Effects of moisture content, molecular weight, and crystallinity on the glass transition temperature of inulin

Effects of saccharide type and extended heating on the Maillard reaction and physicochemical properties of high-solid gelatin gels

This research delves into the Maillard reaction (MR) in high-solid gelatin-saccharide mixtures consisting of 8% and 72% of allulose, fructose, or fructo-oligosaccharides, which were subjected to varied duration (0-60min) of thermal processing prior to gelation. Physicochemical properties of the gels, including color, chemical composition, protein crosslinking, mechanical strength, in-vitro digestibility and antioxidant activities, were characterized. At pH ∼5.5 and intermediate water activities (0.6-0.7), fast browning was observed through sugar degradation and sugar-amine interactions, which were intensified by prolonged heating. The MR reactivity of saccharides followed: AL > FRU > FOS. Characteristic products (MRPs, e.g., α-dicarbonyls, 5-hydroxymethylfurfural, and advanced glycation end products) were identified, with the spectra of MRPs varying significantly between monosaccharides and oligosaccharides. The MR-induced protein glycation and crosslinking exhibited certain negative impacts on the gel strength and in-vitro protein digestibility. Furthermore, all gelatin-saccharide mixtures exhibited augmented antioxidant properties, with the gelatin-AL mixtures displaying the highest free radical scavenging rates.

Water Sorption Isotherm and Critical Water Activity of Amorphous Water-Soluble Carbohydrates Characterized by the Glass Transition Temperature

Water-soluble carbohydrates commonly exist in an amorphous state in foods and undergo glass-rubber transition (glass transition) at the glass transition temperature (Tg). The critical water content (Wc) and critical water activity (awc) are the water content and water activity (aw) at which the glass transition occurs at 298 K (typical ambient temperature), respectively. For amorphous water-soluble carbohydrates, Wc can be predicted from the Tg of anhydrous solid (Tgs) using previously reported equations. However, an approach for predicting awc is still lacking. This study aimed to establish an awc-predictive approach for amorphous water-soluble carbohydrates based on Tgs. First, the water sorption isotherms of four hydrogenated starch hydrolysates were investigated, and the results were analyzed using the Guggenheim-Anderson-de Boer (GAB) model. Second, the effect of Tgs on the GAB parameters (C, K, and Wm) was evaluated using the Tgs values reported in previous literatures. C and Wm decreased and increased logarithmically, respectively, with increasing 1/Tgs. K was fixed to 1 (constant), as it showed little variation. These results enabled the prediction of the GAB parameters from Tgs. The GAB model could then predict awc from Wc, which was determined using the previously established equations. The predicted awc values were in good agreement with the experimentally determined awc. Additionally, we demonstrated that this awc-prediction approach is also applicable to amorphous water-soluble electrolytes and partially water-insoluble carbohydrates. Thus, this approach can be used for the quality control of amorphous water-soluble carbohydrates and carbohydrate-based foods.

Effect of extraction methods on the chemical, structural, and rheological attributes of fructan derived from Arctium lappa L. roots

The focus of this study was the evaluation of how extraction techniques impact the chemical, structural, and rheological attributes of fructans extracted from Arctium lappa L. roots. Three distinct extraction procedures were used, utilizing water as solvent, infusion extraction conducted at ambient temperature (25 °C for 5 min), thermal extraction employing reflux (100 °C for 2 h), and ultrasound-assisted extraction (50 °C for 1.38 h with a 158 W output). Chemical characterization by Nuclear Magnetic Resonance (NMR) and colorimetric analyses revealed the obtaining of inulin-type fructans (yield 83 %). The degree of polymerization (DP) was found to be the lowest for ultrasound-assisted extraction (14.38), followed by the room-temperature (20.41) and thermal (21.14) extraction techniques. None of the extraction techniques appeared to modify the molecular structure of the isolated compounds. In X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses, distinct crystallization patterns were observed for the room-temperature and thermal extraction techniques, though all fractions consistently exhibited characteristic bands of inulin-type fructan. Rheological assessments indicated a viscoelastic nature of the fractions, with those extracted thermally demonstrating a greater viscosity. This study shows that the choice of extraction method can influence the structural characteristics of inulin-type fructans derived from the burdock root.

