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Hydroxycitronellal has been widely used in foods, beverages, perfumery and cosmetics. It can also be used to treat anxiety. The major drawbacks regarding the use of hydroxycitronellal are related to water insolubility, volatility, instability, and sensitization. To overcome these concerns, β-cyclodextrin was adopted as wall material to encapsulate hydroxycitronellal in this work. Hydroxycitronellal-β-cyclodextrin inclusion complex was prepared and the product was characterized. The interaction of hydroxycitronellal and β-cyclodextrin, and the assembly of hydroxycitronellal-β-cyclodextrin inclusion complex were investigated by molecular simulation (MM). The results showed that hydroxycitronellal loading capacity was 8.5%. The thermal stability and lastingness of hydroxycitronellal were improved by the formation of the inclusion complex. The minimum binding energy was –151.2 kJ/mol. Among the perpendicular, staggered parallel and ideally parallel orientation of the inclusion complexes, the minimum energy value was found for the staggered parallel arrangement. These basic data are useful to understand the interaction between hydroxycitronellal and β-cyclodextrin.

(-)-Menthol has been widely used in clinical medicine, flavor, and fragrance. However, high volatility, short retention time, low solubility in water, and whisker growth of menthol are crucial problems for its application. In this paper, (-)-menthol-β-cyclodextrin inclusion complex was fabricated to solve these problems. The product was characterized by X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis. The results showed that menthol was successfully encapsulated in the cavity of β-cyclodextrin. Menthol itself vaporized almost completely at around 120 oC, while the maximum menthol release rate occurred at 267.5 oC after the formation of the inclusion complex. The stability and retention time were improved. The menthol release reaction order, apparent activation energy and the pre-exponential factor were obtained and their values were 0, 142.9 kJ/mol and 1.6 × 1013 respectively. The structure of menthol-β-cyclodextrin inclusion complex was investigated by molecular simulation and the minimum energy, –116.7 kJ/mol, was obtained at –0.8 × 10–10 m.

Porous carbohydrate materials such as tobacco shreds readily absorb moisture and become damp during processing, storage, and consumption (smoking). Traditional humectants have the ability of moisture retention but moisture-proofing is poor.

In this study, the optimum preparation conditions for apple fragrance (AF)/β-cyclodextrin (β-CD) inclusion complex were determined by single-factor experiments with encapsulation efficiency (EE%) and loading capacity (LC%) as indicators. The results of particle size analysis indicated that the average diameter of the inclusion complex was 3.6 µm. DSC analysis indicated that the AF/β-CD inclusion complex had a good stability. The release study showed that the retention rate of the AF was 34.4% 60 days later at 50 °C. Avrami’s equation was used to analyze the release kinetics of fragrance/β-CD inclusion complex under different temperatures. The results showed that the release of encapsulated fragrance was between diffusion limiting kinetics and first-order release kinetics at 4 °C, and first-order mode release mechanism at 25 and 50 °C. These results demonstrated that the stability of encapsulated fragrance was enhanced and achieved the purpose of controlled release.

β-Ionone has a characteristic violet-like odor and is an important flavor and fragrance ingredient used in food and perfumery. Furthermore, it has the ability to selectively kill tumor cells and is a promising anticancer agent. In order to improve its solubility, stability and long-release characteristics, β-ionone was encapsulated in hydroxypropyl-β-cyclodextrin (HP-β-CD) to form inclusion complex. The formation constants (K) and thermodynamics were explored by ultraviolet–visible (UV/V) absorption method. The values of K obtained at 35 °C, 45 °C and 55 °C were 29.6 × 103 l/mol, 8.4 × 103 l/mol and 4.9 × 103 l/mol, respectively. Gibbs free energy changes (ΔG) for the interactions of β-ionone and HP-β-CD at 35 °C, 45 °C and 55 °C were − 26.4 kJ/mol, − 23.9 kJ/mol and − 23.6 kJ/mol, respectively. Enthalpy change (ΔH) and entropy change (ΔS) were − 1.1 kJ/mol and − 2.3 J/(K mol), respectively. The solid β-ionone-HP-β-CD inclusion complex was characterized by FTIR and thermogravity analysis (TGA). The FTIR results confirmed that β-ionone was successfully encapsulated in HP-β-CD and that encapsulation of β-ionone did not change the frame of HP-β-CD. The TGA results showed that the release of most of the β-ionone from β-ionone-HP-β-CD inclusion complex mainly occurred in the temperature range of 210–320 °C. A relative larger release rate appeared at 240 °C and the beginning stage of HP-β-CD decomposition. It also revealed that the thermal stability of β-ionone was improved by the encapsulation technology.

Dimethyl sulfide has been widely used in flavors and can also be used as a solvent and catalyst. However, dimethyl sulfide is volatile, and its lasting power is weak. Furthermore, dimethyl sulfide is insoluble in water and is unstable in some cases. This study concentrated on the encapsulation of dimethyl sulfide in β-cyclodextrin to form an inclusion complex and to improve the durability, water solubility, and stability of dimethyl sulfide. The product was successfully produced and characterized by scanning electron microscopy, diffraction of X-rays, and thermal analysis. The dimethyl sulfide loading capacity is 6.40±0.08%. Based on the thermal release characteristics of dimethyl sulfide, the kinetic and thermodynamic parameters were obtained. The apparent activation energy, pre-exponential factor, and reaction order of the dimethyl sulfide release reaction were obtained and the values were 95.0 ± 0.1 kJ/mol, 1.03 × 10

