Micro-sized hydrothermal carbon supporting metal oxide nanoparticles as efficient catalyst for mono-dehydration of sugar alcohol

Most known catalytic dehydration of sugar alcohols such as D-sorbitol and D-mannitol can only produce di-dehydrated forms as major product,but monodehydrated products are also useful chemicals.Moreover,both di-and mono-dehydration demand a high temperature(150℃ or higher),which deserves further attentions.To improve the mono-dehydration efficiency,a series of metal-containing hydrothermal carbonaceous materials(HTC)are prepared as catalyst in this work.Characterization reveals that the composition of preparative solution has a key influence on the morphology of HTC.In transformation of D-sorbitol,all HTC catalysts show low conversions in water regardless of temperature,but much better outputs are obtained in ethanol,especially at a higher temperature.When D-mannitol is selected as substrate,moderate to high conversions are obtained in both water and ethanol.On the other hand,high mono-dehydration selectivity is obtained for both sugar alcohols by using all catalysts.The origin of mono-dehydration selectivity and role of carbon component in catalysis are discussed in association with calculations.This study provides an efficient,mild,eco-friendly,and cost-effective system for mono-dehydration of sugar alcohols,which means a lot to development in new detergents or other fine chemicals.

Recent advances in catalytic production of sugar alcohols and their applications

Conversion of non-edible biomass into fuels and value-added chemicals has achieved great attention to cope the world's energy requirements. Lignocellulose based sugar alcohols such as sorbitol, mannitol, xylitol, and erythritol can be potentially used as emerging fuels and chemicals. These sugar alcohols can be converted into widely used products(e.g. polymer synthesis, food and pharmaceuticals industry). The heterogeneous catalytic production of sugar alcohols from renewable biomass provides a safe and sustainable approach. Hydrolysis, coupled with hydrogenation and hydrogenolysis has been proved to be more effective strategy for sugar alcohols production from biomass. This review summarizes the recent advances in biomass upgrading reactions for the production of sugar alcohols and their comprehensive applications.

Efficient Synthesis of Sugar Alcohols over a Synergistic and Sustainable Catalyst

A series of catalysts were prepared for sugar alcohols production to overcome the deficiencies of the previous reported catalysts,such as low yield of sugar alcohols,single functi on,in stability,and con troversial role of active sites.The role of each metal and their syn ergistic-cooperati on was discussed in detail with a combi nation of conditional experiments and characterizati ons.The results indicated that bifunctional Nig.ggFetAli.ss catalyst has unique structure with superparamagnetism and excellent activity.The(111)and(200)planes of metallic Ni are the hydrogenation active phases and preferentially exposed on Ni-Al-O_(x) spinel.The desired arabitol or mannitol was obtained by tuning the ratio of Bronsted and Lewis acid sites.The recycling tests indicated that the unique structure of the prepared Ni-based catalyst can suppress leaching and poisoning,which has high textural stability and activity.

Temperature-Dependent Rheological Behaviors of Binary Eutectic Mixtures of Sugar Alcohols for Latent Heat Storage:A Comparative Study with Pure Sugar Alcohols

The temperature-dependent rheological behaviors of five selected binary eutectic mixture sugar alcohols,with great potential for latent heat storage in the range of 353.15 K to 523.15 K,were investigated.It was found that the rheological behaviors of the mixture sugar alcohols depend on those of the pure compounds as well as their molar ratios.The two mixtures of xylitol(75 mol%)+erythritol and erythritol(84 mol%)+d-mannitol behave like pseudoplastic fluids with typical non-Newtonian shear-thinning behaviors,as indicated by the power law index of 0.99(<1).The mixture of d-mannitol(70 mol%)+d-dulcitol is a nonlinear Bingham fluid,exhibiting a slight yield stress(0.001 Pa to 0.01 Pa)at low shear rates.The rest two mixtures containing the cyclic-structured inositol behave like Herschel-Bulkley fluids.The infinite shear viscosities of the eutectic mixtures over the entire temperature range appear to be higher than those of their respective pure compounds,except for inositol.The mixture of xylitol(75 mol%)+erythritol at its melting point shows higher dynamic viscosity of about 0.546 Pa·s than the values of about 0.396 Pa·s and 0.035 Pa·s for xylitol and erythritol,respectively.In addition,the activation energies of viscous flow of the mixtures,as determined by fitting the dynamic viscosity-temperature curves using the Arrhenius model,also exhibit higher values than those of their pure compounds.The activation energy of viscous flow of the mixture xylitol(75 mol%)+erythritol was determined to be about 92400 J/mol in the supercooled liquid state,while the supercooled liquid xylitol and erythritol have much lower values of 83500 J/mol and 51900 J/mol,respectively.Both the increased dynamic viscosities and activation energies of viscous flow can result in deteriorated crystallization performance during latent heat retrieval.

