Colorimetric and antioxidant films based on biodegradable polymers and black nightshade (Solanum nigrum L.) extract for visually monitoring Cyclina sinensis freshness.

In this study, colorimetric and antioxidant films were developed by using cassava starch (CS), κ-carrageenan (KC) and black nightshade fruit anthocyanins (BNA), and their physical and functional properties were investigated. We found BNA presented significant color changes in different pH solutions. And incorporation of BNA significantly increased the tensile strength, water vapor permeability, UV-vis light barrier property, pH-sensitivity and antioxidant activity of CS-KC film. Results of structural characterization indicated that H-bonds were formed between CS, KC and BNA in films and the film compactness was significantly improved by BNA incorporation. Results of the rheological property assay showed the films had high apparent viscosity with an obvious shear-thinning behavior. When applied to monitoring the quality change of Cyclina sinensis, CS-KC-BNA films exhibited significant color changes with the degradation process of C. sinensis qualities. Our results suggested CS-KC-BNA films could be utilized in smart packaging in food industry.

Antioxidant and ammonia-sensitive films based on starch, κ-carrageenan and Oxalis triangularis extract as visual indicator of beef meat spoilage.

In this study, we first investigated the rheological property of sweet potato starch (SPS), κ-carrageenan (KC) and Oxalis triangularis extract (OTE) blends and found that the blends exhibited high apparent viscosity with an apparent shear thinning behavior. And then films based on SPS, KC and OTE were developed and their structural and functional properties were studied. The physico-chemical test results showed that OTE exhibited different colors in solutions with different pH values and the incorporation with OTE and KC could significantly increase the thickness, water vapor permeability, light barrier ability, tensile strength and elongation at break as well as the pH- and ammonia-sensitive properties of the SPS film. The structural property test results showed that some intermolecular interactions between OTE and SPS/KC occurred in SPS-KC-OTE films. Finally, the functional properties of SPS-KC-OTE films were examined and SPS-KC-OTE films showed significant DPPH radical scavenging activity as well as a visible color change in response to changes in beef meat freshness. Our results suggested that the SPS-KC-OTE films could be used as an active and intelligent food packaging material in food industry.

Preparation and characterization of antioxidant and pH-sensitive films based on arrowhead (Sagittaria sagittifolia) starch, κ-carrageenan and black chokeberry (Aronia melanocarpa) extract for monitoring spoilage of chicken wings.

In this study, we firstly developed an antioxidant and pH-sensitive film based on arrowhead starch (AS), κ-carrageenan (KC) and black chokeberry extract (BCE) and its physical and structural properties were investigated. We found BCE showed different colors in different pH solutions and incorporation with KC and BCE could significantly decrease light transmittance, increase thickness, elongation at break and pH-sensitive property of AS film. The results of structural property assay indicated that there were some intermolecular interactions between BCE and AS/KC in AS-KC-BCE films. Secondly, we investigated the rheological property of AS, AS-KC and AS-KC-BCE suspensions and found the suspensions showed an obvious shear-thinning behavior with high apparent viscosity. Finally, the functional properties of AS-KC-BCE films were investigated and AS-KC-BCE films showed strong scavenging activity on DPPH free radical and presented visible colour changes in response to the changes of the chicken wing qualities. The results suggest that AS-KC-BCE films can be used in active and intelligent packaging of food industry.

Silicone Rubber Fabry-Perot Pressure Sensor Based on a Spherical Optical Fiber End Face.

To improve the fringe contrast and the sensitivity of Fabry-Perot (FP) pressure sensors, a silicone rubber FP pressure sensor based on a spherical optical fiber end face is proposed. The ratio of silicone rubber ingredients and the diameter and thickness of silicone rubber diaphragm were optimized by a simulation based on experimental tests that analyzed elastic parameters, and the influence of the radius of a spherical optical fiber and the initial cavity length of the sensor on the fringe contrast was investigated and optimized. Pressure sensor samples were fabricated for pressure test and temperature cross-influence test. Gas pressure experimental results within a pressure range of 0~40 kPa show the average sensitivity of the sensor is -154.56 nm/kPa and repeatability error is less than 0.71%. Long-term pressure experimental results show it has good repeatability and stability. Temperature experimental results show its temperature cross-sensitivity is 0.143 kPa/°C. The good performance of the proposed FP pressure sensor will expand its applications in biochemical applications, especially in human body pressure monitoring.

A mild and efficient extraction method for polysaccharides from Sinonovacula constricta and study of their structural characteristic and antioxidant activities.

