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A classic problem in preservation is the microbes can grow in low-moisture foods. In this paper, the water sorption and thermodynamic properties of glucose/WPI solid matrices were measured, while their molecular mobility was analyzed and associated with the microbial growth of D. Hansenii at various aw and 30 ºC. Although the sorption isotherms, Tg, and relaxation processes of studied matrices were affected by aw and WPI, the microbial growth showed highly dependent on water mobility rather than aw. Hence, we introduced water usability (Uw), derived from the mobility difference between system-involved water and liquid pure water explicating from the classical thermodynamic viewpoint, to describe the dynamic changes of water mobility in glucose/WPI matrices. Despite to aw, the yeast growth rate was enhanced at high Uw matrices concomitantly with a rapid cell doubling time. Therefore, the proposed Uw provides a better understanding of the water relationships of microorganisms in food preservation.

INTRODUCTION: Women and healthcare providers lack adequate information on medication safety during pregnancy. While resources describing fetal risk are available, information is provided in multiple locations, often with subjective assessments of available data. We developed a list of medications of greatest concern during pregnancy to help healthcare providers counsel reproductive-aged and pregnant women. METHODS: Prescription drug labels submitted to the U.S. Food and Drug Administration with information in the Teratogen Information System (TERIS) and/or Drugs in Pregnancy and Lactation by Briggs & Freeman were included (N = 1,186 medications; 766 from three data sources, 420 from two). We used two supervised learning methods (‘support vector machine’ and ‘sentiment analysis’) to create prediction models based on narrative descriptions of fetal risk. Two models were created per data source. Our final list included medications categorized as ‘high’ risk in at least four of six models (if three data sources) or three of four models (if two data sources). RESULTS: We classified 80 prescription medications as being of greatest concern during pregnancy; over half were antineoplastic agents (n = 24), angiotensin converting enzyme inhibitors (n = 10), angiotensin II receptor antagonists (n = 8), and anticonvulsants (n = 7). DISCUSSION: This evidence-based list could be a useful tool for healthcare providers counseling reproductive-aged and pregnant women about medication use during pregnancy. However, providers and patients may find it helpful to weigh the risks and benefits of any pharmacologic treatment for both pregnant women and the fetus when managing medical conditions before and during pregnancy.

Present study developed a strength analysis for relaxation time (τ) in characterizing physicochemical properties and structural transformation of freeze-dried honey/whey protein isolate (H/WPI) and honey/maltodextrin (H/MD) models based on water sorption, time-dependent crystallization, glass transition, and α-relaxation at various water activities (0.11aw to 0.76aw) and 25 °C. Water sorption data of two models explained WPI was a more effectiveness drying stabilizer than MD as H/WPI model owned higher monolayer water content. Crystallization was observed in prepared models with drying-aids content below 50% of mass ratios at water activity above 0.44aw and 25 °C, whereas the extent of crystallization and structural collapse were inhibited by WPI and MD addition based on sorption isotherms. Glass transition temperature, α-relaxation temperature, and τ for two models were composition-dependent and altered by water, WPI, and MD at water activity below 0.44aw. According to strength analysis of τ, the S for H/WPI and H/MD models was affected by drying-aids and could give a quantitative measure to estimate compositional effects on τ. Moreover, a S-involved state diagram was established to determine the critical parameters (water content and S) for controlling structural transformation of honey powder models during production and storage, i.e., collapse and stickiness.

Maltose crystallization affects the processibility and stability of sugar-rich foods. This study introduced a color-based clustering algorithm (CCA) to analyze crystallinity from the images of amorphous maltose/protein models. The XRD and DSC were also implemented in maltose crystallization characterization and validated the CCA analysis. The results indicated that CCA could effectively recognize maltose crystals (R = 0.9942), and amorphous maltose mainly crystallized to anhydrate α-maltose and β-maltose monohydrate according to its morphological aspects measured by CCA, XRD, and DSC. However, protein could change the mechanism of maltose crystal formation by disturbing the mutarotation and recrystallization processes of unstable β-maltose. Besides, maltose crystal formation and crystallinity were governed by molecular mobility as the CCA-derived Avrami indexes changed with the Strength parameter. Compared to XRD and DSC, the proposed CCA can provide a rapid and quantitative measure for maltose crystallinity and has great potential applications in the online detection of sugar crystallization.