Flavor plays a crucial role and is the most important aspect of foods and beverages. β-Ionone is a common flavor compound with a characteristic violet-like odor. An undergraduate flavor compounds chemistry laboratory that provides preparation and characterization of the flavor compound inclusion complex between hydroxypropyl-β-cyclodextrin (HP-β-CD) as a host and β-ionone as a guest is reported. This simple laboratory experiment allows students to become familiar with the concepts of microencapsulation technology and flavor compound inclusion complexes by teaching students how to prepare and characterize the β-ionone–HP-β-CD inclusion complex. A glass flask with a long, graduated neck is used for fabrication of the inclusion complex, which facilitates observation the volume change of β-ionone with and without the addition of HP-β-CD. From the volume change, the β-ionone loading capacity can be calculated. The volume difference of β-ionone also provides an intuitive way for students to understand that β-ionone is encapsulated in HP-β-CD and that the water solubility of β-ionone is improved by encapsulation. This laboratory experiment also allows students to become familiar with the freeze-drying process, thermogravimetric analysis (TGA), and the application of TGA in characterization of the inclusion complex. Formation of the inclusion complex and analysis of the TGA results allow students to understand the characteristics of β-ionone release from the inclusion complex and the improved thermal stability of β-ionone.

Flavors have been widely used in many products. They are volatile compounds and do not often last long in air especially at high temperature. The techniques for slow flavor release and long-lasting scents, for the stability of sensory perception, are much desired. The inclusion complex method encompasses the idea of molecular recognition and interactions through noncovalent bonding. It can provide protection and prevent the loss of volatile aroma materials, and improve shelf-life and enhance the stability of the entrapped ingredients of flavors. In this article, the production of control-release flavor by inclusion complex method was reviewed in considerable detail. The host materials, the method of production flavor inclusion complex, and the methods of characterization of flavor inclusion complex were depicted. The complexation thermodynamics and calculations were also discussed. Cyclodextrins and their derivatives as the host materials were discussed in this paper. Methods of production flavor inclusion complex include solution method (water or water as the main component of the solution, cosolublizer), suspension method, gas/liquid interface method, and solid phase method (co-grinding method, heating in a closed container method, shaking method at room temperature). The methods of characterization of solid inclusion complex mainly include x-ray diffraction technique, Infrared and Raman spectra, solid nuclear magnetic resonance spectroscopy, thermal analysis, mass spectrometry analysis, scanning and transmission electron microscopy. Structures, energies, and some properties of molecules can be studied by computational chemistry. The application of computational chemistry to the study of flavor compound inclusion complexes were discussed. The review indicates that inclusion complex method is an efficient way for encapsulation of flavor compounds. By this method slow flavor release and long-lasting scents can be obtained.

Flavors play crucial role in food industry. Ethyl acetate, as probably one of the most used of all flavor chemicals by volume, is used widely in many industries. However, ethyl acetate is not too stable and can be slowly decomposed by moisture. Furthermore, ethyl acetate is a volatile liquid insoluble in water and it does not last long enough. In order to solve these problems, hydroxypropyl-β-cyclodextrin was used as wall material to encapsulate ethyl acetate in this work. The product was characterized by Fourier transform infrared (FTIR) spectroscopy and thermalgravimetric analysis (TGA). The results showed that the peaks at 1,744 and 1,056 cm-1 in the FTIR spectrum of ethyl acetate disappeared in the FTIR spectrum of ethyl acetate-hydroxypropyl-β-cyclodextrin inclusion complex. After the encapsulation of ethyl acetate, the O-H and C-H stretching absorption of hydroxypropyl-β-cyclodextrin changed. The TGA results showed that from 77°C to 292°C ethyl acetate is released from the ethyl acetate-hydroxypropyl-β-cyclodextrin inclusion complex in temperatures far beyond ethyl acetate 77°C boiling point. This phenomenon confirmed that the lastingness and thermal stability of ethyl acetate can be improved by the formation of an inclusion complex. The loading capacity of ethyl acetate was 4.86 ± 0.08% and ethyl acetate:hydroxypropyl-β-cyclodextrin stoichiometry is close to 1:1. The interaction of ethyl acetate and hydroxypropyl-β-cyclodextrin was investigated using molecular mechanics calculation. The binding energy was calculated and the possible conformation of ethyl acetate-hydroxypropyl-β-cyclodextrin inclusion complex was optimized to the minimum energy. The binding energy minimum is at the 0.44 × 10-10 m point and its value is -103.9 kJ/mol. PRACTICAL APPLICATION: Encapsulation of ethyl acetate in hydroxypropyl-β-cyclodextrin is a possible way to protect ethyl acetate, improve its stability, water solubility, and may also enhance its lastingness.

The present study reported the formation of fragrance/β-cyclodextrin (β-CD) inclusion complexes aimed to promote thermal stability and controlled release. Then, the fragrance/β-CD inclusion complexes were applied in cotton fabrics through impregnation to obtain aromatic cotton fabrics. The surface morphology and structures of the fragrance/β-CD inclusion complexes were examined via scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy; these analysis results confirmed the formation of inclusion complexes. The stability tests were performed by thermogravimetric analysis and the results confirmed these inclusion complexes had good thermal stability. The surface morphology of the cotton fabrics impregnated by fragrance/β-CD inclusion complexes were tested by SEM. Slow-release experiments of the aromatic cotton fabrics performed by gas chromatography-mass spectrometry and an electronic nose proved that the cotton fabrics impregnated by fragrance/β-CD inclusion complexes had excellent slow-release properties. Moreover, the continuous aroma release time of the cotton fabrics impregnated by fragrance/β-CD inclusion complexes reached up to 80 days.

