高频无极放电灯玻壳、内管烤粉工艺的研究

随着照明技术的发展,高频无极放电灯以其高效、环保、节能的特点越来越受欢迎。本文介绍了大功率高频无极放电灯玻壳内壁和内管外壁的三基色荧光粉的烤粉工艺,重点研究了烤粉过程中温度的控制过程和注意事项。

焙烤制品中化学疏松剂体系设计

介绍了化学疏松剂的作用机理，设计配方时所用研究方法，常用疏松剂的类型以及焙烤粉的概念与作用。

焙烤打粉杂粮的淀粉消化组分及餐后血糖反应

以红小豆、黑米、燕麦、山药干、芡实5种杂粮食材为样品,采用体外模拟小肠消化方法,测定焙烤后打粉,并用不同温度冲糊的处理对其中快消化淀粉、慢消化淀粉和抗性淀粉含量的影响;测定进食各样品后3 h的餐后血糖反应。研究发现,焙烤打粉冲糊处理显著降低了除山药干之外其它食材的抗性淀粉含量,提升红小豆餐后血糖反应的幅度最大;冲糊温度可以调控抗性淀粉含量,其中对山药干的影响最大。提示:通过改变食材物理状态和冲糊温度,可以有效调控餐后消化速度,以适应消化能力和血糖控制需求不同的人群。

Changes of Granule Structure and Enzyme Hydrolysability of Starch in Upper Flue-cured Tobacco Leaves During Bulk Flue-curing

[Objective] This study aimed to investigate the changes of granule struc- ture, characteristic and related enzymatic activity of starch in upper flue-cured tobac- co leaves during bulk flue-curing process, to provide theoretical basis for reasonably regulating the starch content in upper flue-cured tobacco leaves and improving the quality of upper flue-cured tobacco leaves. [Method] Changes of amylase activity, enzyme hydrolysability and granule structure of starch in upper flue-cured tobacco leaves were studied during flue-curing process using conventional physical and chemical analysis and SEM. [Result] During the flue-curing process, the starch con- tent of tobacco leaves changed greatly at yellowing stage, and the activity of amy- lase presented the double-peak curve. The SEM observation results showed that most of the starch granules in fresh tobacco leaves were spheroidal and long cylin- drical, while some individuals were in irregular shape, with obvious groove-like in- vagination and layered structure on granule surface; during the flue-curing process, a large amount of starch granules showed layered structure on the surface at yellow- ing stage, and the long cylindrical starch granules were reduced greatly; at the end of flue-curing, there were barely any long cylindrical starch granule in flue-cured to- bacco leaves. Average long-axis-diameter of starch granules in fresh tobacco leaves was 3.21 μm, showing an overall gradually increasing trend during the flue-curing process, which was significantly enhanced at 38 and 42 ℃. The diameter of starch granules increased by more than 60% at the end of 42 ℃ and there was no re- markable difference after 47 ℃. During the flue-curing process, enzyme hydrolysabil- ity of starch in flue-cured tobacco leaves first increased, reached a peak at 38 ~C, and then decreased. [Conclusion] During the bulk flue-curing, the yellowing stage is the critical period for starch content, granule structure and characteristic changes of flue-cured tobacco leaves, it is of positive effects to improve the quality of upper flue-cured tobacco leaves by regulating the flue-curing conditions at yellowing stage.

Effects of Curing Techniques on Starch Contents of Leaves in Different Tobacco Parts with Varying Maturity Degrees

[Objective] The aim was to explore effects of different curing techniques on starch contents of tobaccos from different growth parts and with varying maturity degrees in order to reduce starch content of Yunnan tobacco. [Method] Compar- isons were conducted on tobaccos from upper, middle and down parts （immature, premature, mature and excessive mature） by low temperature and low humidity cur- ing technique, moderate temperature and moderate humidity curing technique, mod- erate temperature and high humidity curing technique to measure starch contents before and after curing. [Result] The results showed starch content of tobacco was increasing upon growth part. Low temperature and low humidity curing technique has poor effects on reduction of starch content; moderate temperature and moderate humidity curing technique improves starch content; moderate temperature and high humidity curing technique dramatically reduces starch content of tobaccos. [Conclu- sion] With consideration of tobacco appearance, inner quality and characters, moder- ate temperature and moderate humidity curing technique is recommended for tobac- co production.