Effect of Water Vapor Sorption on Complex Formation in Amylose-lauric Acid Blend Powder

The purpose of this study was to understand the effect of relative humidity (RH) on amylose-lipid complex (ALC) formation in amylose-lauric acid blend powder held at 50 °C (temperature slightly higher than the melting point of lauric acid) using differential scanning calorimetry (DSC) and X-ray diffraction. From DSC curves, the melting of crystalized lauric acid and two melting peaks of ALC were observed depending on RH. ALC formation was confirmed by X-ray diffraction pattern. The melting enthalpy (∆Hm) of lauric acid in the sample held at RH 0 % was lower than that of lauric acid only though there was no ALC formation. This suggests that crystallization of lauric acid was prevented by amylose. The ∆Hm of lauric acid increased with an increase in RH up to 79.0 % because liquid lauric acid would have fused as the result of enhanced repulsive force between liquid lauric acid and hydrated amylose. The ∆Hm of ALC increased with an increase in RH between 79.0 and 95.0 %. For ALC formation, amylose has to be mobile in the system, but dehydrated amylose is in a glassy (immobilize) state. According to the glass to rubber transition behavior of amorphous polymer, amylose held at 50 °C is suggested to become rubbery (mobile) state at RH 76.0 %. This interpretation will explain the reason why ALC formation began to be observed at the RH range between 72.4 and 79.0 %.

Jerusalem artichoke (Helianthus tuberoses) dietary-fiber powder functionality

The artichoke tuber is full of nutrients, inulin, and phytochemicals. It has been used to treat illnesses including diabetes and colon cancer, as well as in food product formulation, but limited information on the Jerusalem artichoke tuber (JAT) powder characterization exists in the literature, hence in this paper, JAT was freeze and oven-dried. It was powdered into JAT-freeze-dried-(FD)-powder and oven-dried (OD)-powder. This enabled the JAT powder's functional and physical properties to be studied. As a result, JAT powder's morphology, microstructure, and functional groups, as well as the powder foaming, swelling, solubility, antioxidant, color pasting, bulk, packed, and particle distribution properties were studied. Results indicated that the average particle distribution size at Dx90 and Dx80 displayed a distinct difference at p ≤ 0.05, while the bulk (0.39 g/cm-3) and packed (0.48 g/cm-3) densities recorded a lower value for FD powder. The FD powder's foaming capacity (24.0%) was significantly distinct (p ≤ 0.05) from the OD powder. Also, the solubility of FD powder was 6.2 g/g at 50 °C, and that of OD powder was recorded as 2.3 g/g. Again, the FD powder had a higher ABTS+ (34.3 mM (TE)/g dw) and CUPRAC (94.61 mM (TE)/g dw) capacity. Besides, a significant (p ≤ 0.05) dissimilarity among the powder color parameters (L∗, a∗, b∗, C∗, and whiteness) was observed. More so, the XRD and FT-IR characterization established a semi-crystalline or amorphous nature of the powder containing polysaccharides, and a broad halo pattern 2 θ at an angle 19.3° and 20 ° for FD powder and OD powder respectively. The FD powder particles were more agglomerated than those of OD powder. This was seen as a microscopic image, again FD powder revealed a higher pasting temperature and a drop in peak viscosity. Based on the results obtained, JAT (FD and OD) powder has all the quality attributes required of a powder for culinary product formulation.

