Solid Lipid Nanoparticles Containing Dopamine and Grape Seed Extract: Freeze-Drying with Cryoprotection as a Formulation Strategy to Achieve Nasal Powders.

(1) Background: DA-Gelucire® 50/13-based solid lipid nanoparticles (SLNs) administering the neurotransmitter dopamine (DA) and the antioxidant grape-seed-derived proanthocyanidins (grape seed extract, GSE) have been prepared by us in view of a possible application for Parkinson's disease (PD) treatment. To develop powders constituted by such SLNs for nasal administration, herein, two different agents, namely sucrose and methyl-ß-cyclodextrin (Me-ß-CD), were evaluated as cryoprotectants. (2) Methods: SLNs were prepared following the melt homogenization method, and their physicochemical features were investigated by Raman spectroscopy, Scanning Electron Microscopy (SEM), atomic force microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS). (3) Results: SLN size and zeta potential values changed according to the type of cryoprotectant and the morphological features investigated by SEM showed that the SLN samples after lyophilization appear as folded sheets with rough surfaces. On the other hand, the AFM visualization of the SLNs showed that their morphology consists of round-shaped particles before and after freeze-drying. XPS showed that when sucrose or Me-ß-CD were not detected on the surface (because they were not allocated on the surface or completely absent in the formulation), then a DA surfacing was observed. In vitro release studies in Simulated Nasal Fluid evidenced that DA release, but not the GSE one, occurred from all the cryoprotected formulations. Finally, sucrose increased the physical stability of SLNs better than Me-ß-CD, whereas RPMI 2650 cell viability was unaffected by SLN-sucrose and slightly reduced by SLN-Me-ß-CD. (4) Conclusions: Sucrose can be considered a promising excipient, eliciting cryoprotection of the investigated SLNs, leading to a powder nasal pharmaceutical dosage form suitable to be handled by PD patients.

An investigation of excipients for a stable Orf viral vector formulation.

The Orf virus (ORFV) is a promising candidate for vector vaccines as well as for immunomodulatory and oncolytic therapies. However, few publications are available on its infectivity degradation or on suitable additives for prolonging its viral stability. In this study, the non-supplemented ORFV itself showed a very high stability at storage temperatures up to 28 °C, with a linear titer loss of 0.10 log infectious particles per day at 4 °C over a period of five weeks. To prolong this inherent stability, thirty additives, i.e., detergents, sugars, proteins, salts, and buffers as well as amino acids, were tested for their time- and temperature-dependent influence on the ORFV infectivity. A stabilizing effect on the infectivity was identified for the addition of all tested proteins, i.e., gelatine, bovine serum albumin, and recombinant human serum albumin (rHSA), of several sugars, i.e., mannitol, galactose, sucrose, and trehalose, of amino acids, i.e., arginine and proline, of the detergent Pluronic F68, and of the salt Na2SO4. The infectivity preservation was especially pronounced for proteins in liquid and frozen formulations, sugars in frozen state, and arginine und Pluronic in liquid formulations at high storage temperatures (37 °C). The addition of 1% rHSA with and without 5% sucrose was evaluated as a very stable formulation with a high safety profile and economic validity at storage temperatures up to 28 °C. At increased temperatures, the supplementation with 200 mM arginine performed better than with rHSA. In summary, this comprehensive data provides different options for a stable ORFV formulation, considering temperature, storage time, economic aspects, and downstream processing integrity.

Classification and quantification of sucrose from sugar beet and sugarcane using optical spectroscopy and chemometrics.

