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Spray drying is one of the oldest, most common, and economical techniques typically employed for producing dry powders from flowable feeds which can be a solution, dispersion, or even paste. In the food industry, spray drying technology has also been employed as a means for microencapsulation of food active ingredients such as oils, fragrances, and flavors. Spray drying as a microencapsulation technique provides several beneficial functionalities such as easing handling of liquid labile active compounds, enhancing solubility, improving stability, providing protection against degradation, controlling or delaying release, and masking unpalatable tastes or smells. This article reviews the latest findings and research works on microencapsulation of food core materials by spray drying. It is aimed to give an overview of the vast variety of food active compounds studied in this particular area of interest. This article is organized by the type of food core material, i.e., oil, flavors, antioxidants and polyphenols, nutrients, pigments, vitamins, and enzymes, to facilitate comprehensive discussion on physicochemically similar compounds. [ABSTRACT FROM AUTHOR]

Edible oils with physiological functions, such as fish oil and krill oil, which contain polyunsaturated fatty acids (PUFAs), are highly unstable to heat and oxygen. One of the methods for improving the shelf life of these oils is microencapsulation of the oils through spray drying. This mini-review describes the effects of the surface–oil ratio, oil location within the microcapsules, and oil-droplet diameter on the oxidative stability of functional oils in microcapsules prepared through spray drying. The surface–oil ratio, s, can be expressed through the ratio of the average oil-droplet diameter to the average powder diameter, E, by s = 1 − (1 − 2E)3. Additionally, the effects of oil-droplet size and storage temperature on the stability of the encapsulated oil were examined using squalene as a model functional oil. The activation energy Ea of the squalene degradation rate constant of the Avrami equation can be correlated with the average oil-droplet diameter de. The release behavior of the microencapsulated flavors is also discussed because spray drying is also used for the microencapsulation of flavors. The flavor release rate constant of the Avrami equation is related to the oxygen diffusion coefficient of the wall material. [ABSTRACT FROM AUTHOR]

Oil mixtures of medium-chain triglycerides (MCT) and d-limonene in mixing ratios from 10 to 100 wt% were encapsulated in modified starch (wall material) by spray drying to produce oil-rich powders. The oil load (mass ratio of oil mixture to wall material) of the infeed emulsion markedly influenced the properties of the infeed liquid and the characteristics of the resulting powder. The viscosity of the infeed liquid and the particle size of the powder exponentially decreased with increasing oil load, while the emulsion droplet size in the infeed liquid increased. In addition, retention of d-limonene during spray drying also decreased markedly with increasing oil load. Irrespective of the different oil loads and concentrations of the wall material, d-limonene retention was well correlated with the emulsion droplet diameter of the infeed liquid. The encapsulation efficiency of the oil mixture exhibited a maximum value (almost 100%) at an oil load between 0.5 and 1.0, before decreasing at higher oil loads. At an oil load of 2.0, the encapsulation efficiency of d-limonene was reduced to almost zero, while around 40% of the initial MCT was encapsulated in the powder. The increase in oil load also led to increased amounts of surface oil of MCT and d-limonene in the resulting powder due to the increasing emulsion droplet diameter of the infeed liquids. Practical Application: This study proposes the microencapsulation of medium-chain triglycerides under high-oil-load conditions by spray drying. The powders prepared by this process provide significant benefits in terms of rapid energy conversion after consumption without accumulation in the body. Important quality factors of the powder products such as the encapsulation efficiency and the amount of surface oil were examined to understand the optimum process conditions for spray drying. [ABSTRACT FROM AUTHOR]