Although esters were important odorants in light aroma-type liquor, it was still puzzling that sensory interaction between esters made the odor quality of light aroma-type liquor outstanding. The aim of the paper was to investigate perceptual interaction among esters. The odor thresholds of eighteen esters and 35 binary mixture were determined by a three-alternative forced-choice procedure. The relationship between odor threshold and carbon chain length of homologous ethyl esters was investigated. Moreover, 31 binary mixtures present either a synergistic effect or additive action. Furthermore, odor quality and odor intensity were determined by p/τ plot and σ/τ plot, respectively. From the p/τ plot, an ideal sigmoidal function for odor quality was obtained. From the σ/τ plot, for all 120 binary mixtures, just 9 mixtures were in the hyper-additivity area (σ 1.05), and two were in the so-called perfect additivity area (0.95 σ 1.05). Almost one half (48%) showed compromise level. Finally, a significantly difference was observed by flash gas chromatography electronic nose (p .05). Sensory analysis revealed that a mask effect of fruity note was occurred by adding ethyl phenylacetate at various levels (100, 2500, 58,000 ppb) to the fruit recombination and an enhancement effect of floral note was reported by adding phenylethyl acetate at low (1400 ppb) or high level (11,500 ppb). It was noticed that sweet note was significantly enhanced by adding phenylethyl acetate at peri-threshold (3200 ppb).

Lavender fragrance (LF) was encapsulated successfully in ORMOSIL (organically modified silica) via the sol‐gel approach. Silane precursor‐ethylsilicate (TEOS) was modified with methyltrimethoxysilane (MTMS) to enhance the mechanical strength and compatibility of the wall material. Hexadecyl trimethyl ammonium bromide (CTAB) was added as surfactant and polymer for the formation of nanospheres. An encapsulation efficiency of 96.36% was achieved under optimal conditions (water/ethanol ratio of 2 : 1, with pH 9.5, and with a surfactant concentration of 25 mM). Moreover, a scanning electron microscope (SEM) image of the LF nanospheres showed that the nanospheres were spherical with good dispersibility. The Fourier transform infrared spectroscopy (FTIR) analysis indicated that LF was successfully encapsulated in organically modified silica. The result of thermogravimetric (TG) analysis showed that the nanospheres had excellent thermal stability. Furthermore, the SEM image of aromatic wallpaper indicated a successful application of the LF nanospheres in wallpaper.

Aromatic wallpaper was developed in order to provide fragrant atmosphere for inter space with new properties and added value. Micro-encapsulation technology is an effective method to control release of fragrance. If wallpaper is treated with micro-encapsulated fragrance, longer scent holding time is expected. This article reported the detailed preparation processes and analysis of two sorts of wallpapers with gas chromatography-mass spectrometry (GC–MS) and electronic nose (E-Nose). The morphology of blank wallpaper and the aromatic wallpaper were characterized by scanning electron microscopy (SEM). The aroma content of fragrant wallpapers was investigated by head-space solid phase-micro-extraction (SPME) and GC–MS. The employ of an electronic nose to measure the intensity of fragrant release from the wallpaper was also conducted. The release experiments indicated that aromatic wallpaper had the eminent and stable sustained release property. What’s more, the sustained release time of aroma could reach more than 3 months. Meanwhile, the aroma intensity and the comfortable degree were associated with sensory valuation to confirm which one is the best fit for human feelings.

The interactions between nanoparticles and materials must be considered when preparing functional materials. Although researchers have studied the interactions between nanoparticles and inorganic materials, little attention has been paid to those between nanoparticles and bio-based protein materials, like leather. In this study, organically modified silica nanospheres (SiO2 nanospheres) loaded with rose fragrance were prepared using (3-aminopropyl) triethoxysilane (APTES), (3-mercaptopropyl) triethoxysilane (MPTES), or 3-(2, 3-epoxypropyloxy) propyl triethoxysilane (GPTES) using the sol-gel method. To study the interactions between the modified SiO2 nanospheres and leather, a non-cross-linking adsorption experiment was conducted. According to the Dubinin–Radushkevich isotherm calculation, we found that the adsorption process of leather fiber and organically modified silica nanospheres is physical. The average adhesion energies of APTES-, MPTES-, and GPTES-modified SiO2 nanospheres on the leather are 1.34016, 0.97289, and 2.09326 kJ/mol, respectively. The weight gain, adsorption capacity, and average adhesion energy show that the modified SiO2 nanospheres can be adsorbed on leather in large quantities. The sensory evaluation confirmed that GPTES-modified SiO2 nanospheres endowed the leather with an obvious rose aroma.

Mentha-8-thiol-3-one, with a characteristic black currant flavor, has been widely used in blending flavors and perfumes. To improve its shelf-life and stability, and control its release, mentha-8-thiol-3-one-β-cyclodextrin inclusion complex was produced. The inclusion complex was characterized by transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. Kinetics and release characteristics of mentha-8-thiol-3-one from the inclusion complex were determined by thermogravimetric analysis. The results showed that mentha-8-thiol-3-one was successfully encapsulated in β-cyclodextrin, and the loading capacity was about 13.5 %. The inclusion complex aggregates had many geometric shapes and the particle size was mostly in the range of 1–3 μm. The distributions of S, C and O can be observed element maps of mentha-8-thiol-3-one-β-CD inclusion complex. Mentha-8-thiol-3-one release from the inclusion complex mainly occurred in the first stage of pyrolysis. At 236.3 °C, the release rate of mentha-8-thiol-3-one attained the maximum value. The release reaction order was 1.5. The apparent activation energy and pre-exponential factor were 290.8 kJ/mol and 3.19 × 1024, respectively.

