The low bioavailability and poor gastrointestinal instability of curcumin hampers its application in pharmaceutical and food industries. Thus, it is essential to explore efficient carrier (e.g. a combination of polyphenols and proteins) for food systems. In this study, covalent β-lactoglobulin (LG)-dicaffeoylquinic acids (DCQAs) complexes were prepared by combining ultrasound and free radical induction methods. Covalent interactions between LG and DCQAs were confirmed by analyzing reactive groups. Variations in secondary or tertiary structure and potential binding sites of covalent complexes were explored using Fourier transform infrared spectroscopy and circular dichroism. Results showed that the β-sheet content decreased and the unordered content increased significantly (P < 0.05). The embedding rate of curcumin in prepared LG-DCQAs complexes using ultrasound could reach 49 % - 62 %, proving that complexes could embed curcumin effectively. This study highlights the benefit of ultrasound application in fabrication of protein-polyphenol complexes for delivering curcumin.

Tea trichomes were regarded as an essential evaluation index for reflecting tea flavor quality in terms of aroma and influence on infusion color. This study reveals the impact of golden oxidized trichomes on the color, volatile and non-volatile metabolites of black teas through comparative metabolomics combined quantitative analysis on hongbiluo (trichomes-deficiency black teas), hongjinluo (trichomes-rich black teas), and trichomes (from hongjinluo). Forty-six volatile components were detected using headspace solid-phase microextraction gas chromatography-mass spectrometry, while the results suggested that the contribution of trichomes to black teas is limited. A total of 60 marker non-volatile compounds were identified, including catechins, catechin oxidation products, flavonoid glycosides, organic acids, hydrolysable tannins and amino acids. Notably, p-coumaroyl-kaempferol glucosides, and catechin dimers demonstrated high levels in independent trichomes and showed a positive correlation with the brightness and yellow hue of black tea infusions, specifically kaempferol 3-O-di-(p-coumaroyl)-hexoside. Furthermore, results from fractional extraction analysis of separated trichomes provided that N-ethyl-2-pyrrolidinone-substituted epicatechin gallates, acylated kaempferol glycosides, and chromogenic catechins dimers, such as theaflavins, were primary color contributors in oxidized trichomes. Especially, we found that epicatechin gallate (ECG) and its derivates, 3'-O-methyl-ECG and N-ethyl-2-pyrrolidinone-substituted ECG, highly accumulated in trichomes, which may be associated with the varieties of hongbiluo and hongjinluo black teas. Eventually, addition tests were applied to verify the color contribution of trichome mixtures. Our findings employed comprehensive information revealing that golden oxidized trichomes contributed significantly to the brightness and yellow hue of black tea infusion, but their contribution to the aroma and metabolic profile is limited. These findings may contribute to the effective modulation of the infusion color during black tea production by regulating the proportion of tea trichomes or screening trichomes-rich or deficiency varieties.

The capacity differences of seven catechin monomers to produce colors after treating with catechin-free extract were investigated. After 240-min reaction, only (-)-epicatechin (EC) and (+)-catechin (C) presented obvious luminous red color with L* values of 63.32-71.73, a* values of 37.13-46.44, and b* values of 65.64-69.99. Meanwhile, the decrease rate of EC and C was 43.52 %-50.35 %, which were significantly lower than those of other catechin monomers (85.91 %-100 %). The oxidized products of catechin monomers were analyzed by ultra-high performance liquid chromatography-quadrupole-time of flight-mass spectrometry coupled with diode array detector, wherein dehydro-dimers and -trimers (oxidative coupling products of catechins' A-B ring) were found to be the major chromogenic compounds of EC and C. Additionally, the antioxidant capacity of catechin monomers only decreased after 30-min reaction, while along with further enzymatic reaction, catechin monomers presented comparable oxyradical scavenging ability (e.g., the DPPH inhibitory rates of catechin monomers were in the range of 24.42 %-50.77 %) to vitamin C (positive control, DPPH inhibitory rate was 27.66 %). Meanwhile, the inhibitory effects of most catechin monomers on α-glucosidase were enhanced in different degrees. These results provided basis for the development of enzymatically-oxidized catechin monomers as functional food color additives.