BACKGROUND Maltose is an essential derivative of starch. To understand the processability and stability of maltose-containing foods, material characterization of the phase and state transition from its amorphous state is required. Although the crystallization of amorphous maltose is well understood, few studies have reported the relationship between the crystallization and the glass transition temperature (Tg )-related molecular mobility. In this study, water sorption, crystallization, Tg -related α-relaxation, and the corresponding time factor for amorphous maltose and maltose / whey protein isolate (WPI) mixtures are measured at various water activity (aw ) levels and 25 °C. RESULTS The water-additive principle for maltose / WPI mixtures was observed at aw ≤ 0.440 at the molecular level, whereas the crystallization of amorphous maltose occurred at high aw values (≥0.534). The crystal formation and crystallization kinetics of amorphous maltose were affected by water and WPI at aw ≥ 0.534 and 25 °C, as determined by X-ray diffraction. The relationship between Tg and the water content was fitted by the Gordon-Taylor model, and its constant showed a compositional dependence for the maltose / WPI mixtures. The α-relaxation temperature of the amorphous samples decreased due to water plasticization, but increased with an increase in the WPI quantity. The Strength (S) value for amorphous maltose, which was a quantitative estimate of the compositional effects on molecular mobility, was based on the William-Landel-Ferry (WLF) equation. CONCLUSION The S concept exhibits considerable potential for application in controlling the crystallization of amorphous maltose and improving the processability and stability of maltose-containing foods. © 2020 Society of Chemical Industry.

Lactose is a common component found in many foods and dairy products. In this study, the vibrational signatures in the crystalline structure of α-, β-, and α-lactose monohydrate were calculated based on quantum chemistry calculation (QCC), whilst the vibrational spectra in freeze-dried lactose equilibrated at various aw and pre-humidified amorphous lactose (0.33 aw) stored from 25 to 95 °C were determined by using Raman and FT-IR spectroscopies. The vibrational signatures of crystalline lactose were affected by the presence of water according to QCC results. Water plasticization, involving water insertion, exposure of H-bonding sites, and structure disruption, was accelerated by storage temperature based on Raman and FT-IR spectra analysis. Raman spectra indicated that the crystal formation of lactose was affected by aw and storage temperature. Moreover, the spectral changes assigned in OH group provided useful information for determining the critical aw or temperature when Tg-related molecular mobility occurred in lactose-containing products.

In this study, the lactose/Whey Protein Isolate (WPI) composite hydrocolloids were prepared as an printing material for subsequent 3D printing. The results showed that the rheological, viscoelastic, thermal and mechanical properties of the studied hydrocolloids were composition dependent, which was directly linked to the printing fidelity of printed objects. The morphology of all printed objects showed a porous microstructure, and their porosity was changed by lactose addition. This outcome resulted from lactose-derived co-solvation discouraging WPI aggregation during the printing process, which was necessary for improving printing performance. Moreover, an innovative Fluidness concept (F), using material-specific WLF analysis of relaxation times, was introduced to quantify the fluidness of lactose/WPI composite hydrocolloids at a certain decay of timescales (from 10

β-Carotene (β-Car) is insoluble compounds in water and liable to degradation, which has health benefits for human beings. Although layer-by-layer (LBL) emulsions provide a better protection for β-Car towards environmental stresses, the handling and transportation of LBL emulsions still faces restrictions. In this paper, therefore, the LBL emulsions including β-Car were carefully prepared and encapsulated to obtain vitreous encapsulated solids (VES) using trehalose and maltodextrins (MD) as wall materials. Morphological results indicated that the LBL emulsions were formed a spheric shape, in where the polyelectrolyte shell was 30 nm. The MD exhibited the characteristics of not easy to absorb moisture, suitable carrier, and good stabilizer, which could improve the stability of VES systems at studied environmental stresses. Despite compositional effects from MD and environmental stresses, LBL emulsions changed the water sorption behavior of VES as oil dispersion in storage. Strength analysis indicated that LBL emulsions lubricated systems and increased the molecular mobility of wall materials. Structural collapse, rapid color changes, and β-Car loss were confirmed in VES systems at 0.56 a