Sucrose, obtained from either sugar beet or sugarcane, is one of the main ingredients used in the food industry. Due to the same molecular structure, chemical methods cannot distinguish sucrose from both sources. More practical and affordable methods would be valuable. Sucrose samples (cane and beet) were collected from nine countries, 25% (w/w) aqueous solutions were prepared and their absorbances recorded from 200 to 1380 nm. Spectral differences were observable in the ultraviolet-visible (UV-Vis) region from 200 to 600 nm due to impurities in sugar. Linear discriminant analysis (LDA), classification and regression trees, and soft independent modeling of class analogy were tested for the UV-Vis region. All methods showed high performance accuracies. LDA, after selection of five wavelengths, gave 100% correct classification with a simple interpretation. In addition, binary mixtures of the sugar samples were prepared for quantitative analysis by means of partial least squares regression and multiple linear regression (MLR). MLR with first derivative Savitzky-Golay were most acceptable with root mean square error of cross-validation, prediction, and the ratio of (standard error of) prediction to (standard) deviation values of 3.92%, 3.28%, and 9.46, respectively. Using UV-Vis spectra and chemometrics, the results show promise to distinguish between the two different sources of sucrose. An affordable and quick analysis method to differentiate between sugars, produced from either sugar beet or sugarcane, is suggested. This method does not involve complex chemical analysis or high-level experts and can be used in research or by industry to detect the source of the sugar which is important for some countries' agricultural policies.

Phenylpropanoids from Sparganium stoloniferum and their antiplatelet aggregation activities.

Four new ferulic acid sucrose esters, ß-D-(1-O-acetyl-6-O-trans-feruloyl)fructofuranosyl-a-D-2',6'-O-diacetylglucopyranoside (1), ß-D-(1-O-acetyl-6-O-trans-feruloyl)fructofuranosyl-a-D-2',4'-O-diacetylglucopyranoside (2), ß-D-(6-O-trans-feruloyl)fructofuranosyl-a-D-2',4',6'-O-triacetylglucopyranoside (3), ß-D-(1-O-acetyl-6-O-trans-feruloyl)fructofuranosyl-a-D-4',6'-O-diacetylglucopyranoside (4), together with four known phenylpropanoids (5-8) were isolated from the rhizome of Sparganium stoloniferum (Graebn.) Buch.-Ham. ex Juz. Their structures were elucidated by chemical evidence and spectral analysis. Compounds 1-8 exhibited obvious inhibitory effects on ADP-induced platelet aggregation.

Selection of cryoprotectants for freezing and freeze-drying of gold nanoparticles towards further uses in various applications.

Recently, cryopreservation of AuNPs without aggregation has been attempted to improve their long-term stability. This study investigated criteria to select cryoprotectants for AuNPs using a variety of materials, including sugar (sucrose), surfactant (Tween 20), polymers (polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP)), and biopolymer (pectin). For cryoprotective performance, UV-vis spectroscopy reveals the potential of all cryoprotectants for preventing citrate-capped AuNPs (cit-AuNPs) from irreversible aggregation under freezing. While sucrose, PVP, and pectin were more suitable than Tween 20 and PVA as cryoprotectants for lyophilization of AuNPs with the maintained redispersability. For storage and further use, Luria-Bertani agar plate, dynamic light scattering (DLS), and transmission electron microscopy (TEM) results indicate impacts of the cryoprotectant coexisted with AuNPs after resuspension and imply that washing of the restored AuNPs is encouraged. Otherwise, running the restored AuNPs through applications, such as functionalization, protein conjugation, and surface-enhanced Raman scattering (SERS), without washing the cryoprotectant could lead to inaccurate results. This study also serves as a guideline for a comprehensive practice flow of AuNP handling, encompassing the synthesis step, cryopreservation, and use after resuspension.

Natural Products from Physalis alkekengi L. var. franchetii (Mast.) Makino: A Review on Their Structural Analysis, Quality Control, Pharmacology, and Pharmacokinetics.