Foliar application of chelated sugar alcohol calcium fertilizer for regulating the growth and quality of wine grapes

The eastern foothills of Helan Mountain are a production area of high-quality wine grapes,but the low content of water-soluble calcium in the alkaline soil in this area has become an important limiting factor for the production of high-end wines.In this study,7-year-old Cabernet Sauvignon grapes grown at Lilan Winery,which is located at the eastern foot of Helan Mountain in Ningxia,China,were used to examine the effect of exogenous calcium supplementation on fruit growth and berry quality.Calcium sugar alcohol was applied as a foliar spray at 1.2 L/hm^(2)(T1),2.4 L/hm^(2)(T2),3.6 L/hm^(2)(T3),4.8 L/hm^(2)(T4),and 6.0 L/hm^(2)(T5)concentrations at the fruit expansion stage,the early stage of grape veraison,the middle stage of grape veraison,and the later stage of grape veraison.Water control was used for comparison.The results showed that foliar calcium supplementation can significantly enhance the photosynthetic characteristics of wine grape leaves,increase the chlorophyll content of leaves,and improve the quality of grape berries.Under the T3(3.6 L/hm^(2))concentration of exogenous calcium,the transverse diameter,the longitudinal diameter,and fruit shape index of grapes were the highest,which were increased by 1.71%,5.33%,and 3.92%compared to the control,respectively.The application of high calcium concentrations(T4 and T5)inhibited the physiological development of grapes.The spike length,hundred-grain weight,yield of wine grapes,sugar-acid ratio,tannin,and total phenols were the highest in the T2(2.4 L/hm^(2))treatment.The results of principal component analysis based on multiple indicators showed that foliar application of 2.4-3.6 L/hm^(2)chelated sugar alcohol calcium on the leaf surfaces of grape leaves was the most suitable for improving the physiological characteristics and berry quality of wine grapes.

矩形翅片管糖醇相变储热器传热性能分析

对糖醇基矩形翅片管相变储热器传热性能进行数值模拟与实验研究,利用数值模型研究传热流体入口温度、流量以及储热器翅片间距、管间距等参数对充放热性能的影响。研究表明:从运行参数看,由于相变材料导热系数的影响,翅片强化区外流体入口温度与材料相变温度的温差对充放热速率呈正相关;在管内湍流条件下,管内流速在高于0.53 m/s时,不能显著提升储热器的充放热速率;从结构参数看,增加翅片可显著提升翅片区内充放热速率,翅片间距小于10 mm和管间距小于52.5 mm对充放热速率影响不明显。

刺糖3种糖分对小鼠免疫调节及肠道形态结构的影响

试验旨在探究刺糖3种主要糖分对小鼠的免疫调节及空肠形态的影响。通过水提醇沉法和透析法分别得到刺糖多糖(AHP)、刺糖水溶性小分子糖(AHWS)和刺糖醇溶性小分子糖(AHAS)。选取40只昆明小鼠,随机分为4组,分别为对照组(NC组)和试验组(AHAS组、AHWS组、AHP组),每组10个重复,每个重复1只小鼠。NC组灌胃生理盐水,试验组分别灌胃400 mg/(kg·d)的AHAS、AHWS、AHP,0.4 mL/只,每天1次,连续灌胃14 d。结果显示,AHAS、AHWS和AHP的总糖得率分别为42.40%、8.20%、1.90%。与NC组相比,各试验组小鼠胸腺重量均显著增加(P<0.05),AHAS组和AHP组小鼠脾脏重量、脾脏指数显著提高(P<0.05),AHAS组和AHWS组的胸腺指数均显著提高(P<0.05)。与NC组相比,各试验组的血清免疫球蛋白G(IgG)、白细胞介素-4(IL-4)、白细胞介素-17(IL-17)及肿瘤坏死因子-α(TNF-α)含量均显著增加(P<0.05);AHAS组和AHP组小鼠空肠绒毛长度、隐绒比显著升高(P<0.05),隐窝深度显著降低(P<0.05);各试验组小鼠空肠肠道上皮淋巴细胞(IELs)数量均显著提高(P<0.05)。研究表明,刺糖中的AHAS、AHWS和AHP均具有良好的安全性,可以增强机体细胞免疫和体液免疫功能,改善小鼠肠道形态。

