Compositional analysis and rheological characterization of gum tragacanth exudates from six species of Iranian Astragalus

The sugar composition and viscoelastic behaviour of Iranian gum tragacanth exuded by six species of Astragalus was investigated at a concentration of 1.3% and varying ionic strength using a controlled shear-rate rheometer. Compositional analysis of the six species of gum tragacanth by high-performance anion-exchange chromatography with pulsed amperometric detection suggested the occurrence of arabinose, xylose, glucose, galactose, fucose, rhamnose and galacturonic acid residues in the gum structure; however, the proportions of each sugar varied significantly among the gums from the different species of Astragalus, and this variation led to interesting differences in functional properties. Rheological measurements performed on dispersions of the six species of gum tragacanth demonstrated viscoelastic properties. The mechanical spectra derived from strain sweep and frequency sweep measurements indicated that the different gum tragacanth dispersions had distinctive viscoelastic behaviours. Investigation of the viscoelastic properties of the different gum dispersions in the presence of NaCl revealed that the addition of NaCl could lead to slight to drastic decreases in the G′, G″ or η^∗ values of the various gums. In general, the results indicated that the six varieties of gum tragacanth studied exhibited significantly different rheological properties; therefore, these different gums may find use in a variety of applications as stabilisers, thickeners, emulsifiers and suspending agents depending on their rheological behaviour.     

崇左蔗区螟虫为害造成产量和糖分损失及生防效果

目的：为探明广西主要蔗区由于长期连作造成原料蔗生产受螟害损失程度、构成和规律,为有效防控甘蔗螟害,达到高产优质和可持续发展的目的,形成环境友好型生产模式提供科学的决策依据。研究方法：在广西南宁东亚糖业集团所属的5个糖厂蔗区,田间取样调查新植和宿根蔗1008个样本,78600个甘蔗植株二点螟、条螟的株害率、节害率、断尾率...     

莲藕复合果蔬汁配比优化方法探讨

运用Mixture D-optimal设计,以感官评价为响应值,研究了以莲藕、梨、冬瓜和苹果4种原汁的不同配比对复合果蔬汁风味等感官品质的影响,确定了莲藕复合果蔬汁最优配方为:莲藕原汁49%、梨原汁21%、冬瓜原汁10%和苹果原汁20%,成品的糖酸比为20.34。     

钼酸铵分光光度法检测汽凝水微蔗糖含量

利用分光光度法测定糖厂汽凝水中的蔗糖含量。结果表明：在一定条件下,蔗糖在加入盐酸经过加热会转化成葡萄糖与果糖,可被钼酸铵与盐酸所生成的钼酸还原成钼蓝,其颜色深度与蔗糖浓度成正比。蔗糖含量在0～800μg/mL范围内遵守郎伯比尔定律,检测限为0.8μg/L,精密度（RSD）小于3.6%,样品加标回收率在99.99%～100%之间,结果符合要求。     

Pectin methylesterase catalyzed firming effects on low temperature blanched vegetables

The effect of low temperature blanching on firmness of eight vegetables was studied. Preheating vegetables at low temperatures prior to a conventional blanch resulted in firmer products. Temperature and time had significant effects on texture, with temperature the most influential. Under optimal conditions, firmness improvements in preheated vegetables as compared to blanched controls were: Bok choy—3.0 × (65 °C, 45 min); Chinese cabbage—1.8 × (55 °C, 45 min); cabbage—1.6 × (65 °C, 15 min); green bell peppers—1.36 × (70 °C, 15 min); sugar snap peas—1.7 × (65 °C, 30 min); carrots—2.1 × (60 °C, 15 min) and broccoli—2.9 × (60 °C, 15 min). Thermal stability and optimal temperature for pectin methylesterase in homogenates from these vegetables were also analyzed. The relationship between optimum preheating conditions for textural integrity and pectin methylesterase activity is discussed.     

A high-power carbohydrate fuel cell

This paper reports the development of a fuel cell consisting of a vanadium flow battery in which the vanadium ions are reduced by sugar (from a carbohydrate) to oxidation state +3 on one side of a membrane, and are oxidized to state +5 on the other side by oxygen. The theoretical upper limit to the conversion efficiency of the energy in sugar by this method under standard conditions is 54%. We have obtained efficiencies up to 45% in our laboratory tests. This way of using biomass for electricity production avoids the Carnot cycle losses in heat engines.     

Energy use and economical analysis of sugar beet production in Tokat province of Turkey

The purposes of this study were to determine energy consumption of input and output used in sugar beet production, and to make a cost analysis in Tokat, Turkey. Data were collected from 146 sugar beet farms in Tokat, Turkey by using a face-to-face questionnaire performed in January and February 2005. Farms were selected based on random sampling method. The results revealed that total energy consumption in sugar beet production was 39 685.51 MJ ha⁻¹, and accounted for 49.33% of fertilizer energy, and 24.16% of diesel energy. The output/input energy ratio was 25.75 and energy productivity was 1.53 kg MJ ha⁻¹. Results further indicated that 82.43% of total energy input was in non-renewable energy form, and only 12.82% was in renewable form. Economic analyses showed that profit–cost ratio of farms was 1.17. The highest energy cost items were labor, land renting, depreciation and fertilizers. Although intensive energy consumption in sugar beet production increased the yield, it also resulted in problems such as global warming, land degradation, nutrient loading and pesticide pollution. Therefore, there is a need to pursue a new policy to force producers to undertake energy-efficient practices to establish sustainable production systems without disrupting the natural resources. In addition, extension activities are needed to improve the efficiency of energy consumption and to sustain the natural resources.     

福建省甘蔗新品种区域试验研究

通过2001～2002年2年(2新1宿)6个地点的区域试验，参试的甘蔗新品种中闽糖86—2121。粤农91—854表现出高产。稳产、适应性较广的特点，蔗茎产量比闽糖70—611增少达极显著水平，与闽糖86—05增少(或减少)不显著，含糖量比闽糖70—611增少21．82％和12．86％，比闽糖86—05增少0．41％和减少6．98％，适宜于福建蔗区示范推广。闽糖93—246蔗茎产量比闽糖70—611增少不显著，比闽糖86—05减少达显著水平，适应性一般，宿根性较差，含糖量比闽糖70—611增少9．86％，比闽糖86—05减少9．46％，可保留区试。粤C25、福农93—3608蔗茎产量比闽糖70—611减少达不显著和显著水平，比闽糖86—05减少达极显著水平、适应性广，稳产性一般，含糖量比2个对照种都有不同程度的减少，不适宜在福建蔗区示范推广。     

制糖生产环保工作和用水闭合循环的可能性

本文阐述了糖厂开展环保工作的必要性。提出：采用清洁工艺生产，减少排污量，制糖生产用水采用闭合循环的用水，改善企业环境质量，是糖厂生产的必由之路。