Traditional Water Bath Research Articles

Improvement of the Rubbing Fastness of Cotton Fiber in Indigo/Silicon Non-Aqueous Dyeing Systems.

In order to solve the poor rubbing fastness of dyed cotton fiber in the indigo/silicon non-aqueous dyeing system, the process parameters of the silicon non-aqueous dyeing system were optimized. Dyed cotton fiber was post-treated to achieve the optimum dyeing conditions for obtaining a better rubbing fastness. Meanwhile, the dyeing performance of cotton fiber in a traditional water bath and silicon non-aqueous dyeing system was compared. The results showed that the rubbing fastness of dyed cotton fiber in the silicon non-aqueous dyeing system (one dyeing) was lower than that of traditional water bath (twelve cycles), although the color depth of dyed cotton fiber was deeper. For obtaining a good rubbing fastness, the optimum temperature was about 70 °C and the optimal dyeing cycle was one. Moreover, fixing agents can significantly improve the rubbing fastness of dyed cotton fiber. Especially, cationic waterborne polyurethane had an optimal fixing effect on the dyed cotton fiber. Soft finishing would weaken the effect of fixing finishing on the dyed cotton fiber, but the softener can significantly improve the handle of dyed cotton fiber.

Microwave‐irradiated tanning reaction of aluminum with collagen

ABSTRACTGiven the toxicity of chrome tanning in leather industry, ecologically compatible alternatives are intensively researched, in particular on the side of aluminum tanning. Herein, the tanning reaction of aluminum with collagen was investigated using microwave irradiation as a new heating method, and the traditional water bath heating (WBH) was used as control. Results from dynamic light scattering and very‐positive differential scanning calorimetry (DSC) analysis reveal that, microwave heating led to larger particle size and increased main denaturing transition temperature of collagen clusters crosslinked by aluminum sulfate. The aluminum‐tanned collagen products obtained under microwave and WBH methods were further compared and characterized using many techniques including circular dichroism, fluorescence spectroscopy, atomic force microscope, and Fourier transform infrared spectroscopy, DSC, and thermogravimetry. Results verified that both heating methods accelerate the crosslinking reaction of aluminum with collagen and increase the crosslinking degrees. The crosslinked products exhibited improved thermal stability, but no change was observed concerning the binding mode of aluminum with collagen. However, compared to WBH microwave heating has a more positive effect on the aluminum‐tanning processes for the improvement of collagen crosslinking processes and product performances, probably due to both thermal and nonthermal effects of microwave irradiation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48682.

Optimization of microwave assisted lipid extraction from microalga Scenedesmus obliquus grown on municipal wastewater

Efficient cost effective lipid extraction from microalgae is a challenging topic for large scale production of microalgae-based biodiesel. In this study, a microwave-assisted lipid extraction process was applied to the oil-rich green microalga Scenedesmus obliquus grown on municipal wastewater. N-hexane/isopropanol solvent was used as alternative solvent. Optimal extraction parameters were determined as: operational temperature of 130 °C, extraction time of 0.25 h, solvent ratio of N-hexane/isopropanol of 3:2 (V:V), phase ratio of co-solvent/biomass was 50:1 (mL:g). Relative extraction rates of lipid and fatty acid methyl esters (FAMEs) achieved using microwave-assisted extraction (MAE) were 88.25% and 95.58%, respectively, which is higher than traditional water bath heating extraction process (WHE). In addition, compared with WHE, the apparent first order rate constant of MAE was enhanced by 18 times compared to traditional methods. Analysis using scanning electron microscopy indicated that disruption of the cell wall of Scenedesmus obliquus by microwave led to the enhancement of solvents’ penetration and lipid extraction.

Effects of microwave and water bath heating on the interactions between myofibrillar protein from beef and ketone flavour compounds

AbstractThis paper presents the effects of microwave on the structure changes of myofibrillar protein compared with traditional water bath heating method. Under microwave or water bath heating conditions, α‐helix conformation of myofibrillar protein was converted into β‐turn, β‐sheet and randomly coiled structures gradually. T he fluorescence intensity of myofibrillar protein exhibited a marked red shift of the maximum absorption wavelength after microwave or water bath treatment. Total sulfhydryls groups and surface hydrophobicity contents were increased with progressing microwave or water bath treatment time. Results indicated that the thermal effects of microwave dominated the structure changes of myofibrillar protein, and microwaving also had an apparent influence on myofibrillar protein structure compared with water bath heating due to its nonthermal effects, and thus affecting the retention and release of ketone flavour compounds.