The aim of this paper is to develop a mild and efficient extraction method for polysaccharides from Sinonovacula constricta (SCP) using enzyme extraction, and analyze the structural characteristics and antioxidant activities of the two purified polysaccharide fractions (SCP-1 and SCP-2). Firstly, enzyme extraction conditions were optimized, and the conditions were found to be, as follows: enzymolysis time 173.0 min, pH 8.2, enzymolysis temperature 50.0 ℃ and enzyme content 4.0%. Comparison between enzymatic extraction and water extraction was obtained from visual, UV-visible and IR spectrum images. The results clearly indicate that there is no significant difference between them with regard to the composition of the SCP fraction, but the polysaccharide content produced by enzymatic extraction is higher. Then, the physicochemical properties and structural characteristics of SCP-1 and SCP-2 were investigated using FT-TR, UV, GC and HPGPC. The carbohydrate content, sulfuric radicals and uronic acids of the two fractions were detected. Both SCP-1 and SCP-2 were mainly consisted of glucose, but their molecular weights were different. In addition, compared the Fe2+ chelating activity, ABTS+ radical and superoxide radical scavenging activity, and lipid peroxidation inhibition activity of SCP-1 and SCP-2, it turned out that SCP-2 had stronger antioxidant activity than SCP-1.

Feasibility of Using Seaweed (Gracilaria coronopifolia) Synbiotic as a Bioactive Material for Intestinal Health.

The market contains only limited health care products that combine prebiotics and probiotics. In this study, we developed a seaweed-based Gracilaria coronopifolia synbiotic and verified the efficacy by small intestinal cells (Caco-2). We also developed a functional material that promotes intestinal health and prevents intestinal inflammation. G. coronopifolia was used as a red seaweed prebiotic, and Bifidobacterium bifidums, B. longum subsp. infantis, B. longum subsp. longum, Lactobacillus acidophilus, and L. delbrueckii subsp. bulgaricus were mixed for the seaweed's synbiotics. G. coronopifolia synbiotics were nontoxic to Caco-2 cells, and the survival rate was 101% to 117% for a multiplicative effect on cell survival. After cells were induced by H2O2, the levels of reactive oxygen species (ROS) increased to 151.5%, but after G. coronopifolia synbiotic treatment, decreased to a range between 101.8% and 109.6%. After cells were induced by tumor necrosis factor α, the ROS levels increased to 124.5%, but decreased to 57.7% with G. coronopifolia symbiotic treatment. G. coronopifolia synbiotics could effectively inhibit the production of ROS intestinal cells under oxidative stress (induced by H2O2 and tumor necrosis factor α (TNF-α)), which can reduce the damage of cells under oxidative stress. Functioning of intestinal cells could be improved by inhibiting the production of inflammatory factor substances (interleukin 8) with G. coronopifolia symbiotic treatment. Also, gastrointestinal diseases may be retarded by a synbiotic developed from G. coronopifolia to promote intestinal health and prevent intestinal inflammation.

Efficient biosynthesis of γ-decalactone in ionic liquids by immobilized whole cells of Yarrowia lipolytica G3-3.21 on attapulgite.

In this study, the biosynthesis of γ-decalactone (GDL) was successfully conducted in an ionic liquid (IL)-containing cosolvent system using immobilized cells of Yarrowia lipolytica G3-3.21 on attapulgite (ATG). We found the immobilized Y. lipolytica G3-3.21 cells in N-butyl-pyridinium tetrafluoroborate ([BPy]BF4) solution gave the highest activity of C16-Acyl-CoA oxidase and the maximum yield of GDL. The optimum immobilization conditions for the highest yield of GDL were 20 g/L of ATG, 1.5 % of CaCl2 and 2 % of sodium alginate (NaAlg). The optimal [BPy]BF4 content, buffer pH, reaction temperature, shaking speed, castor oil and glucose contents were 7.5 %, 26 °C, 150 rpm, 100 g/L and 10 %, respectively. Under the optimized conditions, the GDL yield was up to 8.05 g/L. After ten times of reuse, the GDL yield was 7.51 g/L, corresponding to 93.3 % of that obtained in the first batch, suggesting a good reusability and potential for industrial applications.

Characterization and bioactivities of a novel purified polysaccharide from Endothelium corneum gigeriae Galli.

