Sucrose Hydrolysis Research Articles

BmTBP upregulates the transcription of BmSuc1 in silkworm (Bombyx mori) by binding to BmTfΙΙA-S.

The BmSuc1 gene, which encodes a novel animal-type β-fructofuranosidase (EC 3.2.1.26), was first cloned and identified in silkworm (Bombyx mori). As an essential sucrase, the activity of BmSUC1 is unaffected by alkaloidal sugar mimics in mulberry leaves. This enzyme may also directly regulate the degree of sucrose hydrolysis in the silkworm midgut. In addition, BmSUC1 is involved in the synthesis of sericin 1 in the silk gland tissue. However, the mechanism underlying the regulation of BmSuc1 transcription remains unclear. In this study, we analyzed the BmSuc1 promoter activity using a dual-luciferase reporter assay and identified 4 regions that are critical for transcriptional activation. The gene encoding a predicted transcription factor (TATA-box-binding protein; BmTBP) capable of binding to the core promoter regions was cloned. A quantitative real-time polymerase chain reaction analysis indicated the gene was highly expressed in the midgut. Downregulating BmTBP expression via RNA interference decreased the expression of BmSuc1 at the transcript and protein levels. An electrophoretic mobility shift analysis and chromatin immunoprecipitation indicated that BmTBP can bind to the TATA-box cis-regulatory element in the BmSuc1 promoter. Furthermore, a bioinformatics-based analysis and a far-western blot revealed the interaction between BmTBP and another transcription factor (BmTfIIA-S). The luciferase reporter gene assay results confirmed that the BmTBP-BmTfIIA-S complex increases the BmSuc1 promoter activity. Considered together, these findings suggest that BmTBP regulates BmSuc1 expression through its interaction with BmTfIIA-S.

Preparation of Hydrolyzed Sugarcane Molasses as a Low-Cost Medium for the Mass Production of Probiotic Lactobacillus paracasei ssp. paracasei F19

In this study, sugarcane molasses (SCM) was pre-treated in a low-cost fermentation medium to produce probiotic biomass of Lactobacillus paracasei ssp. paracasei F19 (LPPF19) with the combination of dilution, centrifugation, and acid hydrolysis (5 molar sulfuric acid, 60 °C/2 h). Microtox analysis, inductively coupled mass spectrometry (ICP-MS), and high-performance liquid chromatography (HPLC) were used to measure the effects of SCM pretreatment on the fermentation process. The results showed that the hydrolysis of sucrose into glucose and fructose was 98%, which represented an increase of 44.4% in the initial glucose content (fermentation-limiting sugar), and harmful heavy metals, such as arsenic, cadmium, and lead, were reduced by 50.3, 60.0, and 64.3%, respectively. After pretreatment, with the supplementation of only yeast extract and salts (Na, K, Mg, and Mn), a biomass of 9.58 log CFU/mL was achieved, approximately ten times higher than that for the control medium used (MRS/DeMan, Rogosa, and Sharpe). The cost reduction achieved compared to this commercial medium was 68.7% in the laboratory and 78.9% on an industrial scale. This work demonstrated that SCM could be used in a cheaper and more effective alternative fermentation to produce LPPF19.

Brassinosteroids Mediate Endogenous Phytohormone Metabolism to Alleviate High Temperature Injury at Panicle Initiation Stage in Rice