Importance of thickness in electromagnetic properties and gel characteristics of surimi during microwave heating

To better apply microwave technology to surimi industry, surimi gels of different thicknesses were investigated. According to the determination of electromagnetic properties of surimi paste, both the maximum penetration depth and absorption peak are less than 1 cm. The results of temperature distribution shown that the highest temperature point of the surimi shifted from the center to the periphery. The coefficient of variation (COV) was the minimum and the temperature distribution the temperature distribution was the most uniform when the surimi thickness was 2.0 cm. Surimi paste with a thickness of 2.0 cm heated by microwaves (2450 MHz) had higher gel properties (16.42 ± 0.22 MPa) and water holding capacity (73.59 ± 0.26%) compared to that heated by the traditional water bath method. Scanning electron microscopy revealed that an ordered and dense network structure formed at a thickness of 2 cm. The optimum thickness (2 cm) for microwave heating was determined based on the electromagnetic characteristics and the temperature distribution of surimi, which provided basis for the application of microwave in surimi products.

Detection of Novel duck reovirus (NDRV) using visual reverse transcription loop-mediated isothermal amplification (RT-LAMP)

Here we present a visual reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for detecting the gene encoding the σB major outer-capsid protein of novel duck reovirus (NDRV). A set of primers, composed of two outer primers, two inner primers and two loop primers, was designed based on the gene of interest. The LAMP reaction was conducted in a traditional laboratory water bath at 65 °C for 50 min. We compared the performance of calcein/Mn2+ and SYBR Green I dyes, as well as electrophoresis on agarose gel stained with GoldView nucleic acid dye to detect the RT-LAMP-amplified products and all assays could be employed to discriminate between positive and negative specimens in visible or UV light. Our data showed that there is no cross-reaction with other viruses and the RT-LAMP technique displayed high sensitivity for detecting NDRV with a minimal detection limit of 200 fg RNA input. This assay was more sensitive than conventional PCR in detecting NDRV both in natural and experimental infection. In conclusion, the RT-LAMP technique was remarkably sensitive, specific, rapid, simple and profitable for the identification of NDRV.

Comparison of multiple thawing techniques on thaw time and stability of hemostatic proteins in canine plasma products.

To compare thawing times of fresh frozen canine plasma between a 37 °C warm water bath, running water bath and dry plasma thawer and compare haemostatic protein stability after thawing in a warm water bath or dry plasma thawer. To measure thawing times, a 240-mL bag of frozen plasma was thawed in warm water bath, running water bath or dry plasma thawer-10 times for each method. To evaluate stability ofhaemostatic proteins, fresh canine donor plasma samples were split into 120-mL bags and 3-mL control aliquots before freezing. Bags were thawed by warm water bath or dry plasma thawer and aliquots equilibrated to room temperature. Concentrations of haemostatic proteins, albumin, D-dimers, prothrombin time and partial thromboplastin time were obtained. The running water bath had the shortest thaw time: median thaw time of 15 minutes versus 18 minutes for both the dry plasma thawer and warm water bath. Statistically significant differences in partial thromboplastin time, factor VII, factor X, von Willebrand factor, and von Willebrand factor collagen binding assay were detected among groups but were unlikely to be clinically relevant. A traditional running water bath provided the fastest thawing time but the dry plasma thawer resulted in the most stable haemostatic proteins.

Optimization of ultrasonic-assisted extraction of antioxidant tannin from young astringent persimmon (Diospyros kaki L.) using response surface methodology

Ultrasonic-assisted extraction (UAE) was applied for tannin extraction from young persimmon (Diospyros kaki L.) and extraction conditions were optimized using response surface methodology to compare with traditional water bath extraction (WBE). The maximum yield (33.96 mg/g) extracted by UAE was obtained under conditions of ultrasonic power 207 W, time 30.9 min, L:S ratio 21.1:1 (mL:g) and 55.0 °C, whereas tannin yield reached 32.39 mg/g under parameters of 73.5 °C, time 63.0 min, and L:S ratio 32.4:1 (mL:g) when using WBE. Comparatively, higher tannin was extracted under optimal UAE condition than WBE method, mainly associated with its great damage on original structure of persimmon pulp and peel based on morphological analysis. While there was no significant difference for UV and FT-IR spectra among tannin extracted by different methods. Moreover, tannin possessed excellent DPPH radical scavenging and ferric reducing activities in a dosage-dependent manner, showing potential application in medicinal and food industry. Practical applications Young astringent persimmon possesses abundant functional tannin that is beneficial to human health. Tannin extraction is the most fundamental process for its further research and application. Traditional methods for bioactive compounds extraction are generally conducted with high temperature, large solvent consumption and long time. This study illuminated that ultrasonic-assisted extraction method had great potential to replace traditional water bath to extract antioxidant tannin from young persimmon.