In the present study, characterization and cardioprotective activities in vivo of a novel purified polysaccharide (PECGp) from Endothelium corneum gigeriae Galli were investigated. The results found that PECGp had a 96 kDa molecular weight. The backbone chains were composed of α-D-Glc and α-L-Rha linked by (1→4) glycosidic bonds. (1→4, 6) linked α-D-Glc and (1→2, 4) linked α-L-Rha in backbone chains with branches consisting of (1→4) linked α-D-Glc and terminal α-D-Glc-6-COOH. The assay of cardioprotective activities demonstrated that PECGp could significantly reduce the ST-segment elevation, prevented abnormal changes of heart muscle morphology, reverse abnormal hemodynamic and hemorheological parameters, rectify disorganized superoxide dismutase, nitric oxide synthase, nitric oxide, malondialdehyde, creatine kinase, creatine kinase MB fraction and lactate dehydrogenase levels. The results suggested that PECGp could be considered as a potential candidate for developing novel cardioprotective agents.

Determination of ethyl carbamate in fermented liquids by ultra high performance liquid chromatography coupled with a Q Exactive hybrid quadrupole-orbitrap mass spectrometer.

In this study, the determination of ethyl carbamate (EC) in fermented liquids (red wines, Chinese liquors and yellow wines) was carried by using ultra high performance liquid chromatography coupled with a Q Exactive hybrid quadrupole-orbitrap mass spectrometer (UHPLC-MS/MS). The parameters usually examined in the method validation were firstly evaluated. Good linearity was obtained with a correlation coefficient of 0.9999. The limits of detection (LOD) and quantitation (LOQ) of EC in sample were 1.8 and 4.0 µg/L, respectively. Recoveries ranged between 107.19% and 110.98%. The precision (relative standard deviation, RSD) of the method was <5%. Furthermore, red wines, Chinese liquors and yellow wines for sale were detected using this method. The results showed that the red wines and Chinese liquors had the normal EC level that was within the limits of the Canadian legislation. The proposed method was simple in sample preparation without using organic solvents in pre-treatment and could be used for the determination of the content of EC in fermented liquids.

Structural characterization, sulfation and antitumor activity of a polysaccharide fraction from Cyclina sinensis.

In the present study, we investigated the preliminary structure, sulfation and antitumor activity of a polysaccharide fraction from Cyclina sinensis (CSPS-1). Results of structural characterization showed that the backbone chain of CSPS-1 was composed of glucose linked by α-(1→4) glycosidic bond, and the branch chain was attached to backbone chain by (1→6) glycosidic bond. CSPS-1 was sulfated by chlorosulfonic acid-pyridine method under different modification conditions according to the orthogonal test L9(3(4)), affording nine sulfated polysaccharides (CSPS-1-S). The optimal sulfation conditions for CSPS-1 were reaction temperature of 65°C, reaction time of 2h and chlorosulfonic acid-pyridine ratio of 1:4. Structural analysis revealed that sulfation had occurred at position of C-6 in CSPS-1. In addition, CSPS-1-S exhibited significantly higher inhibitory activity in vitro against human gastric cancer BGC-823 cells.

Genome shuffling of Aspergillus glaucus HGZ-2 for enhanced cellulase production.

The production of cellulase from Aspergillus glaucus HGZ-2 was improved by using genome shuffling. The starting populations, obtained by UV irradiation, were subjected to recursive protoplast fusion. The optimal conditions for protoplast formation and regeneration were 7 mg/ml snailase and 5 mg/ml cellulase at 34 °C for 3.0 h using 0.7 M NaCl as an osmotic stabilizer. The protoplasts were inactivated under UV for 30 min or heated at 50 °C for 50 min, and a fusant probability of about 100 % was observed. The positive colonies were created by fusing the inactivated protoplasts. The optimal conditions for protoplast fusion were PEG6000 concentration of 35 %, CaCl2 concentration of 0.02 M, and incubation time of 12 min. After two rounds of genome shuffling, one strain (Y) was obtained. Its filter paper cellulase (FPase) and carboxymethyl cellulase (CMCase) activity reached 71 and 70 U/ml, respectively, which were increased by 1.95-fold and 1.72-fold in comparison with that of its ancestor strain. The results indicated that genome shuffling was an efficient means for the improved production of cellulases by A. glaucus HGZ-2.

Optimization for ultrasound-assisted extraction of polysaccharides with antioxidant activity in vitro from the aerial root of Ficus microcarpa.

In this study, optimization of ultrasound-assisted extraction and antioxidant activity of polysaccharides from the aerial root of Ficus microcarpa (FMPS) were investigated. The optimal conditions for extraction of FMPS were determined as followings: ultrasound power 200 W, ultrasound temperature 70°C, extraction temperature 74°C, liquid-solid ratio 35, extraction time 238 min, ultrasound time 49 min. The experimental yield of FMPS (3.44%) obtained under these conditions was well agreement with the value predicted by the model. In addition, Fourier transform-infrared spectroscopy and antioxidant activity assays revealed that FMPS were acidic polysaccharides and had strong Fe2+ chelating activity and moderate hydrogen peroxide scavenging effect. Further work on the purification, structure characterization and antioxidant activity in vivo of FMPS is in progress.