High temperatures cause physiological and biochemical changes and significantly affect young panicle development of rice (Oryza sativa L.). Brassinosteroids play important roles in enhancing crop stress resistance. In this study, we subjected rice cultivars Huanghuazhan (heat-resistant) and IR36 (heat-sensitive) to high temperature (HT, 40 ºC) or normal temperature (NT, 33 ºC) for 7 d at the panicle initiation stage, in conjunction with application of 24-epibrassinolide [EBR, a synthetic brassinolide (BR)] or brassinazole (BRZ, a BR biosynthesis inhibitor) at the beginning of the treatments. HT exacerbated spikelet degeneration and inhibited young panicle growth, which were partially prevented by EBR application, while BRZ application aggravated the reduction in spikelet number. HT decreased the contents of BR, active cytokinins (aCTK), active gibberellins (aGA) and indole-3-acetic acid (IAA), but increased the content of abscisic acid (ABA) in young panicles. The activities of key enzymes involved in sucrose hydrolysis, glycolysis and the tricarboxylic acid cycle in young panicles were decreased with the change of endogenous hormone levels under HT. In addition, the contents of H2O2 and malondialdehyde (MDA) were increased and the activities of antioxidant enzymes were decreased in young panicles. Exogenous application of EBR induced the expression of phytohormone biosynthesis-related genes and down-regulated the expression of phytohormone catabolism-related genes to increase the contents of endogenous BR, aCTK, aGA and ABA, thus promoting the decomposition and utilization of sucrose in young panicles, enhancing the activities of superoxide dismutase, catalase and peroxidase, and reducing the accumulation of H2O2 and MDA in young panicles, whereas application of BRZ had the opposite physiological effects. These results showed that brassinosteroids mediate endogenous phytohormone metabolism to alleviate HT injury at the panicle initiation stage in rice.

Effects of phosphorus application on carbohydrate metabolism in cottonseed kernel during the key development period provided a new insight for phosphorus management in cotton production

Cottonseed provides abundant and high-quality raw materials for biodiesel, fine chemical, and other industries due to its rich oil, but phosphorus-deficient farmland and finite phosphate resource hinder its production. Cottonseed development is based on its carbohydrate, and exploring the response of cottonseed carbohydrate metabolism to phosphorus could contribute to optimizing phosphorus management in cotton production and continuously obtaining high-quality cottonseed. Here, the experiment on phosphorus rates [0 (phosphorus deficient), 100 (phosphorus critical), and 200 (phosphorus excess) kg P2O5 ha−1] was conducted using Lu 54 (low-phosphorus sensitive) and Yuzaomian 9110 (low-phosphorus tolerant) in a field containing 16.9 mg kg−1 available phosphorus to assess the effects of phosphorus on cottonseed yield, cottonseed total phosphorus, ash, and oil contents, carbohydrate metabolism related carbohydrate contents, and enzymes activities. The results showed that phosphorus application increased cottonseed yield and oil content by 32.4%−54.2% and 14.8%−20.1% on average, respectively, which could be attributed to the improvements in sucrose transport and hydrolysis in cottonseed kernel during 18–26 days post anthesis induced by higher total phosphorus content (17.1%−26.7%). During the key development period of cottonseed kernel, phosphorus application increased sucrose content (13.0%−19.4%) by increasing the expression of sucrose transporter genes, and promoted sucrose hydrolysis by elevating enzymes activities, especially sucrose synthase (11.2%−19.1%) in cottonseed kernel. Consequently, phosphorus application increased hexose levels in cottonseed kernel and thus provided more substrates for its development, which promoted the formation of cottonseed kernel biomass (6.2%−10.6%), cottonseed and oil yields. Additionally, carbohydrate metabolism in Lu 54 was more sensitive to phosphorus than Yuzaomian 9110 during the key development period, resulting in greater increases in cottonseed kernel biomass, cottonseed yield, and oil content for Lu 54. Notably, the increments generated by unit phosphate fertilizer on the above indicators attenuated markedly with phosphorus application. Based on sucrose content, the key substance, the critical phosphorus concentration in the subtending leaf to cotton boll (LPC) needed by the efficient operation of the key carbohydrate metabolic pathway was 0.38% for Lu 54 versus 0.34% for Yuzaomian 9110. This report first unveiled the key carbohydrate metabolic pathway regulated by phosphorus for cottonseed and oil yield formation and its demand for LPC during the key development period, providing a new insight for diagnosing and regulating phosphorus in cotton production.

Catalytic production of 1,2-propanediol from sucrose over a functionalized Pt/deAl-beta zeolite catalyst.