Glass transitions in frozen systems as influenced by molecular weight of food components

Freezing is a frequently used way to expand the storage life of foods with high water content. Under suitable cooling rates, frozen systems attain a condition of maximum freeze concentration, which is characterized by the glass transition temperature (T_g '), end point of freezing or onset of melting (T_m '), and concentration of solids (X_s ') in the maximum-freeze-concentrated matrix. The value of T_g ', T_m ', and X_s ' depends on the chemical composition of frozen system. Below T_g ', the rates of deteriorative reactions are significantly reduced. In this article, the data for T_g ', T_m ', and X_s ' of different frozen systems including sugars, starches, proteins, and food are collected and compiled. The trends in T_g ' and T_m ' data of food are investigated using molecular weight (MW) of food components. The T_g ' and T_m ' of most starches (increased by 2.46% to 87.3% and 10.8% to 85.0%) and some protein-rich foods (increased by 5.00% to 53.4% and 25.0% to 52.9%) were higher than the maximum values of sugar-rich foods. Both T_g ' and T_m ' values increased with increasing MW of solids in frozen food, reaching an asymptotic value. Moreover, there were exponential relationships between T_g ' or T_m ' values and MW for sugar and starch-rich foods taken together. Some studies found that frozen storage below T_g ' maintains the higher quality of food that was achieved by fast freezing. However, other studies found that there was no significant difference in the quality of frozen foods between storage temperature below and above T_g '. Therefore, storage below T_g ' is not the only factor for predicting the stability of frozen foods.

Effect of water activity on the mechanical glass transition and dynamical transition of bacteria

The purpose of this study was to clarify the glass-transition behavior of bacteria (Cronobacter sakazakii) as a function of water activity (aw). From the water sorption isotherm (298 K) for C. sakazakii, monolayer water content and monolayer aw were determined to be 0.0724 g/g-dry matter and 0.252, respectively. Mechanical relaxation was investigated at 298 K. In a higher aw range of over 0.529, the degree of mechanical relaxation increased with an increase in aw. From the effect of aw on the degree of mechanical relaxation, the mechanical awc (aw at which mechanical glass transition occurs at 298 K) was determined to be 0.667. Mean-square displacement of atoms in the bacteria was investigated by incoherent elastic neutron scattering. The mean-square displacement increased gradually with an increase in temperature depending on the aw of samples. From the linear fitting, two or three dynamical transition temperatures (low, middle, and high Tds) were determined at each aw. The low-Td values (142-158 K) were almost independent from aw. There was a minor effect of aw on the middle Td (214-234 K) except for the anhydrous sample (261 K). The high Td (252-322 K) largely increased with the decrease in aw. From the aw dependence of the high Td, the dynamical awc was determined to be 0.675, which was almost equivalent to the mechanical awc. The high Td was assumed to be the glass-transition temperature (Tg), and anhydrous Tg was estimated to be 409 K. In addition, molecular relaxation time (τ) of the bacteria was calculated as a function of aw. From the result, it is suggested that the progress of metabolism in the bacterial system requires a lower τ than approximately 6 × 10-5 s.

Effect of inulin on the pasting and retrogradation characteristics of three different crystalline starches and their interaction mechanism

At present, there are hardly any studies about the effect of inulin (IN) on the physicochemical properties and structures of different crystalline starches. In this study, three different crystalline starches (wheat, potato, and pea starch) were compounded with natural IN, and its pasting, retrogradation, and structural characteristics were investigated. Then, the potential mechanism of interaction between IN and starch was studied. The results showed that there were some differences in the effects of IN on the three different crystalline starch. Pasting experiments showed that the addition of IN not only increased pasting viscosity but also decreased the values of setback and breakdown. For wheat starch and pea starch, IN reduced their peak viscosity from 2,515 cP, 3,035 cP to 2,131 cP and 2,793 cP, respectively. Retrogradation experiment dates demonstrated that IN delayed gelatinization of all three starches. IN could reduce the enthalpy of gelatinization and retrogradation to varying degrees and inhibit the retrogradation of starch. Among them, it had a better inhibitory effect on potato starch. The addition of IN reduced the retrogradation rate of potato starch from 38.45 to 30.14%. Fourier-transform infrared spectroscopy and interaction force experiments results showed that IN interacted with amylose through hydrogen bonding and observed the presence of electrostatic force in the complexed system. Based on the above, experimental results speculate that the mechanism of interaction between IN and three crystalline starches was the same, and the difference in physicochemical properties was mainly related to the ratio of amylose to amylopectin in different crystalline starches. These findings could enrich the theoretical system of the IN with starch compound system and provide a solid theoretical basis for further applications.