Purification, characterization and bioactivity of polysaccharides from Glossaulax didyma.

In this study, purification, preliminary characterization, immunostimulatory and hepatoprotective activities of polysaccharides from Glossaulax didyma (GDPS) were investigated. Firstly, crude GDPS was purified by chromatography of DEAE-52 and Sephadex G-100, resulting in three purified fractions of GDPS-1, GDPS-2 and GDPS-3. The three fractions were mainly composed of glucose with the average molecular weight of 161, 197 and 204 kDa, respectively. GDPS-2 was quite different from GDPS-1 or GDPS-3. It had much higher contents of protein and sulfuric radical. For immunostimulatory activities in vitro, the three fractions could significantly stimulate the proliferation of splenocytes and enhance phagocytic activity of peritoneal macrophages. For hepatoprotective activity in vivo, the administration of GDPS significantly decreased the serum levels of alanine aminotransferase, aspartate aminotransferase and tumor necrosis factor-alpha, inhibited the formation of malondialdehyde and restored the liver activities of superoxide dismutase and glutathione peroxidase in Bacillus Calmette-Guerin/lipopolysaccharide-induced liver injury mice. The results suggested GDPS should be a potent natural polymer with immunostimulatory and hepatoprotective activities.

Preliminary separation and purification of resveratrol from extract of peanut (Arachis hypogaea) sprouts by macroporous adsorption resins.

In the present study, the separation and purification characteristics of resveratrol from extract of peanut sprouts (PSE) on 11 macroporous adsorption resins were investigated. The results showed that ADS-5 offered better adsorption and desorption capacity for resveratrol than other tested resins. From the static experiments with ADS-5 resin, we found that the experimental data fitted best to the pseudo-second-order kinetics model and Langmuir isotherm model, and the adsorption was a spontaneous and endothermic process. The separation and purification parameters of resveratrol from PSE were optimised by dynamic adsorption/desorption experiments with the column packed with ADS-5 resin. Under the optimal conditions, after one run treatment with ADS-5 resin, the content of resveratrol in the product was increased 17.9-fold from 1.32% to 23.60%, with a recovery yield of 88.33%. The results demonstrated that ADS-5 resin was a promising basis for large-scale preliminary separation and purification of resveratrol from PSE.

Lactobacillus casei immobilized onto montmorillonite: Survivability in simulated gastrointestinal conditions, refrigeration and yogurt.

This study evaluated the survival of Lactobacillus casei when immobilized onto montmorillonite (MMT) and sodium exchanged montmorillonite (Na-MMT) under stress conditions. The results showed that adsorption of L. casei onto MMT and Na-MMT surface reached equilibrium after 1.5h. The percentages of L. casei adsorbed onto the surfaces of MMT and Na-MMT at equilibrium were 55.3% and 83.7%, respectively. L. casei-mineral complexes were characterized by X-ray diffraction, Fourier transformed infrared and thermogravimetric analysis, indicating that L. casei cells were successfully immobilized onto MMT and Na-MMT. Characterization with scanning electron microscope showed that cells attached well to the surface of clay minerals and numerous L. casei cells were observed to form aggregates with clay mineral particles. Immobilization on MMT and Na-MMT protected L. casei from simulated gastrointestinal conditions. Immobilization preserved the counts of L. casei higher than 107CFUmL-1 throughout the storage at refrigerated conditions. Yogurts prepared with L. casei-mineral complex presented lower values for post-acidification and higher stability compared to the product prepared with the addition of L. casei in free status. The results of this study suggested the efficiency of immobilization by adsorption onto clay minerals to increase the survival of L. casei in simulated gastrointestinal conditions, refrigerated storage and yogurt.

Preliminary characterization and immunostimulatory activity of polysaccharides from Glossaulax didyma.

In the present study, we investigated the preliminary characterization, both in vitro and in vivo immunostimulatory activity of polysaccharides from Glossaulax didyma (GPS). The results of chemical and gas chromatography analysis indicated that GPS was mainly composed of glucose with high contents of uronic acid and sulfate. For immunostimulatory activity in vitro, GPS could stimulate the proliferation of splenocytes and enhance neutral red phagocytosis, TNF-α production level and acid phosphatase activity in mouse peritoneal macrophages. For immunostimulatory activity in vivo, the administration of GPS could significantly increase the level of serum hemolysin in cyclophosphamide-treated mice. The results provided evidences that GPS possessed significant immunostimulatory activity and might be one of important active substances responsible for the immunostimulatory effect of G. didyma.