To eliminate the dependence on fossil fuels and expand the applications of biomass conversion, an efficient Pt/deAl-beta@Mg(OH)2 catalyst was designed, with dealuminated beta zeolite loaded with Pt as the core and Mg(OH)2 as the shell. The catalyst was used to produce 1,2-propanediol (1,2-PDO) from sucrose. The preparation and reaction conditions of the catalyst were optimized. The optimal yield of 1,2-PDO was 33.5% when the conditions were 20 h of dealumination, 3.0 wt% Pt loading, 5.0 wt% Mg(OH)2, 200 mg of catalyst, 10 mL (11.25 mg mL-1) of sucrose solution, an initial H2 pressure of 6 MPa, 200 °C, and 3 h. The core-shell structure of the modified beta zeolite shows good stability, yielding more than 30.0% after three cycles of reuse. Firstly, the molecular zeolite can host more acid sites after dealumination by concentrated nitric acid and this can prolong the catalyst's service life. Secondly, the loading of Pt increases the distribution of acid sites and improves the shape selectivity of the catalyst. The introduction of alkali produces many alkaline sites, inhibits the occurrence of side reactions, and increases the product yield. The above modification methods increase the production of 1,2-PDO by promoting isomerization between glucose and fructose from sucrose hydrolysis and the reverse aldol condensation (RAC) reaction. This paper provides a theoretical basis and reference route for applying biomass conversion technology in practical production, which is of great significance for developing biomass resources into high-value-added chemical products.

HIGH-SPEED COMPUTER POLARIMETER BASED ON CMOS MATRIX

Under the conditions of the COVID-19 pandemic and a full-scale war in Ukraine, the lack of computer equipment for conducting online chemical experiments is experienced. In connection with the implementation of the New Ukrainian School and the development of STEM education, there was an urgent need to develop domestic educational computer equipment. The Department of Physics and Chemistry of H.S. Skivoroda’s Kharkiv National Pedagogical University is developing the SchoolKit software-methodological complex (PMK), which is based on three universal software tools: ColorKit, ChemKit, SoundCardScientificKit. When creating applications, only free software is used, which ensures low cost and, accordingly, accessibility for a wide range of users. A computer polarimeter was developed based on the ColorKit software. A new principle of polarimeter operation is proposed, which is based on computer processing of the image that occurs when optically polarized light is passed sequentially through an optically active solution, a transparent plate with internal tension, and an analyzer. A high-speed computer polarimeter based on a CMOS matrix was developed, a working model was manufactured and tested. The device differs from others since it uses a fundamentally new way of processing visual data and does not contain any mechanical components and polarization modulators. It is also easy to manufacture, and quite reliable. The polarimeter software allows data to be accumulated in the form of tables and displayed in real-time graphical form. The computer polarimeter was used for two years during laboratory classes in the “Mechanisms of Organic Reactions” subject, including online mode. In particular, it was used to experimentally determine the constants of acid hydrolysis of sucrose at different temperatures, concentrations of acid and sucrose. Visual display of measurement results, stability of device operation and good reproducibility of experimentally obtained data allow intensification and/or optimisation of the education process due to the automation of polarimetric measurements. After some improvements and validation, the device is planned to be used in scientific research.

СРАВНЕНИЕ ОРГАНОЛЕПТИЧЕСКИХ И ФИЗИКО-ХИМИЧЕСКИХ ПОКАЗАТЕЛЕЙ НАТУРАЛЬНОГО И ФАЛЬСИФИЦИРОВАННОГО МЕДА

Currently, such falsifications of honey as «sugar honey» (obtained by feeding bees with sugar syrup during the honey collection time) and «artificial honey» (obtained by enzymatic hydrolysis of sucrose) are the most common and difficult to detect. To identify them, the comprehensive assessment of organoleptic and physicochemical parameters is carried out. It’s a labor- and time-consuming process, and, unfortunately, doesn’t always guarantee obtaining objective results. The paper presents the results of palynological, organoleptic and physicochemical analyzes of these falsifications, as well as samples of natural linden tree honey. It has been established that both falsifications were characterized by a low content of pollen grains. The analysis of their organoleptic parameters didn’t reveal significant deviations from the standards. The reliable data have been obtained as the result of a comprehensive assessment of physicochemical parameters, both regulated by State Standards and some additional ones. The determination of hydrogen peroxide content (H2O2 ) is the most promising additional indicators.