Deep eutectic solvent (DES) has been widely developed and applied in extracting the functional components of teas, however, few studies devoted to revealing the composition differences of tea extracts obtained with DES. The present study aims to study the chemical composition and bioactive differences of Dianhong congou black tea extracts prepared by eight choline chloride (ChCl)-based DES. In addition, D-101 macroporous resin was used to remove DES for bioactivity analysis. High performance liquid chromatography (HPLC) and LC-mass spectrometry (LC-MS) were applied to quantitatively and qualitatively analyze chemical composition differences of DES extracts before and after DES removal. Quantitative results showed that DES4 (composed of ChCl and ethylene glycol) was suitable for extracting catechins (e.g., the extracted level of epicatechin gallate was 8.75 mg/g), theaflavins (theaflavin-3,3 '-digallate, 1.59 mg/g), and monosaccharides (glucose, 4.97 mg/g), meanwhile DES5 (composed of ChCl and glycerol) was proved to be effective for extracting free amino acids (with highest level of theanine, 19.72 mg/g). LC-MS based metabolomics results showed that DES2 (ChCl-citric acid), DES3 (ChCl-proline), and DES4 had considerable remaining amounts of flavonoid glycosides, theasinensins, and hydrolysable tannins after DES removal. Although purified DES5 extract contained a comparable amount of these marker compounds to other purified DES extracts, its antioxidant and alpha-glucosidase inhibitory activities were the lowest among others. Combining results from above, DES4 was proved to be the optimum solvent for extracting functional components of Dianhong congou black tea. The finding provided basis for the application of DES extraction method in tea science.

We previously found that green tea polysaccharide conjugates (gTPCs) have antibacterial activity against Escherichia coli. In this study, the effect of hydrophobic property on the antibacterial activities of gTPCs was evaluated to elucidate their property-activity relationship. Three gTPCs (gTPCs-5 h, gTPCs-12 h and gTPCs-24 h) were extracted from green tea with the ethanol precipitation time of 5 h, 12 h and 24 h, respectively. These three gTPCs did not differ significantly in terms of molecular weight distribution, amino acids composition and zeta potentials. Fourier transform infrared spectroscopy results revealed that gTPCs-5 h and gTPCs-12 h processed more hydrogen bonds than gTPCs-24 h. The surface hydrophobicity and contact angle of gTPCs-5 h were larger than that of gTPCs-12 h and gTPCs-24 h. The antibacterial activity of gTPCs against E. coli decreased in the order of gTPCs-5 h > gTPCs-12 h > gTPCs-24 h. There wasn't significant difference among the zeta potentials of E. coli treated by gTPCs-5 h, gTPCs-12 h and gTPCs-24 h, but the bacterial contact angles of E. coli treated by gTPCs-5 h were higher compared with those of the other two gTPCs. Furthermore, gTPCs-5 h exhibited higher activity to decrease bacterial membrane proteins, and increase bacterial membrane permeability than the other two gTPCs. In conclusion, gTPCs with higher hydrophobicity property exhibited stronger antibacterial activity against E. coli.

CMOR is a heavy-duty manipulator system applied to the maintenance of fusion reactor components. On the basis of fully considering the configuration characteristics of the manipulator, the geometric solution based on coordinate transformation combined with the analytical method is used to solve the inverse kinematics of the manipulator. First, the modified D-H method is used to establish the link coordinate system model of the CMOR carrier manipulator, and the forward kinematics is deduced. Then, based on the end pose 0T7 and the geometric structure of the manipulator, the movement range of the redundant degree of freedom d1 is deduced, and the remaining joint angles are obtained through the mapping solution and verified in MATLAB. The simulation results show that the method has high precision, reduces the overall calculation amount, and is conducive to the real-time and accurate maintenance movement of the carrier manipulator, which is of great significance for the maintenance of fusion reactors.

