The effect of low‐temperature plasma for improving wool and chitosan‐treated wool fabric properties

In this study, plasma treatment was used to modify the surface properties of wool fabrics by partial removal of the scales and the lipid layer. The effects of low‐pressure pseudo‐discharge in oxygen gas on the dyeing properties of untreated and pretreated wool fabrics are discussed. Three dyes were used, namely acid dye, 1:2 metal complex dye and reactive dye. Different exposure times (1–5 min) of oxygenated plasma treatment were effected to improve the hydrophilicity, wettabillity, dyeability and the washing and light fastness properties of the dyed wool fabrics (which were increased by increasing the plasma exposure time). Also, the washing and light fastness properties of the chitosan‐treated wool fabrics were investigated. In addition, the presence of chitosan before or after the plasma exposure had no effect on the washing and light fastness properties of the wool fabrics.     

Effects of pH on the stress–strain properties of wool fabric

In wool dyeing and finishing processes, fabric is often treated under conditions of different pHs and is subjected to a variety of physical and chemical environments. This work investigates fabric tensile properties at three different fabric pHs. Wool fabric extensibility under a 5 N/cm load was observed to be greatest at the wool isoelectric point of pH 4.8 and lower at both pH 2.1 and pH 7.2. The impact of pH on fabric extensibility was found to be similar to the variation in fabric hygral expansion previously observed. Fabric stress–strain curves at different pHs showed that for a given fabric extension level, the work required to stretch a fabric was less at pH 2.1 than at pH 4.8. These results suggest that the strength of wool fabric is at maximum when the pH of the fibres is close to the wool isoelectric point and that for consistency, the pH of fabric should be adjusted before standard strength tests are carried out.     

Preparation and characterization of β-cyclodextrin grafted silk fabric

ABSTRACT

Silk fabrics were treated by β-cyclodextrin (β-CD) in the presence of citric acid (CA) as crosslinking agent and sodium hypophosphite (SHP) as catalyst using pad dry cure technique. CA is expected to react with β-CD and hydroxyl groups of silk fibroin via esterification reaction. Four independent factors including curing time, curing temperature, β-cyclodextrin, and citric acid concentrations were selected, and effects of these factors on the weight gain of the samples were examined. Fourier transformed infrared spectrometer (FTIR), weight gain, differential scanning calorimetry (DSC), Thermal gravimetric (TGA) and differential thermal analysis (DTA), and field-emission scanning electron microscope (FE-SEM) were employed to confirm the changes of the silk fabrics. The effect of crosslinking reaction on the color changing of samples was investigated by measurement yellowness index of the treated fabrics. The results revealed that the weight gain could reach up to 22% when fabric was treated with 50 g/L β-CD, 100 g/L CA under 170°С for 3 min. FTIR and thermal analysis demonstrated that β-CD had been grafted onto silk fabric successfully.     

Effect of combined treatment of hydrolysis and polymerization with transglutaminase on β-lactoglobulin antigenicity

The effect of combined treatments of hydrolysis with different proteases, and subsequent polymerization with transglutaminase on the antigenic activity of β-Lg was studied. For the hydrolysis of β-Lg using Alcalase, Neutrase or bromelain, the reaction conditions were 3?% β-Lg and enzyme:substrate 25?U?g^?1 of protein, as was defined using factorial study. Under these conditions, the degree of hydrolysis (DH) of the hydrolysates was 12.6?% when obtained with Alcalase and approximately 4?% with Neutrase or bromelain. Post-hydrolysis polymerization did not result in an increase in molecular mass of the protein, but these samples presented a lower DH, determined by trinitrobenzenosulfonic acid (TNBS) method, suggesting that polymerization had occurred. Hydrolysis with the three enzymes reduced the β-Lg antigenicity, as evaluated by ELISA and immunoblotting analyses. The IgE-binding responses were practically null (<9?μg?mL^?1), 22.82 and 55.73?μg?mL^?1 towards the hydrolysates obtained with Alcalase, bromelain, and Neutrase, respectively. The post-hydrolysis polymerization increased or had no significant effect (P?≥?0.05) on the antigenic response of the hydrolysates.     

