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Whey protein isolate (WPI)-ascorbic acid (AA) solutions were used to generate powders using spray drying technology. The powders changed color during storage. In this study, spray-dried powders with different ratios of WPI to AA were aged under different conditions. Significant redness generation was observed by heating spray-dried WPI-ascorbic acid powders up to 80 °C rapidly, and redness was generated over a longer time (up to 3 to 5 days) at room temperature. This change in redness was used to develop a packaging indicator for tracking temperature and time, which may be used to indicate the degree of food freshness by visual observation. Another application was to make the aged powders into tablets, and red liquid extracts have been leached out of the tablets into aqueous solutions. The colors of the solutions with the aged WPI-AA powders and their red extract changed at different pHs (from 3 to 11). These extracts were coated onto paper to create low toxicity pH indicators for food testing. [ABSTRACT FROM AUTHOR]

Ultraviolet light-induced discoloration is a noticeable issue when heat-treated wood is used outdoors. In this study, titanium dioxide (TiO2) particles were electrochemically deposited on the surface of heat-treated wood via a high-voltage electrostatic field (HVEF). Natural and artificial weathering tests were carried out to evaluate the anti-weathering properties after the electrochemical deposition. During HVEF treatment, Ti particles were triggered in the form of Ti4+. Ti4+ grafted with the hydroxyl groups of hemicellulose and lignin in the form of Ti–OH, and TiO2 was produced due to the oxidizing atmosphere generated by HVEF. TiO2 and Ti–OH played roles as UV absorbers, reducing degradation and discoloration of heat-treated wood. The photodegradation of lignin was alleviated effectively during both the artificial and natural weathering. The stability of wood color was remained. After the artificial weathering, the values of L*, a* and b* of the electrochemical depositied sample were 55, 10 and 25, respectively. The leaching amount of TiO2 after artificial or natural weathering was less than 6% or 40%, respectively determined by atomic absorption spectroscopy. The results suggest the feasibility of the electrochemical deposition of TiO2 for improving the anti-weathering properties of heat-treated wood and provide an effective strategy for industrial wood modification. [ABSTRACT FROM AUTHOR]

In the study, in order to determine the color changes of the fabrics with acid and base vapors, fabric was placed in the color change observation cabinet and then hydrochloric acid or ammonium hydroxide vapor was fed into the system and color change was determined with the camera. When HCl acid vapor is fed in the color change observation cabinet, the yellow color at pH 7 slightly shifted through orange, but no significant color change occurred between pH 1-6. Keywords: Halochromic dye; smart textile; dyeing; fastness; color change; cotton; ; ; ; ; ; EN Halochromic dye smart textile dyeing fastness color change cotton ZH 9125 9138 14 11/21/22 20221220 NES 221220 Introduction In recent years, there has been an increasing interest in color-changing materials, also known as "chameleon textiles." Exhaust dyeing according to wool dyeing process In these experiments, studies were carried out with the approach that halochromic dye could dye cationized cotton fiber like an acid dye that dyes wool, due to its anionic character. [Extracted from the article]

The aim of this study is to examine the effect of chlorhexidine (CHX), ozone and photodynamic (PDT) therapy on the microleakage of reinforced glass ionomer cement and on tooth discoloration. The class V cavities were opened on the buccal faces of 96 extracted molar teeth and the samples were divided into four groups (n = 24). Before and after cavity disinfection, color measurement of teeth was determined by using a spectrophotometer. The groups were separated into two subgroups and restored with ACTIVA and Giomer. One thousand thermal cycles were applied to the teeth at 5–55 C. After the penetration of 0.5% basic fuchsin, teeth were examined with a stereomicroscope and SEM. The data were statistically analyzed using the Mann Whitney U-test and the Kruskal Wallis test. The differences were statistically significant among the cavity disinfectants on the occlusal edge in the ACTIVA groups (p <.05), There was no significant difference considering cavity disinfectants on occlusal and gingival margins in the Giomer groups (p >.05). While ozone gas showed an acceptable color change in teeth, CHX and PDT caused the discoloration in teeth. It was concluded that the Ozone gas does not affect the microleakage of the reinforced glass ionomer cements and does not cause detectable color change. CHX and PDT reduce the microleakage of ACTIVA at the enamel level. [ABSTRACT FROM AUTHOR]

