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.

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.

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.

Irritable bowel syndrome and food interaction

Irritable bowel syndrome(IBS) is one of the most common gastrointestinal disorders in Western countries. Despite the high prevalence of this disorders, the therapeutic management of these patients is often unsatisfactory. A number of factors have been suggested to be involved in the pathogenesis of IBS, including impaired motility and sensitivity, increased permeability, changes in the gut microbiome and alterations in the brain-gut axis. Also food seems to play a critical role: the most of IBS patients report the onset or the exacerbation of their symptoms after the meals. Recently, an increasing attention has been paid to the role of food in IBS. In this review we summarize the most recent evidences about the role of diet on IBS symptoms. A diet restricted in fermentable, poorly absorbed carbohydrates and sugar alcohols has beneficial effects on IBS symptoms. More studies are needed to improve our knowledge about the relationship between food and IBS. However, in the foreseeable future, dietary strategies will represent one of the key tools in the therapeutic management of patients with IBS.

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.

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.

Diverse Functional Roles of Monosaccharide Transporters and their Homologs in Vascular Plants： A Physiological Perspective

Vascular plants contain two gene families that encode monosaccharide transporter proteins. The classical monosaccharide transporter（-like） gene superfamily is large and functionally diverse, while the recently identified SWEET transporter family is smaller and, thus far, only found to transport glucose. These transporters play essential roles at many levels, ranging from organelles to the whole plant. Many family members are essential for cellular homeostasis and reproductive success. Although most transporters do not directly participate in long-distance transport, their indirect roles greatly impact carbon allocation and transport flux to the heterotrophic tissues of the plant. Functional characterization of some members from both gene families has revealed their diverse roles in carbohydrate partitioning, phloem function, resource allocation, plant defense, and sugar signaling. This review highlights the broad impacts and implications of monosaccharide transport by describing some of the functional roles of the monosaccharide transporter（-like） superfamily and the SWEET transporter family.

Recyclable Cu Salt-Derived Brønsted Acids for Hydrolytic Hydrogenation of Cellulose on Ru Catalyst

Brønsted acid-catalyzed hydrolysis of cellulose,the most abundant source of biomass in nature,is the critical step for its depolymerization and subsequent conversion to sugar alcohols and other important chemicals.Mineral acids are highly active;however,the difficulties in recycling and disposal limit their practical applications.

Modulating of food glycemic response by lactic acid bacteria

There are some strategies for modulating the glycemic response of food through synthesized metabolites such as organic acids,fatty acids,sugar alcohols,bioactive peptides,and exopolysaccharides by bacteria,yeast,and/or fungi during fermentation.The different species of lactic acid bacteria (LAB) are the most important option in fermented food production because they are considered food-grade,their products can be directly used in food,their usability of a cheap and wide range of substrate,and suitable for genetic modification.They can contribute to lowering the glycemic load of nutrition through their organic acid,alcohol,polysaccharides,and vitamin production.This study aimed to review the effects of lowering the glycemic responses of foods by LAB via metabolites produced and their contribution to human well-being in this way.