Preparation and properties of phytosterols with hydroxypropyl β-cyclodextrin inclusion complexes

In order to enhance the solubility and bioavailability of phytosterols (PS), cyclodextrin–PS (CD–PS) inclusion complexes were prepared and the properties of PS-β-cyclodextrin (PS-β-CD) and the inclusion mechanism of its derivative hydroxypropyl β-cyclodextrin (PS-HP-β-CD) in solution were also evaluated. The effects of crucial parameters on cyclodextrin–sterol inclusion efficiency were optimized, including solvent type, β-CD/PS molar ratio, temperature, PS content and reaction time; 92–98?% inclusion efficiency was achieved under the conditions of HP-β-CD/PS ratio 3:1–4:1, PS concentration 15–20?mM, temperature 50–55?°C, reaction time 12?h. For β-CD host, butanol was a good solvent for PS inclusion reaction. The properties of CD–PS inclusion complexes were characterized by differential scanning calorimetric, scanning electron microscopy, UV–Vis scanning spectrophotometer (UV–Vis) and fourier transform infrared spectroscopy (FT-IR), which demonstrated that there are intermolecular hydrogen bonds between PS and HP-β-CD in inclusion complex, resulting in the formation of amorphous form. To clarify the mechanism of the increase in the solubility and bioactivity of HP-β-CD–PS inclusion complexes, the structure of CD as well as the interaction of the HP-β-CD–PS inclusion formation was elucidated. The conclusions indicated that PS-HP-β-CD showed higher water solubility with greater solubilizing and complexing capabilities than PS-β-CD and PS itself.     

Effect of enzyme treatment with β-glucosidase on antioxidant capacity of mulberry (Morus alba L.) leaf extract

This study was carried out to investigate the effect of enzyme treatment with β-glucosidase on antioxidant capacity of the mulberry leaf extract (MLE) using oxygen radical absorbance capacity (ORAC) and cellular antioxidant capacity (CAC) assay. The MLE was prepared by autoclaving at 121°C for 15 min and treated with β-glucosidase for 9 hr. High pressure liquid chromatography (HPLC) analysis showed that only qercetin-3-β-d-glucose (QT-G) among quercetin (QT) glycosides of MLE, including QT-G, quercetin-3-O-glucose-6″-acetate (QT-GA), and rutin (RT), was converted into QT by 3 hr treatment with β-glucosidase. The in vitro peroxyl radical- and hydroxyl radical scavenging capacity significantly increased after the enzyme treatment using β-glucosidase for 6 and 9 hr, respectively. The metal chelating activity increased after the enzyme treatment using β-glucosidase for 3 hr. The intracellular antioxidant capacity of MLE to protect AAPH- and Cu²⁺-induced oxidative stress in HepG2 cells significantly increased after the enzyme treatment using β-glucosidase for 3 and 6 hr, respectively, indicating that QT may be released from QT-G by β-glucosidase and penetrate into cell membrane so that it can contribute to the intracellular antioxidant capacity of MLE.     

Effect of β-cyclodextrin on physical properties of nanocapsules manufactured by emulsion–diffusion method

This study was carried out to investigate the effect of β-cyclodextrin (β-CD) as a cryoprotectant on the eugenol encapsulated nanocapsules. Nanocapsules (NCs) were prepared by emulsion–diffusion method and frozen at various temperatures (−30 °C to −10 °C). Physical stability of the NCs was determined by particle size analysis and morphological observation using scanning or transmission electron microscopy before and after freezing or freeze-drying process. Freeze-thawed and freeze-dried NCs without β-CD were remarkably aggregated. The particle size of NCs without β-CD was significantly increased as decreasing freezing temperature. On the contrary, NCs with β-CD were slightly increased in the range of 370–400 nm. Significant particle aggregation was not shown at NCs with β-CD at all freezing temperatures. In this study, β-CD could was effective as a cryoprotectant to maintain physical stability of NCs after freezing or freeze-drying. β-CD could be useful to protect NCs from freezing stress.     

