柠檬酸甘油脂的合成

以柠檬酸、乙酸酐、脂肪酸单甘酯为原料，合成了各项质量指标符合ＦＡＯ／ＷＨＯ标准，ＥＷＧ和ＦＣＣ－Ⅲ标准的柠檬酸甘油酯（ＣＭＧ），确定了合成的最佳工艺路线，并以此为原料配制了两种复合型抗氧剂，抗氧效果优。     

液体复合抗氧剂的研制

本文以柠檬酸、乙酸酐、脂肪酸单甘酯为原料，合成了各项质量指标均符合ＦＡＯ／ＷＨＯ标准的柠檬酸脂肪酸甘油酯确定了合成的最佳工艺路线，并以此为原料配制了两种在常温下呈液态的复合型抗氧化剂。试验结果证明其抗氧化效果超过了国外同类产品，在油脂及含油食品中具有广泛的应用价值。     

果酸钙合成条件的研究

用正交实验确定了合成果酸钙的投料摩尔比为碳酸钙：柠檬酸：苹果酸=8：2：5。反应温度为50℃，投料顺序为将碳酸钙粉加入到柠檬酸与苹果酸的混合溶液中，加水量为反应原料质量总和的2倍，用该方法合成的果酸钙，钙含量适中，溶解度较高。     

单烷基（醚）柠檬酸酯二钠盐的合成

介绍了由月桂醇（硬脂醇，月桂醇聚氧乙烯醚（ＥＯ＝２．７）），柠檬酸，氢氧化钠合成单烷基（醚）柠檬酸酯二钠盐的方法。讨论了催化剂、温度、时间等因素对酯化反应的影响，并测定了有关产品的物性。     

乙二醇在柠檬酸抗皱整理中的应用

以柠檬酸和乙二醇为原料制备无甲醛抗皱整理剂，研究不同摩尔比不同反应时间对整理效果的影响。根据整理后的棉织物的各项物理机械性能来探讨乙二醇与柠檬酸酯的合成反应规律，确定最佳应用工艺。     

解脂耶罗维亚酵母菌利用地沟油联产柠檬酸和胞内油脂

以地沟油为原料,以解脂耶罗维亚酵母菌(Yarrowia lipolytica)为发酵菌株,进行柠檬酸和胞内油脂的同时发酵。结果发现,发酵过程中柠檬酸和胞内油脂同时保持较高产量的最佳发酵条件为:接种量为5×108个细胞/L培养基,碳源质量浓度为80.0 g/L,摇床培养转速为180 r/min。在该条件下,柠檬酸和胞内油脂的产量分别达到33.6 g/L和44.9 g/100 g(细胞干重)。进一步研究发现,Y.lipolytica以地沟油为原料合成柠檬酸和胞内油脂的发酵过程包括3个阶段:细胞生长阶段、油脂合成阶段和柠檬酸合成阶段。地沟油转化为胞内油脂后,其脂肪酸饱和程度降低。     

马铃薯磷酸化酶催化制备柠檬酸磷酸酯及条件优化

目的 柠檬酸磷酸酯(Phosphate citrate,PC)是存在于哺乳动物线粒体中的一种天然活性物质。研究发现柠檬酸磷酸酯可以抑制含钙晶体的形成,防止钙晶体在骨组织中的沉淀,能够作为一种潜在治疗骨关节炎和结石等疾病的药物。方法 鉴于现有柠檬酸磷酸酯合成路线复杂、成本高,不易大规模生产等问题,本文以柠檬酸为原料,三聚磷酸钠作为磷酰化试剂,利用植物马铃薯中天然存在的磷酸化酶为催化剂,催化合成了柠檬酸磷酸酯,采用单因素和响应面实验法探究了柠檬酸与三聚磷酸钠物料比、反应温度和反应时间对产物含量的影响,通过傅里叶红外光谱分析和电导率测定其结构。结果 柠檬酸与三聚磷酸钠物料比为1:3.8,反应温度为29℃,反应时间为19.5 h,产物含量可达50.57%。结论 本合成方法简单易行,成本低,产物含量高,为柠檬酸磷酸酯的合成提供了新的方法。     

ＮＡＳＩＣＯＮ固体电解质材料的溶胶－凝胶合成与ＣＯ２敏感器件研究

以常规试剂为原料，采用溶胶－凝胶法合成了ＮＡＳＩＣＯＮ固体电解质材料，并以该合成材料为基础，制备了小型固体电解质型ＣＯ２传感器，测试表明，所制备的器件对ＣＯ２气体表现出良好的线性敏感特性、快速的响应恢复和较强的抗干扰能力。     

