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Glycogen is important for transmission of V. vulnificus undergoing disparate environments of nutrient-rich host and nutrient-limited marine environment. The malZ gene of V. vulnificus encoding a maltodextrin glucosidase was cloned and over-expressed in E. coli to investigate its roles in glycogen/maltodextrin metabolism in the pathogen. The malZ gene encoded a protein with a predicted molecular mass of 70 kDa. The optimal pH and temperature of MalZ was 7.0 and 37 °C, respectively. MalZ hydrolyzed maltodextrin to glucose and maltose most efficiently, while hydrolyzed other substrates such as starch, maltose, β-cyclomaltodextrin, and glycogen less efficiently. The activity was enhanced greatly by Mn2+. It also exhibited transglycosylation activity toward excessive maltotriose. The malZ knock-out mutant accumulated 2.3–5.6-fold less glycogen than the wild type when excessive maltodextrin or glucose was added to LB medium, while it accumulated more glycogen than the wild type (3.5-fold) in the presence of excessive maltose. Growth and glycogen accumulation of the mutant were retarded most significantly in the M63 minimal medium supplemented with 0.5% maltodextrin. Side chain length distributions of glycogen molecules were varied by the malZ mutation and types of the excessive carbon source. Based on the results, MalZ of V. vulnificus was likely to be involved in maltose/maltodextrin metabolism, thereby balancing synthesis of glycogen and energy generation in the cell. The bacterium seemed to have multiple and unique pathways for glycogen metabolism according to carbon sources.

Klebsiella variicola is a Gram-negative bacterium belonging to the Klebsiella pneumoniae species complex. It is frequently isolated from many plants, where it is involved in nitrogen fixation and growth. However, it has also been described as associated with disease in humans and animals. Escherichia coli and K. pneumoniae are related members of the Enterobacteriaceae family that metabolize maltose and maltodextrins. However, only isolates of the K. pneumoniae species complex metabolize starch. In E. coli , four enzymes metabolize maltodextrins, including a periplasmic ?-amylase (MalS), a cytoplasmatic amylomaltase (MalQ) , a maltodextrin phosphorylase (MalP), and a maltodextrin glucosidase (MalZ). Considering the medical and agricultural importance of K. variicola and to better understand its role in maltodextrin degradation, the malZ gene was cloned from an isolate of this species, and the coded protein was recombinantly expressed and characterized. The K. variicola MalZ protein sequence was 79% identical to the E. coli MalZ and is the fifth enzyme and second maltodextrin glucosidase characterized from the GH13_21 CAZy subfamily. Its modeled monomeric structure shows ?-stranded amino- and carboxy-terminal domains and a catalytic domain with a (?/?)8-barrel. The 70 kDa expressed enzyme could promote glucose release from maltoheptaose and other maltodextrins. The enzyme’s optimum temperature was 30°C. The K M and V max for maltoheptaose were 32.7 mM and 2.58 ?mol/min of glucose released, respectively. Considering the characteristics of degrading maltodextrins, the release of glucose from this substrate, and the high profit of recombinant expression, the enzyme expressed in this work could be used in the industrial degradation of starch as a saccharifying enzyme.

The aim of the current work was to produce sodium alginate (SA) maltodextrins (MD) based functional films incorporated with phenolic extract of Azolla pinnata leaves fern (AF) by solution molding technique. AF with different concentrations (0.8, 1.2 and 1.6% w/w) were integrated inside SA.MD films. The resulted films were characterized to investigate the surface structure by scanning electron microscope (SEM), thermal disposal by (DSC), crystallization by X-ray diffraction (XRD), potential interaction by (FT-IR) and some mechanical properties. The SEM micrographs indicated that the higher concentration (1.6%) of AF extract caused development of wrinkles on the surface of films. And as a result, there were a significant decrease of elongation at break (EB) and tensile strength properties of films to 55.01 and 58.42%, respectively. By continues addition of AF extract to SA.MD films, the film thickness increased from 0.124 to 0.181 mm, the scavenging and antimicrobial properties were enhanced by the attendance of ferulic acid, rutin, thiamine, tamarixetin, astragalin, quercetin, chlorogenic acid and epicatechin inside extracts. Furthermore, the films solubility, swelling degree and water vapor permeability were decreased to 13.08%, 26.41% and 1.662 × 10− 10 g H2O/m s p.a. The resulted films could be utilized as composite packaging material for different food applications.