Production of polyhydroxybuyrate (PHB) from switchgrass pretreated with a radio frequency-assisted heating process

Effects of radio frequency (RF) heating as a biomass pretreatment process to generate hydrolysates for polyhydroxybuyrate (PHB) were evaluated in all production steps from pretreatment to enzymatic hydrolysis to fermentation. Switchgrass was pretreated under alkaline conditions with RF-assisted heating (traditional water bath (WB) heating as control) and subsequently enzymatically hydrolyzed. Fermentation was conducted with recombinant Escherichia coli strain for PHB production using the hydrolysates as carbon sources with or without yeast extract (YE) supplemented. Results indicated that the hydrolysates generated through RF pretreatment performed consistently better for PHB production than WB (50% higher PHB levels without YE). YE supplementation (up to 5 g/L) enhanced fermentation under all conditions and diminished the difference among performances of fermentations. When adding 2 g/L YE, PHB production increased by 200% and 80% for WB and RF hydrolysates, respectively. Supplementation of 5 g/L YE brought the final PHB concentration to be very close to each other for all three fermentation conditions. Compared to traditional heating process, the unique heating mechanism of RF generates harsher conditions (under regular pressure) to disrupt the biomass structure more completely and generate more nutrients for bacterial fermentation. RF was therefore proved to be an efficient process for biomass pretreatment.

Effects of Microwave Radiation and Water Bath Heating on the Physicochemical Properties of Actomyosin from Silver Carp (Hypophthalmichthys molitrix)during Setting

Changes in the physical and chemical characteristics of actomyosin, isolated from silver carp (Hypophthalmichthys molitrix), induced by heating in a water bath and microwave oven were investigated. Ca2+-ATPase showed a heating-time-dependent decrease in activity, suggesting denaturation of myosin and dissociation of the actomyosin complex. The decrease in actomyosin solubility indicates the formation of protein aggregates. In addition, reactive sulfhydryl (R-SH) groups increased and total SH (T-SH) groups decreased with heating, indicating the formation of disulfide bonds through SH oxidation or disulfide interchanges. The differences of surface hydrophobicity (S0) showed microwave heating has an inhibitory effect on protein conformation changes. Fourier transform infrared confirmed the conformational changes of silver carp actomyosin. This study demonstrated that microwave heating can effectively depressed actomyosin structural changes during heating and provided useful information for surimi production. Practical Applications At present, there is lot of research about heat-induced gel from fish protein, but the way they used are traditional water bath or ohmic heating. Though reports of microwave heating on structure and the characteristics of fish protein are few, it is important for surimi gelation and microwave sterilization. We supposed microwave heating could influence the structure of fish protein and improve the quality of surimi. A preliminary study of microwave heating on actomyosin not only can enrich theory of heated induced protein gel also has important scientific value.

Improvement of radio frequency (RF) heating-assisted alkaline pretreatment on four categories of lignocellulosic biomass.

Pretreatment plays an important role in making the cellulose accessible for enzyme hydrolysis and subsequent conversion because it destroys more or less resistance and recalcitrance of biomass. Radio frequency (RF)-assisted dielectric heating was utilized in the alkaline pretreatment on agricultural residues (corn stover), herbaceous crops (switchgrass), hardwood (sweetgum) and softwood (loblolly pine). Pretreatment was performed at 90°C with either RF or traditional water bath (WB) heating for 1h after overnight soaking in NaOH solution (0.2g NaOH/g Biomass). Pretreated materials were characterized by chemical compositional analysis, enzyme hydrolysis, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The glucan yields of RF-heated four categories of hydrolysates were 89.6, 72.6, 21.7, and 9.9%. Interestingly, RF heating raised glucan yield on switchgrass and sweetgum but not on corn stover or loblolly pine. The SEM images and FTIR spectra agreed with results of composition analysis and hydrolysis. GC-MS detected some compounds only from RF-heated switchgrass. These compounds were found by other researchers only in high-temperature (150-600°C) and high-pressure pyrolysis processes.

