNT method is fast, simple and well-suited to high throughput test baking conditions encountered in the evaluation of large numbers of breeder lines. A new objective parameter, loaf top ratio, was also introduced and found to correlate well with dough strength and dough handling properties.     

Application of urease inhibitor improves protein composition and bread‐baking quality of urea fertilized winter wheat

Background: Nitrogen losses is an economic problem for wheat production and a high risk to the environment. Therefore, improved N fertilizer management is a key to increasing the N efficiency and minimizing N losses. To increase N efficiency, enhanced fertilizers such as urea combined with urease inhibitor can be used. Aims: The aim of present study was to evaluate the effects of different N forms on grain storage protein subunits in winter wheat and to examine whether the observed changes correlate with parameters of baking quality. Methods: The investigation was performed over two consecutive years at two locations in Germany. Protein subunits were analyzed by SDS‐PAGE. Results: Protein concentrations were similarly increased after fertilization with ammonium nitrate and urea + urease inhibitor. Analysis of the individual storage protein fractions indicated that both fertilizers specifically enhanced ω‐gliadins and HMW glutenins, but the effect was more pronounced in the ammonium nitrate treatment. Application of urea + urease inhibitor had greater influence on the protein composition and resulted in higher specific baking volume as well as the best fresh keeping ability, in comparison with urea treatment. Conclusion: Considering that the urea + urease inhibitor treatment resulted in almost comparable improvements of NUE and baking quality, with the additional benefit of reduced N losses in combination with easy handling, urea + urease inhibitor can be recommended as a viable alternative to both urea alone and ammonium nitrate treatments. This opens up an opportunity for the reduction of N loss in wheat production when use of urea is preferred.     

烘烤凋萎期失水速度对烟叶质量的影响

凋萎期失水速度在烟叶质量的形成过程中具有重要作用,是影响烟叶质量的关键指标。为了优化烘烤工艺,寻找最佳的凋萎期失水速度,以秦烟96为试验材料,2014~2015年在甘肃陇南地区应用变频技术通过风量调节研究了烘烤凋萎期7组失水速度对烟叶质量的影响。试验结果表明,凋萎期失水速度控制在5~7 g∕(kg·h)之间,不但可以让未变黄的烟叶继续变黄,消除青烟,让已变黄的烟叶适度失水,同时降低了变黄后烟叶的水分含量,为烟叶定色创造了条件,有利于防止棕色化反应的发生。     

基于模糊PID控制的六安瓜片远红外烘焙机设计

根据六安瓜片烘焙工艺的要求,设计了用于拉火工序的远红外烘焙机。茶叶采用不锈钢输送带输送,整机采用3层结构,每层输送带由独立的变频电机驱动,输送带上方布置有陶瓷红外线辐射器,通过红外线温度传感器采集叶温,并研制了基于模糊控制的PID温度控制器来控制温度。试验表明:远红外烘焙机碎茶率为5%(人工烘焙碎茶率为15%),叶温为80°C,人工审评结果认为其成茶品质优于炭火烘焙。     

绿春县草果烘烤房利用状况分析及对策

绿春县于2006年先后建盖了20个砖混结构的节能草果烘烤房,但目前这些烘烤房的使用率极低,其主要原因是烘烤房分布偏远,种植户无力购买煤炭等.烘烤草果会导致对森林资源的消耗逐年加大,对生物多样性产生负面影响,使生态环境遭到破坏.藉此,提出对到"节能草果烘烤房"烘烤草果的农户给予一定的扶持,对烘烤房指定专人管理,对农户自建的草果烘烤房进行拆除等对策.     

我国焙烤食品机械的现状与发展

论述了我国焙烤食品机械、包装机械存在的问题,以及行业发展所面临的形势和任务,并提出了今后发展的对策。     

Use of the SDS-sedimentation test and SDS-polyacrylamidegel electrophoresis for screening breeder's samples of wheat for bread-making quality

Summary Gelprotein or SDS-insoluble gel-forming glutenin was isolated from wheat flour by extraction with an aqueous 1.5% SDS solution. Remarkable intervarietal differences were observed both in amount and subunit composition of these proteins.The amount of gelprotein and the SDS-sedimentation volume both proved to be good parameters for the bread-making quality of wheat cultivars. A high correlation was observed between amount of gelprotein and SDS-sedimentation volume. The amount of gelprotein was therefore tentatively assumed to be the essential basis of the SDS-sedimentation test.The subunit composition of the gelprotein was studied by SDS-PAGE after reduction of SS bonds by mercaptoethanol. It was found that the average bread-making quality of wheat cultivars and progeny of the cross Atlas 66 x Atys which possessed subunits 3 and 10, coded for by chromosome 1D, was significantly higher than that of wheat samples possessing subunit 2 and 11, their allelic counterparts.     

常规储藏过程中小麦烘焙品质变化机理的研究

研究了在室温常规储藏过程中小麦烘焙品质的变化和蛋白质各部分质和量的变化。结果表明，经过储藏小麦的烘焙品质有所改善，且在达到工艺后熟时最佳，随后有所下降。在储藏过程中，小麦蛋白质各部分的质和量均发生了变化，并与烘焙品质的变化具有一定的相关性。由此可以推测，小麦烘焙品质的变化可能是由于小麦蛋白质的质和量布的变化引起的。