Glass Transition Temperature of PLGA Particles and the Influence on Drug Delivery Applications

Over recent decades, poly(lactic-co-glycolic acid) (PLGA) based nano- and micro- drug delivery vehicles have been rapidly developed since PLGA was approved by the Food and Drug Administration (FDA). Common factors that influence PLGA particle properties have been extensively studied by researchers, such as particle size, polydispersity index (PDI), surface morphology, zeta potential, and drug loading efficiency. These properties have all been found to be key factors for determining the drug release kinetics of the drug delivery particles. For drug delivery applications the drug release behavior is a critical property, and PLGA drug delivery systems are still plagued with the issue of burst release when a large portion of the drug is suddenly released from the particle rather than the controlled release the particles are designed for. Other properties of the particles can play a role in the drug release behavior, such as the glass transition temperature (T_g). The T_g, however, is an underreported property of current PLGA based drug delivery systems. This review summarizes the basic knowledge of the glass transition temperature in PLGA particles, the factors that influence the T_g, the effect of T_g on drug release behavior, and presents the recent awareness of the influence of T_g on drug delivery applications.

Effects of glass transition and hydration on the biological stability of dry yeast

The purpose of this study was to determine the effects of glass transition and hydration on the storage stability of baker's dry yeast (Saccharomyces cerevisiae). The glass transition temperature (T_g ) of the yeast decreased with increase in water activity (a_w ), and a_w at which glass transition occurs at 25 °C was determined as the critical a_w (a_wc ). From mechanical relaxation measurements at 25 °C, the yeast exhibited a large mechanical relaxation above the a_wc , and the degree of mechanical relaxation increased gradually with increasing a_w . This behavior corresponded to a gradual increase in molecular mobility with increasing a_w in the rubbery liquid state. Freezable water was observed from a_w ≥0.810, and the proportion of freezable water increased with increasing a_w . Examination of the effect of a_w on the residual biological activity of yeast samples stored at 25 °C for 30 days revealed maximum residual biological activity at a_w  = 0.225 to 0.432. In the lower a_w range, the residual biological activity decreased because of oxidation of lipids. In the higher a_w range, the residual biological activity decreased gradually with increasing a_w . The yeast samples maintained a relatively high residual biological activity, because they could maintain relatively low molecular mobility even in the rubbery liquid state, as suggested by their mechanical relaxation behavior. At a_w ≥0.809, residual activity decreased to a negligible value. This could be explained by the appearance of secondary hydrate water (freezable water). Hydrate water protects yeast cells from lipid oxidation but reduces the T_g . As a result, the yeast cells are stabilized maximally only at the a_wc . PRACTICAL APPLICATION: Although the growth rate of yeast cells becomes negligible below a certain a_w , the biological activity of dry yeast decreases gradually during storage. The fact that dry yeast can be maximally stabilized at the a_wc is practically useful as a criterion for controlling storage stability. In addition, it was found that a remarkable reduction in the molecular mobility, which is otherwise ordinarily increased due to the glass-to-rubber transition, is prevented in yeast. It is possible that the crystallization of amorphous sugar can be prevented by yeast extract. The suggested effect is expected to result in enhanced quality of carbohydrate-based foods.

Physical and structural characteristics of starch-based and conventional cookies: Water sorption, mechanical glass transition, and texture properties of their crust and crumb

The physical properties of starch-based cookie (gluten free and low fat) were compared with those of conventional cookie in consideration for the difference between crust and crumb parts. The internal porosity of the samples was measured by X-ray computed tomography. The starch-based cookie had a higher porosity (0.61) than the conventional cookie (0.42). The mechanical glass-transition temperature (T_g ) of the samples was evaluated by the thermal rheological analysis. The anhydrous mechanical T_g of the starch-based cookie was much lower than that of the conventional cookie. The T_g -depression of the starch-based cookie induced by water sorption was more gradual than that of the conventional cookie. For both types of cookie, the crust components were more resistant to water plasticizing than crumb components because of the difference of the equilibrium water contents at each water activity. For the texture analysis of crust components, the whole samples were fractured. The starch-based cookie had a lower fracture force, distance, and energy than the conventional cookie at each water activity point. For the texture analysis of crumb components, a portion of the crust was removed from the whole samples, and the exposed crumb was compressed by a plunger. From the texture profile, a normalized linear length was evaluated. The normalized linear length for the starch-based cookie was higher than that for the conventional cookie. These results were corresponded to the differences in the undeveloped gluten and fat contents.

