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The inclusion complexation behavior between 10-undecyn-1-ol and cyclodextrin (CD) derivatives, namely, randomly methylated beta-CD (RM-beta-CD) and hydroxypropyl-beta-CD (HP-beta-CD), was studied in terms of solubility improvement, apparent stability constant, and the inclusion ratios of the resultant inclusion complexes. The aqueous solubility of 10-undecyn-1-ol was greatly improved through complexation with the CD derivatives. RM-beta-CD is comparatively more efficient in solubilizing 10-undecyn-1-ol with an apparent stability constant outstripping that of HP-beta-CD by about an order of magnitude. Comparative in vitro evaluations of the growth inhibition effects of inclusion complex solutions toward Rosellinia necatrix, a phytopathogenic fungus, were performed. In comparison with the positive control, appreciable improvements of the antifungal activity of 10-undecyn-1-ol through the addition of CD derivatives were observed visually. The improvement was evaluated in terms of area covered by the mycelia of Rosellinia necatrix and their growth rate. RM-beta-CD was proven to be more effective compared to HP-beta-CD with regard to the reduction of both fungal mycelium-covered area and growth rate constant, presumably owing to greater solubility enhancement by RM-beta-CD and thus the bioavailability of 10-undecyn-1-ol. Inclusion complexation of 10-undecyn-1-ol with CD derivatives suggests a potential means for production of an environmentally friendly 10-undecyn-1-ol-based fungicide to counteract R. necatrix.

The polymer-coated inclusion complex powder formation of D-limonene and β-cyclodextrin obtained by spray drying was investigated with respect to the effects of various types of polymer coating agents on the powder particle size and morphology. The addition of the polymer coating agent affected the average particle size, morphology, and internal structures of the spray-dried powders. The average particle diameter of the uncoated spray-dried powders was approximately 5 µm. The powder particle size increased upon the addition of a polymer coating reagent. With the addition of 9 wt% of the polymer coating agent, an average diameter of approximately 80 µm was obtained for the spray-dried powder particles. However, further addition showed a negligible effect on the particle size. Inclusion complex crystals were observed on the surface and inside of the powder particles. [ABSTRACT FROM PUBLISHER]

A linearly ramped humidity system coupled with automatic sampling gas chromatography has been developed. The apparatus was adopted to measure the dynamic release flux of D-limonene included in spray-dried β-cyclodextrin (β-CD) and the polymer-coated counterparts under linearly ramped humidity (0.375%/min) at constant temperature (50°C). The release flux profiles of D-limonene were analyzed using a mathematical model based on an extended Arrhenius equation. The activation energy of D-limonene release flux from β-CD was 278 (kJ/mol), which was the highest among the powders and around twice as high as our previous results obtained by the conventional static method. [ABSTRACT FROM AUTHOR]

The crystal transformation method using ethanol as a dehydration medium is a new method which can create a porous crystal. In this study α-cyclodextrin (α-CD) hexahydrate was transformed by this method and porous ethanol dihydrate crystal was obtained. The pore volume measured was 0.25 mL/g and the median pore diameter was 0.11 μm. Dissolution rate of this crystal was several times higher than that of (α-CD) hexahydrate or anhydrate obtained by drying. [ABSTRACT FROM AUTHOR]

The spray drying conditions affect the retention of flavor compounds in the mimetic rice flavor powder. The wall material is one of the factors of pronounced importance that dictates the flavor retention of the rice flavor powder during spray drying. In this study, we focused on making rice flavor powder by spray drying from mimetic rice flavor oil and the binary mixtures of α-cyclodextrin (α-CD) and highly branched cyclic dextrin (HBCD) as wall material. The composition of α-CD and HBCD influenced the flavor retention and the amount of surface oil on the resultant spray-dried powders. The optimum α-CD content was 67%, at which a spray-dried powder of the highest flavor retention and the least amount of surface oil was obtained. [ABSTRACT FROM AUTHOR]

The retentions of alcohol dehydrogenase (ADH) activity during drying and storage were investigated at various temperatures and relative humidities for various carbohydrate solutions. The highest retention of ADH activity after drying was obtained for the mixture of trehalose and methyl-ß-cyclodextrin. For a single dried droplet, the effects of humidity on the storage stability of ADH were reversed between the trehalose solution and the blend of trehalose and methyl-ß-cyclodextrin. However, the addition of methyl-ß-cyclodextrin decreased the residual activity of ADH during storage. The carbohydrate matrix structure after drying might influence mainly the storage stability of ADH encapsulated in the mixed carbohydrate of trehalose and methyl-ß-cyclodextrin. [ABSTRACT FROM AUTHOR]

Powdery encapsulation of shiitake flavor was investigated by spray drying with the mixture of cyclodextrin (CD) and maltodextrin (MD). Solubilities of cyclic sulfur compounds except hexathiepane increased with a-CD concentration. Stability constant of lenthionine to a-CD was 5.30 mmol -1 L. The retentions of lenthionine and hexathiepane depended on a type of cyclodextrin. When the encapsulant was a-CD, the addition of MD had a remarkable effect on increasing the flavor retention. This might be due to the high stability constants of shiitake flavors in a-CD. The encapsulant in 3 wt% of a-CD and 27 wt% of MD resulted in the highest retention for lenthionine and other shiitake flavors except hexathiepane. This result suggests that shiitake flavors except hexathiepane have almost same stability constants to a-CD. [ABSTRACT FROM AUTHOR]

Investigates powdery encapsulation of shiitake flavors, extracted from dried shiitake, by spray drying. Increase in flavor retention with an increase in drying air temperature and solid content; Decrease in flavor retention with an increase in dextrose equivalents of maltodextrin; Markedly increased flavor retention due to the use of α-cyclodextrin and maltodextrin in combination as an encapsulant.