The calyxes and fruits of Physalis alkekengi L. var. franchetii (Mast.) Makino (P. alkekengi), a medicinal and edible plant, are frequently used as heat-clearing and detoxifying agents in thousands of Chinese medicine prescriptions. For thousands of years in China, they have been widely used in clinical practice to treat throat disease, hepatitis, and bacillary dysentery. This systematic review summarizes their structural analysis, quality control, pharmacology, and pharmacokinetics. Furthermore, the possible development trends and perspectives for future research studies on this medicinal plant are discussed. Relevant information on the calyxes and fruits of P. alkekengi was collected from electronic databases, Chinese herbal classics, and Chinese Pharmacopoeia. Moreover, information was collected from ancient documents in China. The components isolated and identified in P. alkekengi include steroids, flavonoids, phenylpropanoids, alkaloids, nucleosides, terpenoids, megastigmane, aliphatic derivatives, organic acids, coumarins, and sucrose esters. Steroids, particularly physalins and flavonoids, are the major characteristic and bioactive ingredients in P. alkekengi. According to the literature, physalins are synthesized by the mevalonate and 2-C-methyl-d-erythritol-4-phosphate pathways, and flavonoids are synthesized by the phenylpropanoid pathway. Since the chemical components and pharmacological effects of P. alkekengi are complex and varied, there are different standards for the evaluation of its quality and efficacy. In most cases, the analysis was performed using high-performance liquid chromatography coupled with ultraviolet detection. A pharmacological study showed that the crude extracts and isolated compounds from P. alkekengi had extensive in vitro and in vivo biological activities (e.g., anti-inflammatory, anti-tumor, immunosuppressive, antibacterial, anti-leishmanial, anti-asthmatic, anti-diabetic, anti-oxidative, anti-malarial, anti-Alzheimer's disease, and vasodilatory). Moreover, the relevant anti-inflammatory and anti-tumor mechanisms were elucidated. The reported activities indicate the great pharmacological potential of P. alkekengi. Similarly, studies on the pharmacokinetics of specific compounds will also contribute to the progress of clinical research in this setting.

Uncovering the multi-level response of Glycine max L. to the application of allelopathic biostimulant from Levisticum officinale Koch.

The interest expressed by the agriculture in the category of innovative biostimulants is due to the intensive search for natural preparations. Our study is the first ever to report a complex approach to the use of allelopathic extracts from Levisticum officinale Koch. roots in soybean cultivation, includes analyses of morphological observations, and analyses of biochemical indicators. Hot method of aqueous extraction was applied. The extracts were administered via foliar application and soil treatment. Lovage extracts had high contents of polyphenolic compounds and rich micro- and macroelemental composition. The infusions did not contain gibberellic acid and indole-3-acetic acid but the abscisic acid and saccharose, glucose, and fructose were found. The extracts modified soybean plant physiology, as manifested by changes in biometric traits. Plants responded positively by increased yield. Seeds from the treated plants had higher contents of micro- and macroelements, as well as total concentrations of lipids (with a slight decrease in protein content). In addition, they featured changes in their amino acid profile and fatty acid composition. The application of allelopathic biostimulant caused increased concentrations of isoflavones and saponins. The natural biostimulants from Levisticum officinale may become a valuable tool in the sustainable agriculture.

Encapsulation of ginger oleoresin in co-crystallized sucrose: development, characterization and storage stability.

Ginger oleoresin was emulsified with gum acacia and encapsulated in a sucrose matrix by co-crystallization. The increased void space and surface area of sucrose provided a porous base for the incorporation of oleoresin. This co-crystallization led to modification from crystalline to irregular agglomerates, as evident from X-ray diffraction and differential scanning calorimetry. Hygroscopicity, water sorption isotherms and water activity demonstrated changes due to the change in crystallinity of sucrose. The active components such as [6]-, [8]- and [10]-gingerols and [6]-shogaol were quantified by HPLC. The encapsulation efficiency of [6]-gingerol was 45.59%. The storage kinetics at different relative humidity levels and temperatures indicated [6]-gingerol to be the most stable among the gingerols studied. A temperature of 25 °C and relative humidity of 33% proved to be the best storage conditions for the ginger flavoured sugar cubes. Thus, co-crystallization for the encapsulation of ginger oleoresin serves a dual purpose, i.e., protection and a mode of delivering a spicy flavour.