Effects of Exogenous Amylases and Metal Ions on the Amylase Specific Activities and Starch Degradation of the Upper Leaves of ‘KRK_(26)' during Flue-curing

Objective] The aim of this study was to investigate the effects of exoge-nous amylases and Ca2＋, Mn2＋ and K＋ on the amylase specific activities and starch degradation of the upper leaves of ＇KRK26＇ planted in Yunnan Province during flue-curing. [Method] The amylase specific activities and starch degradation of the leaves were determined by using spectrophotometry. [Result] The 8 U/g exogenous α-amy-lase could improve the specific activity of the leaf α-amylase at yel owing and color-fixing stages, but could not at stem-drying stage, and similarly, the 80 U/g exoge-nous β-amylase could improved the specific activity of the leaf β-amylase at the yel owing stage and the early period of color-fixing stage. The leaf starch could be enhanced to degrade by the exogenous α- or β-amylases and the enhancing effect of the former was stronger than that of the later. 1.50 mg/ml Ca2＋ improved the specific activity of the leaf （α＋β）-amylase mainly due to its enhancing effect on the leaf α-amylase, and increased the starch degradation. 4 mmol/L Mn2＋ inhibited the leaf α-amylase from yel owing to the early period of color-fixing and the β- and （α＋β）-amylases from the yel owing to the later period of color-fixing, but enhanced the leafα-amylase from the later period of color-fixing to the later period of stem-drying and the β- and （α＋β）-amylases at the later period of stem-drying. Meanwhile, Mn2＋ ham-pered the starch degradation during yel owing, but promoted it from the early period of color-fixing to stem-drying. 1 mg/ml K＋ enhanced the leaf α-, β- and （α＋β）-amy-lases during the yel owing stage, but lowered them from the early period of color-fix-ing to the later period of stem-drying, and always inhibited the leaf starch degrada-tion. [Conclusion] The exogenous α-, β- amylases and Ca2＋ of suitable concentra-tions could be used to treat the tobacco leaves before flue-curing to improve the leaf starch degradation during the curing.

Effect of Water Control before Transplanting and Rooting Powder Treatment on Tobacco Seedling Quality and Physiological Properties at Green Stage

Cultivating strong seedlings is an important guarantee for the production of high-quality flue-cured tobacco, while there are many disadvantages in tobacco floating system that is commonly adopted in China. To improve the tobacco floating system, with Xiangyan No.3 as experimental material, the effects of water control before transplanting and rooting powder treatment on tobacco seedling quality and physiological properties at green stage were investigated. The results showed that： （1） water control showed small influence on tobacco seedling quality, while rooting powder treatment and water control ＋ rooting powder treatment showed great influence on tobacco seedling quality, mainly represented by reduced plant height, thickened stem and increased dry matter accumulative amount; （2） water control before transplanting and rooting powder treatment all improved leaf chlorophyll content and root vigor of tobacco seedlings, and the effect of water control ＋ rooting powder treatment was best, followed by rooting powder treatment and water control; （3） all treatments increased the nitrate reductase and invertase activity, and reduced the MDA content of tobacco seedlings, and the effect of water control ＋ rooting powder treatment was best, followed by rooting powder treatment and water control. Mean- while, the treatment effect 10 d before the transplanting was better than that 5 d before the transplanting. In overall, the improvement effects of water control 10 d before transplanting ＋ rooting powder treatment on tobacco seedling quality and physiological properties at green stage were the best.

Various Temperature of Vacuum and Conventional Roasting on Color Alteration and Polyphenols Content of Cocoa Powder

This study has the objective to found out the temperature and raosting time of cocoa powder in order to gain color, aroma and taste favored by the panelist and has high polyphenol content. The roasting time in this research has been determined 35 min, and roasting temperature of 80, 90, 100, 110, 120, 130, 140 and 150 ℃ with vacuum and conventional system. From those temperatures ranges, we would take the three best levels according to organoleptic test result. The three selected temperatures would be tested for changing in polyphenol content during roasting process. Color alteration would be physically analyzed using color reader （PCE-RGB）. However, phenol total content was analyzed using colorimetric method of Folin-Ciocalteu. Result of this study showed that color alteration percentage （RGB model analysis） during conventional roasting is higher （43%） compared with vacuum roasting system （2%） Subsequently, organoleptic test result showed that from roasting temperatures between 80 ℃ and 150 ℃, cocoa powder favored by the panelist were those that was treated in temperature 100 ℃, 110 ℃ and 120 ℃. Other results indicated that vacuum roasting implementation could increase polyphenol content. While vacuum roasting of 60.8 cm Hg in 120 ℃ with roasting time of 25 min has obtained 10.57% total phenolic, or increasing as much as 1.22%.

The Advanced Approaches to Nutritional and Breadmaking Quality of Wheat, Barley and Rye Flour

This work is focused on the characterization and rapid analytical determination of cereal flour quality with regard to nutritional and breadmaking quality. Starch, protein and non-starch polysaccharides are the main components of cereals. The content and quality of proteins and content of damaged starch is important because of the technological quality of flours. The high content of high molecular weight proteins is substantial for bread technology especially, while soluble protein fractions and non-starch polysaccharides are important for nutrition. The set of wheat, barley and rye flours and their blends were analyzed and their properties and their qualitative parameters were determined. Principal component analysis （PCA） was used on Fourier transform-infrared （FT-IR） spectra in the 1,200-800 cm1 wavenumber region and significant correlations of various nutritional and breadmaking parameters were observed. Results showed that the FT-IR spectroscopy and PCA can serve for rapid screening and classification of cereal flour quality.