甜菜(Beta Vulgaris L·)不同类型品种蔗糖代谢酶活性的变化及其与糖分含量关系的初步研究

本实验研究了四个不同类型品种的甜菜在生育前期叶片和叶柄中的蔗糖合成酶和蔗糖磷酸合成酶酶活性的变化特点及其与蔗糖含量的关系,并探讨了对生长发育和块根含糖率的影响。叶柄中蔗糖合成酶活性在不同类型品种间存在着差异。表现为丰产型品种大于高糖型品种,通过成对样本差异显著性测定达到了极显著程度(3.39867≤T≤5.06725P_(0.01)=3.25)。另外,14—18叶期叶柄中的蔗糖合成酶活性与收获期块根含糖率呈极显著负相关γ=—0.4847(α=0.005)。据此,甜菜生育前期叶柄中的蔗糖合成酶活性可作为选育或鉴定高糖型品种的参考指标。根据叶柄中蔗糖磷酸合成酶活性大于叶片,且蔗糖含量也是叶柄显著高于叶片的事实,甜菜叶柄中存在着蔗糖合成的过程。     

Effect of Vacuum Impregnation-Dehydration on the Mechanical Properties of Apples

The effect of sucrose solution concentration and vacuum/atmospheric pressure periods on the mechanical properties of apples (Gala var.) was studied through a stress relaxation test. The empiric model proposed by Peleg was used to fit the curves and the parameters a (level of relaxation) and b (relaxation rate) were evaluated. The experimental results obtained in this study showed that vacuum impregnation conditions had a great influence on the final mechanical properties of the apples. The Peleg model fitted well the data from the stress relaxation curves and may be useful for assessing sample deformation resulting from the vacuum impregnation process.     

环境友好制药行业通用润滑油的研发与应用

针对制药机械行业通用机械设备的要求,采用具有环境友好型蔗糖多酯作为基础油。通过运用模糊层次分析方法（FAHP）对添加剂配方的优选,复配选择适合的复合添加剂。研制油可满足制药行业机械设备在特定工况条件下的使用要求。     

Time-dependent flow properties of starch–milk–sugar pastes

The time-dependent flow properties of starch–milk–sugar (SMS) pastes have been studied. The flow properties were assessed from the measurement of the shear stress versus time of shearing at constant shear rate. Corn and wheat starches were used in this study, while the sugars were glucose, sucrose, and fructose. The Weltman model was used to evaluate the flow properties of SMS pastes prepared under different conditions. SMS pastes heated at 95 and 85 °C exhibited a thixotropic behavior, while pastes heated at 75 °C behaved like a rheopectic fluid. It was noted that the thixotropy occurred at high shear stress (above 50 Pa), and the rheopexy occurred at low shear stress (below 45 Pa). The degree of thixotropy, as assessed by the Weltman model parameters, increased significantly with starch concentration, and with less pronounced effect with sugar concentration. The effect of sugar type on the degree of thixotropy of SMS pastes heated at 95 °C decreased in the following order: fructose>sucrose>glucose. The type of starch played a role in the time-dependent flow properties of the SMS paste, with a general conclusion that wheat starch had a greater degree of thixotropy than corn starch.     

Fast simultaneous analysis of caffeine, trigonelline, nicotinic acid and sucrose in coffee by liquid chromatography–mass spectrometry

A rapid liquid chromatography–mass spectrometry method for the simultaneous quantification of caffeine, trigonelline, nicotinic acid and sucrose in coffee was developed and validated. The method involved extraction with hot water, clarification with basic lead acetate and membrane filtration, followed by chromatographic separation using a Spherisorb^® S5 ODS2, 5 μm chromatographic column and gradient elution with 0.3% aqueous formic acid/methanol at a flow rate of 0.2 mL/min. The electrospray ionization source was operated in the negative mode to generate sucrose ions and in the positive mode to generate caffeine, trigonelline and nicotinic acid ions. Ionization suppression of all analytes was found due to matrix effect. Calibrations curves prepared in green and roasted coffee extracts were linear with r² > 0.999. Roasted coffee was spiked and recoveries ranged from 93.0% to 105.1% for caffeine, from 85.2% to 116.2% for trigonelline, from 89.6% to 113.5% for nicotinic acid and from 94.1% to 109.7% for sucrose. Good repeatibilities (RSD < 5%) were found for all analytes in the matrix. The limit of detection (LOD), calculated on the basis of signal-to-noise ratios of 3:1, was 11.9, 36.4, 18.5 and 5.0 ng/mL for caffeine, trigonelline, nicotinic acid and sucrose, respectively. Analysis of 11 coffee samples (regular or decaffeinated green, ground roasted and instant) gave results in agreement with the literature. The method showed to be suitable for different types of coffee available in the market thus appearing as a fast and reliable alternative method to be used for routine coffee analysis.     