Physicochemical and functional properties of native and modified agave fructans by acylation

Native agave fructans were modified by an acylation reaction with lauric acid. Native and modified fructans were characterized using NMR, FTIR and various physicochemical and functional properties at different pHs were evaluated. NMR and FTIR spectra demonstrated the incorporation of lauric acid in the molecular structure of fructans. Modified agave fructans exhibited a color, moisture and water activity similar to native fructans, but properties such as solubility, swelling capacity, emulsifying activity and foam capacity were significantly modified by the acylation reaction mainly when the samples were analyzed at different pHs. The thermogram of the acylated fructans evidenced significant changes in thermal properties when compared with native fructans and acylated fructans were able to form micellar aggregates. In general, modified fructans showed improved functional properties in comparison with native fructans representing an important opportunity to improve the functionality of the foods in which it is incorporated.

Roles of maltodextrin and inulin as matrix formers on particle performance of inhalable drug nanocrystal-embedded microparticles

The objective of this study was to investigate the influence of inulin (IL) and maltodextrin (MD) as matrix formers on the physical properties of drug nanocrystal-embedded microparticles (NEM) during spray-drying and storage. The redispersibility, aerodynamic performance and phase behaviour of NEM/MD and NEM/IL stored at different water activity (a_w) values were evaluated. NEM with 2 g/g (relative to the weight of drug) of IL and MD exhibited the excellent performance after spray-drying. The water activity significantly influenced the redispersibility and aerodynamic performance of NEM/MD and NEM/IL. The NEM/MD presented a higher T_g at all a_w values than did NEM/IL. The moisture-induced collapse of the amorphous glassy matrix of IL and MD could be responsible for the poor redispersibility and aerodynamic performance of NEM/IL and NEM/MD, respectively. The NEM/MD exhibited better aerodynamic performance at high a_w (0.528) than did NEM/IL. Therefore, MD could be an excellent matrix former for inhalable NEM.

Moisture sorption characteristics of food powders containing freeze dried avocado, maltodextrin and inulin

Moisture adsorption isotherms of the freeze-dried powders containing avocado, maltodextrin and inulin with different ratio, were determined using gravimetric static method of saturated salt solutions at 25 °C and the range of the water activity from 0.11 to 0.86. The data obtained were evaluated using sorption models: BET (Brunauer-Emmett-Teller), GAB (Guggenheim, Anderson and deBoer), Peleg, Lewicki, Oswin and Henderson. The goodness of the fit evaluated on the basis of criteria such as coefficient of the determination and root mean square values. Sorption isotherm of the pure avocado powder was III type while curves plotted for others powders showed sigmoid shape. It was found that the Peleg model was the most adequate for representation of the sorption data of all analyzed blends. In order to characterize the research material, chemical composition of the edible part of the avocado fruit was determined. Main component of the dry matter was fat.

Stability of bifidobacteria entrapped in goat's whey freeze concentrate and inulin as wall materials and powder properties

Goat's whey was submitted to two cycles of block freeze concentration process, resulting in concentrate 1 and concentrate 2. Concentrate 1 was added with 5 g of inulin and both concentrates were inoculated with Bifidobacterium animalis ssp. lactis BB-12, the concentrates were then denoted as feed solutions 1 and 2, respectively. Feed solutions were spray-dried, resulting in powder 1 and 2. The stability of the bifidobacteria entrapped within the powders was evaluated for both spray-dried powders stored at 4 °C and 25 °C for 60 days. The spray-dried powders were also evaluated in relation to their physical and thermal properties. It was noted that Bifidobacteria displayed increased stability at refrigeration temperature. Analysis of physical properties indicated that the addition of inulin resulted in increased water solubility. However, both spray-dried powders displayed less flowability, as well as a yellow-greenish color. By evaluating the spray-dried powders thermal properties, it was possible to confirm that goat whey concentrates behave as excellent wall materials.