The effects of brewing water on the sensory attributes and physicochemical properties of tea infusions made from Chinese teas were investigated. The tea infusions brewed in water with higher pH and total dissolved solids (TDS), generally had a darker color and lower overall sensory acceptability. Moreover, those infusions had less catechins, particularly galloylated-catechins, and lower antioxidant capacity. The teas with less fermentation contained more galloylated-catechins and had higher antioxidant capacity, but were much more susceptible to high mineral brewing water. Green tea was proved to be the most susceptible one, whereas dark tea the most stable one. Green tea infusions prepared with higher pH/TDS water were more rapidly oxidized, resulting in a darker color due to polymerization of catechins, when exposed to the air. These findings suggested that low mineral brewing water was better for Chinese tea, both from the sensory and health benefit perspectives.

A natural antioxidant emulsifier, tea polysaccharide conjugate (TPC), was isolated from Chin brick tea. The impact of TPC on β-carotene stability and bioaccessibility in oil-in-water nanoemulsions was assessed. TPC exhibited strong antioxidant activity and could be used to fabricate stable nanoemulsions (d < 140 nm). The extent of lipid digestion was considerably lower for lipid droplets coated by TPC (68%) than Tween 80 (94%) or whey protein isolate (WPI) (89%), probably because TPC formed interfacial layers that hindered the access of lipases to lipids. The chemical stability of β-carotene in TPC-nanoemulsions was markedly higher than in those formulated with Tween 80 or WPI due to the high antioxidant activity of TPC. The bioaccessibility of β-carotene (20-30%) was independent of emulsifier type. TPC from Chin brick tea can therefore be used as a dual-purpose functional ingredient in emulsified foods.

The oil-in-water (O/W) emulsions were prepared from Scutellaria baicalensis polysaccharide conjugates (SBPC) as an emulsifier and medium-chain triglyceride (MCT). Effects of pH, metal ions and heat treatment on the emulsion stability were investigated. Compared to that of 0.20. 1.00 wt% SBPC and 2.00 wt% GA, 2.00 wt% and 3.00 wt% SBPC stabilized emulsion droplets had a smaller particle size and were more stable during 10-day storage at 25 degrees C. The average particle sizes (d(32)) of emulsions containing metal ions varied from 4.54 to 6.62 mu m (0.100-0.500 mol/L Na+), from 2.63 to 3.86 mu m (0.010-0.050 mol/L Ca2+), and from 2.66 to 7.89 mu m (0.001-0.030 mol/L Al3+), as well as the zeta potential varying from 17.63 to 19.67 mV (Na+), from 16.50 to 18.13 mV (Ca2+) and from 15.02 to 18.56 mV (Al3+). SBPC emulsion possessed stability under pH 3.0-7.0 and thermal treatment at 70-100 degrees C during the 10-day storage period. Furthermore, SBPC emulsion inhibited oxidative polymerization of EGC. The average retention rate of EGC was 88.28% on the 10th day. This research provides a new way for development and application of SBPC as an emulsifier.

Polysaccharide conjugates were water-extracted from low-grade green tea; this extract was designated as TPC-W. Various concentrations of TPC-W (0.5, 1.0, 1.5, 2.0, and 3.0 wt%) were then used as an emulsifier stabilize to oilin-water emulsions prepared using medium chain triglycerides. The emulsion stabilized using 2.0 wt% TPC-W remained relatively constant during 10 days of storage at 25 degrees C, with the mean particle diameter (MPD) (d(32)) and zeta potential increasing from 1.8 to 2.4 mu m and from -19.8 to -18.9 mV, respectively. The effect of metal ions (Na+, Ca2+, and Al3+) and the pH value on the stability of the 2.0 wt% TPC-W emulsions was also studied at 25 degrees C for 10 days. The system remained stable at Na+ concentrations between 0.10 and 0.50 mol/L and Ca2+ concentrations below 0.030 mol/L, with little change in the MPD (d(32)) of the emulsion droplets. When Al3+ was added to the emulsion system, the MPD (d(32)) of the emulsion changed significantly; the addition of 0.001 mol/L Al3+ increased the MPD (d(32)) from 2.2 to 5.8 mu m. The MPD (d(32)) of 2.0 wt% TPC-W emulsions with pH values of 2.0-4.0 increased significantly during the storage period, but remained stable for emulsions in the pH range 5.0-8.0. The results revealed new applications of TPC-W extracted from low-grade green tea as an emulsifier.