Effects of dietary fatty acid composition on the growth of the tiger puffer Takifugu rubripes were examined. Eight experimental diets were formulated with fish meal and casein as the major ingredients, providing 45.0-48.2% crude protein. Pollack and squid liver oils were used for the control diet while experimental diets contained three levels of EPA-DHA concentrated (C-HUFA) oils, soybean oil, linseed oil, and combinations of them, providing 0.5-5.5% n-3 HUFA and 5.0-11.1% crude lipid. Triplicate groups of fish with a mean body weight of 18.7 g per dietary treatment were fed the diets twice daily to apparent satiation, 6 days per week for 8 weeks. The final body weight and weight gain of the fish fed the soybean oil diet without C-HUFA oils were significantly lower than those fed the control diet. Both parameters were not statistically different among the other dietary groups, although the values obtained for the linseed oil diet without C-HUFA oils were lower. Similar trends were seen for SGR and feed efficiency. However, significantly lower PER values compared to the control were observed for the lower C-HUFA and the vegetable oil without C-HUFA oil groups. These results indicate that tiger puffer can be produced successfully with diets containing more than 1.5% n-3 HUFA. [ABSTRACT FROM AUTHOR]

S-Adenosyl-L-methionine (SAM) production from Saccharomyces cerevisiae K-9 was comparatively stable under slightly acidic conditions (pH 3.0-5.0) and at low temperature (20-25°C). The kinetics of SAM degradation and 5'-methylthioadenosine (MTA) formation in yeast solution at high temperature (40-60°C) were described by zero-order reactions and the activation energy levels were 104 and 102 kJ/mol, respectively. The optimum retention of SAM after spray drying was obtained at 120°C inlet air temperature. The water content of the powder has a significant effect on the stability of SAM. The SAM yeast powder with trehalose and maltodextrin (dextrose equivalent, DE = 25), used as carrier solids, exhibited higher stability. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this study was to examine the effect of dietary lipid level on the growth, feed utilization, body composition, and blood characteristics of tiger puffer Takifugu rubripes. Triplicate groups of 10g initial body weight fish were fed five isonitrogenous experimental diets formulated with increasing lipid levels (5.9, 11.0, 16.3, 21.4 and 25.7%) using pollack liver oil, twice daily to apparent satiation, 6days per week for 8weeks (trial 1). Survival during the 8-week rearing period ranged from 76.7 to 96.7% and survival of fish fed the 5.9% lipid diet was significantly lower than for fish fed 16.3% lipid. Weight gain and specific growth rate (SGR) were significantly greater for fish fed diets with 5.9, 11.0 and 16.3% lipid compared to other treatments. Feed efficiency and protein efficiency ratio (PER) increased with increasing dietary lipid level up to 16.3%, and decreased slightly thereafter. Similar trends were observed for blood triglyceride, hematocrit value, and hepatosomatic index of the cultured fish. Hemoglobin decreased but glucose increased with increasing lipid level and other parameters were independent of dietary composition. Proximate composition of dorsal muscle and liver was not clearly related to dietary composition. After 8weeks rearing, fish were randomly divided into duplicate groups per dietary treatment and reared for 16weeks as described above (trial 2). Weight gain and SGR were the highest in fish fed the 5.9% lipid diet and tended to decrease with increasing level of dietary lipid although initial body weight was lower for the higher lipid groups. On the other hand, feed efficiency and PER values for fish fed the 5.9% lipid diet were significantly lower than for fish fed the other diets. Increasing dietary lipid improved feed utilization significantly without serious effects on fish growth and health condition when it was less than 11%. [Copyright &y& Elsevier]

Inclusion of the water-soluble fraction of blue mussels Mytilus galloprovincialis as a feed additive was examined with tiger puffer Takifugu rupbripes. The control diet mainly consisted of fish meal, potato starch, and pollack liver oil. Experimental diets were formulated to replace 30% and 40% of the fish meal protein with defatted soybean meal (SBM), and were supplemented with 0–20% mussel extracts. Fish of 18 g initial body weight were fed each diet to satiation, twice daily, 6 days per week for 7 weeks at 20°C. Weight gain and protein efficiency ratio of fish fed the diet containing SBM without the extract were significantly lower than those of the control at the 30% replacement level. Addition of 5% or 10% extract improved the growth and feed utilization to levels comparable to those of the control. At 40% substitution, statistically identical growth and feed performance to the control were obtained for diets supplemented with 10% or 20% extract; however, performance for 5% addition was significantly lower. Thus, the water-soluble fraction of blue mussels would be an effective feeding stimulant in aquaculture feed for tiger puffer that makes it possible to replace 30–40% of fish meal protein with SBM. [ABSTRACT FROM AUTHOR]