Menthyl acetate has a characteristic, fresh, pungent flavor and a cool mouthfeel. It has been widely used in many products. Because of its high volatility and short shelf-life, menthyl acetate-β-cyclodextrin inclusion complex was produced to provide protection, enhance stability and control release of menthyl acetate. The inclusion complex was characterized by Fourier transform infrared spectroscopy, x-ray diffraction. The results show that menthyl acetate was successfully encapsulated in β-cyclodextrin. Menthyl acetate loading capacity was obtained from the weight loss difference between blank β-cyclodextrin and inclusion complex, and the value is about 8.5 %. Kinetics and release characteristics of menthyl acetate from complex were determined by thermogravimetric analysis. Menthyl acetate release mainly occurred in the first stage before β-CD decomposition. Because menthyl acetate-β-CD inclusion complex is a poor conductor of heat, the methyl acetate release peak shifted towards higher temperature with an increase in heating rate. Menthyl acetate release activation energies were obtained and the average value is 258.7 kJ/mol. Kinetics and release characteristics are basis data for better understanding the mechanism and the combination of host and guest.

The styrallyl acetate (SA) nanocapsules were prepared using complex coacervation with gelatin (G) and gum arabic (GA) as the wall materials. The stability of the nanocapsules formed at different pH (4.8, 4.5, 4.2, 3.9, 3.6), wall concentration (0.5%, 1.0%, 1.5%, 2.0%, 2.5%) and the ratio of oil/emulsifier (1:2, 1:1, 2:1, 3:1) were evaluated. The results showed that the formation and stability of nanocapsules were influenced by these factors. The optimal process conditions were determined depending on the most stable aqueous system with the highest encapsulation efficiency. The optimum conditions were as follows: pH 4.5, the total concentration 1% and the ratio of core oil/emulsifier 1:1. The results of nuclear magnetic resonance (NMR) indicated that SA was encapsulated in G and GA successfully and the structure of SA and the wall materials was not changed. The further stability of optimal nanocapsules was assessed. Nanocapsules loaded with oil presented good stability over 8 months. Furthermore, the thermal stability was analysed by thermogravimetric analysis (TGA) and the results showed that the SA nanocapsules exhibited excellent thermal stability than the pure oil. Copyright © 2016 John Wiley & Sons, Ltd.

Maillard reaction products containing 0–86.67% (w/w) enzymatically hydrolyzed chicken breast (chicken base) were analyzed. Descriptive sensory analysis was conducted and the 5 sensory attributes of meaty, caramel, umami, continuity, and off-flavor were used for evaluation. A sample group containing 65.00% chicken base had high scores for meaty note. A sample group containing 86.67% had a high score for caramel note. The electronic nose was used for measurement of flavor quality changes based on a metal oxide sensor (MOS) array. GC-MS was used for identification of volatile compounds. Heterocyclic sulfur and nitrogen oxygen compounds (especially 2-methyl-3-furanthiol, 2-methyl-furan, 2-pentyl-furan, 2-acetyl-furan, bis (2-methyl-3-furyl) disulfide, furfural, 2-acetyl-pyrrole, 1-methyl-pyrrole, thiazole, and 4-methyl-thiazole) were responsible for meaty and caramel attributes. Statistical analysis was used to interpret the distribution of samples and correlations among variations.

Encapsulation aims at protecting components, providing controlled release, preventing oxidation and extending the shelf life. The inclusion complex of citral and monochlorotriazinyl-β-cyclodextrin has been studied. The scanning electron microscopy result showed that the dried citral–monochlorotriazinyl-β-cyclodextrin inclusion complexes formed aggregates with many geometric shapes in the size range 1–2 μm, and the transmission electron microscopy result shows that the inclusion complex aggregates were expressed through a bicontinuous “worm-type” pore system. Fourier transform infrared spectroscopy results show that citral enters the cavity of monochlorotriazinyl-β-cyclodextrin. The citral loading capacity determined from thermogravimetric data is about 8.96 %, and a 1:1 stoichiometry is obtained. Pyrolysis characteristics of the inclusion complexes were determined. Geometries of host, guest and the host–guest inclusion complex were optimized using molecular mechanics calculations. The binding energies for the most stable complexes geranial/monochlorotriazinyl-β-cyclodextrin and neral/monochlorotriazinyl-β-cyclodextrin are −143 and −162 kJ mol−1, respectively. The shapes and orientations of those complexes were presented.

Styralyl acetate (SA) was encapsulated in gelatin and gum Arabic using complex coacervation. The response surface methodology was carried out to explore effects of wall concentration and the amount of SA on the yield, encapsulation efficiency, and oil loading capacity and to optimize the process conditions. The results of optimization showed that the wall concentration of 1.35 % (w/v) and the SA of 2.23 g were used, the highest yield of 72.8 %, encapsulation efficiency of 80.6 % and oil loading capacity of 66.2 % were obtained. The morphologies were observed by an optical microscope and scanning electron microscopy (SEM), respectively. Microcapsules exhibited excellent thermal stability than SA by thermogravimetric analysis (TGA). Moreover, Fourier transform infrared and X-ray diffraction examined structure changes of wall materials and core oil.

The inclusion complex of citral with monochlorotriazine-β-cyclodextrin (MCT-β-CD) was prepared and grafted to the fabric. The chemical structure of the inclusion complex was characterized by Fourier transform infrared spectroscopy. The particle size distribution of Citral-MCT-β-CD. Inclusion complex was measured with dynamic light scattering (DLS). The loading capacity was investigated by Ultraviolet–visible absorption spectroscopy and thermo-gravimetric analyzer, and the morphology of the fabric grafted with inclusion complex of citral with MCT-β-CD was characterized by scanning electron microscope (SEM). Results showed that the inclusion complex of citral with MCT-β-CD was successfully prepared and grafted to the fabric. The particle size was in nano size, approximately to 200–300 nm. The load capacity was about 9%. Citral release rate was significantly lower than the unfinished one because of chemical bond with the fabric. This method may provide a new technique to produce aromatic cotton with control ...