The effect of green tea polysaccharide conjugate (gTPC) on the growth of E. coli was evaluated. gTPC has optimal antibacterial concentrations for E. coli DH5 alpha (4.00 mg/mL) and 25,922 (1.00 mg/mL), with the antibacterial rates of 55.75 % and 50.65 % respectively. The results of scanning electron microscopy (SEM) and transmission electron microscope (TEM) indicated that gTPC-treated E. coli cells showed obvious morphological changes, part of the cell wall became blurred, and the leakage of cytoplasmic content were observed. The proportion of the propidium iodide (PI) permeable E. coli cells treated using 0.50-2.00 mg/mL gTPC was between 8.79 %-9.49 % as well as 14.10 % (4.00 mg/mL gTPC) and 15.10 % (6.00 mg/mL gTPC). Reactive oxygen species (ROS) production of 1.00-4.00 mg/mL gTPC treated E. coli increased by 26.57 %-38.19 % with a significant increase level (p < 0.01). The outer membrane disruption played a key role in the antibacterial activity of gTPC against E. coli. This research result will open a new application field of tea polysaccharide conjugates.

Aroma assessment remains difficult and uncertain in the present sensory assessment system. It is highly desirable to develop a new assessment method to discriminate the quality of various teas in the tea market. In the present work, based on linear discriminant analysis and principal component analysis, the aroma of dry and wet samples of different Xi-hu Longjing and Pu-erh teas were tested and differentiated by electronic noses (e-nose). The results confirm that e-nose can discriminate different priced Xi-hu Longjing tea samples in the range of 80-800 RMB/500 g and varying storage years of Pu-erh tea samples. Furthermore, for the detection of both dry and wet samples of Longjing and Pu-erh teas, the results reveal that all samples have specific aroma characteristics that e-nose can recognize. More importantly, contribution analysis in sensors indicates that nitrogen oxides, methane and alcohols are the characteristic components that contribute to the fragrances of different priced Xi-hu Longjing teas, while nitrogen oxides, aromatic benzene and amines make the fragrances of Pu-erh teas with different storage years disparate. Practical Application This work demonstrates that e-nose can rapidly distinguish tea products with different price levels and varying storage years. With the advantages of ease of use, high portability and flexibility, e-nose will be widely expanded and applied in refined processing and the development of flavored foods.

The solubilities of betulinic acid in binary solvent mixtures of THF + water in the temperature range of (278.2-318.2)K were determined by an analytical method. The solubility of betulinic acid in a binary solvent mixture increased with the increase of molar fraction of THF and the temperature. The solubilities data were correlated with a semi-empirical equation. The calculated solubilities showed good agreement with the experimental data. According to the Van't Hoff equation and the Gibbs equation, the thermodynamic properties for the solution process including Gibbs energy, enthalpy, and entropy were obtained. The crystal habit of betulinic acid changes in morphology at different solvent mixtures was observed using SEM. (C) 2014 Published by Elsevier B.V.

While the rapid development in optical and storage technique enable us to easily acquire large amount of microscopy images, it is still a great challenge for biological researchers to analyze these huge data and draw meaningful and statistically sound conclusions. In this paper, we take single particle point spread function fitting problem into consideration and implement fast algorithm on the CPU+GPU heterogeneous architecture. Our approach is tested on real-world dataset and achieve about 23 ~40x faster than the traditional fitting algorithm.