采前喷施氯化钙和糖醇钙对‘蜂糖李’果实品质及贮藏性能的影响

为探讨采前喷钙对‘蜂糖李’品质的影响,该文以‘蜂糖李’为材料,在采前喷施质量分数为1%、1.5%、2%的氯化钙和稀释800、1200、1600倍糖醇钙溶液,并在八成熟时采收果实,将果实在温度(4±1)℃、相对湿度(90±5)%条件下进行贮藏,贮藏0 d和贮藏60 d测定‘蜂糖李’果实品质,研究采前喷施氯化钙和糖醇钙对果实品质和贮藏性能的影响。结果表明,贮藏0 d时,对于不同质量分数的氯化钙和稀释倍数的糖醇钙处理组,采前喷施1.5%氯化钙处理均能提高‘蜂糖李’果实采收时的单果重、纵横径、果形指数;贮藏60 d时,采前喷施1.5%氯化钙处理的果实失重率最低、硬度下降和多酚氧化酶活力增加的幅度最低,并保持较高的可溶性蛋白含量、可溶性固形物含量、可滴定酸含量、总酚含量及过氧化物酶活力。采前喷施1.5%氯化钙处理有利于‘蜂糖李’果实贮藏保鲜,该研究可为采后‘蜂糖李’果实贮藏保鲜提供参考。

钾肥与赤霉素互作对烟株生长发育与上部烟叶质量的影响

【目的】探明钾肥与赤霉素互作对烟株生长发育与上部烟叶质量的影响,为改善上部烟叶品质提供理论支撑。【方法】以云烟87为试材,采用随机区组试验,设置CK:常规生产操作;TK_(1):常规生产操作,成熟期喷施2 g/kg糖醇螯合钾;TK_(2):常规生产操作,基肥增施草木灰1500 kg/hm^(2),打顶期喷施20 mg/kg赤霉素;TK_(3):常规生产操作,基肥增施草木灰1500 kg/hm^(2),打顶期喷施20 mg/kg赤霉素和成熟期喷施2 g/kg糖醇螯合钾4个处理,分析不同处理对烤烟上部烟叶的田间农艺性状、生理指标、烤后烟叶的化学成分、经济性状及土壤养分含量的影响。【结果】成熟期,与CK相比,TK_(1)、TK_(2)和TK_(3)处理均提高上部6片烟叶的叶面积,增幅分别为0.79%、14.91%和20.88%;TK_(1)处理较CK降低上部叶开片度,TK_(2)和TK_(3)处理分别提高0.73%和2.35%。相较CK,TK_(1)、TK_(2)和TK_(3)处理烤后烟叶的钾含量分别显著提高6.63%、12.15%和16.02%(P<0.05),上等烟率分别增加0.70%、17.53%和54.24%,烟碱含量分别降低10.86%、16.85%和15.74%,糖碱比分别提高2.97%、21.93%和25.65%,钾氯比分别提高19.65%、15.79%和27.72%。【结论】相较于单纯提升基肥施钾量或叶面钾肥与赤霉素的互作,基肥中增施草木灰并结合打顶期喷施赤霉素与成熟期喷施糖醇螯合钾的协同措施更有利于提高上部烟叶的叶面积、开片度与钾含量,优化糖碱比和钾氯比,降低烟碱含量,且能显著提高上等烟比例,是提升烟叶品质的有效方法。