A simple, rapid and solvent-free multi-residue method has been developed and applied to confirm and quantify a series of volatile compounds in five cherry wines by gas chromatography coupled with mass spectrometry (GC–MS). Four parameters (e.g., coating material of fiber, temperature and time of extraction, and addition of sodium chloride in the solution) of headspace solid-phase micro-extraction (HS-SPME) were optimized, resulting in the best extraction condition including 50/30 μm DVB/CAR/PDMS fiber, 45 min and 50 °C of SPME, and 2 g of sodium chloride addition in the wine during the extraction. The SPME had LODs and LOQs ranging from 0.03 to 7.27 μg L−1 and 0.10 to 24.24 μg L−1 for analytic compounds, respectively. Repeatability and reproducibility values were all below 19.8%, with mean values of 12.7% and 10.5%, respectively. Regression coefficients (R2) of detective linearity of the standard curves was higher than 0.9852. Moreover, relative recoveries of analytical targets were achieved in a range of 60.7–125.6% with good relative standard deviation values (≤20.6%). In addition, a principal component analysis (PCA) was used to analyze the aroma profiles of the wines, which indicated that five samples were distinctly divided into two groups based on their different geographical origins and volatile compounds.

Flavour plays a crucial role in food and is the most important aspect of milk. Milk has a pleasant smell and milk flavour can be used in several products. However, how to recreate milk flavour has rarely been reported. Therefore, the creation of milk flavour is of great interest. This study focused on the creation and imitation of milk flavour. The approach to flavour creation involves identifying the attributes of the flavour and developing an impactful, authentic flavour. Accordingly, to create a milk flavour, the notes of milk flavour were identified by smelling and tasting milk. Based on the identified notes, aroma ingredients were selected to blend into a milk-flavour. After olfactory discrimination, several modifications and adjustments were made and a typical milk flavour formula was obtained. The results showed that the milk flavour has the following notes: milky, acidic, vanilla-like, caramel-like, aldehydic, fruity, beany, buttery, meaty, and vegetative. Lactones, acids, aldehydes, alcohols, ketones, esters, sulphur compounds, furans, and nitrogen compounds can provide these notes. Based on the developed formula, a harmonious flavour with typical characteristics of milk was obtained by blending the selected aroma ingredients.

Stir bar sorptive extraction and thermal desorption system followed by gas chromatography-mass spectrometry (SBSE-TDS/GC-MS) have been applied to the characterization of selected volatile compounds of Chinese liquors. Calibration curves were achieved for quantification with correlation coefficients ranging from 0.9875 to 0.9996. Limits of detection (LODs) and limits of quantification (LOQs) were obtained ranging from 0.007 to 17.89 μg L−1 and from 0.02 to 69.6 μg L−1, respectively. Repeatability was between 0.2 and 7.0 % while intermediate precision was between 0.1 and 7.5 %. Afterward, five Chinese liquors having different flavor types were investigated using the SBSE-TDS/GC-MS method. A total of 87 volatile compounds, including 40 esters, 12 alcohols, 8 acids, 2 phenols, 8 aldehydes and ketones, 7 acetals, 6 furans, 1 sulfuric compound, and 3 pyrazines, were identified and quantified. The obtained results of GC-MS were then subjected to analysis of variance (one-way ANOVA) followed by partial least squares regression (PLSR). ANOVA results indicated that 52 components (p ≤ 0.05) were useful in characterizing the five liquor aromas. It showed that the ANOVA-PLSR model could well elucidate the correlation between liquors and the identified volatile compounds and could well indicate the possibility to discriminate sauce-flavor and strong-flavor liquors.

In this paper, the current status of amino acid extraction from animal waste biomass and reducing sugar from plant waste biomass by hydrolysis in subcritical and supercritical water was reviewed. The properties of subcritical and supercritical water, reactor systems, reaction kinetics, reaction mechanism, and effects of different factors (temperature, time, and catalyst) on yield were summarized. Subcritical and supercritical water hydrolysis is a biorefinery approach for both protein and sugar—one treatment. Hydrolysis at subcritical and supercritical conditions may provide an efficient process for recovering useful chemicals from biomass wastes and for the disposal of biomass wastes.

A microcapsule of sweet orange oil was prepared by the gelation of sodium alginate with Ca2+. Orthogonal experiments were designed to investigate the encapsulation efficiency (EE) to be adopted as the target index. The optimum conditions were obtained as follows: sodium alginate concentration 2% (w/v), CaCl2 concentration 1.5% (w/v), ratio of core material to wall material 1.5:1, and emulsifying agents 0.1% (w/v) Tween80 and 0.1% (w/v) glyceryl monostearate. Under these conditions, the highest EE was 76.1%. Chitosan was added to prepare chitosan-coated calcium alginate (CCCA) and chitosan–calcium alginate complex (CCAC) gel beads. The influence of the addition of chitosan on microcapsule's morphology, EE and release characteristic was the focus of study. For these three types of microcapsules, the results showed that both surface smoothness and EE in descending order were CCAC, CCCA and calcium alginate (CA) gel beads, while the order of release rate was CA, CCCA and CCAC gel beads. These three types of microcapsules could be used in chewing gum, puffed food and other food products to control release and prevent volatilization of flavour because of their different characteristics or properties. Copyright © 2014 John Wiley & Sons, Ltd.