The acute toxicities of boron were examined for Japanese flounder Paralichthys olivaceus and red sea bream Pagrus major in terms of fish size and water temperature. Japanese flounder of 0.1–70.0 g and red sea bream of 0.6–20.3 g were exposed to different concentrations of boron for 96 h at 20°C under semi-static conditions. In both fish species, the median lethal concentration (LC50) for 96 h of boron increased linearly with increasing fish size, ranging from 108 to 252 mg B/L for the flounder, and from 97 to 172 mg B/L for the sea bream. The effect of water temperature on acute toxicity was examined for Japanese flounder of 0.6 and 1.5 g at 10, 15, 20 and 25°C, and for red sea bream of 0.6 and 2.4 g at 12, 15, 20 and 25°C. The toxicity of boron for the flounder increased linearly with increasing water temperature. The 96 h LC50 values ranged from 299 to 108 mg B/L for the 0.6 g flounder and from 350 to 113 mg B/L for the 1.5 g flounder. A similar trend was shown for the 2.4 g red sea bream; however, the relationship for the 0.6 g red sea bream was not significant. [ABSTRACT FROM AUTHOR]

Larval false clown anemonefish of about 12 h after hatching were fed newly-hatched brine shrimp nauplii in natural (control) and copper-added seawater (40–640 µg–Cu/L) at 26.5 ± 0.5°C for 14 days. Survival rate of the fish increased with increasing copper concentrations up to 160 µg–Cu/L. The rates at 80 and 160 µg–Cu/L were 65 and 80%, respectively, and were significantly higher than that of the control (30%). A positive effect of copper addition on the survival rate was also observed in the other rearing experiment with the fish from seven different spawning chances. Growth rate of the survival fish was not affected by copper concentrations. The copper concentration of the survived fish increased with increasing copper concentrations in the rearing water. [ABSTRACT FROM AUTHOR]

Although the π/4 phase shift modulation schemes used in quadrature phase shift keying (QPSK) are important approaches to ensuring efficient frequency usage in digital portable telephone systems, they also require linearity of the power amplifiers, they also require linearity of the power amplifiers, which is an undesirable constraint from the standpoint of efficiency. In this work, we describe a unified approach to this problem based on the idea that distortion can be effectively decreased by creating dips or “bumps” in the intermod characteristics, due to the dependence of the adjacent channel power (ACP) leakage on input power. For the special case of an impedance Zes connected to the gate of a FET, we use Volterra series to quantitatively demonstrate how the appearance of such dips or bumps is related both to Zes and to the fifth intermod (IM5). We then show analytically that when these dips or bumps are generated effectively, they can suppress IM5. Finally, we show that the resulting decrease in intermodulation distortion and improved efficiency make this method useful in the design of MMIC power amplifiers used in Personal Handy Phone (PHS) service. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 85(4): 10–21, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.1100 [ABSTRACT FROM AUTHOR]

Anemonefish, including the false clownfish Amphiprion ocellaris, are attractive model organisms because of their unique features, such as sex change and brilliant color patterns in mutants. However, anemonefish are not widely used to study gene function using reverse genetic approaches owing to microinjection difficulties and subsequent rearing and hatching of embryos without parental care. A. ocellaris embryos are spawned on a hard substrate and cared for by their parents until hatching. However, the eggs need to be detached from the substrate and raised without their parents to perform successful microinjection. We established a method to culture and hatch A. ocellaris embryos without spawning substrates or parental care. We found that changing water and generating water flow are critical for culturing the embryos, and that water flow (as physical stimulation) and complete darkness in the dark period are necessary for successful hatching. We further investigated the effectiveness of microinjection into the yolk sac of fertilized eggs rather than into the cytoplasm, which makes microinjection easier. A reporter RNA injected into the yolk sac was transferred to the cytoplasm and translated, indicating that yolk sac microinjection is an efficient alternative as has been used for zebrafish. These findings highlight the potential of A. ocellaris as an experimental model organism for reverse genetics, and our methods could be applied to other anemonefish species. [ABSTRACT FROM AUTHOR]