Effect of hydroxypropyl β-cyclodextrin on physical properties and transition parameters of amylose–lipid complexes of native and acetylated starches

The effect of hydroxpropyl β-cyclodextrin (HPβ-CD) on physical properties and digestibility of wheat, potato, waxy maize and high-amylose maize starches before and after acetylation was studied. Effect of HPβ-CD on amylose–lipid complexes in native and acetylated potato starches synthesized using α-lysophosphatidylcholine was also studied. Acetylation increased swelling factor, amylose leaching, peak viscosity and susceptibility to α-amylase hydrolysis, but decreased gelatinization temperature and enthalpy and gel hardness in all starches. HPβ-CD markedly increased swelling factor and amylose leaching in native and acetylated wheat starches but had little or no impact on other starches. Wheat starch gelatinization enthalpy decreased in the presence of HPβ-CD but gelatinization temperature of all the starches was slightly increased. HPβ-CD had no influence on enzymatic hydrolysis. Melting enthalpy of amylose–lipid complex in both native and acetylated wheat starches was decreased by HPβ-CD. Acetylation also decreased the melting enthalpy of amylose–lipid complex in wheat starch. Similar trend of thermal transitions was observed in the presence of HPβ-CD for the amylose–lipid complexes synthesized in potato starch. Acetylation reduces the complex formation ability of the amylose polymer. Similar to gelatinization, acetylation widened the melting temperature range of amylose–lipid complexes while shifting it to a lower temperature. Higher swelling and amylose leaching, and decreased gelatinization temperature and enthalpy resulting from acetylation of wheat starch is consistent with its influence on starch hydration. Similar effects resulting from the inclusion of HPβ-CD were consistent with the disruption of amylose–lipid complex by HPβ-CD which promotes granular hydration.     

Effect of β-cyclodextrin on the long-term retrogradation of rice starch

In this study, the impact of the addition of β-cyclodextrin (β-CD) on long-term retrogradation of rice starch was investigated by texture profile analysis (TPA), differential scanning calorimeter (DSC), and X-ray diffraction (XRD). Results showed that the addition of β-CD presented a crucial role in retarding the long-term retrogradation of starch. The present β-CD also significantly decreased crystallization rate (k), and increased avrami exponent (n). The increase in exponent value indicated that the addition of β-CD transformed the nucleation type due to the formation of amylose–lipid-β-CD complex. Further, the presence of β-CD produced an additional peak 5.2 Å of the gelatinized gel, and retarded crystalline type of the retrograded gel from V- to B-pattern, probably corresponding for the nucleation type transformation.     

Study on uniformity of wettability improvement of wool fabric treated by atmospheric pressure plasma jet北大核心

The influence of process parameters on uniformity of wettability improvement of wool fabric treated by atmospheric pressure plasma jet (APPJ) wettability was explored. The wool fabrics were treated by APPJ under different oxygen flow rate, jet-to-substrate distance and treatment time. The wetout time of wool fabrics before and after APPJ treatment was measured. The diffusion photos of water drop on wool fabric surface were taken by digital camera. The morphological and chemical changes on the fiber surface were characterized by scanning electron microscopy ( SEM ) and X-ray photoelectron spectra (XPS) respectively. It was concluded that the uniformity of wettability improvement of wool fabric treated by APPJ increased and then decreased with the increasing oxygen flow rate and jet-to-substrate distance and increased with the increasing treatment time.     

Effect of ultrasound treatment on the wet heating Maillard reaction between β-conglycinin and maltodextrin and on the emulsifying properties of conjugates

Soy β-conglycinin (7S) was grafted with maltodextrin (MD) by combined ultrasound treatment and wet heating Maillard reaction in this work. The physicochemical and emulsifying properties of 7S–MDH (classical wet heating) and 7S–MDUH (ultrasound-assisted wet heating grafting) have been investigated. Ultrasound treatment could speed up the conjugation process and obtain a protein–polysaccharide conjugate that exhibits superior functionality compared with the one obtained simply by wet heat treatment. The degree of grafting of 32.73 % was obtained in 30 min by ultrasound-assisted wet heating , whereas classical wet heating required 60 min. SDS-PAGE analysis indicated that 7S globulin had become complex with MD to form conjugates of higher molecular weight. Reduction in the contents of lysine and arginine during the graft reaction indicated that these two amino acid residues had the covalent linkage between 7S and MD. The results of secondary structure showed that grafted 7S had decreased α-helix level and increased β-sheet and unordered coil levels. In addition, ultrasound-assisted treatment significantly changes in surface hydrophobicity (H ₀), emulsifying activity index and emulsifying stability index of 7S (p < 0.05). Moreover, the emulsions of 7S–MDUH were stable under unfavorable conditions, such as extreme pH, ionic strength and heat treatment temperature, which is mainly due to changes in surface hydrophobicity (H ₀) and secondary structure, resulting in a reduction in protein molecular steric hindrance in an increase in molecular flexibility. This study demonstrated that combined ultrasound treatment and wet heating Maillard reaction could potentially be applied as a method to prepare 7S–MD conjugates.     