This research focuses on exploring commercial heat treatment on western hemlock product quality for potentially new applications and markets for this abundant Pacific Northwest coast softwood species. In this regard, flatsawn and quartersawn kiln-dried hemlock boards were subjected to the ThermoWood® process in a commercial unit at three temperatures, i.e. 170°C, 212°C, 230°C and for 2 h. Samples were cut from treated and untreated boards for evaluation of basic density, hygroscopicity, water absorption, anti-swelling efficiency, color change, Janka hardness, and dynamic modulus of elasticity. Results revealed that basic density, hygroscopicity, and water absorption decreased at higher treatment temperatures, while dimensional stability considerably increased. Treatment temperatures had a minor effect on hardness and stiffness, but they made the samples darker in color. No significant property differences between the two cuts were observed. Within the scope and limitations of this study, the treatment that enables improved dimensional stability and provides a darker color without significantly affecting hemlock strength was the 212°C/2 h combination. Further research is required to fully determine the performance of thermally modified hemlock under expanded treatment combinations for interior and exterior applications. [ABSTRACT FROM AUTHOR]

The commercially available paprika at 16.25% (db) moisture was quickly finish-dried using microwaves at higher power density (5–25 W g−1). The moisture diffusivity was estimated using Fick's second law of diffusion and the generalized kinetic model was used to estimate the color degradation rates. The moisture diffusivity and color degradation showed a close correlation with the difference between the average product temperature (T) achieved due to microwave heating, and average glass transition temperature (Tg) of paprika. Acceleration in moisture diffusion and color degradation was observed with the rise in the difference between the T and Tg. Further, the color degradation rate showed correlation with monolayer moisture content, average moisture content, T, and Tg of paprika during finish drying. The constants of the Gordon and Taylor model showed the less plasticization effect of water. Also, Tg showed a good correlation between water activity and moisture content. The activation energies for moisture diffusion and color degradation were found to be 92.53 and 11.03 kJ mol−1, respectively. The microstructural analysis of finish-dried paprika showed the expanded and newly formed intercellular spaces. The developed correlations can be used to simulate heat and mass transfer operations such as drying and sterilization. [ABSTRACT FROM AUTHOR]

Processing methods of Misai Kucing still remain crude and lack technological advancements. In terms of drying, very few studies have attempted to apply advanced drying technology to improve Misai Kucing quality and drying time. This paper presents first attempt to improve Misai Kucing drying kinetics and product quality through solar-assisted heat pump drying and comparison was made against solar drying. Experimental results showed that solar-dried samples had the greatest total color change and loss of two bioactive ingredients as compared to solar-assisted heat pump-dried samples due to its longer time process, higher drying temperature, and chlorophyll degradation. By comparing the statistical values, it showed that the Page model had the best goodness of fit at all tested dried samples by both drying methods. [ABSTRACT FROM AUTHOR]

The impact of the spectral composition of light on the discoloration of paint pigments has been investigated for the case of lead chromate sulfate, an unstable yellow pigment used by Vincent van Gogh and other painters. With LEDification, museum lighting is moving from using halogen to LED lamps. LED light sources have a significantly different spectral composition than halogen lamps. To understand the impact of these differences on pigment stability, the wavelength dependence of pigment discoloration was determined. Contrary to the expectation that lower wavelength photons induce more damage than higher wavelength ones, UV (394 nm), blue, and cyan light all lead to similar levels of discoloration of a pigment for the same level of radiant power. By understanding this wavelength dependence, it becomes possible to create white light LED lamps with a spectral composition tuned to minimize the degradation effect. An existing LED solution with a modified emission indeed resulted in 30% less color change in the experiment than halogen. Furthermore, a method is proposed to optimize the LED spectra by tuning to the properties of each specific artifact. Simulations show that this can reduce the damage of the light source by 45% in specific cases. [ABSTRACT FROM AUTHOR]