蔗糖还原浸出锰阳极泥中锰的研究

采用蔗糖还原浸出阳极泥中的锰,通过正交实验和单因素实验,探讨了搅拌速率、液固比、反应温度、反应时间、硫酸浓度、蔗糖浓度等因素对阳极泥锰浸出率的影响,正交实验表明,各因素影响锰浸出率的大小顺序为:硫酸浓度蔗糖浓度浸出温度浸出时间。较优的工艺条件为:硫酸浓度3.5 mol/L,蔗糖浓度70 g/L,液固比为4∶1,搅拌速率100 r/min,反应温度70℃,反应时间40 min,锰浸出率达到98%。     

Succinylation of Non-ionic Surfactants: Physicochemical Characterization,Functional Properties,Biodegradability and Mathematical Modeling of the Polarity Tuning

Anionic surfactants comprising succinic acid end groups were synthesized by succinylation of non-ionic surfactants using succinic anhydride as a potentially bio-sourced building block. A solvent- and catalyst-free synthesis was designed for succinic anhydride mono esterification with octyl-, decyl and dodecylpolyxylosides, di- and tetraethylene glycol dodecylethers and glycerol monolaurate. The physicochemical and functional properties of anionic surfactants thus obtained were studied and compared with their non-succinylated counterparts. A correlation between these properties and the polarity changes induced by the addition of the hydrophilic succinic acid moiety was established. The biodegradability of the succinylated surfactants has also been investigated. Finally, through a desirability function approach, mathematic predictions were correlated to the properties in order to find an optimum and to discriminate surfactants with respect to targeted physicochemical properties and resulting applications.     

Effects of Particle Size of Sucrose Suspensions and Pre-incubation of Enzymes on Lipase-Catalyzed Synthesis of Sucrose Oleic Acid Esters

The effects of high-speed homogenization, high-intensity ultrasound, and their combination were evaluated for the reduction of the particle size of sucrose crystals to enhance solvent-free lipase-catalyzed synthesis of sucrose oleate at 65 °C. The combination of homogenization and ultrasound greatly decreased the particle size of suspended sucrose crystals in mixtures of oleic acid/sucrose oleate (86 wt% monoester and 14 wt% diester at a ratio of 90/10 w/w) from 88 to 18 μm. The suspension-based medium was charged to a stirred tank bioreactor that also contained immobilized lipase from Rhizomucor miehei or Candida antarctica (Lipozyme^®IM and Novozym^® 435, respectively; Novozymes, Franklinton, NC, USA), that was pre-incubated in oleic acid for several different temperatures (23–60 °C), durations (4–24 h), and stir rates (50–400 rpm, radius of 3 cm), prior to use. The optimal performance was achieved using C. antarctica lipase (83.3 wt% ester, consisting of 46 wt% monoester) in the presence of molecular sieves (18 wt%). The low water concentration (~0.12 wt%) did not affect the activity of C. antarctica lipase.     

Effects of Sucrose Esters on Isothermal Crystallization of Palm Oil‐based Blend

The effects of sucrose esters (SEs) with different acyl chain lengths, namely, lauryl (L‐195), palmitoyl (P‐170), stearoyl (S‐170), oleoyl (O‐170), and erucyl (ER‐190), on isothermal crystallization of a palm oil‐based blend (PO–PS) were studied. From this study, it was found that both α‐ and β′‐crystals coexisted following crystallization of PO–PS from melt to room temperature. Addition of SEs P‐170 and S‐170, which had saturated acyl chains similar to PO–PS, resulted in an accelerating crystallization rate, promoting the appearance of α‐crystals and transition to β′‐crystals and increasing viscosity of PO–PS blend. SE O‐170, which is liquid at room temperature, had little effect on blend crystallization. SEs L‐195 and ER‐190, with an acyl chain dissimilar to PO–PS, inhibited triacylglycerol bonding or further integration to the surface of crystals and reduced the crystallization rate and viscosity of the PO–PS blend. The PO–PS blend with SE L‐195 and ER‐190 contained large crystals and resulted in slower formation of α‐crystals and transformation to β′‐crystals. Results from this study indicate that crystallization of PO–PS was greatly influenced by acyl–acyl interactions between acyl chains of SEs and triacylglycerols.