Effect of pulsed-light processing on the surface and foaming properties of β-lactoglobulin

Pulsed-light processing was used to treat β-lactoglobulin (BLG) solutions. The impact of pulsed light (PL) on the structural properties of this protein was explored through far-UV, CD spectral analysis, size exclusion chromatography, surface hydrophobicity and NMR spectroscopy. Changes on these physicochemical properties were related to surface rheology, surface tension, foam stability and foam capacity of the non-treated and treated BLG to elucidate adsorption mechanism and consequences on foaming capacity. Conformational modification of BLG was related with PL total fluence as important conformational changes increased when total fluence was higher. Consequently, adsorption rate of treated BLG at the air/water interface was faster than native BLG. Additionally, treated BLG formed highly elastic interfaces. This was found to have an impact on the foam stability. Pulsed-light treatment seemed to enhance the overall strength of the interface, resulting in more stable foams.     

Effect of barley β-glucan on water redistribution and thermal properties of dough

The effect of adding barley (Hordeum vulgare L.) β-glucan (BBG) to dough on the water redistribution and the thermal properties of dough was studied by TGA and DSC. Combined with LF-NMR to analyse the competition and redistribution mechanism of water at the ¹H level. The mass loss of the dough measured by TGA was reduced by an average of 2.11% with BBG added. BBG increased the water retention of the dough, delayed the water loss process. The LF-NMR results showed that at the same water absorption the T21 of the 3% BBG dough was longer while its T22 was shorter than those of the control. BBG has different effects on the different states of water in the dough. BBG increased the free sulfhydryl content in dough during heating, while the adverse effects of BBG on the biopolymer reactions, such as disulfide bond, could be partially relieved by regulating water content.     

Effect of high-pressure treatment on denaturation of bovine β-lactoglobulin and α-lactalbumin

The effect of high-pressure treatment on denaturation of β-lactoglobulin and α-lactalbumin in skimmed milk, whey, and phosphate buffer was studied over a pressure range of 450–700 MPa at 20 °C. The degree of protein denaturation was measured by the loss of reactivity with their specific antibodies using radial immunodiffusion. The denaturation of β-lactoglobulin increased with the increase of pressure and holding time. Denaturation rate constants of β-lactoglobulin were higher when the protein was treated in skimmed milk than in whey, and in both media higher than in buffer, indicating that the stability of the protein depends on the treatment media. α-Lactalbumin is much more baroresistant than β-lactoglobulin as a low level of denaturation was obtained at all treatments assayed. Denaturation of β-lactoglobulin in the three media was found to follow a reaction order of n = 1.5. A linear relationship was obtained between the logarithm of the rate constants and pressure over the pressure range studied. Activation volumes obtained for the protein treated in milk, whey, and buffer were −17.7 ± 0.5, −24.8 ± 0.4, and −18.9 ± 0.8 mL/mol, respectively, which indicate that under pressure, reactions of volume decrease of β-lactoglobulin are favoured. Kinetic parameters obtained in this work allow calculating the pressure-induced denaturation of β-lactoglobulin on the basis of pressure and holding times applied.     

Effect of high-pressure treatment on in-vitro digestibility of β-lactoglobulin

The effect of high-pressure (HP)-treatment on β-lactoglobulin (β-Lg) was investigated using in-vitro pepsin digestion under simulated gastric conditions. HP-treatment of β-Lg at 400 MPa for 10 min only slightly increased its subsequent hydrolysis by pepsin. However, higher pressure treatments (600 and 800 MPa) resulted in rapid digestion of β-Lg. After these higher pressure treatments, β-Lg disappeared in less than 1 min of pepsin incubation as determined by SDS-PAGE analysis. Mass spectrometry analysis of the digestion products at corresponding incubation times revealed rapid and progressive degradation of β-Lg. Most (> 90%) of the peptide products following pepsin digestion of HP-treated β-Lg were less than 1500 Da in size. Peptide products from pepsin digestion were identified and mapped to β-strand regions (Leu₃₂–Leu₅₄ and Phe₈₂–Leu₁₀₄) and to the N- and C-terminals regions (Leu₁–Leu₁₀ and Ser₁₅₀–Leu₁₅₆) of β-Lg. While these regions corresponded to known IgE epitopes of β-Lg, the predominant peptides resulting from 60 s of incubation were short (7–10 residues) in length. These results demonstrate that HP-treatment increased the digestibility of β-Lg and represents a promising processing technology for reducing the allergenicity of known allergens in a wide variety of food materials.Industrial relevanceHigh-pressure treatment is widely used to enhance the functional attributes of food proteins. The potential for enhanced nutritional value of β-Lg was also demonstrated here by its increased digestibility. High-pressure treatment followed by incubation with proteases may represent a method for the commercial production of bioactive peptides such as inhibitors of angiotensin converting enzyme. More importantly, high-pressure-induced unfolding of milk proteins may reduce their allergenicity. Unfolded proteins are less likely to become agents of immunological sensitization because they are more readily hydrolyzed. Thus high-pressure treatment applied to food ingredients such as whey protein isolate may contribute to the development of hypoallergenic foods.     