Fundamental knowledge of physicochemical properties of polymeric food materials is of practical importance in food and pharmaceutical industry. Effects of water, molecular weight, and lactose addition on glass transition temperature (Tg), α-relaxations, and relaxation time (τ) of amorphous poly (vinyl pyrrolidone) (PVP) and maltodextrin (MD) were studied at various aw and 25 °C. Water sorption behaviour of amorphous PVP and MD was Mwavg–dependent at aw ≤ 0.44, whereas the molecular size effects dominated the sorption process of MD at aw ≥ 0.56 and 25 °C. Fractional water sorption was confirmed in studied polymers/lactose mixtures at aw ≤ 0.44 in molecular scale, whilst collapsed structure of above mixtures were observed at aw ≥ 0.44 during storage up to 20 days at 25 °C. Despite of the calorimetric onset Tg of amorphous polymers/lactose mixtures showed a composition-independent at aw ≤ 0.44, Tg, α-relaxation, and τ of PVP and MD were disturbed by water, molecular weight and size, and adding lactose. Structural strength (S) of PVP was determined by its molecular weight at aw ≤ 0.44, whereas molecular size dominated the S of MD at 0.44 ≤ aw ≤ 0.76 due to water migration. The changes of aw and lactose addition significantly disturbed the S of studied polymers. Moreover, a combined use of water sorption isotherm and the relationship of S and aw gave a quantitative measurement of compositional effects and could be used to control the physicochemical properties of amorphous food polymers, such as collapse.

The glass transition and corresponding glass transition temperature (T g ) as found for food solids have received considerable attention, and their relationships with food solid behavior in various processes and food storage have been disputed. However, understanding glass transition-associated relaxations and their coupling with physicochemical properties of food materials is still a challenging and developing area of food material science. This review shows the improved understanding of the glass transition, structural relaxations, and corresponding relaxation times (τ) as well as their relevant applications on glassy food solids. Above information contributes to understanding of physical changes, molecular mobility, and solid flow characteristics of food components around their glass transition during processing and storage. We also emphasized the limitations of “fragile” concept in food solids and introduced a “strength, S” parameter to measure and describe solid flow characteristics of amorphous food mixtures by using a William-Landel-Ferry (WLF)-based approach for the analysis of α-relaxation derived τ above T g . The use of the S concept, therefore, can provide a quantitative measure to estimate compositional effects on τ and the control of solid properties, such as stickiness, caking, collapse, and crystallization.

Freeze-dried lactose and lactose/whey protein isolate (WPI) mixtures were used as amorphous food models at various aw, and the effects of temperature and water and WPI contents on physical state were analyzed. Thermal behavior and mechanical properties were studied and Williams-Landel-Ferry (WLF) model was fitted to structural relaxation times (τ). The WLF-analysis gave a strength parameter (S) that was used to describe structural strength of the food solids. Our results showed that lactose and WPI in mixtures exhibited fractional water sorption. Thermal properties and structural strength of the solids were affected by water and WPI while Tg measured for the lactose/WPI systems followed that of the lactose component and showed phase separation of lactose and proteins. A relationship between S and water content was established, whereas the crystallization of amorphous lactose was more rapid in systems with a smaller S. Therefore, S provided a simple and convenient measure of τ controlling structure formation in food processing as well as to control lactose crystallization. Industrial relevance Sugars are common ingredients and often used as a mixture with other components, e.g., proteins, in the food and pharmaceutical industries. Thus, understanding the physical state and thermal behavior of sugar containing food materials has a great importance in the development of processing and shelf life control procedures for such ingredients and relevant products. This study provides physicochemical information about thermal and mechanical properties of freeze-dried lactose/whey protein systems used as food models at various water activities. Data on water sorption, time-dependent lactose crystallization, calorimetric glass transition and crystallization temperatures, and structural relaxation times can be used to understand and predict structural changes during processing and storage of relevant foods. Moreover, the structural strength concept, described in this study, allows of the control of crystallization behavior as a physical state and time-dependent phenomenon, and therefore, stability of food and pharmaceutical materials