国内外糖醇类食品添加剂安全性及标准法规现状研究

减糖已经成为人们健康生活的重要追求,其中,糖醇作为一种代糖,因低能量和高甜度的特性,在食品加工中得到了广泛应用。本文通过对甘露糖醇、赤藓糖醇、麦芽糖醇/麦芽糖醇液、木糖醇、山梨糖醇/山梨糖醇液、乳糖醇六种糖醇类食品添加剂的安全性、国内外的使用规定进行比对分析,并针对性提出措施建议,旨在推动糖醇类食品添加剂的良性发展。

不同加强节点对‘宝石解百纳’利口酒品质的影响

以‘宝石解百纳’葡萄为原料进行发酵,设置残糖量为156、126、96 g·L^(-1)的3组发酵液;以‘白玉霓’白兰地为基酒,用不同糖度的发酵液配成酒度分别为22%、20%、18%(Vol)的酒样,并通过顶空固相微萃取-气相色谱-质谱联用技术,检测挥发性香气组成,调查不同加强节点对‘宝石解百纳’利口酒理化性质和感官品质的影响。结果表明,‘宝石解百纳’发酵液总糖为96 g·L^(-1)时终止发酵,与设定的理想目标节点差异较小;感官总得分以发酵液低残糖低酒度(残糖96 g·L^(-1)、酒度18%)和中残糖低酒度(残糖126 g·L^(-1)、酒度18%)组合相对较高,其中低残糖低酒度组合在香气优雅细腻度和口感结构协调性得分最高。以该组合为对象共检测出41种挥发性香气,包括C6醇2种、高级醇5种、脂肪酸乙酯13种、酸类和乙酸酯各3种、其他酯类6种、4种萜烯类;呋喃醛类2种;酚类、醛类和内酯类各1种。本研究初步探明了高品质利口酒的加强节点工艺,同时明确了‘宝石解百纳’利口酒的挥发性香气组成,为国产利口酒工艺研发提供了参考。

赤藓糖醇对表皮葡萄球菌生长和生物膜形成的影响

表皮葡萄球菌是人体皮肤的常驻优势菌,其丰度和生物学特性的改变会影响皮肤菌群和皮肤的稳态,从而引发皮肤问题甚至皮肤病。赤藓糖醇常作为保湿剂被应用于化妆品中,但关于其对皮肤菌群的影响却鲜有报道。文章以低生物膜形成菌株表皮葡萄球菌CCSM0287、产生物膜表皮葡萄球菌ATCC35984和不产膜表皮葡萄球菌ATCC12228为研究对象,研究赤藓糖醇对菌株生长和生物膜形成的影响。结果表明,赤藓糖醇浓度与3种表皮葡萄球菌的生长存在密切关联,在低浓度(0.0625%~0.125%)时,能够促进菌体生长,而高浓度时(0.5%~8%)则会抑制菌体生长,并且不同菌株对同一浓度赤藓糖醇的反应也存在一定的差异。添加2%赤藓糖醇可以明显抑制3种表皮葡萄球菌菌体的生长。采用结晶紫半定量法测得赤藓糖醇能够显著抑制生物膜表皮葡萄球菌ATCC35984生物膜的形成,并且随着赤藓糖醇浓度的增加,其对ATCC35984生物膜形成的抑制作用也会增强。由此可见,赤藓糖醇可作为调节剂调节表皮葡萄球菌菌体的生长和生物膜的形成。

近红外光谱技术快速检测露酒指标的研究

为实现露酒理化指标的快速检测,结合露酒检测的实际需要和相关检测标准的要求,运用近红外光谱技术,建立了露酒酒精度和总糖的快速检测模型。结果表明:通过筛选不同光谱预处理方法和波数范围,运用偏最小二乘法(PLS)建立模型,使用内部交叉验证得到最优模型,酒精度和总糖指标模型的相关系数(R^(2))值分别为0.9984和0.9934,预测模型线性良好,交叉验证均方根(RMSECV)分别为0.258和2.24,预测误差较小。使用盲样对露酒各指标的模型进行外部验证,酒精度和总糖的相对标准偏差分别为0.36%和2.01%,符合生产检测的需求,可运用于露酒的日常检测分析。