Resistant maltodextrin (RMD), derived from the heat treatment of corn starch, is a water-soluble fermentable functional fibre. Its benefits include being a satiating prebiotic, reducer of glucose and triglycerides in the blood, and promoter of good gut health. Despite its functionality, there is still further need for investigations of its use as a food formulating ingredient and their physicochemical property changes. This study aimed to evaluate the effect of RMD addition on the physicochemical and structural properties of spray-dried orange juice powders. The physicochemical properties evaluated were water content, hygroscopicity, bulk density, porosity, water solubility, water absorption index, colour, and microstructure. We found RMD addition improved the orange juice spray-dried powder productivity. Samples with RMD were more porous and less hygroscopic, and they presented low water content; physicochemical properties desirable for powders. Therefore, to reach a compromise between powders’ functionality and physicochemical property changes, especially colour, the addition of 5 RMD% is recommended.

This study investigates the influence of polysaccharides with varying dextrose equivalent on the free volume and pharmaceutical stability of lyophilized formulations. Free volume, estimated from the ortho-positronium pick-off annihilation lifetime using positron annihilation lifetime spectroscopy, was used as a proxy for the molecular mobility of the formulation matrices and their stability. Formulations containing polysaccharides with higher dextrose equivalent, such as maltodextrin, exhibited reduced free volume and enhanced stability. Furthermore, the addition of a sugar or a polyol to these formulations was found to be effective, producing even smaller free volume. These findings underscore the potential for rational excipient design based on the dextrose equivalent to improve formulation stability.

Abstract Fructooligosaccharides (FOS), Ad-fructooligosaccharides (Ad-FOS), resistant maltodextrin (RMD), and maltooligosaccharides (MOS) are commercially available prebiotic oligosaccharides. In this study, the effects of prebiotics on the human gut microbial ecosystem were evaluated using an in vitro gut model. FOS and Ad-FOS showed tolerance to digestion, whereas RMD and MOS showed moderate digestion by digestive enzymes. In in vitro fecal fermentation, Bifidobacterium spp. increased in the following order: FOS, Ad-FOS, MOS, and RMD, whereas Bacteroides spp. increased in RMD medium. Bacteroides xylanisolvens exhibited cross-feeding by enabling the growth of other beneficial bacteria during co-culture in RMD medium. In metabolome analysis, total short-chain fatty acids (SCFAs) were highly produced in the following order: RMD, FOS, MOS, and Ad-FOS; acetate in the order of FOS, MOS/RMD, and Ad-FOS; butyrate in the order of RMD, MOS, FOS, and Ad-FOS; and propionate only in RMD. In addition, the conversion of betaine to trimethylamine was rarely affected in the following order: MOS, RMD, FOS, and Ad-FOS. Lastly, the four oligosaccharides inhibited the adhesion of pathogenic Escherichia coli to human epithelial cells to a similar extent. The comparative analysis results obtained in this study will provide comprehensive information of these substances to manufacturers and customers. The oligosaccharides, FOS, Ad-FOS, RMD, and MOS, exhibited prebiotic effects, but their action patterns and efficacy vary owing to their different digestibility, fermentability, and cross-feeding interactions in complex microbiome ecosystems.

Spray-drying technique is widely used in the production of powder from fruit juices. Carrier type and inlet temperature are two major factors that influence drying efficacy and powder quality. In this study, barberry juice (Berberis vulgaris L.) was powdered using 12% (w/v) maltodextrin with 4–7 and 16.5–19.5 dextrose equivalents (DEs) at two different inlet temperatures at 130 and 150 °C. Moisture content, bulk density, hygroscopicity, color, total anthocyanin content (TAC), microstructure, glass transition temperature and the X-ray diffraction of the prepared powders were investigated. The inlet temperatures and the utilization of maltodextrin with different DEs as the carrier agent, had different effects on the physicochemical properties of the prepared powders. By increasing the inlet temperature, the moisture content decreased while hygroscopicity increased. At inlet temperature of 130 °C, powders prepared with lower maltodextrin DEs had higher moisture content and bulk density, but lower hygroscopicity (p < 0.05). The SEM result demonstrated that, a decrease in color of the powder by increasing the inlet temperature. Darker particles with higher a* values and total anthocyanin contents (4.68 mg/g) were obtained when a larger amount of maltodextrin with lower DEs was utilized. At the lower inlet temperature, the powder particles had smoother surfaces. The glass transition temperature of the powders ranged from 47.1 to 54 °C based on different inlet temperature and DEs as well as moisture content. The amorphous surfaces of the dried particles were verified via X-ray diffraction profiling. Overall, applying different DEs in combination and lower inlet temperature led to the more appropriate physical and functional properties to the barberry powder. The TAC significantly depended upon the carrier agent, the inlet air temperature, and the interaction between the two variables.