Abstract: Dehydration of dihydrate trehalose to its anhydrous form was performed via crystal transformation in a pressure pan with a differential scanning calorimeter using ethanol as the drying medium. The effect of water content of ethanol on the dehydration kinetics was investigated by differential scanning calorimetry (DSC), under two experimental conditions: isothermal and temperature ramping. The data sets collected were analysed by the Avrami equation and the Arrhenius plots for isothermal conditions and by Kissinger’s method for non-isothermal measurements. The Kissinger plots revealed click point temperatures (CPTs) which were dependent on the water content of ethanol. At temperatures below the CPTs, higher activation energies were found, whereas at temperatures above the CPTs, lower activation energies were estimated. The anhydrous trehalose crystals obtained by crystal transformation using ethanol of 0.005–2.5% water content were visually observed as aggregates of nano-sized acicular crystals, which inherited the shapes of the dihydrate trehalose crystals. [Copyright &y& Elsevier]

Spray drying is commonly used as a dehydration technique in the pharmaceutical industry for making powdery products directly from liquid. It is also an attractive alternative for obtaining solid pharmaceutical molecules that are traditionally produced by freeze drying. Spray drying is often regarded as a harsh drying method, due to the high temperature of the drying gas. Therefore, some excipients were added to improve the stability in manufacturing process and storage. Emphasis was placed on the encapsulation of proteins by spray drying and crystal transformation method. [ABSTRACT FROM AUTHOR]

Abstract: The crystal transformation of dihydrate trehalose to anhydrous trehalose was investigated using ethanol and a new type of crystal particle with porous structure could be obtained. The specific surface area of the anhydrous crystal transformed at 50°C was 3.3m2/g, with a median pore diameter of 0.21μm, and void volume of 0.22mL/g. The crystal transformation was monitored by measuring the crystal moisture content. The crystal transformation rates could be correlated with the Avrami equation, using the mechanism parameter n =11.5, suggesting that the change of surface area occurred during crystal transformation from dehydrate to anhydrous trehalose. The apparent activation energy of the crystal transformation was 132kJ/mol. [Copyright &y& Elsevier]

Two feeding experiments were conducted to elucidate growth performance of tiger puffer in a 10 m³ water volume closed system. In experiment 1, 1000 fish of 3.5 g average body weight were fed tiger puffer commercial feed twice daily to apparent satiation, 6 days a week for 224 days. Sand-filtered sea water was used and no water was exchanged during the rearing period. Immediately after cutting of lower teeth at day 112, daily feed consumption decreased greatly and 60 fish died in few days. Feeding rates recovered and then decreased gradually as nitrate levels increased from 600-1048 mg N/L. Fish grew to 343 g with 91% survival rate and 87% feed efficiency. Rearing conditions of experiment 2 were similar to experiment 1, except that culture water was exchanged to maintain the nitrate level less than 600 mg N/L during the 224-day experiment. Mortality and reduction of feed consumption occurred immediately after teeth cutting as was observed in experiment 1. Significant reduction of feed intake was not found during other rearing periods. Fish of 3 g grew to 303 g with 91% survival rate and 72% feed efficiency. [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]

The distribution of stress during drying of fresh Japanese noodle (udon) was investigated by mathematically modelling the changes in shrinkage and other mechanical properties, this allowed crack formation to be predicted. It was observed that the shrinkage coefficients were nearly the same in all three directions with changing moisture content, and the degree of shrinkage was independent of the temperature. The Young's modulus, yield stress and fracture stress could be expressed as exponential functions of moisture content. Changes in stress distribution during drying were calculated by coupling the moisture transfer equation with the constitutive equation using a finite element method. The calculated stress distribution indicated that a rapid drying rate causes extensive internal tensile stress in udon. The scheme used in the present study was found to effectively represent the potential for crack formation along the central axis, this was shown to be consistent with the actual cracking pattern. [ABSTRACT FROM AUTHOR]