Interconvertible stretched and contracted helices of mono-substituted polyacetylenes (SPA)s prepared using a [Rh(norbornadiene)Cl]2-amine or alcohol catalyst are demonstrated along with the reason for why the Rh catalytic system was used. The interconversions between their helices with color changes in the solid state were controlled by choosing the polymerization solvents, substituents, and/or external stimuli. The accordion-like helix oscillation, HELIOS, of the aliphatic polyacetylene ester main chain was found in a solution where restricted rotations around the O‒C bond in the ester side-chain are dynamically synchronized. The magnetic behavior of thecisandtransradicals of SPAs produced through the rotational scission of thecisC=C bonds is also reported. [ABSTRACT FROM AUTHOR]

This paper aims to study the influence of temperature and relative humidity (RH) during intermittent heat pump drying at 28.6–40.6°C, 16.2–26.7% RH,α = 0.2–1.0, and the comparison was made against fan drying (27°C, 39.7% RH,α = 1.00). It was observed that the effects of temperature and RH on drying rate were significant when moisture content was high. Experimental results showed that intermittent heat pump drying at 28.6°C, 26.7% RH,α = 0.2 of edible bird’s nest greatly reduced effective drying time by 84.2% and color change compared to fan drying, and retained the good energy efficiency. [ABSTRACT FROM PUBLISHER]

Objective:The aim of thisin vitrostudy was to examine the color changes in resin cements polymerized under lithium disilicate glass ceramic material (IPS Empress 2). Material and methods:A pressable ceramic material (10 mm × 1 mm) placed between the curing unit tip and resin cement was used to simulate the impact of light transmission on restoration. Light-polymerized Variolink II, dual polymerized Variolink II, Multilink Automix, Clearfil Esthetic Cement, Panavia F 2.0, RelyX Veneer, and Nexus 3 resin cement specimens were polymerized by a high-power light-emitting diode curing unit (Demi). A spectrophotometer (Vita EasyShade) was used to measure the colorimetric values of the specimens. Color changes were determined by the CIEL*a*bcolor system. Total color differences () of the resin cement specimen with or without the ceramic specimen were calculated. Analysis of variance, Tukey’s honestly significant difference and paired t-tests were used to analyze the data (α = 0.05). Results: There were significant differences amongvalues with or without the ceramic specimen (p < 0.05). The light-polymerized Variolink II resin cement specimens induced the greatest color changes with or without the ceramic specimen ( = 14.21 and = 2.32). Thevalues of all resin cements with the ceramic specimen were less than 2.5 and the Panavia F 2.0 specimens induced the smallest color changes ( = 0.95). Conclusions: Light polymerization of resin cements is a significant factor affecting the color of the final restoration, but lithium disilicate glass ceramics of 1-mm thickness appeared to have a masking effect on the color changes in resin cements. [ABSTRACT FROM PUBLISHER]

This article presents the authors' first attempt to improve quality of edible bird's nest through continuous and intermittent low-temperature drying (25 and 40°C) with infrared and ultraviolet C (UVC) treatments. The attributes of quality were compared in regard to quality of hot-air-dried samples at 70-90°C. Experimental results showed that a significant improvement in the quality of edible bird's nest in terms of minimizing color changes and rehydration capacity using intermittent low-temperature drying with infrared and UVC drying profile. However, it was also found that any drying method has less significant effect on the nitrite content of edible bird's nest. [ABSTRACT FROM AUTHOR]