Effects of processing parameters on furan formation in canned strawberry jam.

The formation mechanism of furan has been studied extensively in model systems, however, furan formation in real foods are complex and far from being fully understood. In this study, the effects of acid-regulating agent (citric acid), sugar addition (glucose, fructose and sucrose) and thickening agents (xanthan gum, κ-carrageenan and pectin) on furan levels in strawberry jams were studied; meanwhile the formation pathway of furan in canned strawberry jam was proposed by carbon module labeling (CAMOLA) technique. Our results suggested low pH promoted furan formation in strawberry jam. Besides, fructose produces more furans than sucrose and glucose, and the addition of xanthan gum reduced furan levels significantly. The kinetic data showed that ascorbic and dehydroascorbic acid degradation followed first-order kinetics while rate of furan formation followed zero-order kinetics. This study presented the possibility of mitigating furan formation in canned strawberry jams by optimization of processing parameters and addition of xanthan gum.

UHPLC/MS and NMR-Based Metabolomic Analysis of Dried Water Extract of Citrus-Type Crude Drugs.

Citrus-type crude drugs (CCDs) are commonly used to formulate decoctions in Kampo formula (traditional Japanese medicine). Our previous study reported metabolomic analyses for differentiation of the methanol extracts of Citrus-type crude drugs (CCDs) using ultra-HPLC (UHPLC)/MS, and 13C- and 1H-NMR. The present study expanded the scope of its application by analyzing four CCD water extracts (Kijitsu, Tohi, Chimpi, and Kippi); these CCDs are usually used as decoction ingredients in the Kampo formula. A principal component analysis score plot of processed UPLC/MS and NMR analysis data indicated that the CCD water extracts could be classified into three groups. The loading plots showed that naringin and neohesperidin were the distinguishing components. Three primary metabolites, α-glucose, ß-glucose, and sucrose were identified as distinguishing compounds by NMR spectroscopy. During the preparation of CCD dry extracts, some compounds volatilized or decomposed. Consequently, fewer compounds were detected than in our previous studies using methanol extract. However, these results suggested that the combined NMR- and LC/MS-based metabolomics can discriminate crude drugs in dried water extracts of CCDs.

Effects of concentrations, temperature, pH and co-solutes on the rheological properties of mucilage from Dioscorea opposita Thunb. and its antioxidant activity.

The mucilage from Dioscorea opposita (DOM) dispersions presented shear-thinning behaviour that well fitted to the Power Law model. The effects of different concentrations (2%-10% w/v), temperatures (25-80 °C), pH (3.0-9.0), freeze-thaw conditions (thawed at 25 °C and 4 °C), co-salts (KCl and CaCl2) and co-sugars (sucrose, fructose and mannose) on the rheological properties were investigated. Generally, higher concentrations, neutral pH, Ca2+ and sugars increased the viscosity of DOM, while increasing temperature (25-65 °C) had opposite effects. The results suggested that cross-linked networks exist in DOM, and viscosity changes may be related to the ionisation of carboxyl groups, structural changes and enhancement/reduction of molecular interactions. Particularly, Ca2+ could interact with uronic acids of two or more polysaccharide molecules, modify the network-structure through cross-linking with carboxyl groups, and enhance the stronger carboxylate-cation2+-carboxylate interactions. Therefore, DOM is suitable for food applications as thickening or gelling agents in aqueous solutions.

Effect of Sucrose Esterified Fatty Acid Moieties on the Crystal Nanostructure and Physical Properties of Water-in-oil Palm-based Fat Blends.

