Hot air expansion of potato starch pellets with different water contents and salt concentrations

The expansion and puffing kinetics of commercial potato starch pellets were examined using a hot air fan oven in order to determine the puffing kinetics. The time for the onset of expansion showed uni-molecular type kinetic behaviour and was modelled by an Arrhenius plot. A pseudo-activation enthalpy for pellet expansion was also determined. The initial moisture content of the commercial pellets was controlled and the changes in the extent of puffing and the pseudo-activation enthalpy were found. The effect of type and quantity of cation in the formulation was then investigated. Expansion occurred even when no cation was added although the presence of cation did improve pellet expansion. The ratio of the native and pre-gelatinized starch in the pellets was also varied and showed to have limited effect on the extent of expansion. The puffing mechanism is discussed in light of these observations.     

硫酸钙氨法制取硫酸钾新工艺的实验研究

利用K2 +2 ,Ca2 +/ /SO2 -4 ,Cl2 -2 ,NH3—H2 O混合体系相图作为工艺指导 ,进行硫酸钙制取硫酸钾工艺的相图研究和分析 ,确定实验优选因素及水平并进行正交实验 ,根据实验结果进行极差分析 ,得出新的结论。合适的工艺条件为 :氨浓度为 40 % ,配料比n( 2KCl) :n(CaSO4 ·2H2 O)为 1:1,反应温度为 5℃ ,反应时间为 1h。     

云南省耿马县蔗区土壤主要养分状况分析研究及对策

对云南省耿马县蔗区耕作层土壤养分的测定表明，该县土壤的有机质含量为中等，氮素营养中上，钾素供给中下，磷素供给中下。各村片差别较大，部分土壤养分严重缺乏，土壤明显酸化。土壤主要养分的供给总体上处于中下水平。根据该蔗区土壤养分状况提出相应对策。     

我国冬油菜区土壤肥力变化及施肥效果演变

本文分析了1961—1965年、1981—1985年及2004—2006年3个时期我国冬油菜种植区的土壤肥力状况,氮、磷、钾及硼肥的施用效果,氮、磷、钾肥的农学效率及肥料贡献率。结果表明,与20世纪60年代相比,近期油菜主产区耕地土壤有机质、全氮、碱解氮、速效磷及有效硼含量大幅度上升;土壤有机质、速效磷及有效硼含量较20世纪80年代也略有增加。但由于土壤养分临界值水平的提高,近期土壤有效氮、磷、钾、硼的缺乏范围存在扩大趋势。田间肥效试验结果表明,以增产量为标准,近期施用氮、磷、钾、硼油菜籽增产高于其它两个时期。施肥在油菜籽产量中的贡献率从1961—1965年间的23．8％和1981—1985年间的54．5％增长到2004—2006年间的55．1％。总体上,我国冬油菜种植区土壤养分肥力稳中有升,但速效养分相对缺乏面积扩大;施肥对油菜籽单产的贡献率增大,油菜丰产必须建立在科学施肥的基础上。     

氮磷钾肥施用对甘蓝型春油菜产量及肥料利用效率的影响

利用大田试验研究氮、磷、钾肥对青海省互助县种植的甘蓝型春油菜产量、养分吸收量和肥料利用效率等指标的影响。结果表明,氮肥和磷肥对春油菜（甘蓝型杂交油菜青杂2号）籽粒产量的提高有显著作用,钾肥的影响相对较小;与不施肥对照相比,氮、磷、钾肥的施用可显著促进成熟期春油菜地上部N、P、K素累积量（P〈0.05）;不同肥料的春油菜农学利用率分别为5.3kg/kg N、5.6kg/kg P2O5和1.7kg/kg K2O;肥料表观利用率分别为N 33.6%、P2O57.8%和K2O 52.0%,N、P、K肥对油菜籽产量的偏生产力分别为28.0kg/kg N、46.7kg/kg P2O5和26kg/kg K2O。青海省互助县种植条件下,当春油菜产量水平在3 504kg/hm2时,NPK配施条件下每生产100kg籽粒需要吸收N、P2O5、K2O量分别为4.6kg、2.0kg和5.6kg,氮磷钾比为1∶0.43∶1.21。油菜生产实践中实现高产目标需同时关注地力培肥和平衡施肥两方面。     