A prediction method for color changes based on the time–temperature superposition principle (TTSP) was developed for acetaminophen solution. Color changes of acetaminophen solution are caused by the degradation of acetaminophen, such as hydrolysis and oxidation. In principle, the TTSP can be applied to only thermal aging. Therefore, the impact of oxidation on the color changes of acetaminophen solution was verified. The results of our experiment suggested that the oxidation products enhanced the color changes in acetaminophen solution. Next, the color changes of acetaminophen solution samples of the same head space volume after accelerated aging at various temperatures were investigated using the Commission Internationale de l’Eclairage (CIE) LAB color space (a*,b*,L* and ΔE*ab), following which the TTSP was adopted to kinetic analysis of the color changes. The apparent activation energies using the time–temperature shift factor ofa*,b*,L* and ΔE*abwere calculated as 72.4, 69.2, 72.3 and 70.9 (kJ/mol), respectively, which are similar to the values for acetaminophen hydrolysis reported in the literature. The predicted values ofa*,b*,L* and ΔE*abat 40 °C were obtained by calculation using Arrhenius plots. A comparison between the experimental and predicted values for each color parameter revealed sufficiently highR2values (>0.98), suggesting the high reliability of the prediction. The kinetic analysis using TTSP was successfully applied to predicting the color changes under the controlled oxygen amount at any temperature and for any length of time. [ABSTRACT FROM AUTHOR]

The microfade tester is used to assess fading rates of fugitive colors of collection items. The paper presents the research considerations to design a simple, less expensive and portable contact microfade tester that could serve as a screening tool for conservators. Hardware design for such an instrument is presented that includes variations in light source (xenon or LED) and measuring head (ball lens or angled holder fiber), and does not need refocusing between measurements. Performance of the portable microfade tester versions was tested on lab samples and a paper based collection item and based on the ability to rank light sensitivity relative to that of ISO Blue Wool Standards 1, 2 or 3. The results are compared to the ranking obtained with the bench instrument when testing sensitivity of the same items for the same duration. All versions of the portable hardware were found suitable for use as a screening tool to discriminate light-sensitive collection items, with performance of the portable microfade testers using an LED optimized for samples more fugitive than Blue Wool Standard 3. These portable microfade testers need not replace the bench microfade tester as the presented portable microfade tester versions are only suitable to test collection items tolerating surface contact with the instrument. [ABSTRACT FROM AUTHOR]

This study evaluated wood color change (ΔE*) and the surface quality in 10 tropical wood species painted with three finishes (composed of wax and polyurethane). Two weathering conditions were tested: natural weathering (NW) and artificial weathering (AW). The results showed that the application of these finishes, decreased the luminosity (L*), increased the redness (a*) and the yellowness (b*) parameters in all species. ΔE*, after weathering exposure, was affected significantly byL*,a*, andb, whereas for finished or pretreated wood,L* andb* are the main parameters affecting ΔE* in the 10 tropical species studied. ΔE* values found in different finishes and pretreatments are cataloged as total change of color. Other important results were that tropical light colored timber with natural pretreatment produced higher ΔE* than dark colored timber. The stains and fungal development were observed in polyurethane finishes in NW, but not in AW. The irregular and mosaic flaws were not observed in any kind of finish or pretreatment of surface. The values of the quality index created, which considered long and short lines and switch flaws, were lowest in NW and in waxy finish, while the highest value was obtained with the polyurethane finish. [ABSTRACT FROM PUBLISHER]

Conservation treatments may cause alterations to the aesthetic qualities and appearance of paper materials, including their color. The scientific evaluation of color change to measure the effects of conservation treatments is therefore valuable information for the conservator weighing the advantages and disadvantages of the various treatments and approaches available. In this study, two Japanese tissue papers (Yukyu-shi and Sekishu Mare) were treated with plant dyes including black tea, henna, fresh and dried Eucalyptus cinerea leaves, as well as selected watercolors and acrylic paints. Paper specimens were subjected to both moist-heat artificial aging and accelerated photo-aging and color changes were measured using spectrophotometry and microfading tests. Color change is here defined as a change in light/dark, red/green, and yellow/blue coordinates in the International Commission on Illumination (CIE) color space of light reflected from a colored surface before and after an intervention such as accelerated aging. The findings of this study show that paper samples treated with plant dyes experienced larger and more perceptible color changes, as measured by spectrophotometry, compared to untreated controls and samples treated with watercolors and acrylic paints. Thus, plant dyes have poor color stability after moist-heat aging when compared with watercolors and acrylic paints. Nevertheless, papers treated with alizarin crimson acrylic paint, dried eucalyptus leaves, and black tea exhibited minimal color change after photo-aging. This study provides paper conservators with a better understanding of toning materials and their color stability when chosen for paper conservation treatment. [ABSTRACT FROM AUTHOR]