The effect of air velocity on the drying kinetics of Japanese noodle (udon) was investigated. The drying of fresh udon was carried out under six air velocities of 0.50, 0.75, 1.00, 1.25, 1.88, and 3.00 m/s at a constant temperature (40°C) and relative humidity (70%). The drying rate increased with air velocity. The apparent moisture diffusivities were determined using a diffusion model taking internal and external mass transfer resistances into account. The effect of air velocity on the apparent moisture diffusivity was found to have no influence on the drying rate for air velocity above 2 m/s in the initial drying stage, 1 m/s in the main drying stage, respectively. The effect of air velocity on udon drying has been determined, hence allowing optimal air velocity estimation from the economic point of view. [Copyright &y& Elsevier]

The effects of temperature and relative humidity (RH) on the drying kinetics were investigated to identify the optimal drying conditions for Japanese noodle (udon). Drying of fresh udon was carried out under nine conditions involving three temperatures (20, 30 and 40°C) and three RHs (60, 70 and 80%) at a constant airflow. The apparent moisture diffusivities were determined using a diffusion model taking into account both the internal and external mass transfer resistances. The effect of RH on the apparent moisture diffusivity was found to be smaller than that of temperature, but could not be neglected. A modified Arrhenius-type equation of diffusivity involving a RH term was proposed and used for the calculation of moisture content with time. The proposed equation was found to be effective for representing the drying process of fresh udon. [Copyright &y& Elsevier]

The retention of emulsified flavor during spray drying was investigated under various compositions of feed liquid. Drying of the emulsion solution was carried out in a spray dryer, equipped with a centrifugal atomizer. The retention of d-limonene during spray dying was nearly hundred percent independent of the composition of the feed liquid, whereas the retention of ethyl butyrate emulsified by gum arabic (GA) was much lower (0–20%). The retention of ethyl butyrate was markedly dependent on the concentration of maltodextrin and the type of emulsifier, indicating that the stability of emulsion is a controlling factor for flavor retention. The use of mixing emulsifiers, adjusting of density of ethyl butyrate, and the addition of 1% gelatin were quite effective procedures to improve the retention of ethyl butyrate, particularly when emulsified by GA. [ABSTRACT FROM AUTHOR]

Desorption isotherms of Japanese noodle (udon) were obtained at 20, 30 and 40°C, and analyzed by several isotherm models. The desorption isotherm data satisfactorily correlated with the GAB equation and the Oswin and Smith equations. The binding energy of moisture was calculated by Clausius–Clapeyron equation and found to be negligibly small above the moisture content of 0.163 kg water/kg solid. The sorption enthalpy calculated from the Arrhenius plot of GAB parameter was similar to the binding energy from Clausius–Clapeyron equation at GAB monolayer moisture content. [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.

Natural antifouling products have been the subject of considerable attention. We screened marine algae for antifouling activity and discovered omaezallenes, the new bromoallene-containing natural products isolated from the red alga Laurencia sp. Described is the isolation, structure elucidation, and total syntheses of omaezallenes. The relative and absolute configurations of natural omaezallenes were unambiguously established through total synthesis. The antifouling activities and ecotoxicity of omaezallenes were also evaluated. [ABSTRACT FROM AUTHOR]

Natural antifouling products have been the subject of considerable attention. We screened marine algae for antifouling activity and discovered omaezallenes, the new bromoallene-containing natural products isolated from the red alga Laurencia sp. Described is the isolation, structure elucidation, and total syntheses of omaezallenes. The relative and absolute configurations of natural omaezallenes were unambiguously established through total synthesis. The antifouling activities and ecotoxicity of omaezallenes were also evaluated. [ABSTRACT FROM AUTHOR]