Advances in the Application of Microcapsules as Carriers of Functional Compounds for Food Products

Natural bioactive compounds and living cells have been reported as promising products with beneficial properties to human health. The constant challenge regarding the use of these components is their easy degradation during processing and storage. However, their stability can be improved with the microencapsulation process, in which a compound sensitive to adverse environmental conditions is retained within a protective polymeric material. Microencapsulation is a widely used methodology for the preservation and stabilization of functional compounds for food, pharmaceutical, and cosmetic applications. The present review discusses advances in the production and application of microcapsules loaded with functional compounds in food products. The main methods for producing microcapsules, as well as the classes of functional compounds and wall materials used, are presented. Additionally, the release of compounds from loaded microcapsules in food matrices and in simulated gastrointestinal conditions is also assessed.

Effect of maltodextrin reduction and native agave fructans addition on the physicochemical properties of spray-dried mango and pineapple juices

The effects of the partial replacement of maltodextrin by native agave fructans on the characteristics of spray-dried pineapple and mango powder were evaluated in this study. An experimental 3³ design, three concentrations of maltodextrin (5, 7, and 10%), three concentrations of native agave fructans (0, 2, and 4%), and three feed temperatures (110, 115, and 120  ℃) were used. The results using the treatment in which only maltodextrin was used as a reference indicated that an increment in the inlet temperature decreases the moisture content, a_w, and solubility. Likewise, an increase (more than 2%) in fructans concentration generates products with increased a_w, moisture, hygroscopicity, wettability, and greater solubility. Additionally, no modification of storage stability was observed. Mango and pineapple powder color were affected mainly by the inlet temperature, causing an increase in luminosity (L*) and a decrease in parameter ( a*). A scanning electron microscopy showed spherical powder particles with certain contractions; powder stability in treatments with native agave fructans was not modified in the treatment at 2%. Finally, the addition of 2% agave fructans as carrier material was able to reduce the maltodextrin concentration of the spray drying process.

Effect of drying parameters on the physical, morphological and thermal properties of spray-dried inulin

This study focuses on the thermal, morphological and physical properties of spray-dried chicory root inulin using a thermogravimetric analyzer, environmental scanning electron microscopy, X-ray diffractogram and modulated differential scanning calorimetry. Different spray-drying conditions were investigated by varying inlet temperature, outlet temperature and aspirator speed. The starting material was semicrystalline. A feed temperature of 95°C was employed, which produced a completely transparent solution for spray drying. At that particular temperature, the powder samples obtained were entirely amorphous and morphology resembled each other except for higher solid content. The low glass transition temperature (T g) (106.83°C) was evident by treating low-molecular-weight samples, whereas high-molecular-weight samples exhibited high T g (125.81°C). The semicrystalline samples due to the high concentration and milky dispersion exhibited high decomposition temperature. The feed temperature, molecular weight and concentration of the samples tend to have a significant effect on the properties of spray-dried inulin.

Inhalable siRNA-loaded nano-embedded microparticles engineered using microfluidics and spray drying

Medicines based on small interfering RNA (siRNA) are promising for the treatment of a number of lung diseases. However, efficient delivery systems and design of stable dosage forms are required for inhalation therapy, as well as cost-effective methods for manufacturing of the final product. In this study, a 3D-printed micromixer was used for preparation of siRNA-dendrimer nanocomplexes, which were subsequently processed into microparticle-based dry powders for inhalation using spray drying. By applying the disposable micromixer, nanocomplexes were prepared of an average hydrodynamic diameter comparable to that of nanocomplexes prepared by manual mixing, but with narrower size distribution and low batch-to-batch variation. The nanocomplexes were processed into nanoembedded microparticles using different saccharide excipients. Data showed that siRNA integrity and bioactivity are retained after processing, and nanocomplexes could be reconstituted from the dry powders. The amorphous saccharide excipients trehalose and inulin provided better stabilization than crystalline mannitol, and they enabled full reconstitution of the nanocomplexes. In particular, a binary mixture of trehalose and inulin showed optimal stabilization, and enhanced cellular uptake and gene silencing efficiency. This study demonstrates that inexpensive and scalable micromixers can be used to optimize the production of siRNA-dendrimer nanocomplexes, and they can be applied in combination with spray drying for the engineering of dry powder formulations suitable for delivery of siRNA to the therapeutic target site.