Encapsulated sodium supplementation of 4 weeks does not alter salt taste preferences in a controlled low sodium and low potassium diet

Preference for saltiness is learned by oral exposure to salt taste; however, some data suggest a role for bodily sodium and potassium levels on salt taste preferences as well. The objective was to investigate whether encapsulated sodium and potassium supplementation lead to altered salt taste responses among adults with high blood pressure on a low sodium and low potassium diet. Twenty-six participants with untreated upper-range prehypertension or stage 1 hypertension were on a fully controlled low sodium and low potassium diet (both targeted at 2 g/day) for 13 weeks. Participants received capsules with sodium (3 g/d), potassium (3 g/d), or placebo, for 4 weeks each, in randomized order in a double blind crossover design. Sensory evaluation was done before and after each supplementation period and involved ratings of pleasantness and intensity in different salt (NaCl) concentrations in food and water, desire-to-eat salty food, and detection threshold for NaCl. Neither sodium supplementation nor potassium supplementation led to alterations in salt taste responses in food and water, and did not affect detection threshold (P = 0.59). There was no clear role for sodium or potassium supplementation on desire-to-eat salty food. In addition, we did not find effects of reduced oral exposure to salt over weeks, through the sodium-reduced diet, on salt taste preferences, in contrast to earlier studies. In conclusion, the results of this study suggest preference for saltiness is independent of changes in bodily sodium or potassium levels.     

Influence of sodium replacement on the salting kinetics of pork loin

The partial replacement of sodium chloride by other salts has been proposed as a possible strategy to reduce the sodium content of cured meat products. Nevertheless, there is very little knowledge as regards the influence of salts other than sodium chloride on salting kinetics.The aim of this study was to evaluate the effect brought about by substituting sodium chloride with potassium, calcium and magnesium chloride on the salting kinetics of dry cured loins. The results showed very important changes in the salting pattern depending on the type of salts. Partial substitution of sodium affected both water and ion transport during the salting process. The presence of KCl decreased water loss while CaCl₂ and MgCl₂ had the opposite effect. However, replacement of up to 50% NaCl by KCl had no significant effect on the salting kinetics in the case of the control formulation. Calcium and magnesium cations penetrated with difficulty into the muscle remaining in the brine formed during the pile salting process. Moreover, the presence of calcium and magnesium cations considerably reduced the sodium and potassium content of the salted loin.     

热活化过硫酸盐降解典型选矿药剂苯甲羟肟酸的研究

采用热活化过硫酸钾(PS)降解典型选矿药剂苯甲羟肟酸(BHA),考察不同温度、PS浓度、BHA浓度、pH及阴阳离子等条件对BHA降解效果的影响,分析降解产物及体系活性物种以明确体系降解机理,并通过绿豆芽发芽试验验证降解体系毒性变化。实验结果表明：PS浓度越高,温度越高降解效果越好,在70°C及1.5 mmol/L PS的条件下,反应120 min后,20 mg/L BHA的降解率达91.34%;强酸性和强碱性条件均能促进BHA的降解;HCO3-^、SiO32-^和Cu2+^促进了BHA的去除;降解过程以SO4.-^氧化为主.热活化PS降解BHA的主要中间产物为苯甲酸和羟胺,且Cu²⁺的存在促进了羟胺到气态氮的转化。绿豆发芽试验证明经降解后的反应体系毒性较原始溶液明显下降。     

3,5-二硝氨基-1,2,4-三唑钾盐的晶体结构

用Ｘ线单晶衍射方法测定题称化合物晶体结构。它属单斜晶系,Ｐａ空间群,晶胞参数为：ａ＝６．５９７（２）Ａ,ｂ＝５．１６７（２）Ａ,ｃ＝１０．４２７（５）Ａ,β＝９５．２３０,晶胞中分子数Ｚ＝２,吸收因子为７．４９１,最终偏离因子Ｒ＝０．０３９。