营养强化剂柠檬酸钴螯合物的微波辅助合成

钴是人和动物体内一种必需的微量矿物元素,是维生素B_(12)组成成分,具有重要的生理、生化功能。以柠檬酸和乙酸钴为原料通过微波固相反应以及柠檬酸和碳酸钴为原料通过固液反应两种方法合成了柠檬酸钴螯合物,用EDTA配位滴定、元素分析、红外光谱、X射线粉末衍射和热分析等对螯合物的组成和结构进行了表征。实验结果表明,两种方法得到的柠檬酸钴螯合物的组成为Co(H_2cit)·5H_2O,XRD分析表明所合成的螯合物为单一物相,红外光谱证实中心钴离子与柠檬酸中脱质子的羧基及羟基O原子和配位水分子中的O原子配位,螯合物有良好的热稳定性,热分解残余物为氧化钴。     

琥珀酸单酯的合成与应用

以琥珀酸酐，分子蒸馏单甘酯为原料，合成了各项质量指标均符合ＦＡＯ／ＷＨＯ标准的琥珀酸单甘酯。确定了合成该产品的最佳工艺条件，并进行了验证实验。同时对该产品的应用做了较全面的论述。     

The Effects of Citric Acid on the Properties of Thermoplastic Starch Plasticized by Glycerol

The effects of citric acid on the properties of glycerol‐plasticized thermoplastic starch (GPTPS) were studied. In the presence of citric acid and glycerol, native cornstarch granules are transferred to a continuous phase as shown by scanning electron microscopy (SEM). As shown by thermogravimetric analysis (TGA), the improvement in thermal stability confirms that the adhesion between citric acid, glycerol, water and starch in TPS was enhanced with the addition of citric acid. It was proven by Fourier transform infrared (FTIR) spectroscopy that citric acid can form stronger hydrogen‐bond interactions with starch than glycerol. Both FTIR spectroscopy and X‐ray diffractometry of citric acid‐modified GPTPS (CATPS) revealed that citric acid can effectively inhibit starch re‐crystallization (i.e. retrogradation), because of the strong hydrogen‐bond interaction between citric acid and starch. Rheology studies revealed that citric acid can obviously decrease the shear viscosity and improve the fluidity of TPS. Citric acid can also improve the elongation of GPTPS and ameliorate the water resistance of GPTPS at high relative humidities, but decreased the tensile stress.     

The effect of citric acid and pH on growth and metabolism of anaerobic Saccharomyces cerevisiae and Zygosaccharomyces bailii cultures

The effects of citric acid at pH values of 3.0, 4.0, and 4.5 on growth and metabolism of anaerobic Saccharomyces cerevisiae and Zygosaccharomyces bailii cultures were investigated. S. cerevisiae and Z. bailii exhibited similar tolerances to citric acid, as determined by growth measurements, at all three pH values investigated. The citric-acid-induced growth inhibition of both yeast species increased with increasing pH values, indicating that the antimicrobial mechanism of citric acid differs from that of classical weak-acid preservatives. In S. cerevisiae, citric acid shifted the primary energy metabolism towards lower ethanol production and higher glycerol production, thus resulting in lower ATP production. These metabolic changes in S. cerevisiae were pH-dependent; i.e. the higher the pH, the lower the ATP production, and they may explain why growth of S. cerevisiae is more inhibited by citric acid at higher pH values. In Z. bailii, citric acid also caused an increased glycerol production, although to a lesser extent than in S. cerevisiae, but it caused virtually no changes in ethanol and ATP production.     

降低低糖南瓜脯水分活度的研究

研究了氯化钠、柠檬酸、壳聚糖、丙二醇、丙三醇和磷酸二氢钠等添加剂对低糖南瓜脯水分活度(aw)的影响,并通过正交试验筛选出降低南瓜脯aw的添加剂组合。结果表明,降低低糖南瓜脯aw的强弱顺序依次为丙二醇>柠檬酸>氯化钠>丙三醇>壳聚糖>磷酸二氢钠,0.2%柠檬酸和1.0%丙二醇具有较强的协同降低果脯aw的作用,能将低糖南瓜脯aw降低至0.60以下。     

甘油与柠檬酸酯化交联对棉织物抗皱整理的影响

以柠檬酸和甘油为原料制备无甲醛抗皱整理剂,研究不同浓度配比和不同反应时间对整理效果的影响。根据整理后棉织物的各项物理机械性能来探讨甘油与柠檬酸酯的合成反应规律,确定最佳应用工艺。     

苎麻织物的柠檬酸/多元醇抗皱整理

针对柠檬酸整理苎麻织物易泛黄的缺点,系统研究了柠檬酸/ 多元醇联合整理技术。通过高温焙烘阶段柠檬酸与多元醇之间的酯化反应,减少乌头酸等不饱和酸副产物的产生,进而显著提高了整理后苎麻织物的白度。研究了醇的种类、柠檬酸的浓度、柠檬酸与丙三醇的比例以及焙烘工艺条件对苎麻织物抗皱整理效果的影响。结果表明：丙三醇与柠檬酸联合整理可获得良好的整理效果;当丙三醇与柠檬酸物质的量比为2：1,柠檬酸质量分数为４％,次磷酸钠质量分数为5.5%,渗透剂JFC质量浓度为1g/L,预烘温度为100℃,焙烘时间为5 min,焙烘温度为175 ℃,时间为3 min时,整理后苎麻织物的折皱回复角为194°,白度为76.83%,断裂强力为375N。     