A novel β-fructofuranosidase produced by Penicillium citreonigrum URM 4459: purification and biochemical features

Fructooligosaccharides (FOS) are prebiotics of interest to the food industry. These compounds can be produced through the transfructosylation reaction by the enzyme fructofuranosidase. This enzyme is widely produced by fungi in a medium rich in sugar. Therefore, in this work, the main objectives were production, purification, biochemical characterization of a novel fructofuranosidase enzyme by Penicillium citreonigrum URM 4459 and synthesize and evaluate the antibacterial potential of fructooligosaccharides. With respect to sucrose hydrolysis, the optimal pH was 5.5, the apparent Km for purified FFase was 3.8 mM, the molecular mass was 43.0 kDa, estimated by gel filtration on Superdex increase G75 controlled by AKTA Avant 25 and confirmed by 10% SDS-PAGE under denaturing condition. Also, the isoelectric point was 4.9. The fractions obtained with enzymatic activities, both stable at acidic pH and high temperatures, as well as being able to produce FOS. Regarding antibacterial activity, the FOS produced in this study showed better results than commercial FOS and other carbon sources. Thus, this work presents relevant data for the use of P. citreonigum to produce fructofuranosidase and consequently FOS and can be used in the food and pharmaceutical industry.

Effect of Carbon Sources on Glutamate Production from Corynebacterium glutamicum 2262

A comparative study between natural and synthetic environments is carried out by realizing six fermentation experiments in batch culture. The objective of this study is to consider the effect of carbon sources on growth and the production of glutamic acid by Corynebacterium glutamicum 2262. The difference between the culture media lies in the carbon source. Two natural environments of date juice, one of which is treated with invertase to hydrolyse sucrose with a concentration of total sugars of 88 g/L. Four synthetic media with a concentration of 34 g/L sugars: medium containing mixed sugars (glucose + fructose + sucrose) with rates proportional to that of date juice, the other three media are composed of a single sugar (either glucose, fructose, or sucrose). The results showed that Corynebacterium glutamicum is able to use the three sugars whether they are single or mixed, although the best results of glutamate production (8.41 g/L) are obtained on the mixture of three sugars, which explains the interest and valorisation of date waste. On the other hand, the date juice-based media are shown to have a glutamate concentration of 7.98 g/L during the hydrolysis of sucrose of date juice.

Knowledge of fermentation dynamics allows for reducing sugar levels in yeast-leavened pastry

Many food companies try to reduce the sugar content in their products. For yeasted cereal-based products, knowledge about the sugar production and consumption dynamics during processing, including sucrose hydrolysis, and its impact on product quality is key in achieving this. We showed before that in fermented pastry, sucrose is entirely hydrolysed into glucose and fructose by yeast invertase and that the contribution to sweetness of glucose, partly consumed by yeast, is negligible compared to that of fructose. Therefore, this study investigated the possibility of using fructose instead of sucrose in fermented pastry to decrease end product total sugar content. Fermentation dynamics, product height and sweetness factor were compared for recipes with 14% sucrose, 14% fructose and 10% fructose (dry matter flour base). Sucrose replacement had a small impact on fermentation dynamics and no significant impact on product height. Fermented pastry samples made with 10% fructose did not have significantly more fructose in the end product than those made with 14% sucrose. Moreover, samples made with 10% fructose had the same sweetness factor as samples made with 14% sucrose, while the end product contained 33% less sugar. It would be interesting to explore these findings in other fermented high-sugar bakery products.

High-yield production and purification of prebiotic inulin-type fructooligosaccharides

Due to the health-promoting effects and functional properties of inulin-type fructooligosaccharides (I-FOS), the global market for I-FOS is constantly growing. Hence, there is a continuing demand for new, efficient biotechnological approaches for I-FOS production. In this work, crude inulosucrase InuGB-V3 from Lactobacillus gasseri DSM 20604 was used to synthesize I-FOS from sucrose. Supplementation with 1 mM CaCl2, a pH of 3.5–5.5, and an incubation temperature of 40 °C were found to be optimal production parameters at which crude inulosucrase showed high conversion rates, low sucrose hydrolysis, and excellent stability over 4 days. The optimal process conditions were employed in cell-free bioconversion reactions. By elevating the substrate concentration from 570 to 800 g L−1, the I-FOS concentration and the synthesis of products with a low degree of polymerization (DP) could be increased, while sucrose hydrolysis was decreased. Bioconversion of 800 g L−1 sucrose for 20 h resulted in an I-FOS-rich syrup with an I-FOS concentration of 401 ± 7 g L−1 and an I-FOS purity of 53 ± 1% [w/w]. I-FOS with a DP of 3–11 were synthesized, with 1,1-kestotetraose (DP4) being the predominant transfructosylation product. The high-calorie sugars glucose, sucrose, and fructose were removed from the generated I-FOS-rich syrup using activated charcoal. Thus, 81 ± 5% of the initially applied I-FOS were recovered with a purity of 89 ± 1%.