Despite being the initial choice for treating toxoplasmosis, sulfadiazine and pyrimethamine have limited effectiveness in eliminating the infection and were linked to a variety of adverse effects. Therefore, the search for new effective therapeutic strategies against toxoplasmosis is still required. The current work is the first research to assess the efficacy of spiramycin-loaded maltodextrin nanoparticles (SPM-loaded MNPs) as a novel alternative drug therapy against toxoplasmosis in a murine model. Fifty laboratory-bred Swiss albino mice were divided into five groups: normal control group (GI, n  = 10), positive control group (GII, n  = 10), orally treated with spiramycin (SPM) alone (GIII, n  = 10), intranasal treated with SPM-loaded MNPs (GIV, n  = 10), and orally treated with SPM-loaded MNPs (GV, n  = 10). Cysts of  Toxoplasma gondii  ME-49 strain were used to infect the mice. Tested drugs were administered 2 months after the infection. Drug efficacy was assessed by counting brain cysts, histopathological examination, and measures of serum CD19 by flow cytometer. The orally treated group with SPM-loaded MNPs (GV) showed a marked reduction of brain cyst count (88.7%), histopathological improvement changes, and an increasing mean level of CD19 (80.2%) with significant differences. SPM-loaded MNPs showed potent therapeutic effects against chronic toxoplasmosis. Further research should be conducted to assess it in the treatment of human toxoplasmosis, especially during pregnancy. Graphical Abstract

PurposeMaltodextrin (MDX) is a polysaccharide food additive commonly used as oral placebo/control to investigate treatments/interventions in humans. The aims of this study were to appraise the MDX effects on human physiology/gut microbiota, and to assess the validity of MDX as a placebo-control.MethodsWe performed a systematic review of randomized-placebo-controlled clinical trials (RCTs) where MDX was used as an orally consumed placebo. Data were extracted from study results where effects (physiological/microbial) were attributed (or not) to MDX, and from study participant outcomes data, before-and-after MDX consumption, for post-publication ‘re-analysis’ using paired-data statistics.ResultsOf two hundred-sixteen studies on ‘MDX/microbiome’, seventy RCTs (n = 70) were selected for analysis. Supporting concerns regarding the validity of MDX as a placebo, the majority of RCTs (60%, CI 95% = 0.48–0.76; n = 42/70; Fisher-exact p = 0.001, expected < 5/70) reported MDX-induced physiological (38.1%, n = 16/42; p = 0.005), microbial metabolite (19%, n = 8/42; p = 0.013), or microbiome (50%, n = 21/42; p = 0.0001) effects. MDX-induced alterations on gut microbiome included changes in the Firmicutes and/or Bacteroidetes phyla, and Lactobacillus and/or Bifidobacterium species. Effects on various immunological, inflammatory markers, and gut function/permeability were also documented in 25.6% of the studies (n = 10/42). Notably, there was considerable variability in the direction of effects (decrease/increase), MDX dose, form (powder/pill), duration, and disease/populations studied. Overall, only 20% (n = 14/70; p = 0.026) of studies cross-referenced MDX as a justifiable/innocuous placebo, while 2.9% of studies (n = 2/70) acknowledged their data the opposite.ConclusionOrally-consumed MDX often (63.9% of RCTs) induces effects on human physiology/gut microbiota. Such effects question the validity of MDX as a placebo-control in human clinical trials.

‘Cempedak’ ( Artocarpus integer ) is an aromatic fruit that looks similar to jackfruit. Response surface methodology was used to optimize the spray-drying process to produce ‘cempedak’ fruit powder, with inlet air temperature (140–180 °C) and maltodextrin (DE 10) concentrations (5–15% w/w) as independent variables. Statistical analysis revealed that these variables significantly affected process yield, moisture content, water activity, hygroscopicity, L * value of powder and carotenoid content. Inlet air temperature had a negative correlation with all significant variables. At the same time, maltodextrin concentration was found to be positively correlated with all significant powder variables except process yield and moisture content. The recommended optimum spray-drying conditions for drying ‘cempedak’ juice were inlet air temperature and maltodextrin concentration of 160 °C and 15% (w/w), respectively. Under optimized spray-drying conditions, the yield of ‘cempedak’ powder was 60.5%, with moisture content, water activity, hygroscopicity and carotenoid content of 6.07%, 0.22, 25.8 g/100 g and 1.00 mg/g, respectively.