Prediction of the Mould-Free Shelf Life of Muffins

In this article, the effect of commonly used ingredients in muffins (sugar, glycerol, potassium sorbate, acidic agent, salt), with and without ethanol surface spraying and pasteurization on the shelf life, was examined. Citric acid, sodium diacetate, and tartaric acid were used as acidic agents. The investigation was based on a statistical design of experiments. Using simple first order factorial designs, reliable models were constructed revealing the effects of the selected ingredients, and their interactions on the shelf life. The effectiveness of preservation ranked high to low as: (combination of citric acid, potassium sorbate, ethanol, and pasteurization), (combination of citric acid, potassium sorbate, and ethanol), (combination of citric acid and potassium sorbate), (combination of sodium diacetate and potassium sorbate), (combination of tartaric acid and potassium sorbate).     

卷烟中非挥发性有机酸、糖类、某些氨基酸和磷酸的同时测定

以山梨醇作内标,羟胺吡啶和BSTFA 1%TMCS为衍生化剂,采用GC法同时测定了国内外21种牌号卷烟中的木糖、阿拉伯糖、鼠李糖、果糖、甘露糖、半乳糖、葡萄糖、蔗糖、麦芽糖、天门冬氨酸、天门冬酰胺、丙二醇、丙三醇、乳酸、丙二酸、苹果酸、柠檬酸和磷酸。结果显示:①丙二醇和阿拉伯糖的RSD>10%,乳酸、天门冬酰胺、鼠李糖、半乳糖和麦芽糖的RSD>5%,其它成分的RSD<5%;②除丙二酸、半乳糖、鼠李糖、丙三醇和阿拉伯糖的回收率介于70%~75%外,其它组分的回收率>80%;③在所分析的卷烟样品中,进口混合型卷烟中柠檬酸、天门冬氨酸、天门冬酰胺、丙二醇和丙三醇含量较国产烤烟型卷烟的高,而糖类的含量则普遍较低,其它成分差别不大。     

Fresh cut ‘Tommy Atkins’ mango pre-treated with citric acid and coated with cassava (Manihot esculenta Crantz) starch or sodium alginate

This work aimed to evaluate quality parameters of ‘Tommy Atkins’ mango slices pre-treated with citric acid and cassava starch or sodium alginate edible coatings, with or without glycerol. Samples only treated with citric acid were also evaluated. Mango slices dipped in sanitising solution were used as control. Colour parameters, mechanical properties, weight loss and respiration rate were analysed during 15 days at 5 °C. Cassava starch coating, with or without glycerol, provided higher stress at failure and lightness values than control sample throughout storage (p ≤ 0.05). The citric acid promoted colour preservation, but increased significantly samples weight loss during storage. Sodium alginate coatings did not maintain quality characteristics, showing stress at failure and lightness values lower than control after 15 days. All coatings reduced respiration rate, but citric acid dipping and cassava starch coating without glycerol treatments were more effective, reaching values around 41% lower, when compared to control sample.

Industrial Relevance

Fresh-cut mangoes are appreciated world-wide for its exotic flavour and nutritional composition. However, their shelf life is limited by changes in colour, texture, appearance and microbial growth. The edible coatings act as gas and water vapour barrier, extending the storage time of fresh-cut fruit and vegetables. Thus, cassava starch and alginate are alternatives to preserve minimally processed mangoes, maintaining the quality parameters of fresh fruit. This work is useful for the minimal processing industry in order to increase shelf life of fresh-cut mangoes, which can be considered an alternative to fast food and other ready-to-eat products, attending the demand for healthy and convenient foodstuffs.     

柠檬酸甘油共混热塑性淀粉的制备及性质研究

以糯米淀粉为原料,加入甘油、柠檬酸制备热塑性淀粉。通过试验得到热塑性淀粉制备的最佳工艺条件,即反应时间60 min、反应温度120℃、柠檬酸与糯米淀粉质量比为0.4∶1、甘油与糯米淀粉质量比为0.3∶1,热塑性糯米淀粉达到最高取代度0.118。并通过红外图谱分析和差示扫描量热检测,证明柠檬酸甘油共混制备的热塑性糯米淀粉与原糯米淀粉相比透明度明显提高,黏度显著降低。处理后的淀粉发生了部分酯化反应,其热稳定性明显提高,增强了热塑性糯米淀粉的生产加工能力。