Water sorption-induced crystallization, α-relaxations and relaxation times of freeze-dried lactose/whey protein isolate (WPI) systems were studied using dynamic dewpoint isotherms (DDI) method and dielectric analysis (DEA), respectively. The fractional water sorption behavior of lactose/WPI mixtures shown at aw ≤ 0.44 and the critical aw for water sorption-related crystallization (aw(cr)) of lactose were strongly affected by protein content based on DDI data. DEA results showed that the α-relaxation temperatures of amorphous lactose at various relaxation times were affected by the presence of water and WPI. The α-relaxation-derived strength parameter (S) of amorphous lactose decreased with aw up to 0.44 aw but the presence of WPI increased S. The linear relationship for aw(cr) and S for lactose/WPI mixtures was also established with R2 > 0.98. Therefore, DDI offers another structural investigation of water sorption-related crystallization as governed by aw(cr), and S may be used to describe real time effects of structural relaxations in noncrystalline multicomponent solids.

Water sorption, crystallization, calorimetric glass transition temperature ( T g ), structural relaxations and relaxation times ( τ ) of freeze-dried sugars (lactose and trehalose) and whey protein isolates (WPI) in mixed systems were measured at various water activities ( a w ≤ 0.76, and 25 °C). The results indicated that sugar/WPI mixtures showed fractional water sorption behavior. The crystallization and crystalline forms of lactose were affected by trehalose and WPI based on XRD analysis. DMA analysis showed that the α-relaxation temperatures ( T α ) at loss modulus peak at frequency of 0.5 Hz for sugar/protein systems were affected by the presence of water and WPI. The τ and T α −T g relationships in sugar/WPI systems were successfully modeled by using the WLF model. The WLF-type structural strength ( S ), indicating decrease of τ from 10 2 to 10 −2 s, of trehalose decreased with a w up to 0.44 (from 15.8 to 12.1 °C) but WPI increased S . Moreover, a relationship for S and water content for glass forming sugar systems at a w ≥ 0.56 was established. The S concept gave a quantitative measure to estimate compositional effects on τ and could be used to estimate crystallization of food solids components.

Structural relaxations and relaxation times, τ, of lactose in freeze-dried amorphous lactose and lactose-WPI mixture systems were studied with glass transition data. The results indicated that Tg, enthalpy relaxation and α-relaxation temperature, Tα, of amorphous lactose was affected by the presence of lactose crystals and WPI at 0.33 aw (25 °C) due to water migration. The τ and Tα−Tg relationship of the materials was successfully modeled by the WLF equation with the material-special constants (−C1 and C2). A strength parameter, S, indicating decrease of τ from 102 to 10−2 s, could be used to measure the structural stability of lactose systems above their glass transition. The strength of amorphous lactose decreased with aw increasing up to 0.44 and enhanced by α lactose crystals and WPI in storage at 0.33 aw. Hence, the strength parameter provided a simple and convenient means to measure compositional effects on structure formation in food processing.

Water sorption, time-dependent crystallization and XRD patterns of lactose and lactose–WPI mixtures were studied with glass transition data. The results indicated that the sorbed water of lactose–WPI mixtures was fractional and water content of individual amorphous components in lactose–WPI mixtures at each aw from 25 °C to 45 °C could be calculated. Crystallization occurred in pure lactose whereas partial crystallization was typical of lactose–WPI mixtures (protein content ≤ 50%) at intermediate and high aw (> 0.44 aw) from 25 °C to 45 °C. The extents of crystallization were significantly delayed by WPI. The Tg values of lactose–WPI systems showed the composition-dependent property in systems and might indicate the occurrence of phase separation phenomena during 240 h storage. XRD showed no anhydrous β-lactose and mixed α-/β-lactose with molar ratios of 4:1 crystals in crystallized lactose–WPI systems (70:30 and 50:50 solids ratios). Reduced crystallization in the presence of WPI was more pronounced possibly because of reduced nucleation and diffusion during crystal-growth. The present study showed that WPI could present an important role in preventing sugar crystallization.