Stabilization of freeze-dried Lactobacillus paracasei subsp. paracasei JCM 8130T with the addition of disaccharides, polymers, and their mixtures

Although freeze-drying is a widely used dehydration technique for the stabilizing of unstable lactic acid bacteria, Lactobacillus paracasei subsp. paracasei JCM 8130^T (L. paracasei) is destabilized after freeze-drying and subsequent storage. In order to improve the stability of freeze-dried L. paracasei, effects of disaccharides (sucrose and trehalose), polymers (maltodextrin; MD and bovine serum albumin; BSA), and their mixtures on the survival rate of freeze-dried L. paracasei were investigated. The survival rate of non-additive sample decreased slightly after freeze-drying but decreased drastically after subsequent storage at 37 °C for 4 weeks. The reduction was diminished by the addition of disaccharides and polymers. The stabilizing effect of disaccharides was not affected by the co-addition of MD. In contrast, the disaccharide-BSA mixtures had a synergistic stabilizing effect, and the survival rates were largely maintained even after storage. It is suggested that the synergistic effect originates from the conformational stabilization of the dehydrated bacteria.

Effect of the biobased linear long-chain monomer on crystallization and biodegradation behaviors of poly(butylene carbonate)-based copolycarbonates

In this work, high-molecular-weight poly(butylene carbonate)-based copolycarbonates with highly enhanced crystallization property were successfully prepared, by randomly copolymerizing with a biobased linear long-chain aliphatic diol.

Physical properties of inulin and inulin-orange juice: physical characterization and technological application

In this work two systems based on a carbohydrate polymer were studied: inulin as model system and inulin-orange juice as complex system. Both system were stored at different water activity conditions and subsequently characterized. Water adsorption isotherms type II were fitted by the GAB model and the water monolayer content was determined for each system. From thermal analyzes it was found that at low water activities (aw) systems were fully amorphous. As aw increased, crystallinity was developed. This behavior was corroborated by X-ray diffraction. In the inulin-orange juice system, crystallization appears at lower water activity caused by the intensification of the chemical interaction of the low molecular weight species contained in orange juice. Glass transition temperature (Tg), determined by modulated differential scanning calorimeter, decreased with aw. As water is adsorbed, the physical appearance of samples changed which could be observed by optical microscopy and effectively related with the microstructure found by scanning electron microscopy.

A user-friendly model for spray drying to aid pharmaceutical product development

The aim of this study was to develop a user-friendly model for spray drying that can aid in the development of a pharmaceutical product, by shifting from a trial-and-error towards a quality-by-design approach. To achieve this, a spray dryer model was developed in commercial and open source spreadsheet software. The output of the model was first fitted to the experimental output of a Büchi B-290 spray dryer and subsequently validated. The predicted outlet temperatures of the spray dryer model matched the experimental values very well over the entire range of spray dryer settings that were tested. Finally, the model was applied to produce glassy sugars by spray drying, an often used excipient in formulations of biopharmaceuticals. For the production of glassy sugars, the model was extended to predict the relative humidity at the outlet, which is not measured in the spray dryer by default. This extended model was then successfully used to predict whether specific settings were suitable for producing glassy trehalose and inulin by spray drying. In conclusion, a spray dryer model was developed that is able to predict the output parameters of the spray drying process. The model can aid the development of spray dried pharmaceutical products by shifting from a trial-and-error towards a quality-by-design approach.