Flavour plays an important role and has been widely used in many products. Usually, the components of flavour are volatile and the sensory perception can be changed as a result of volatilization, heating, oxidation and chemical interactions. Encapsulation can prevent the loss of volatile aromatic ingredients, provide protection and enhance the stability of the core materials. This work concentrated on production of a transparent lavender flavour nanocapsule aqueous solution. The results showed that a transparent lavender flavour microcapsule aqueous solution can be produced using hydroxypropyl-β-cyclodextrin (HP-β-CD) as wall material. The combination and interaction of flavour and wall materials were investigated by pyrolysis. Pyrolysis characteristics and kinetic parameters of the flavour nanocapsule were determined. During thermal degradation of blank HP-β-CD and flavour-HP-β-CD inclusion complex, three main stages can be distinguished. Due to the vaporization of lavender flavour encapsulated in HP-β-CD, the thermogravimetric (TG) curve of blank HP-β-CD shows a leveling-off from room temperature to 269 °C, while the TG curve of flavour-HP-β-CD inclusion complex is downward sloping in this temperature range. The kinetic parameters are helpful in understanding the mechanism of molecular recognition between hosts and guests.

The stable adsorption of chitosan nanoparticles (CNs) onto cotton fabrics was successfully developed without any chemical binders. The adsorption kinetics, thermodynamics, and capacities under different experimental conditions were investigated. The structure and laundering durability of CNs-adsorbed cotton fabrics (CNs-cotton) were also characterized by Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), and Thermo Gravimetric Analysis (TGA). The adsorption capacities of cotton for CNs declined with the increasing CNs particle size and temperature. By contrast, adsorption capacities increased with the increasing adsorption pH and CNs mass concentration. The kinetic adsorption of CNs onto cotton fabrics was found to follow the pseudo-second-order kinetic model. The adsorption mechanism reflected a complex process, and the intra-particle diffusion was not the only rate-limiting step. The transfer and diffusion rates progressively increased with the decrease of adsorption temperature and CNs particle size. The negative values of the standard Gibbs free energy changes (ΔG°) and the standard enthalpy (ΔH°) indicated that the adsorption was exothermic and spontaneous at 5–75°C. The superior laundering resistance of CNs-cotton was demonstrated after 30 consecutive washes, thereby proving the stable adsorption of CNs onto cotton fabrics without chemical binders. POLYM. COMPOS., 36:2093–2102, 2015. © 2014 Society of Plastics Engineer

The interactions between nanoparticles and materials must be considered when preparing functional materials. Although researchers have studied the interactions between nanoparticles and inorganic materials, little attention has been paid to those between nanoparticles and bio-based protein materials, like leather. In this study, organically modified silica nanospheres (SiO2 nanospheres) loaded with rose fragrance were prepared using (3-aminopropyl) triethoxysilane (APTES), (3-mercaptopropyl) triethoxysilane (MPTES), or 3-(2, 3-epoxypropyloxy) propyl triethoxysilane (GPTES) using the sol-gel method. To study the interactions between the modified SiO2 nanospheres and leather, a non-cross-linking adsorption experiment was conducted. According to the Dubinin&ndash, Radushkevich isotherm calculation, we found that the adsorption process of leather fiber and organically modified silica nanospheres is physical. The average adhesion energies of APTES-, MPTES-, and GPTES-modified SiO2 nanospheres on the leather are 1.34016, 0.97289, and 2.09326 kJ/mol, respectively. The weight gain, adsorption capacity, and average adhesion energy show that the modified SiO2 nanospheres can be adsorbed on leather in large quantities. The sensory evaluation confirmed that GPTES-modified SiO2 nanospheres endowed the leather with an obvious rose aroma.

Flavors represent a small but significant segment of food industry. Taro gives a pleasant nut-like odor when cooked. Taro flavor can be used in many products, so developing a taro flavor is of interests. This paper concentrates on preparation and simulation of taro flavor according to the notes of taro, which are distinct flavors or odor characteristics. The results show that the notes of taro flavor can be classified as caramellic note, roast note, milky note, beany note, green note, aldehydic note, sweet note, nutty note, vegetative note, and fruity note. According to the notes of cooked taro odor and the raw materials selected, a typical taro flavor formula is given. The taro flavor blended is pleasant, harmonious, and has characteristics of the odor of cooked natural taro.

The aim of this work was to encapsulate lavender oil by complex coacervation using gelatin and gum Arabic as encapsulants. The effects of various factors including pH value, the core/wall ratio, wall material concentration, stirring speed, cross-linkers and homogenization rate on the appearance, mean particle size, yield, loading capacity (LC) and encapsulation efficiency (EE) were investigated. The optimal conditions (pH 3.5, core/wall 3:2, wall material concentration 1%, stirring speed 450 rpm, homogenization rate 19 000 rpm and glutaraldehyde as cross-linker) for preparing spherical multinuclear microcapsules were obtained. At the optimal conditions, the highest yield is 65.8 ± 1.0%; the maximum LC is 61.3 ± 0.7%; the highest EE is 66.0 ± 0.3%. The effect of three different cross-linkers on the hardening effectiveness of multinuclear microcapsules containing lavender oil was investigated. Glutaraldehyde and transglutaminase exhibit similar microcapsule hardening effectiveness. When tannic acid was used instead of glutaraldehyde and transglutaminase, the mean particle size and EE remained the same as that when hardening with glutaraldehyde or transglutaminase, but the morphology obviously changes, while the yield and LC significantly decrease. Copyright © 2013 John Wiley & Sons, Ltd.