Formulation and design of amorphous food solids structures for improved dehydration properties, stabilization of active components, and controlled structure deterioration require materials science characterization of components and mixtures. However, understanding phase transitions associated with structural relaxations and their coupling with properties of food materials is still a challenging and developing area of food materials science. Our laboratory has developed a new approach for the use of α-relaxation times (τ) and introduced a “Strength, S” concept, which is the temperature difference between the material temperature and its calorimetric onset glass transition temperature (Tg) that gives rise to a 104 reduction in τ (or viscosity), for characterization of noncrystalline food materials, their properties and performance in typical processing and storage conditions where a component or miscible components within food structure may undergo phase and state transitions. Besides the S concept of amorphous food solids, the Deborah number (De) was applied to provide a useful translation of measured τ to real experimental timescales. Our systems were composed of crystalline and amorphous lactose, trehalose, and whey protein isolates (WPI) at various water activities (0 ≤ aw ≤ 0.76) at 25 °C to 45 °C. Differential scanning calorimetry (DSC), dynamic-mechanical (DMA) and dielectric (DEA) analysis, static sorption measurement (SSM) and dynamic dewpoint isotherm (DDI) analysis, and powder X-ray diffractometry (XRD) were used in material characterization and determination of glass transition temperatures (Tg), α-relaxation temperatures (Tα) and corresponding τ (aw ≤ 0.44), water sorption (0.11 ≤ aw ≤ 0.76), time-dependent crystallization (0.65 ≤ aw ≤ 0.76) and crystalline forms of components. The static water sorption data and calorimetric Tg were modeled by using Guggenheim-Anderson-de Boer (GAB) and Gordon-Taylor (GT) relationships, respectively. Moreover, the William-Landel-Ferry (WLF) relationship was used to model the τ and Tα−Tg relationships of amorphous solids systems, where vi material-specific constants C1 and C2 were used to obtain S values. Both SSM and DDI measurements were part of fractional water sorption analysis of sugars/WPI mixtures at aw ≤ 0.44 which allowed quantification of water in specific components within solids mixtures from 25 °C to 45 °C. Such quantification of water in component fractions was required for the use of Tg data in solids characterization. DDI data also showed that the critical aw for water sorption-related crystallization of lactose (aw (cr)) was strongly affected by protein content at 25 °C. Crystallization of amorphous sugars in sugar/WPI mixtures was delayed by protein due to reduced nucleation and retarded diffusion during crystal-growth. XRD patterns showed that the crystalline forms of lactose and trehalose could be affected by the presence of water and WPI. The crystallization and crystalline forms of amorphous lactose were affected by trehalose and WPI based on XRD analysis. XRD showed no anhydrous β-lactose and mixed α-/β-lactose with molar ratios of 4:1 crystals in crystallized lactose/WPI systems (7:3 and 1:1 solids ratios). The enthalpy relaxation (H-relaxation) of amorphous lactose was affected by the presence of lactose crystals and WPI at 0.33 aw (25 °C) due to water migration. The Tα at loss modulus (E’’) and dielectric loss (ε’’) peak at each frequency for sugars was affected by the presence of crystals and protein. Tα shifted to higher temperatures with increasing frequency but it decreased steeply as water content increased. The WLF-derived S values of sugars decreased with aw increasing up to 0.44 aw but the presence of WPI and α-type of lactose crystals increased S. An instant crystallization of amorphous lactose in heating was more rapid in systems with a smaller S, which also had more extensive water plasticization and lower instant crystallization temperature. We also found that the S values could be estimated from water contents of glass forming sugar systems. S gives a quantitative tool to estimate compositional effects on τ and for the control of time-dependent solids transformations, such as crystallization. Amorphous food solids, such as sugars and proteins, are common ingredients in the food and pharmaceutical industries. Thus, understanding the physicochemical vii properties of glass forming food solids has a great importance in the development of processing and shelf life control procedures for such ingredients and relevant products. Relaxation times refer to the time factor corresponding to material response to a change in internal or external thermodynamic conditions such as temperature and aw, which can provide a new approach for the description of process-structure-function relationships to foods and food constituents. While the “Fragility” concept developed by Angell may predict some properties of single glass-forming food components, our WLF-type S concept, which was set to show a decrease of τ from 102 to 10-2 s above glass transition, was superior for the description of relaxation times and solids characterization, and therefore, stability and industrial applicability of relevant foods and pharmaceutical materials. For example, the S parameter as a new food property can be used to formulate materials in order to improve material performance during drying and powder handling. Also, it can be used to control and predict the physicochemical properties and performance of food solids during storage.