The effects of sucrose ester of fatty acid (SEF) on the nanostructure and the physical properties of water-in-oil (W/O)-type emulsified semisolid fats were investigated. Model emulsions including palm-based semisolid fats and fully hydrogenated rapeseed oils with 0.5% SEF or fractionated lecithin, were prepared by rapidly cooling crystallization using 0.5% monoacylglycerol as an emulsifier. The SEFs used in this study were functionalized with various fatty acids, namely, lauric, palmitic, stearic, oleic, and erucic acids. Cryogenic transmission electron microscopy (cryo-TEM) was used to observe the sizes of the solvent- extracted nanoplatelets. The solid fat content (SFC), oil migration value, and storage elastic modulus were also determined. The average crystal size, which was measured in length, of the fat blends with SEFs containing saturated fatty acids (namely, palmitic and stearic acids) was smaller than that of the SEFs containing unsaturated fatty acids (namely, oleic and erucic acids). The effects exerted by these fatty acid moieties on the spherulite size in the corresponding bulk fat blends were observed via polarized microscopy (PLM). The results suggest that nanostructure formation upon the addition of SEF ultimately influenced these aggregated microstructures. Generally, smaller platelets resulted in higher SFC in the fat phase, and a high correlation between the SFC and the G' values in W/O emulsion fats was observed (R2 = 0.884) at 30°C. In contrast, the correlation was low at 10℃. Furthermore, samples with larger nanocrystals had a higher propensity for oil migration. Thus, the addition of SEF regulated the fat crystal nanostructure during nucleation and crystal growth, which could ultimately influence the physical properties of commercially manufactured fat products such as margarine.

Expression Level of Mature miR172 in Wild Type and StSUT4-Silenced Plants of Solanum tuberosum Is Sucrose-Dependent.

In potato plants, the phloem-mobile miR172 is involved in the sugar-dependent transmission of flower and tuber inducing signal transduction pathways and a clear link between solute transport and the induction of flowering and tuberization was demonstrated. The sucrose transporter StSUT4 seems to play an important role in the photoperiod-dependent triggering of both developmental processes, flowering and tuberization, and the phenotype of StSUT4-inhibited potato plants is reminiscent to miR172 overexpressing plants. The first aim of this study was the determination of the level of miR172 in sink and source leaves of StSUT4-silenced as well as StSUT4-overexpressing plants in comparison to Solanum tuberosum ssp. Andigena wild type plants. The second aim was to investigate the effect of sugars on the level of miRNA172 in whole cut leaves, as well as in whole in vitro plantlets that were supplemented with exogenous sugars. Experiments clearly show a sucrose-dependent induction of the level of mature miR172 in short time as well as long time experiments. A sucrose-dependent accumulation of miR172 was also measured in mature leaves of StSUT4-silenced plants where sucrose export is delayed and sucrose accumulates at the end of the light period.

Cryopreservation of Plant Shoot Tips of Potato, Mint, Garlic, and Shallot Using Plant Vitrification Solution 3.

Cryopreservation of shoot tips facilitates long-term storage of plant genetic resources which can otherwise only be propagated vegetatively. The vitrification approach using the cryoprotectant plant vitrification solution 3 (PVS3, 50% sucrose and 50% glycerol) is easy to handle, has shown to produce high regrowth percentages in a number of potato, mint, garlic, and shallot accessions, and is, thus, highly suitable for routine cryopreservation of plant genetic resources. In the current chapter, the vitrification procedure is described for potato, mint, garlic, and shallot and includes details about modifications for the different plant species. Special emphasis is given on the preparation of the different culture media, solutions, the culture conditions prior and post-cryopreservation, and the preparation of the shoot tips from different sources. Furthermore, protocols to introduce plants into in vitro culture and methods to estimate cryopreservation success are provided.

Metabolic engineering for the production of butanol, a potential advanced biofuel, from renewable resources.