Biomass is recognized as an important solution to energy and the environmental problems related to fossil fuel usage. The rational utilization of biomass waste is important not only for the prevention of environmental issues, but also for the effective utilization of natural resources. Pyrolysis and hyrolysis in subcritical water are promising processes for biomass waste conversion. This paper deals with hydrolysis and pyrolysis of peanut shells. Hydrolysis and pyrolysis kinetics of peanut shell wastes were investigated for the in-depth exploration of process mechanisms and for the control of the reactions. Hydrolysis kinetics was conducted in a temperature range of 180–240 °C. A simplified kinetic model to describe the hydrolysis of peanut shells was proposed. Hydrolysis activation energy as well as the pre-exponential factor was determined according to the model. The target products of peanut shell hydrolysis, reducing sugars, can reach up to 40.5 % (maximum yield) at 220 °C and 180 s. Pyrolysis characteristics were investigated. The results showed that three stages appeared in this thermal degradation process. Kinetic parameters in terms of apparent pyrolysis activation energy and pre-exponential factor were obtained by the Coats–Redfern method.

This paper describes a new approach to the analysis of switched mode power converters utilizing coupled inductors and presents a novel canonical circuit model for N-winding coupled inductors. Waveform and ripple of the winding current in a coupled inductor converter can be easily determined using the developed model similar to those obtained in an uncoupled inductor converter. Influence of coupling coefficient on converter steady state and transient performances is readily predicted by the proposed model and a comparison of coupled and uncoupled inductor converters is provided. It is found that coupling among windings effectively alters the phase node voltage waveforms driving the coupled inductors. Through coupling, a converter is capable of responding faster to load transient depending on the coupling coefficient and control mechanism, and this dependency is analytically revealed in the paper. Some design constraints regarding coupling coefficient are also discussed for two-winding and multi-winding coupled inductors in power converter applications. Finally, a two-phase buck regulator is experimentally tested to verify the proposed model.

Reducing sugar, as a biomass energy precursor, can be further transformed to fuel alcohol in a fermentation process by means of micro-organisms or yeast. This study investigated the production of reducing sugars from bean dregs waste by hydrolysis in subcritical water. It was investigated that the effect of reaction temperature, reaction time and CO2 on reducing sugar yield. The optimum hydrolysis technology conditions were obtained. The addition of carbon dioxide led to an increase in reducing sugar yield. The highest yield of total reducing sugars is 65.7% at 300 °C and 360 s. Kinetics was conducted in a temperature range of 260–300 °C. Since the reaction kinetics in sub-critical water is very complicated, a simplified kinetic model to describe the hydrolysis of bean dregs wastes is proposed. The differential equations resulting from the model were fit to experimental data to obtain kinetic rate constants. By means of the Arrhenius plot, the activation energy as well as the pre-exponential factor was determined. A good agreement between the simplified model and the experimental data was obtained. The kinetic parameters provided useful information for understanding the hydrolysis reaction of bean dregs waste. Based on the results, this method could become an efficient method for biomass wastes liquefaction, producing valuable reducing sugars.

The recovery of waste substances is important not only for the prevention of environmental issues, but also for the rational utilization of natural resources. Hydrolysis reaction in sub-critical water is a promising method for the treatment of organic wastes and has been attracting worldwide attention. In this paper, sub-critical water hydrolysis was employed as a method for producing amino acids, reducing sugars, bio-oil and gas fuels from biomass wastes. The current statuses of these useful chemicals production from biomass wastes by hydrolysis in sub-critical water were reviewed. The review indicates that sub-critical water hydrolysis can be an efficient process for recovering useful chemicals from biomass wastes. This method is renewable, sustainable, efficient, and safe for the environment.

This study investigated the production of value-added amino acids from bean dregs by hydrolysis in subcritical water. It was investigated that the effect of reaction temperature, reaction time and CO2 on amino acid concentration in the hydrolysates of bean dregs. The product of amino acid was determined by Amino Acid Analyzer. The results show that a variety of amino acids are produced. The concentrations of arginine, lysine and alanine were relatively high in the hydrolysate. Temperature and time have a great influence on the hydrolysis reaction. The effects of reaction temperature and time on concentration of different amino acids vary. The addition of carbon dioxide led to an increase in amino acid yield due to the acceleration of acid hydrolyzed catalysis steps. The highest yield of total amino acids is 22% (0.22 g/g of dry bean dregs) at 330°C and 30 min. This method may provide a practical and economical solution for the disposal of bean dregs wastes.

Amino acids play an important physiological role in all life-forms and can be recovered from bean dregs waste using sub-critical water hydrolysis. This work deals with the hydrolysis kinetics of bean dregs. Kinetics was conducted in a temperature range of 200-240°C using a 300-ml stainless steel batch reactor. Since the reaction kinetics in sub-critical water is very complicated, a simplified kinetic model to describe the hydrolysis of bean dregs is proposed: a single consecutive reaction. The differential equations resulting from the model were fit to experimental data to obtain kinetic rate constants. By means of the Arrhenius plot, the activation energy as well as the pre-exponential factor was determined. A good agreement between the simplified model and the experimental data was obtained. The kinetic parameters provided useful information for understanding the hydrolysis reaction of bean dregs. The experimental results show that the best hydrolysis technology is: reaction temperature 200°C, reaction time 20 min. Under this condition, the total amino acid yield reaches 52.9%. Based on the results, this method could become an efficient method for bean dregs liquefaction, producing valuable amino acid.

In order to improve the utilization of bird wastes, the hydrolysis technology optimization and reaction kinetics for amino acid production by extremely low acids in subcritical water have been conducted. In this experiment, the raw material was chicken intestines and the research target was the yield of amino acids. The effects of reaction temperature, reaction time and H 2 SO 4 concentration in reactant system on amino acid yields were investigated using the orthogonal test and the optimum hydrolysis technology conditions were obtained. The experimental results show that the best hydrolysis technology is: reaction temperature 533 K, reaction time 28 min, H 2 SO 4 concentration in reactant system 0.02 wt.%. Under this condition, the amino acid yield reaches 11.49%. The results of chemical reaction kinetics experiment indicate that the total velocity constants of chicken intestine hydrolysis in subcritical water with H 2 SO 4 concentration in reactant system 0.02 wt.% are 1.52 × 10 −2 , 3.35 × 10 −2 , 11.58 × 10 −2 , and 14.01 × 10 −2 at 473 K, 503 K, 533 K, and 553 K respectively. The reaction kinetics order is 1.52, activation energy is 64.44 kJ/mol and the pre-exponential factor is 1.91 × 10 5 .