In this study, mussel meat was wet and dry brined and dipped in two different (hickory and maple) liquid smoke flavorings (LS) for different lengths and number of times. Their colors were analyzed by acquiring and analyzing images. Both wet and dry brining changed the color of the mussel meat, measured by the ΔE values based on original colors. Wet brining had a “lightening” effect (increasingL* values), while dry brining resulted in “darkening” (lowerL* values). There were also shifts ina* andb* values. Different number of LS dips and dipping durations significantly changed colors (p< 0.05). However, there was no significant difference between the applications of hickory and maple LS. Color continued to change after treatment, during storage. Image analysis can accurately measure both the distribution and the average color of mussels after brining and after LS applications. [ABSTRACT FROM AUTHOR]

The effect of γ-ray irradiation on the color and structure of the nucleus and cultured pearl nucleus is studied experimentally. By using a (60Co) γ-ray irradiator, the nucleus originating from freshwater shell is irradiated. Consequently, the color of the nucleus is altered from white to blackish brown or gray by an increase in the irradiation dose treatments. The structural identification of all samples has been confirmed using X-ray diffraction. It is clearly found that all the samples are composed of aragonite, a common phase of the mineral CaCO3. A slight change in the crystallinity of the sample is observed when irradiated with high dose of radiation. Scanning electron microscopy images show that there are no morphological changes by irradiation. UV–Vis spectroscopic measurement is used to distinguish and analyze the change of color due to different irradiation doses. With an increase in the γ-ray radiation doses, a red shift in the absorption edge of the optical spectra of pearl nucleus is observed. Electron spin resonance signal shows mainly the presence of radiation-induced radicalsas color center defects within the samples. An increase in the defects with a gradual increase in the radiation dose depicts that the defect-level transition is the dominant mechanism for the color change in the pearl nucleus. [ABSTRACT FROM PUBLISHER]

In this study, we evaluated the effects of drying under atmospheric and vacuum pressure on the drying time, checking, and color change of sugi boxed-heart timber dried at the same dry-bulb temperature and the same wet-bulb depression. The results obtained were as follows: Sugi boxed-heart timber specimens dried at any temperature under vacuum pressure had a shorter drying time than the specimens dried under atmospheric pressure. At moisture content above fiber saturation point and at the same dry-bulb temperature, the specimens dried under vacuum pressure had a drying rate that was almost twice as fast as that of the specimens dried under atmospheric pressure. Sugi boxed-heart timber specimens dried under both atmospheric and vacuum pressure at a higher drying temperature had a shorter drying time than the specimens dried at a lower drying temperature. Apart from the sugi boxed-heart timber specimen dried at a temperature of 100°C under atmospheric pressure, no surface checks were observed for the specimens dried under vacuum pressure or at the other temperatures dried under atmospheric pressure. Slight internal checks were observed in sugi boxed-heart timber specimens dried at a temperature of 100°C under both atmospheric and vacuum pressure. After planer shaving, there was no significant difference between kiln drying under atmospheric pressure and that done under vacuum pressure in terms of the color change (ΔE*) for both sapwood and heartwood of sugi boxed-heart timber specimens. [ABSTRACT FROM AUTHOR]

Value addition to several agri-products such as grains, beans, and millets can be achieved by sprouting followed by thermal treatment. These value-added products can then be suitably formulated and fortified using cost-effective technologies so that they may be used as instant food, weaning food for babies, or functional food. Finger millets, used extensively by Asian and African communities, were studied. Sprouted finger millets were blanched (using hot water and steam) and dried using a fluidized bed dryer. This led to quality enhancement in terms of higher protein content, digestibility, and bioavailable micronutrients. The drying of sprouted millets (ragi in this case) over the temperature range of 40–70°C was studied. Later, the effect of infrared and pan roasting was studied to determine its effect on protein content and other sensory parameters. Dehydrated sprouted finger millets flour can be used for making noodles, papads, unleavened bread, and several other Indian cuisines such as idli, chakli, porridge, and gruel for newborns. [ABSTRACT FROM AUTHOR]