肉桂酸-D-甘露糖醇酯的酶法合成优化

为合成一种高效、安全及高酯化率的糖醇酯,以肉桂酸和D-甘露糖醇为底物,采用脂肪酶Novozyme 435催化合成肉桂酸-D-甘露糖醇酯。通过薄层色谱、高效液相色谱和液相色谱串联质谱对目标产物进行表征。利用响应面试验对反应条件进行优化,确定肉桂酸D-甘露糖醇酯的最佳合成工艺条件。结果表明:肉桂酸-D-甘露糖醇酯的最佳合成条件为肉桂酸与D-甘露糖醇摩尔比为1∶3、脂肪酶Novozyme 435加入量为底物质量分数的6.8%、反应溶剂为叔戊醇5 mL、分子筛加入量为0.1 g/mL、反应温度为65℃。在该条件下反应120 h,肉桂酸与D-甘露糖醇酯的酯化率为(79.45±0.25)%,其中肉桂酸D-甘露糖醇单酯与肉桂酸D-甘露糖醇双酯的产率分别为(25.94±0.18)%、(53.51±0.31)%。

Post-meiotic apozygotic combinatory process in sugar beet (<i>Beta vulgaris</i>L.)

The effect of colchicine on phenotypic classes ratio of the enzyme locus controlling alcohol dehydrogenase (ADH1) in sugar beet agamospermous progenies was analysed. The obtained data are indicative of the thing that colchicine causes polytenization of homological chromosome regions carrying marker locus Adh1 alleles. Theoretical calculation of the formation of egg cells frequencies and those of further development of cells entering embryogenesis without fertilization, also the diminution calculation of excessive chromosome regions carrying marker locus alleles have been made. The coincidence of theoretical and experimental ratios of phenotypic classes indicates the existence of post-meiotic apozygotic combinatory process in plants.

糖蜜发酵工业废液农用的环境安全风险

糖蜜是甘蔗或甜菜制糖工业的一种副产物。糖蜜发酵工业主要指制糖工业的下游工业中以糖蜜为发酵原料的酒精和酵母等发酵工业。在糖蜜发酵酒精和酵母过程中可产生大量废液(即糖蜜发酵工业废液)。出于对这类糖蜜发酵工业废液的资源化利用考虑,很多产糖国(如巴西、印度和中国等)都有将这类废液以直接土地处置方式用于农作物灌溉施肥或土壤改良。由于糖蜜发酵工业废液属于处理难度大的高浓度有机废水,还属于多种重金属污染废水,随着一些产糖国对糖蜜发酵工业废液的长期农田处置,所引发出土壤-作物-水系生态环境问题也日益暴露。目前,我国部分企业以这类废液为原料生产有机水溶肥料,其产品在水溶肥市场上占一定比重(约占32%),但对这类废液长期农用的环境安全风险研究及其监测数据尚不充足。本文收集了1980年以来国内外公开发表的关于糖蜜发酵工业废液水质污染特征及其农用的环境影响等相关科研文献,通过对相关研究数据调研和综述分析,评估糖蜜发酵工业废液农用的环境安全风险:(1)糖蜜发酵工业废液水质严重超标,且具有生态毒性特征。这类废液含高负荷有机污染物、强酸性、高盐度,并含多种重金属等污染物,除As、Hg、Cd、Pb和Cr等5种重金属外,还含有Mn、Cu、Zn、Ni和Se等,且污染物浓度大多超出《农田灌溉水质标准》(GB 5084-2021)。(2)糖蜜发酵工业废液农用存在农田污染风险。从该类废液农灌的土壤样品中检出Cu、Cd、Cr、Zn、Ni、Mn、Pb和Cl等污染物,其浓度是对照土壤的10-641倍。(3)糖蜜发酵工业废液农用存在农产品安全风险。用该类废液灌溉的作物,如小麦和芥菜籽粒中也检出Cu、Cd、Cr、Zn、Ni、Mn和Pb等污染物,其浓度是对照作物的3-12倍,均已超出FAO/WHO规定的允许限值,且大多超出我国《食品中污染物限量》(GB 2762-2017)标准。鉴于糖蜜发酵工业废液农用存在的环境安全风险,长期使用可能对人类健康产生危害。因此,有必要对以该类废液为原料的有机水溶肥料产品加强质量检测及风险管控,进而为糖蜜发酵工业废液农用提供安全保障。