The flavor inclusion powder was prepared by spray drying, using the combined encapsulation method of inclusion by β-cyclodextrin (β-CD) and emulsified by gum arabic (GA). d-Limonene and ethyl n-hexanoate were used as model flavors. The application of high pressure by Microfluidizer to the mixture of flavors and β-CD slurry was an effective means of forming inclusion complex. Flavor retention during spray drying under various compositions of the encapsulants was investigated. The flavor retention using the blended encapsulant was increased by adding GA in the encapsulant. The characteristics of release of encapsulated flavor during storage were evaluated at 50°C and 75% of relative humidity. The release rate of flavor in spray-dried powder depended on kinds of the flavors and composition of the encapsulant. The blending MD and β-CD in the feed liquid decreased the release rate of flavors. The rate of release of flavor was analyzed by Avrami's Equation. [ABSTRACT FROM AUTHOR]

Cites a study examining the effects of modified cyclodextrins (CD) hydroxypropyl-β-CD and methyl-β-CD on cDNA-expressed human cytochrome P-450 (CYP) activities. Ability of modified CD to inhibit the activities of CYP2C19 and CYP3A4; Enhancement by CD of the CYP2C9 activity by 140 to 176 percent; Inhibition by methyl-β-CD of CYP1A2 and CYP2D6 at higher concentrations.

Abstract: Inclusion complexation reactions between isothiocyanates (ITCs), namely, allyl isothiocyanate (AITC) and phenyl isothiocyanate (PITC), and randomly methylated β-cyclodextrin (RM-β-CD) displayed “AP” type solubility isotherms, indicating continuous increases in the stoichiometry of the inclusion complexes. The complex powders were prepared by spray drying and their heat stability was studied by thermal analysis and heat treatment in paraffin. The solid-state dissociation reactions were satisfactorily described by the unimolecular decay law. The apparent activation energy of dissociation, E D, was determined to be 48 and 58kJ/mol, respectively, for the AITC/RM-β-CD and PITC/RM-β-CD complexes, while the apparent activation energies of decrease of ITCs in paraffin, E P for the pure AITC and PITC, and the corresponding inclusion complexes were 26, 48, 44, and 54kJ/mol, respectively, suggesting volatility suppression and physical stabilisation by inclusion complexation as the plausible mode of stabilisation of the ITCs in paraffin. A compensation effect in the kinetics of depletion of the ITCs in paraffin was established. [Copyright &y& Elsevier]

Abstract: The dissociation of a crystalline complex of cyclomaltohexaose (α-cyclodextrin) and 1-methylcyclopropene has been studied in response to stepwise rising relative humidity at 50°C using a dynamic vapor sorption instrument. The dissociation of the inclusion complex was monitored with a proton transfer reaction mass spectrometer. The increase in relative humidity generally triggered the complex dissociation. However, the dissociation was greatly retarded at 80% relative humidity, presumably owing to collapse of the crystalline structure. Abrupt dissociation was observed at 90% relative humidity which corresponded to complex dissolution. The changes in powder X-ray diffraction pattern of the inclusion complex during the storage period were also investigated. [ABSTRACT FROM AUTHOR]

The thermally stimulated dissociation of the inclusion complex of 1-methylcyclopropene (1-MCP) with α-cyclodextrin (α-CD) in solid state was studied by means of thermogravimetry (TG) and differential scanning calorimetry (DSC). The mass loss of 1-MCP/α-CD inclusion complex occurs in four separated phases with the thermal dissociation of the inclusion complex and release of 1-MCP taking place in the second phase between 90 and 230 °C. The kinetic parameters of the dissociation reaction (the apparent activation energy of dissociation, ED, the reaction order of thermal dissociation, n, and the pre-exponential factor, k0) were evaluated. The dissociation reaction was satisfactorily described by the unimolecular decay law, where the reaction order, n = 1. The effect of the molar ratio of 1-MCP to α-CD (inclusion ratio) in the inclusion complex on the temperature dependence of the dissociation reaction was also studied. The ED decreased with increasing inclusion ratio indicating higher complex stability at lower inclusion ratios. The extrapolation of the ED of the inclusion complexes with different inclusion ratios to 1 mol 1-MCP/mol α-CD yielded the "true" ED of 20.9 ± 2.8 and 18.1 ± 0.2 kJ/mol for TG and DSC, respectively. The "true" ln k0TG and the "true" ln k0DSC were also determined by extrapolation, yielding values of +4.5 ± 1.0 and −0.3 ± 0.3, respectively. [ABSTRACT FROM AUTHOR]