Sensitive and Portable Detection of Bacteria Using Exonuclease-III (Exo-III) Assisted Signal Amplification and Personal Glucose Meters.

Despite major advances in combating pathogenic bacteria caused infection, infectious diseases remain a major cause of death today. A variety of bacteria detection approaches have been established by exploiting the aptamer to specifically identify target. However, these methods require specific equipment or laboratory based instruments, which is expensive and not easily available to the public. To deal with this issue, we develop here a portable and sensitive pathogenic bacteria detection approach through integrating capture probe based recognition and Exo-III assisted signal amplification. In this method, a designed capture probe identifies the surface protein of target bacteria, leading to the release of blocker sequence. The released blocker sequence mediates Exo-III enzyme based signal amplification, generating a large amount of signal strand DNA (ssDNA) sequences. The obtained ssDNA works as a linker to conjugate streptavidin magnetic beads (SMBs) with DNA invertase. After magnet based enrichment and washing away of free DNA invertase, the SMBs-DNA invertase complex is used to catalyze the hydrolysis of sucrose into glucose for PGM readout. Based on this, the approach exhibits a 6 order of magnitudes in detecting Staphylococcus Aureus (S. aureus) with the limit of detection as low as 78cfu/mL. In addition, the capability to specifically detect target bacteria and high repeatability (relative standard deviation, 4.44%) endows the method wider applicable scenes. In all, the established shows a promising prospect in the detection of bacteria pathogen and the early-diagnosis of bacterial infections.

The starch-sugar interconversion mechanism during bulb development of Cardiocrinum giganteum (Wall.) Makino revealed by transcriptome and metabolite analysis

Cardiocrinum giganteum bulbs are rich in starch and natural compounds that benefit health. To better utilize the bulb starch of C. giganteum as an edible resource, understanding of the kinetics of starch and sucrose accumulation as well as the involved metabolic pathways in different developmental stages of the bulbs are required. In this study, we compared the dynamic changes in the transcriptomes and metabolomes of the bulbs over different developmental stages. A total of 43,692 differentially expressed genes and 508 metabolites were identified, which were clustered into nine co-expression clusters based on biological functions. Starch and sucrose metabolic pathways were identified at both the transcriptome and metabolome levels, revealing that activating the pathways of starch synthesis as well as sucrose synthesis and hydrolysis could be main conversion modes in starch-sugar interconversion. The data showed that the starch synthesis genes GBSS, SS3, GBE and ISA were expressed to highest levels at the stage of three-four years of C. giganteum development (c3y-c4y), concomitantly with the highest starch contents in this period. This revealed that the starch from the developing bulbs is optimally harvested at this stage. Meanwhile, sucrose synthesis genes were active and sucrose metabolites were maintained in balance during this stage, providing carbohydrate resources for starch biosynthesis. In the four-five year stage of development (c4y-c5y), the contents of sucrose metabolites increased, starch synthesis slowed down and sucrose hydrolysis genes were activated. Moreover, qRT-PCR analysis showed that the temporal expression patterns of starch and sucrose biosynthesis genes were largely consistent with the RNA-seq results. Taken together, these findings provide important information on the regulatory mechanisms of starch-sugar interconversion during C. giganteum bulb development.

Physiological and Transcriptomic Analyses Reveal the Effects of Elevated Root-Zone CO2 on the Metabolism of Sugars and Starch in the Roots of Oriental Melon Seedlings.