Butanol is an important chemical and potential fuel. For more than 100 years, acetone-butanol-ethanol (ABE) fermentation of Clostridium strains has been the most successful process for biological butanol production. In recent years, other microbes have been engineered to produce butanol as well, among which Escherichia coli was the best one. Considering the crude oil price fluctuation, minimizing the cost of butanol production is of highest priority for its industrial application. Therefore, using cheaper feedstocks instead of pure sugars is an important project. In this review, we summarized butanol production from different renewable resources, such as industrial and food waste, lignocellulosic biomass, syngas and other renewable resources. This review will present the current progress in this field and provide insights for further engineering efforts on renewable butanol production.

Firmosides A and B: two new sucrose ferulates from the aerial parts of Silene firma and evaluation of radical scavenging activities.

Two new tri-ferulates of sucrose, firmosides A and B (1 and 2, respectively), together with 18 known compounds (3-20), were isolated from the aerial parts of Silene firma. The structures of the isolated compounds were elucidated by various spectroscopic methods, including 1D, 2D NMR, and high-resolution electro-spray ionization-mass spectrometry (HR-ESI-MS). All the isolated compounds were evaluated for their free radical scavenging activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. As a result, two new compounds (1, 2) and 11 demonstrated significant radical scavenging activity, implying the usefulness as antioxidant agents.

Hypothermia induced by central injection of sucralose potentially occurs via monoaminergic pathways in the hypothalamus of chicks.

Oral administration of sucralose has been reported to stimulate food intake through inducing hypothalamic neuropeptide Y (NPY) in mice and fruit flies. However, the underlying mechanisms of action of sucralose in hypothermia and NPY and monoamine regulation remain unknown. The aim of the present study was to investigate central effects of sucralose on body temperature, NPY, and monoamine regulation, as well as its peripheral effects, in chicks. In Experiment 1, 5-day-old chicks were centrally injected with 1 µmol of sucralose, other sweeteners (erythritol and glucose), or saline. In Experiment 2, chicks were centrally injected with 0.2, 0.4, and 1.6 µmol of sucralose or saline. In Experiment 3, chicks were centrally injected with 0.8 µmol of sucralose or saline, with a co-injection of 100 µg fusaric acid (FA), an inhibitor of dopamine-ß-hydroxylase, to examine the role dopamine in sucralose induced hypothermia. In Experiment 4, 7-16-day-old chicks were orally administered with 75, 150, and 300 mg/2 ml distilled water or sucralose, daily. We observed that the central injection of sucralose, but not other sweeteners, decreased body temperature (P < .05) in chicks; however, the oral injection did not influence body temperature, food intake, and body weight gain. Central sucralose administration decreased dopamine and serotonin and stimulated dopamine turnover rate in the hypothalamus significantly (P < .05). Notably, sucralose co-injection with FA impeded sucralose-induced hypothermia. Sucralose decreases body temperature potentially via central monoaminergic pathways in the hypothalamus.

The effect of osmotic dehydration on the polyphenols content in onion.

BACKGROUND: The onion is one of the most popular vegetables in the world, often used in the food industry. The purpose of this work was to determine the effect of osmotic dehydration of onions after storage in solutions containing various amounts of sucrose and sodium chloride on the course of osmoconcentration and the level of polyphenols in the dehydrated vegetables. The results could be useful to define the dehydration conditions under which a product retains the highest content of these health-promoting substances. METHODS: Onions var. Robusta were used. The vegetables were stored for six months at 0°C (air relative humidity 75–80%). They were cut into quarters just before dewatering. Samples of 20 ±1 g were dehydrated for five hours in a 40–60°Bx sucrose solution and a 5–15% NaCl solution (25°C); the weight ratio of the sample to the solution was 1:5. The contents of polyphenols and dry matter were determined. RESULTS: The use of a mixture of two osmotic agents (sucrose, sodium chloride) was more effective in the increase of dry matter content than using only sucrose. Nearly 49% dry matter content in onion was obtained by using a 60% solution (50% sucrose + 10% NaCl) for five hours. The greatest differences in the content of total polyphenols occurred during the first hour. After this time, retention amounted to 48–90%, depending on the concentration of sucrose (40–60%) and sodium chloride (5–15%). The retention of diglycosides of quercetin (mainly quercetin-3,4’-diglucoside) was lower than that of monoglycosides (mainly quercetin-4’- -glucoside). Following dehydration in a solution containing 60% sucrose and 10% NaCl, after three hours, there was about one third of the initial amount of the above-mentioned compounds in onion. CONCLUSIONS: The increase in the concentration of the hypertonic solution, being a mixture of sucrose and sodium chloride, causes a reduction in the retention of total polyphenols in osmotically dehydrated onions. The smallest losses occur after applying a 40% sucrose solution with NaCl up to 10%.