Purification, characterization and immunostimulatory activity of polysaccharide from Cipangopaludina chinensis.

In this study, we investigated the purification, preliminary characterization and immunostimulatory activity in vivo of polysaccharide from Cipangopaludina chinensis (CCPS). Firstly, crude CCPS was prepared by hot water extraction. And the crude CCPS was sequentially purified by chromatography of DEAE-52 and Sephadex G-100, resulting in two purified fractions of CCPS-1 and CCPS-2. We found the two fractions were homogeneous heteropolysaccharides mainly composed of rhamnose and glucose with the average molecular weight of 226 and 235 kDa, respectively. CCPS-2 was quite different from CCPS-1. It had much higher content of uronic acid and sulfuric radical. For immunostimulatory activity in vivo, crude CCPS could significantly increase the thymus and spleen indices, enhance the macrophage function, and increase the level of serum hemolysin in cyclophosphamide-treated mice, suggesting CCPS had a potent immunostimulatory activity and could be explored as a potential natural immunomodulatory agent.

Preliminary characterization and potential hepatoprotective effect of polysaccharides from Cipangopaludina chinensis.

In the present study, we investigated the preliminary characterization, in vitro antioxidant and in vivo heptoprotective activities of polysaccharides from Cipangopaludina chinensis (CCPS). The results of chemical and gas chromatography analysis indicated that CCPS was mostly composed of glucose with high contents of uronic acid and sulfate. For antioxidant activities in vitro, CCPS showed medium lipid peroxidation inhibition effect and high Fe²âº chelating and hydroxyl radical scavenging activities. For hepatoprotective activity in vivo, the administration of CCPS significantly decreased the serum levels of alanine aminotransferase and aspartate aminotransferase, inhibited the formation of malondialdehyde in liver and tumor necrosis factor-alpha (TNF-α) in serum and restored the liver activities of superoxide dismutase, glutathione peroxidase in BCG/LPS-induced immunological liver injury mice. The results suggested that CCPS had a significant protective effect against BCG/LPS-induced immunological liver injury. The hepatoprotective effect of CSPS might be partly due to its immunoregulatory effect by inhibiting TNF-α production and antioxidant activities to protect biological systems against the oxidative stress, which were dependent on the chemical and structural properties of CCPS. Further work on the structure of CCPS is in progress.

Extraction, characterization and biological activities of polysaccharides from Amomum villosum.

In the present study, the extraction, purification, characterization and biological activities of polysaccharides from the seeds of Amomum villosum (ASP) were investigated. Firstly, the optimal parameters for the extraction of ASP were obtained by using a Box-Behnken Design as follows: extraction temperature 78.8 °C, extraction time 71.3 min and ratio of water to raw material 39.3 ml/g. Then, the crude ASP was sequentially purified by chromatography of DEAE-52 and Sephadex G-100, resulting in three purified fractions of ASP-1, ASP-2 and ASP-3. The results showed that ASP-3 had a larger molecular weight and higher contents of protein, sulfuric radical and uronic acid than the other polysaccharide fractions. Furthermore, ASP-3 showed relative stronger inhibitory activity on the growth of HepG2 cells. Finally, ASP had strong free radical scavenging activities in vitro and significantly prevented the formation of malondialdehyde and enhanced the activities of antioxidant enzymes in CCl4-induced liver injury mice.

Antioxidant activity and potential hepatoprotective effect of polysaccharides from Cyclina sinensis.

In the present study, we investigated the preliminary structure, in vitro antioxidant and in vivo hepatoprotective activities of polysaccharides from Cyclina sinensis (CSPS). The analytic results of Fourier transform-infrared spectroscopy indicated the presence of α-type glycosidic linkages in CSPS-1 or CSPS-2, and the average molecular weights for CSPS-1, CSPS-2 and CSPS-3 were 69, 81 and 101 kDa, respectively. For antioxidant activities in vitro, crude CSPS, CSPS-1, CSPS-2 and CSPS-3 showed moderate H(2)O(2) scavenging activity, lipid peroxidation inhibition effect and strong Fe(2+) chelating activity. For hepatoprotective activity in vivo, the administration of CSPS significantly decreased serum levels of alanine aminotransferase and aspartate aminotransferase, inhibited the formation of malondialdehyde and enhanced the activities of liver superoxide dismutase and glutathione peroxidase in carbon tetrachloride-induced liver injury mice. These results suggested that CSPS had potent antioxidant and hepatoprotective activities.