Improvement of acetone–butanol–ethanol (ABE) production from switchgrass pretreated with a radio frequency-assisted heating process

Radio frequency (RF) heating assisted alkaline pretreatment was evaluated as an emerging technology to generate hydrolysates for acetone–butanol–ethanol (ABE) fermentation. Traditional water bath (WB) heating was utilized as a control. ABE fermentation was conducted with Clostridium beijerinckii 8052 using the hydrolysates as carbon sources with or without yeast extract (YE, as supplemented complex nitrogen sources). Results indicated that the hydrolysates generated through RF pretreatment (RFH) performed consistently better for ABE fermentation than the hydrolysates generated through WB (WBH), with or without yeast extract (YE) supplementation. Without YE addition, fermentation with RFH generated 50% higher ABE than that with WBH. YE supplementation (up to 5g/L) enhanced fermentation under all conditions and diminished the difference among performances of fermentations. ABE production with 1 and 2g/L YE supplementation increased by 15% and 107% than those without YE for WBH, while for RFH the increase were 1% and 55%, respectively. Supplementation of 5g/L YE brought the final solvent production to be very close to each other with either WBH or RFH. Therefore, we concluded that RFH contained more nutrients than WBH which made a big difference for the ABE fermentation. RF could be explored as an efficient method for biomass pretreatment. This study provided valuable references for developing a sustainable system to convert lignocellulosic biomass into bioenergy in an economically efficient manner.

Mechanisms for improving mass transfer in food with ultrasound technology: Describing the phenomena in two model cases

The aim of this work was to demonstrate how ultrasound mechanisms (direct and indirect effects) improve the mass transfer phenomena in food processing, and which part of the process they are more effective in. Two model cases were evaluated: the hydration of sorghum grain (with two water activities) and the influx of a pigment into melon cylinders. Different treatments enabled us to evaluate and discriminate both direct (inertial flow and “sponge effect”) and indirect effects (micro channel formation), alternating pre-treatments and treatments using an ultrasonic bath (20kHz of frequency and 28W/L of volumetric power) and a traditional water-bath. It was demonstrated that both the effects of ultrasound technology are more effective in food with higher water activity, the micro channels only forming in moist food. Moreover, micro channel formation could also be observed using agar gel cylinders, verifying the random formation of these due to cavitation. The direct effects were shown to be important in mass transfer enhancement not only in moist food, but also in dry food, this being improved by the micro channels formed and the porosity of the food. In conclusion, the improvement in mass transfer due to direct and indirect effects was firstly discriminated and described. It was proven that both phenomena are important for mass transfer in moist foods, while only the direct effects are important for dry foods. Based on these results, better processing using ultrasound technology can be obtained.

Determination of Acrylic Denture Resin Surface Roughness by Different Processing Techniques

Background: Poly (methyl methacrylate) (PMMA) seems to be the most commonly used material in the construction of denture base due to its advantages. However, it is still far from being ideal in fulfilling the physical and mechanical properties. Therefore, attempts to improve the properties of PMMA were taken by the researcher through many ways The purpose of this study was to estimate the effect of different processing techniques on surface roughness of acrylic base denture resin. Materials and Methods: A total sample of (50) specimens were prepared; these specimens were divided into 3 main processing techniques, and 5 experimental sub-groups (n=10): Group (A), acrylic denture base material processed by conventional water bath technique (74C for 1 and half hours then boiled for 30 min; Group (B), acrylic resins processed by microwave oven at (500 Watts) for 3 min; Group (C) samples processed by autoclave device with 3 different timing set up : (C1) for l0 min, (C2) for 20 min and (C3) for 30 min. This is done to make a comparison of different autoclave polymerization conditions on the surface roughness of denture base resin. Results: Statistically, there was no significant difference between the traditional water bath group technique and an autoclave system when the specimen processed at (121C/210Kpa) for 30 min. However, there was a statistically significant difference compared to other experimental groups. Conclusion: The autoclave processing technique could be the new alternative system to process the acrylic resin base material alongside the conventional methods. The experimental group prepared by autoclave system at (121C/21Kpa) for 30 min showed an improvement in the surface roughness compared to microwave and water bath techniques.

A non-aqueous dyeing process of reactive dye on cotton

Based on previous work, the feasible method for dyeing cotton with reactive dye in dye/decamethyl cyclopentasiloxane (D5) suspension system was re-established by increasing the system stability using selected surfactants, and taking the color depth (K/S value) as the evaluation index, the dyeing process parameters such as temperature, dyeing duration, pick-up ratio of alkali solution on fabric, as well as the alkali concentration were optimized further for setting up dyeing conditions. The dyeing results produced by new method showed that the dye uptake could reach nearly 100% without any salt as accelerating agent. Since just a little water was used in the process, hydrolysis of reactive dyes was restrained, fixing rate was increased, and the apparent color depth of the dyed sample was much better than traditional water bath dyeing. The washing fastness and rubbing fastness of samples were satisfactory.