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 ramping method for humidity at constant temperature was used to evaluate the release of D-limonene from spray-dried powder using a handmade dynamic vapor sorption (DVS) instrument. The release fluxes of D-limonene from spray-dried powder at two different liquid feed temperatures, 40 and 80°C, were used to evaluate the flavor release properties of spray-dried powder. The flavor fluxes for 40°C of liquid feed temperature were faster than those for 80°C over the whole humidity range. [ABSTRACT FROM AUTHOR]

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: β-Maltose monohydrate was transformed into an anhydrous form by ethanol-mediated method under several temperatures with agitation. A new stable anhydrous form of β-maltose (Mβs) was obtained, as substantiated by the X-ray diffraction patterns. Mβs obtained by this method presented a fine porous structure, resulting in greater specific surface area compared to those of β-maltose monohydrate and anhydrous β-maltose obtained by vacuum drying (Mβh). The crystal transformation presumably consisted of two steps: dehydration reaction from the hydrous to amorphous forms and crystal formation from the amorphous forms to the noble anhydrous form. The kinetics of these reactions were determined by thermal analysis using Jander’s equation and Arrhenius plots. The overall activation energies of the dehydration reaction and the formation of anhydrous maltose were evaluated to be 100 and 90kJ/mol, respectively. [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 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 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]

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]

Abstract: The microencapsulation of l-menthol was studied by spray drying, using gum arabic (GA) and modified starch (CAPSUL, HI-CAP 100) as capsule materials. The results showed a higher retention of l-menthol with the increasing of initial solid concentration. HI-CAP 100, showed a higher retention than the other capsule materials. However, it also showed a higher residue of l-menthol on the surface of powder especially at the high concentration of l-menthol in the feed emulsion. That might be from the interaction between the wall materials and l-menthol which can re-crystallize to form whisker after the spray drying. Furthermore, the release characteristics of l-menthol were also investigated. The release rate increased upon elevation of relative humidity and temperature. The activation energies of the release of l-menthol from GA wall matrices at 75 and 83%RH were 140 and 48 kJ/mol, respectively. Industrial relevance: Controlled release of food constituents is currently receiving highest interest. This study aimed to better understand some of the processing and storage conditions. Decrease in emulsion droplet size led to increased flavor retention during spray drying. Interesting electron-micrographs of the spray dried capsules are provided as well as data on water absorption isotherms and release rate constants vs. storage temperatures. Clear industrially relevent data regarding capsule size, matrix, material, water activity and temperature during storage are provided. [Copyright &y& Elsevier]

Abstract: The microencapsulation of d-limonene by spray drying was investigated with respect to the effects of emulsion droplet size, powder particle size, as well as to the effects of various kinds of matrices (gum arabic, maltodextrin, and modified starch) on its stability. It was realized by studying release characteristics and oxidative stability during storage. The release and the oxidation decreased deeply with an increase in powder and emulsion particle size for gum arabic and maltodextrin materials. Further, the distributions of emulsion size in the powder showed an increase in the fraction of large emulsion droplets and changed to a bimodal distribution. However, the modified starch HI-CAP 100 showed a higher stability of encapsulated d-limonene than the others. The influence of powder and emulsion size on its encapsulated flavor as well as the change in the emulsion size during storage could not be observed. Industrial Relevance: Spray drying is a common and useful unit operation for microencapsulation of food ingredients. Data on emulsion droplet size and on powder size on product stability provide conflicting results which makes a systematic study regarding these factors highly relevant. The data suggest that an optimal size of flavour powder should be selected for high retention during spray drying, stability during storage and for the ability to control release of flavour. [Copyright &y& Elsevier]

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]

Investigates the release characteristics of flavor from spray-dried powder in boiling water and the flavor retention in the rice after cooking. Simulation by Avrami's equation of the behavior of flavor release into the boiling water; Correlation between the retention of d-limonene and ethyl n-hexanoate in cooked rice with the flavor amount of spray-dried powder added.