麸曲酱香型白酒酿造工艺研究及微量成分分析

目的:将麸曲替代部分大曲酿造酱香型白酒,研究其酿造工艺及产品特点。方法:以感官评分值和酒醅酒精含量为评价指标,通过单因素试验研究小麦添加量、酵母添加量和麸曲添加量对麸曲酱香型白酒品质的影响,利用响应面优化试验对麸曲酱香型白酒的酿造工艺进行优化,并利用液相色谱法对白酒的微量成分进行分析。结果:小麦添加量为投料量的16.0%,高梁添加量为79.0%,稻壳添加量为5.0%,酵母添加量为7.0%,麸曲添加量为7.0%时,发酵成熟的酒醅中酒精含量为5.96%,利用此工艺蒸馏出的麸曲酱香型白酒感官评分值为72.1,贮存6个月后感官评分值为86.3,白酒酒质丰富,酱香突出。结论:酿造工艺符合酱香型白酒发酵过程要求,产品具有典型酱香型白酒特征。

糖醇类甜味剂的甜味与副味影响因素研究

糖醇因甜味纯正、热量低、安全健康等优势,成为理想的代糖甜味剂,具有广阔的应用前景。然而,对糖醇类甜味剂感官属性的影响因素研究较少。作者以赤藓糖醇、木糖醇、麦芽糖醇和山梨糖醇为研究对象,采用成对比较和排序法等感官分析方法,研究不同粒径、温度以及溶液质量浓度对糖醇类物质的甜味、清凉感、苦味和异味的影响差异。结果显示,在室温下,不同粒径糖醇晶体的清凉感均表现出显著差异(P<0.05),麦芽糖醇和山梨糖醇的甜味也有显著性差异(P<0.01),这两个属性基本都显示出粒径越大、强度越小的特点;升温后,不同颗粒间的异味和苦味差异更容易分辨,也会使清凉感的感知变弱;高质量浓度赤藓糖醇在热饮中表现出了比较显著的增甜效果;对于木糖醇、麦芽糖醇和山梨糖醇,在冷热条件下的甜味感知差异在不同质量浓度溶液下的表现相似。

几种典型天然甜味剂的功能活性及食品加工应用

近年来,随着消费者对健康产品的需求,天然甜味剂成为食品加工中重要加工原料,主要原因是其高甜度、低热量、低升糖的特点。消费者认知的提升及企业对产品的不断开发共同促进了天然甜味剂在我国的发展。天然甜味剂不仅可以应用于食品生产,还具有调节肠道菌群、抗氧化、美白、保护神经、抗癌、抗病毒、抗糖化和抗糖尿病等功能活性,但我国对于此方面的开发和利用还不慎广泛。该研究将重点围绕几种典型天然甜味剂的功能活性进行综述,并对其在乳制品、饮料、焙烤食品、海产品等食品加工中的应用现状深入探讨,以期为天然甜味剂的扩大开发应用提供参考依据。

HPLC-ELSD法测定梅子提取物中糖和糖醇的含量

建立了一种高效液相色谱-蒸发光散射法(HPLC-ELSD)同时测定梅子提取物中果糖、葡萄糖、山梨醇、蔗糖、麦芽糖水合物、麦芽三糖、麦芽四糖的方法。分离采用Grace Prevail Carbohydrate ES色谱柱,柱温为30℃;流动相为乙腈-水,流速为1.00 mL/min;检测使用蒸发光散射检测器,漂移管温度为60℃,氮气流速为2.50 L/min。结果表明,果糖、山梨醇、葡萄糖、蔗糖、麦芽糖水合物、麦芽三糖、麦芽四糖分别在34.69~2 220.00、16.22~1 038.00、38.66~2 474.00、24.53~1 570.00、22.91~1 466.00、6.09~390.00、14.69~940.00μg/mL范围内线性关系良好,精密度良好,重复性的相对标准偏差(RSD)为1.00%~4.09%,各目标物的回收率为85.5%~110.1%,精密度为0.3%~4.6%(n=6)。本方法在30 min内实现了糖和糖醇的分离,灵敏度和重复性检测较好,有效避免了溶剂及温度的影响,测量结果较准确且操作方便,可用于批量检测梅子提取物中糖和糖醇的含量。