Effect of β-cyclodextrin addition on quality of precooked vacuum packed potatoes

The usefulness of β-cyclodextrin (β-CD) in enhancing the food and nutritional quality of precooked potatoes was studied. After blanching, potato slices (Solanum tuberosum var. Agata) were cooled. This was followed by dipping in solutions containing β-CD, ascorbic and citric acids, either alone or in combination with β-CD, and vacuum packaging in pouches. The potatoes were pasteurised/precooked and cooled. These samples were then analyzed for colour parameters, microbial count, Resistant Starch (RS) concentration, fat content after a frying test immediately and after 7, 14 and 28 days of storage at 4 °C. Results showed that dipping with β-CD gave the lightest colour (ΔL*) and a more attractive appearance. However, growth of aerobic mesophilic bacteria was observed in samples dipping in solutions with β-CD alone. From the nutritional point of view, the effect of β-CD on the RS content of potatoes may be related to storage time.     

Effect of ultraviolet irradiation on molecular properties and immunoglobulin production-regulating activity of β-lactoglobulin

To utilize ultraviolet (UV) irradiation as a means to prepare hypo-allergenic food, we investigated the molecular weight profile, secondary structure content, fluorescence spectrum, and immunoglobulin (Ig) production-regulating activity of β-lactoglobulin after UV-irradiation. UV-irradiation caused a change on the molecular size distribution, disruption of the ordered structure, and decrease of emission intensity of β-lactoglobulin. The alteration on Igs production regulating activity of β-lactoglobulin by UV-irradiation was observed in the mouse spleen lymphocytes system. These results suggest that UV-irradiation is effective for alteration of molecular properties and antigenicities of β-lactoglobulin and such treatment should be useful for the preparation of low allergenic foods.     

Development and research on digital inkjet printing of wool/cashmere fabric北大核心

In this study, the wool fabric suitable for digital inkjet printing was designed and development by optimizing spinning and weaving process parameters. The influences of yarn steaming process, single slurry and different proportions composite slurry on digital inkjet printing quality were discussed. The results showed that the low temperature and short time secondary steaming process was used in order to increase color absorption capacity of fiber. It should be a reasonable choice of spinning and weaving speed, and reduce the generation of defects for improving the quality of printing. The composite slurry printing quality was better than single slurry, and the printed fabric had a high color yield, pure color and a clear pattern with the ratio of DGT-7 to alginate 2: 2.     

The impact of nitrogen low temperature plasma treatment upon the physical–chemical properties of polyester fabric

An approximate theoretical analysis of the cantilever stiffness test is presented. This yields convenient formulae for calculating the bending parameters of fabrics. The formulae show good agreement with Peirce's empirical equation and reasonable agreement with Grosberg and Swani's graphical method.     

Research on the dyeing behavior of wool fabric with natural phytolacca berry dyes北大核心

The natural dyes was extracted from mature Phytolacca berries for wool fabric dyeing, the influence of different dyeing process parameters on the dyeing depth was investigated in the case of direct dyeing, Al3+ as mordant was applied to improve the dyeing fastness, the antibacterial properties of dyed wool fabric was tested. The results showed that: the dyeing depth K/S value increased with the ratio of solid to liquid and tended to flatten when the ratio was 1 : 8. 33. The K/S value increased with temperature, the dyed fabric color changed from red to pale yellow when the temperature was over 60 °C. The K/S value declined with NaCl concentration increased. The K/S had maximum color yield when the pH value was 3.5. Al3+ could improve the washing and rubbing fastness of dyed fabric. The dyed fabric had good antimicrobial properties.