AIMThe genetic polymorphisms of the alcohol metabolizing enzymes alcohol dehydrogenase 1B (ADH1B) rs1229984 may modulate individual differences in alcohol oxidizing capability. A case-control study was conducted to evaluate the genetic effects of these functional single-nucleotide polymorphisms on the development of esophageal cancer.METHODSHere, a total of 1001 esophageal squamous cell carcinoma (ESCC) cases and 1391 controls were recruited. Genotypes were determined by DNA sequencing. Differences in the distributions of demographic characteristics, selected variables, and genotypes of ADH1B rs1229984 variants between cases and controls were evaluated using the χ(2) test. Associations between ADH1B genotypes and the risk of esophageal cancer were estimated by computing the odds ratios (ORs) and their 95% confidence intervals (CIs) using logistic regression analyses for crude ORs and adjusted ORs when adjusting for age, gender, and tobacco use status.RESULTSThere were no significant differences between ESCC patients and controls in terms of age and sex distributions, suggesting that the frequency matching was adequate. However, significantly, more smokers were presented among the ESCC cases than among controls (63.1% vs. 49.2%; p=2.14 × 10-11). Smokers had an increased risk for developing ESCC (adjusted OR=2.17, 95% CI=1.78-2.64). This result clearly indicated that smoking is a risk factor for the ESCC in our study population. We found that subjects carrying the rs1229984 GG genotype had significantly increased risk of ESCC (adjusted OR, 2.81; 95% CI, 2.18-3.62; p=1.05 × 10-15) compared with the AA genotype.CONCLUSIONThe functional polymorphisms ADH1B rs1229984 may contribute to susceptibility to esophageal cancer.

The solubilities of betulinic acid in methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 1-hexanol, ethyl formate, ethyl acetate, butyl acetate, acetone, and tetrahydrofuran were measured by an analytical method in the temperature range of (278.2 to 318.2) K. The experimental data were correlated with a three-parameter empirical equation and UNIQUAC model, respectively. The calculated solubilities showed good agreement with the experimental data over this temperature range. Furthermore, the relation of the solubilities and the crystal habit were discussed.

Extended Finite State Machine (EFSM) is a powerful technique for modeling and deriving test sequences from system of interests and has been widely applied to many areas. However, test data generation from EFSM model is yet a challenging task. In this paper, we explore an efficient optimization algorithm for test data generation for specified paths in EFSM models. The proposed algorithm uses Simulated Annealing (SA) strategy to generate test data for paths from EFSM models. We verify the proposed algorithm on four classical EFSM models and compare with Genetic Algorithm (GA). The experimental results show that the SA strategy is more efficient and stable than the GA in test data generation for EFSM models.

Data clustering aims at finding the hidden patterns in a large collection of data and a large body of effective algorithms have been proposed to partition the data in the past three decades. However, most of the algorithms fail to handle data that expose a manifold structure which is common in many data-driven application, such as interpretation and recognition of video, handwritten character and image data. In this paper, we study the problem of clustering on manifold that aims to partition a set of input data into several clusters each of which contains data points from a simple low-dimensional manifold. We apply the basic assumption of local and global consistency on the manifold. A novel algorithm name CMLGC is proposed to find the proper clusters on the manifold. Our research can also be seen as an instance of manifold learning. The encouraging results on several synthetic and real-world data set are obtained which validate our proposed algorithm.

Clustering on multiple views is witnessing increasing interests in both real-world application and machine learning community. A typical application is to discover communities of joint interests in social network, such as Facebook and Twitter. The network can be simply modeled as a graph in which the nodes are the people while the links show relationship between the people. There may exist many relationships between a pair of nodes, such as classmates, collaborators, playmates and so on. it is important to consider how to use these graphs together rather than a single graph if we want to understand the network and their participants effectively. Motivated by the fact, we present a clustering algorithm using spectral analysis in which multiple graphs are considered to get the clusters. Our study can also be considered as an instance of multi-views learning. The experimental results on UCI data set and Corel image data demonstrate the promising results that validate our proposed algorithm.

We often face the situation where very limited labeled data are available to learn an effective classifier in target domain while there exist large amounts of labeled data with similar feature or distribution in certain relevant domains. Transfer learning aims at improving the performance of a learner in target domain given labeled data in one or more source domains. In this paper, we present an algorithm to learn effective classifier without or a few labeled data on target domain, given some labeled data with same features and similar distribution in source domain. Our algorithm uses the data edit technique to approach distribution from the source domain to the target domain by removing “mismatched” examples in source domain and adding “matched” examples in target domain. Experimental results on email classification problem have confirmed the effectiveness of the proposed algorithm.