Green grass fragrance has been widely used in many fields. However, fragrances are volatile compounds that do not last long. In order to prolong its odor, nanocapsules encapsulated green grass fragrance were prepared. The paper deals with the preparation of green grass fragrance nanocapsules by emulsion polymerization. N-butylcyanoacrylate (BCA) with excellent biocompatibility and biodegradability was used as encapsulant. The nanocapsule suspension systems were characterized and its stability was investigated. The physicochemical properties of polymeric nanocapsules (average diameter and polydispersity) were evaluated as a function of time to assess the system stability. The result showed that the system (containing 0.8% of green grass fragrance, with a polydispersity index (PDI) near 0.1 and an average diameter in the range of 20-30 nm) was an ideal state and relatively stable. Besides, the distinction of stability of three nanocapsule suspensions with different green grass fragrance content was also obvious from scanning electron microscopy (SEM).

The paper deals with the preparation of linalool nanocapsules by emulsion polymerization using n-butylcyanoacrylate (BCA) as encapsulant. The nanocapsule emulsions were characterized and their stability and rheological properties were investigated. The physicochemical properties of nanocapsule emulsions (average diameter, polydispersity and rheological property) were evaluated as a function of time to assess system stability. Besides, rheological curve of polymeric nanocapsule emulsions tested under the steady state model were fitted well according to Carreau model with 4 parameters, and the data after the fitting was analyzed. The result showed that the system (containing 0.8 % (w/w) of linalool, 1.6 % (w/w) of EL-40 and 0.4 % (w/w) of BCA) that a polydispersity index (PDI) kept near 0.1, which was monodisperse and had a narrow peak, was an ideal state and relatively stable; and the mechanical stability of a nanocapsule emulsion systems could be estimated by rheological test to some extent.

Microwave treatment (MW) was used to improve the sound absorption capacity of Pinus sylvestris var. mongolica wood. The effects of the processing parameters such as MW intensity, processing time, and board thickness on the sound absorption of treated wood were investigated. Microstructure changes of the wood after microwave treatment were observed using scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP). It was found that the microwave treatment significantly enhanced the sound absorption capacity of the wood in the middle frequencies. The optimum microwave treatment parameters for Pinus sylvestris var. mongolica wood to achieve an improved permeability are: MW intensity of 18 Kw, board thickness of 30 mm, and processing time of 80 s. The maximum sound absorption coefficient of treated wood was 0.51. Micro-voids were formed in treated wood due to the destruction of the pit membranes, the wood ray cells, as well as the damage in the intercellular layer of the longitudinal tracheids. The number of micro-voids ranging from 7427.6 nm to 400 um increased, resulting in the increase in the air permeability and in sound absorption by the treated wood.

A new single-stage, single-switch power factor correction converter with output electrical isolation is proposed in this paper. The topology of this converter is derived by combining a boost circuit and a forward circuit in one power stage. To improve the performance of the AC-DC converter (i.e., good power factor correction, low total harmonic distortion (THD) and low DC bus voltage), two bulk storage capacitors are adopted. Its excellent line regulation capability makes the converter suitable for universal input application. Due to its simplified power stage and control circuit, this converter presents a better efficiency, lower cost and higher reliability. Detailed steady state analysis and design procedure are presented. To verify the performance of the proposed converter, a design example along with P-simulation program with integrated circuit emphasis (PSPICE) simulation and experimental implementation are given. The measured power factor and efficiency are 99% and 87% at low line (i.e. 110 VAC) operation, and 95% and 81% at high line (i.e. 220 VAC) operation, respectively.

It is shown that an incorrect parameter limit in the existing Pspice pulsewidth modulated (PWM) switch model has been detected. The main objective of this work is to alert users of such models to a potential source of simulation error under certain parameter specifications as shown here. Simulation of the boost converter operating in discontinuous conduction mode (DCM) based on the incorrect model results in either convergence problems or wrong results. Correction of the model is provided and its validity is verified using a specific converter example. The results illustrate how the old and corrected models produce different results when the boost converter is subjected to some transients under sudden load variations.

In this paper, a small-signal model for a new single-switch single-stage switched-mode power-factor-correction (PFC) converter is presented. The model is obtained by applying the small-signal perturbation technique to the circuit equations derived from the state-space averaging method. By applying the perturbation and averaging techniques over one switching cycle, the DC and small-signal equivalent circuit representations of this converter are derived. The result shows that this converter exhibits the transfer characteristics of a second-order low-pass system for the output-to-input transfer function and that of a combined second-order low-pass and band-pass system for the output-to-control transfer function. The validity of the proposed mathematical model was verified by the given experimental results for a specified design example.

By performing a detailed analysis of switching-mode power supplies based on swithed-capacitor circuits, their fundamental steady-state characteristics are found. A few basic step-down and step-up converters are considered. No approximations, such a averaging techniques are required. The on-resistances of the transistors, forward voltages of the diodes and equivalent-series resistances of capacitors are taken into account. Design-oriented formulas of the DC voltage ratio, trade-offs allowing for the best possible efficiency, the smallest possible ripple and the best possible line and load regulation give the design values of the number of capacitors in the switched-capacitor circuit, of their capacitances and of the switching frequency.