Root-zone CO2 is a major factor that affects crop growth, development, nutrient uptake, and metabolism. Oriental melon is affected by root-zone gases during growth, the microstructure, sugar and starch contents, enzymatic activities related to sugar and starch metabolism, and gene expression in the roots of oriental melon seedlings were investigated under three root-zone CO2 concentrations (CK: 0.2%, T1: 0.4%, T2: 1.1%). Elevated root-zone CO2 altered the cellular microstructure, accelerated the accumulation and release of starch grains, disrupted organelle formation, and accelerated root senescence. The sugar and starch contents and metabolic activity in the roots increased within a short duration following treatment. Compared to the control, 232 and 1492 differentially expressed genes (DEGs) were identified on the 6th day of treatment in T1 and T2 plants, respectively. The DEGs were enriched in three metabolic pathways. The majority of genes related to sucrose and starch hydrolysis were upregulated, while the genes related to sucrose metabolism were downregulated. The study revealed that oriental melon seedlings adapt to elevated root-zone CO2 stress by adjusting sugar and starch metabolism at the transcriptome level and provides new insights into the molecular mechanism underlying the response to elevated root-zone CO2 stress.

Phylogenomics of a Saccharomyces cerevisiae cocoa strain reveals adaptation to a West African fermented food population

SummaryVarious yeast strains have been proposed as candidate starter cultures for cocoa fermentation, especially strains of Saccharomyces cerevisiae. In the current study, the genome of the cocoa strain S. cerevisiae IMDO 050523 was unraveled based on a combination of long- and short-read sequencing. It consisted of 16 nuclear chromosomes and a mitochondrial chromosome, which were organized in 20 contigs, with only two small gaps. A phylogenomic analysis of this genome together with another 105 S cerevisiae genomes, among which 20 from cocoa strains showed a geographical distribution of the latter, including S. cerevisiae IMDO 050523. Its genome clustered together with that of a West African fermented food population, indicating a wider adaptation to West African food niches than cocoa. Furthermore, S. cerevisiae IMDO 050523 contained genetic signatures involved in sucrose hydrolysis, pectin degradation, osmotolerance, and conserved amino acid changes in key ester-producing enzymes that could point toward specific niche adaptations.

Protein engineering of invertase for enhancing yeast dough fermentation under high-sucrose conditions.

During yeast dough fermentation, such as the high-sucrose bread-making process, the yeast cells are subjected to considerable osmotic stress, resulting in poor outcomes. Invertase is important for catalyzing the irreversible hydrolysis of sucrose to free glucose and fructose, and decreasing the catalytic activity of the invertase may reduce the glucose osmotic stress on the yeast. In this study, we performed structural design and site-directed mutagenesis (SDM) on the Saccharomyces cerevisiae invertase (ScInV) in an Escherichia coli expression system to study the catalytic activity of ScInV mutants in vitro. In addition, we generated the same mutation sites in the yeast endogenous genome and tested their invertase activity in yeast and dough fermentation ability. Our results indicated that appropriately reduced invertase activity of yeast ScInV can enhance dough fermentation activity under high-sucrose conditions by 52%. Our systems have greatly accelerated the engineering of yeast endogenous enzymes both in vitro and in yeast, and shed light on future metabolic engineering of yeast.

A saliva α-glucosidase MpAgC2-2 enhance the feeding of green peach aphid Myzus persicae via extra-intestinal digestion

Aphids feed on plant phloem sap that contains massive amounts of sucrose; this not only provides vital nutrition for the aphids but also produces high osmotic pressure. To utilize this carbon source and overcome the osmotic pressure, sucrose is hydrolyzed into the monosaccharides, glucose and fructose. In the green peach aphid (Myzus persicae), we show that this process is facilitated by a key α-glucosidase (MpAgC2-2), which is abundant in the aphid salivary gland and is secreted into leaves during feeding. MpAgC2-2 has a pH optimum of 8.0 in vitro, suggesting it has adapted to the environment of plant cells. Silencing MpAgC2-2 (but not the gut-specific MpAgC3-4) significantly increased the amount of sucrose ingested and hindered aphid feeding on the phloem of tobacco seedlings, resulting in a smaller body size, as well as lower α-glucosidase activity and glucose levels. These effects could be rescued by feeding aphids on tobacco plants transiently expressing MpAgC2-2. The transient expression of MpAgC2-2 also led to the hydrolysis of sucrose in tobacco leaves. Taken together, these results demonstrate that MpAgC2-2 is a salivary protein that facilitates extra-intestinal feeding via sucrose hydrolysis. Our findings provide insight into the ability of aphids to digest the high concentration of sucrose in phloem, and the underlying mechanism of extra-intestinal digestion.