Poly(vinyl alcohol) (PVA) polymer was prepared using the casting technique. The obtained PVA thin films have been irradiated with electron beam doses ranging from 20 to 300 kGy. The resultant effect of electron beam irradiation on the structural properties of PVA has been investigated using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), while the thermal properties have been investigated using thermo-gravimetric analysis and differential thermal analysis (DTA). The onset temperature of decompositionT0and activation energy of thermal decompositionEawere calculated, results indicate that the PVA thin film decomposes in one main weight loss stage. Also, the electron beam irradiation in dose range 95–210 kGy led to a more compact structure of the PVA polymer, which resulted in an improvement in its thermal stability with an increase in the activation energy of thermal decomposition. The variation of transition temperatures with electron beam dose has been determined using DTA. The PVA thermograms were characterized by the appearance of an endothermic peak due to melting. In addition, the transmission of the PVA samples and any color changes were studied. The color intensity ΔEwas greatly increased with increasing electron beam dose, and was accompanied by a significant increase in the blue color component. [ABSTRACT FROM AUTHOR]

A new dye chemosensor molecule toward Hg2+ detection based on rhodamine 6G was synthesized by the condensation reaction of compound 2 and 2-amino-5,6-dimethyl-benzimidazole. Chemosensor 1 showed highly selective functions toward Hg2+ recognition with compared to other examined metal ions. The chemical structures of all the intermediates and chemosensor 1 were characterized by 1H NMR, Mass Spectrometer, and elemental analysis. Upon the addition of Hg2+, chemosensor 1 exhibited a remarkable emission change from colorless to green fluorescence. Additionally, the absorption color change from colorless to light pink in UV-vis range was observed. However, other metal ions such as Cu2+, Ag2+, Co2+, Pb2+, Zn2+, Fe3+, Fe2+, and Mg2+ did not accompany any noticeable spectral change. [ABSTRACT FROM AUTHOR]

Properties of fast-growing timbers with low durability can be improved by thermal modification. Thermal modification is an eco-friendly method of improving durability of wood. In this work, specimens of rubberwood (Hevea brasiliensis) and silver oak (Grevillea robusta) were thermally modified in vacuum between 210 to 240°C for 1 to 8 hours, and their weight loss, color, and chemical changes evaluated. Rate of thermal degradation was determined from weight loss data. The color of the modified wood darkened and was uniform throughout. CIE lightness color coordinate (L*) decreased with treatment severity, while chroma coordinates a* and b* increased initially, but later decreased with increased process severity. FTIR analysis showed degradation of cell wall polymers resulting in generation of structures which are responsible for color darkening of thermally modified wood. Mechanical properties (bending strength, MOR, and bending stiffness, MOE) of heat-treated wood decreased. A decrease in hydroxyl groups reduced the hygroscopic nature, resulting in increased dimensional stability of thermally modified wood. [ABSTRACT FROM PUBLISHER]

There are several indicators used in different titration procedures for the determination of acids and bases in solutions. Out of these, a widely preferred method is the rapid volumetric analysis because of its simplicity, reliability, and cost-effectiveness. In the present work, the indicator evaluated is extracted from a food waste category, namely black gram (Vigna mungo) husk of India. The new indicator has been characterized as a mixture of three isomeric forms of quercitin-3-O-pentoside, which is a flavonol, using LC/MS/UV data. The indicator color change is pH dependent, pH < 7 (pale pink), pH > 7 (yellow), and pH 7 (colorless), which imparts a sharp color change at the endpoint. The novelty of the method is that the permutations and combinations of different indicators used for the analyses of strong-weak acids/bases can be avoided by adopting this procedure. The efficiency of the indicator is cross-checked by comparing the titration results with those of standard indicators and conductometry. The importance of this approach is that the indicator functions around the neutral pH thus minimizing the possible errors. [ABSTRACT FROM PUBLISHER]