Enhanced extraction of osthole and imperatorin from Cnidium monnieri by infrared-accelerated enzyme pretreatment

In this work, a temperature-controllable infrared (IR) radiation system with a mechanic stirrer was developed for IR-accelerated enzyme pretreatment of traditional Chinese medicines prior to the extraction of bioactives. The feasibility and performance of this unique system were demonstrated by enzyme pretreatment of Cnidium monnieri, used as the model sample. To investigate enzymatic pretreatment assisted by infrared energy, experiments were carried out to evaluate the effects that enzyme type, pH and the concentration of the enzyme solution, incubation time and temperature have upon the enzymatic activity. Statistical treatment of the results revealed that the selected parameters were all significant. The optimum parameters were obtained as follows: 0.2 mg ml−1 pectinase solution, and incubated at pH 6.0 for 2 min at 35 °C. At optimized conditions, the extraction yields of osthole and imperatorin were 18.11 mg g−1 and 7.27 mg g−1 in pectinase treated sample, increased by 10.2% and 7.9%, respectively, compared with those in the control group. The results also showed that using infrared radiation as an energy source, the efficiency of enzyme pretreatment was significantly enhanced compared with conventional water bath assisted enzymatic pretreatment (p < 0.05), and the extraction rates of osthole and imperatorin by infrared-assisted extraction were significantly higher than those obtained with ultrasound-assisted extraction (p < 0.05). More importantly, the enzymatic pretreatment time was significantly shortened to 2 min of infrared assisted enzymatic pretreatment from 1 h of traditional water bath assisted enzymatic pretreatment. With the advantage of environment-friendliness, low cost, easy operation and high efficiency, the present enzyme pretreatment setup will find wide applications in enzyme pretreatment for natural product extraction in large scale.

Non-Aqueous Dyeing of Reactive Dyes in D5

C.I. Reactive Red 195 was used for non-aqueous dyeing in D5 (Decamethyl Cyclopentasiloxane) and appropriate surfactants were selected to ensure the dyes dispersed stably in D5 medium. The feasible method for reactive dyeing in dyes/D5 suspension system was established through repeated experiments. At the same time, taking the color depth (K/S value) as the evaluation index, the process factors in dyeing such as temperature, dyeing duration, pick-up ratio of alkali solution on fabric, as well as the alkali concentration were optimized for setting up dyeing conditions. The results showed that, the dye up-take could reach nearly 100% without any salt as accelerating agent. Since just a little water was used in the process, hydrolysis of reactive dyes was restrained, fixing rate was increased, and the apparent color depth of the dyed sample was much better than traditional water bath dyeing. The washing fastness and rubbing fastness of samples dyed in dyes/D5 system were satisfactory.

The Use of Microwave Energy to Polymerize Acrylic Resins

Microwave-processed acrylic resins were introduced in dental practice as an alternative for conventional heat-processed in order to provide easier and faster processing. Microwave polymerized acrylic resins seem to possess adequate physical and biological properties. This paper presents a literature revision about acrylic resin polymerization by microwave energy, establishing a comparison between this method and the traditional water bath polymerization in the aspects of mechanic, biologic and physical properties.

Amino acid composition, molecular weight distribution and antioxidant activity of protein hydrolysates of soy sauce lees

The proteins of soy sauce lees (SSLP) were hydrolysed by Alcalase in the presence of ultrasound or traditional water bath to obtain hydrolysates S2–S6. The analysis of protein content indicated that enzymatic hydrolysis could significantly improve the extraction efficiency of proteins. By determination of molecular weight distribution, >10 and 5–10 KDa fractions of native SSLP (S1) decreased during hydrolysis, whilst 3–5 KDa fraction increased. Gradual increases of free, total and antioxidant amino acids were observed for S1–S4, and the differences between S4 and S6 were slight. Tyrosine was the major free amino acid of S1–S6, whilst glutamic acid had the highest amount in total amino acid composition. S2–S6 showed stronger DPPH radical scavenging activities in a dose-dependent manner than S1. All the results suggested that ultrasound treatment showed an inhibition behaviour on the enzymatic hydrolysis of SSLP.