One-pot synthesis of 5-hydroxymethylfurfural from cellobiose and sucrose using niobium-modified montmorillonite catalysts

The synthesis of platform chemical 5-hydroxymethylfurfural (5-HMF) provides favorable and efficient paths for the utilization of renewable biomass resources. In this work, highly active niobium-modified montmorillonite (Nb-Mont) catalysts were synthesized by a facile and ion-exchange method and were used for the one-pot conversion of cellobiose and sucrose to 5-HMF with optimal results. 5-HMF yield of 68.6% was obtained from cellobiose in a methyl isobutyl ketone (MIBK)/saturated salt water (SSW) biphasic solvent at 170 °C after 3 h. With sucrose as substrate in DMSO at 140 °C after 2 h, 5-HMF yield was 65.4%. The presence of Lewis and Brønsted acid sites on Nb-Mont facilitate the hydrolysis of cellobiose and sucrose and play essential roles in the subsequent isomerization of glucose monomer and the dehydration of fructose monomer. A possible reaction mechanism was proposed for the transformation of cellobiose and sucrose into 5-HMF, and the isomerization process of glucose monomer was the most critical step, confirmed by density functional theory (DFT) calculations. [NbO(OH)2]+ species as active sites could effectively reduce the activation energy of the isomerization process, which accelerated the synergetic proton transfer process. Nb-Mont was recycled at least four times without a prominent loss in the catalytic activity. In this study, a promising catalytic strategy was provided for heterogeneous Nb containing catalysts used in the effective synthesis of 5-HMF from carbohydrates.

Inulin-type fructans and short-chain fructooligosaccharides-their role within the food industry as fat and sugar replacers and texture modifiers-what needs to be considered!

Inulin and oligofructose are classes of prebiotics belonging to a group of nondigestible carbohydrates referred to as inulin-type fructans. While short-chain fructooligosaccharides are enzymatically synthesized from the hydrolysis and transglycosylation of sucrose. Inulin-type fructans and short-chain fructooligosaccharides act as carbon sources for selective pathways supporting digestive health including altering the composition of the gut microbiota along with improving transit time. Due to their physicochemical properties, inulin-type fructans and short-chain fructooligosaccharides have been widely used in the food industry as partial replacements for both fat and sugar. Yet, levels of replacement need to be carefully considered as it may result in changes to physical and sensory properties that could be detected by consumers. Furthermore, it has been reported depending on the processing parameters used during production that inulin-type fructans and short-chain fructooligosaccharides may or may not undergo structural alterations. Therefore, this paper reviews the role of inulin-type fructans and short-chain fructooligosaccharides within the food industry as fat and sugar replacers and texture modifiers, their impact on final sensory properties, and to what degree processing parameters are likely to impact their functional properties.

Microfluidic paper-based analytical device for determination of sucrose in sugarcane juice using Benedict's reagent.

This work presents a microfluidic paper-based analytical device (μPAD) for the determination of sucrose using the Benedict's test. An asymmetric dumbbell-shaped hydrophobic barrier was produced by rubber stamping the barrier pattern onto a laboratory filter paper. Hydrochloric acid and solution containing sucrose were successively deposited onto the sample reservoir of the μPAD attached to a glass slide. The device was placed in a plastic bag and dipped into boiling water for accelerating the hydrolysis of sucrose into the reducing sugars. Then the Benedict's reagent was added at the narrow straight channel connecting the two circular zones of the μPAD, which was replaced in the plastic bag and heated again for reduction of Cu(II) by the reducing sugars. Precipitate of brick-red copper(I) oxide was formed. The image of the μPAD was recorded by a smartphone. The ratio of the red to blue intensities gave linear correlation with the concentration of sucrose in the range of 0.5-10% w/v. The relative standard deviation of the measurement was less than 5% for 2 and 4% w/v sucrose (n = 10), with limit of determination, calculated using standard deviation of regression divided by slope of calibration, of 0.26% w/v sucrose. The method was successfully validated using the dinitrosalicylic acid method for sucrose measurement. Percent recoveries of sucrose were evaluated using ten sugarcane samples. The recoveries were in the range of 89 to 101%, demonstrating that there were no significant sample matrix effects on the quantification.