A wide-ranging sample set consisting of dry pigments, dyed textiles, organic and aniline-based dyes, gouaches and watercolors, fluorescent inks, and natural history specimens was exposed to light in air (20.9% oxygen) and near-anoxic environments. After a light dosage of approximately 17.5 Mlux-hours under controlled temperature and humidity conditions, 113 of 125 samples (90% of the sample set) were shown to exhibit less color change in a low-oxygen environment compared with its behavior in air. Thirty-nine percent of this subset displayed color change in anoxia that was between two and four times lower than that observed in air, whereas 47% showed color change in anoxia reduced by a factor of four or more. In contrast, six samples exhibited greater color change in anoxia than in air - these samples included Prussian blue watercolor (three samples), Antwerp blue watercolor, Verdigris dry pigment, and Fluorescent Yellow Winsor & Newton Gouache. Although the results from this small sample subset may cause concern when considering the use of anoxia in the conservation of cultural heritage, particularly for colorant systems whose behavior in anoxia has not yet been identified, this study demonstrates the overwhelming benefits of anoxic light exposure for the vast majority of samples investigated here. [ABSTRACT FROM AUTHOR]

Drying is a commonly used postharvest operation for medicinal and aromatic plants. Their high initial moisture contents, requirement of moderate drying temperatures, and quick deterioration of their quality attributes make their drying processes energy intensive and time consuming. These properties may also cause the dried product to be of heterogeneous quality. A contact dryer that transferred energy to drying plants mainly by heat conduction was developed and tested by mixing or not mixing batches of 15 kg of chopped peppermint plants. The contact dryer had three main operational units: a drying table, a mobile mixing/aeration car, and a control panel. The contact dryer was operated with one of four drying programs. All programs affected the completion duration of drying, essential oil content, and dried product color differently. The shortest drying time (15 h) was obtained using the drying program of gradually increased water temperature from 55-60 to 75-80°C in 6 h and mixing/aeration. However, mixing and aeration changed the product color slightly more and partially increased essential oil loss. These drawbacks can be alleviated by selecting the appropriate duration of mixing and aeration. The menthol and menthone percentages of fresh peppermint essential oil ranged from 31.02 to 34.02% (average value: 32.52%) and 23.23 to 26.47% (average value: 24.85%), respectively. The menthol and menthone percentages of dried peppermint essential oil ranged from 22.74 to 42.07% and from 8.95 to 21.76%, respectively. The significant variations in the essential oil composition of dried peppermint leaves within replications were possibly caused by the variations associated with the age and cutting order of fresh peppermint plants at harvest. [ABSTRACT FROM AUTHOR]

Aim: The purpose of this article is to study a detailed mechanism of printing when film-coated tablets were irradiated by UV laser at a wavelength of 355 nm. Methods: Hydroxypropylmethylcellulose (HPMC) film containing titanium dioxide (TiO2) and the film not containing TiO2 and TiO2 powder were lirradiated by the UV laser and estimated by the morphological observation by zoom stereo microscope, thermogravimetric analysis (TGA), total color difference (d E), X-ray powder diffraction (XRD), and dispersive Raman microscopy. Results: In the case of the film containing TiO2, the film showed a visible change in its color from white to gray by the UV laser irradiation. By zoom stereo microscope, it was found that the entire UV laser-irradiated area was not grayed uniformly, but many black particles, whose diameter was about 2 μm, were observed on the film. When TiO2 powder was irradiated by the UV laser, a visible change in its color from white to gray was observed similar to the case of the film containing TiO2. There were many black particles locally in the UV laser-treated TiO2 powder by the morphological observation, and these black particles, agglomerates of the grayed oxygen-defected TiO2, were associated with the visible change of the TiO2. Conclusion: It was found that the film-coated tablets were printed utilizing the formation of the black particles by the agglomeration of the grayed oxygen-defected TiO2 by the UV laser irradiation. [ABSTRACT FROM AUTHOR]

In the presence of catalysts such as sodium acetate, zinc chloride, magnesium perchlorate, and magnesium chloride hexahydrate, acetylation of wood at 75°C was investigated. The results showed that it was possible to endow wood with high dimensional stability at low temperature by a catalyzed acetylation method. In particular, the magnesium chloride-catalyzed acetylation of wood showed very little or no effect on the color change or mechanical property of wood, as contrasted to those of the zinc chloride or magnesium perchlorate-catalyzed treatment, which showed a great effect. In addition, the concentrations of catalysts proved to have an effect on weight percent gain. [ABSTRACT FROM AUTHOR]