Influence of salivary conditioning and sucrose concentration on biofilm-mediated enamel demineralization.

INTRODUCTION: The acquired pellicle formation is the first step in dental biofilm formation. It distinguishes dental biofilms from other biofilm types. OBJECTIVE: To explore the influence of salivary pellicle formation before biofilm formation on enamel demineralization. METHODOLOGY: Saliva collection was approved by Indiana University IRB. Three donors provided wax-stimulated saliva as the microcosm bacterial inoculum source. Acquired pellicle was formed on bovine enamel samples. Two groups (0.5% and 1% sucrose-supplemented growth media) with three subgroups (surface conditioning using filtered/pasteurized saliva; filtered saliva; and deionized water (DIW)) were included (n=9/subgroup). Biofilm was then allowed to grow for 48 h using Brain Heart Infusion media supplemented with 5 g/l yeast extract, 1 mM CaCl2.2H2O, 5% vitamin K and hemin (v/v), and sucrose. Enamel samples were analyzed for Vickers surface microhardness change (VHNchange), and transverse microradiography measuring lesion depth (L) and mineral loss (∆Z). Data were analyzed using two-way ANOVA. RESULTS: The two-way interaction of sucrose concentration × surface conditioning was not significant for VHNchange (p=0.872), ∆Z (p=0.662) or L (p=0.436). Surface conditioning affected VHNchange (p=0.0079), while sucrose concentration impacted ∆Z (p<0.0001) and L (p<0.0001). Surface conditioning with filtered/pasteurized saliva resulted in the lowest VHNchange values for both sucrose concentrations. The differences between filtered/pasteurized subgroups and the two other surface conditionings were significant (filtered saliva p=0.006; DIW p=0.0075). Growing the biofilm in 1% sucrose resulted in lesions with higher ∆Z and L values when compared with 0.5% sucrose. The differences in ∆Z and L between sucrose concentration subgroups was significant, regardless of surface conditioning (both p<0.0001). CONCLUSION: Within the study limitations, surface conditioning using human saliva does not influence biofilm-mediated enamel caries lesion formation as measured by transverse microradiography, while differences were observed using surface microhardness, indicating a complex interaction between pellicle proteins and biofilm-mediated demineralization of the enamel surface.

5-Hydroxymethylfurfural accumulation plays a critical role on acrylamide formation in coffee during roasting as confirmed by multiresponse kinetic modelling.

This study aims to investigate in depth the mechanism of acrylamide formation in coffee during roasting. For this purpose, a comprehensive kinetic model including the elementary steps for acrylamide formation was proposed. The changes in sucrose, reducing sugars, free amino acids, asparagine, acrylamide, 3-deoxyglucosone, methylglyoxal, glyoxal, and 5-hydroxymethylfurfural were monitored in coffee during roasting at 200, 220 and 240 °C. Dominant pathways of complex reactions leading to acrylamide were unravelled by means of multiresponse kinetic modelling approach. The results of the model indicated that sucrose degrades into glucose and a reactive fructofuranosyl cation. Interestingly, glucose takes part mostly in the formation of intermediates, glyoxal and especially 3-deoxyglucosone rather than acrylamide formation. On the other hand, fructofuranosyl cation contributed mostly to the formation of 5-hydroxymethylfurfural which was found to be the most important intermediate precursor of acrylamide formed in coffee during roasting.