For the visual express-control over animal product freshness, the sensor devices based on conducting polymer films (polyaniline, poly-o-methoxyaniline, and poly-o-toluidine) have been proposed. Sensor action is based on a change in the spectral properties and the corresponding color transitions in conjugate polymer films on the transparent surface at a low partial pressure of ammonia (NH3) which is evolved at the loss of protein product freshness. [ABSTRACT FROM AUTHOR]

Water diffusivity, vitamin C degradation, and color change were assessed in two batches of cactus pear that were dried; one by regular air-drying; and the other one by applying partial osmodehydration followed by air-drying. The drying was done with a convection oven at 40, 50, 60, and 70°C. The pretreatment was performed by immersing the samples for 3 hours in a 40°Brix sucrose solution at 40°C. An analysis of variance (ANOVA) with a confidence level of 95% (p < 0.05) revealed that water diffusivity was mainly affected by the temperature and the pretreatment. Both the vitamin C loss and the color change behaved as a first-order reaction; the set temperature used was found to be the most important factor in the process. [ABSTRACT FROM AUTHOR]

The flame resistance, color change, strength, and decay resistance of colloidal silica‐fixed (CSW), propionylated only, and propionylated dual‐treated wood (CSPW) composites were evaluated. The oxygen indexes of the CSPW composites were similar to the CSW composites but much higher than those of untreated woods and the propionylated woods. The oxygen indexes increased with an increase in the weight percent gain of the colloidal silica (WPG csi ) in the composites, showing an effective reduction in the flammability by the fixation of colloidal silica. The CSPW composites showed little or no difference in the modulus of elasticity and modulus of rupture compared with the untreated woods, indicating little or no significant reduction in strength properties of the wood specimens. The color difference of the wood specimens before and after treatment changed slightly. Minimal weight losses of the CSPW composites occurred upon fungal attack by T. versicolor and F. palustris , showing good decay resistance by propionylation of the composites. [ABSTRACT FROM AUTHOR]

A D-optimal experimental design with three center points was used to evaluate the influence of spray-drying conditions on the physicochemical properties of a powdered product obtained by drying cactus pear juice. Drying was performed in a laboratory spray-dryer (Pulvis GB 22 model) at two inlet air temperatures (205 and 225°C), and two compressor air pressures (0.10 and 0.20 MPa). Commercial maltodextrins (10 and 20 DE) were used as carrier agents at two levels (18 and 23%). Moisture content and hygroscopicity were evaluated in the powder, and vitamin C retention and total color change were measured in the reconstituted product. Analysis of variance (ANOVA) was performed with a confidence level of 95% (p <0.05). Moisture content of spray-dried powder and vitamin C retention of reconstituted product was mainly determined by the temperature-pressure, T*P, interaction. While for hygroscopicity, the pressure-concentration, P*C, interaction was the most important factor. The reconstituted product showed a slight change of total color (AE) with respect to natural juice and a significant effect of the maltodextrin concentration was found in this property. [ABSTRACT FROM AUTHOR]

Drying experiments were conducted on raw potato slices, using atmospheric pressure superheated steam and hot air as drying media at 170 and 240°C. Mass changes of the material were continuously measured, the conditions of cross section near the surfaces were observed with an electron microscope, also color changes of their surface were measured during drying. The respective drying methods and temperature conditions were compared and it was found that, in the case of superheated steam drying, moisture content temporarily increases due to steam condensation in the initial stage of drying, therewith, as well as starch gelatinization rapidly develops. Meanwhile, in case of hot air drying, starch gelatinization occurs more slowly than with superheated steam drying and that non-gelatinized starch granules remain on the surface when drying was completed. Furthermore, surface color measurements showed that samples dried by superheated steam were more reddish than ones dried by hot air and the surfaces were more glossy, because no starch granules remain on the surface in case of superheated steam drying. [ABSTRACT FROM AUTHOR]