Lycopene is very susceptible to degradation once released from the protective chromoplast environment.In this study,oil-in-water(O/W)nanoemulsions coupled with spray drying technology were applied for the encapsulatio...Lycopene is very susceptible to degradation once released from the protective chromoplast environment.In this study,oil-in-water(O/W)nanoemulsions coupled with spray drying technology were applied for the encapsulation and stabilization of lycopene extracted from tomato waste.Tomato extract was obtained by ultrasound-assisted extraction.Nanoemulsions were prepared by a high-speed rotor stator using isopropyl myristate as the oil phase and Pluronic F-127 as the emulsifier for the aqueous external phase.The effect of emulsification process parameters was investigated.Spray drying of the produced emulsions was attempted to obtain a stabilized dry powder after the addition of a coating agent.The effect of different coating agents(maltodextrin,inulin,gum arabic,pectin,whey and polyvinylpyrrolidone),drying temperature(120-170℃),and feed flow rate(3-9 ml·min^(-1))on the obtained particles was evaluated.Results revealed that the emulsion formulation of 20/80(O/W)with 1.5%(mass fraction)of Pluronic F-127 as stabilizer in the aqueous phase resulted in a stable nanoemulsion with droplet sizes in the range of 259-276 nm with a unimodal and sharp size distribution.The extract in the nanoemulsion was well protected at room temperature with a degradation rate of lycopene of about 50%during a month of storage time.The most stable emulsions were then processed by spray drying to obtain a dry powder.Spray drying was particularly successful when using maltodextrin as a coating agent,obtaining dried spherical particles with mean diameters of(4.87±0.17)μm with a smooth surface.The possibility of dissolving the spray dried powder in order to repristinate.The original emulsion was also successfully verified.展开更多
To investigate soapless emulsion copolymerization in the presence of a solid phase, copolymerization experiments were carried out for the styrene-butyl acrylate-K_2S_2O_8-water system by using barium sulfate powder,wh...To investigate soapless emulsion copolymerization in the presence of a solid phase, copolymerization experiments were carried out for the styrene-butyl acrylate-K_2S_2O_8-water system by using barium sulfate powder,which is assumed to be chemically inert.Reaction conditions were varied with respect to barium sulfate powder quantity,initiator concen- tration and temperature.These factors were investigated with respect to the effect on reaction rate and conversion,polymer particle number and diameter,and latex stability.展开更多
The graphene oxide powder(GOP)obtained from the spray drying process often exhibits poor redispersibility which is considered due to the partial reduction of GO sheets.The reduction of drying temperature can effective...The graphene oxide powder(GOP)obtained from the spray drying process often exhibits poor redispersibility which is considered due to the partial reduction of GO sheets.The reduction of drying temperature can effectively increase the redispersibility of GOP,but result in a decreased drying efficiency.Herein,we found that the redispersibility of GOP is strongly affected by its microstructure,which is determined by the feed concentration.With the increase of feed concentration,the GO nanosheet assembly varies from the disordered stacking to relatively oriented assembly,making the morphology of the GOP transform from balllike(the most crumpled one)to flakelike(the least crumpled one),and the 0.8 mgml 1 is the threshold concentration for the morphology,structure,and redispersibility change.Once the feed concentration reaches 0.8 mg ml 1,the appearance of the nematic phase in droplet ensures the relatively oriented assembly of GO sheets to form the layered structure with a low crumpling degree,which greatly improves the polar parts surface tension of the solid GOP,making the GOP easier to form hydrogen bonding with water during the redispersion process,thus stabilizing dispersion.This work provides useful information for understanding the relationships between the morphology,microstructure,and final redispersibility of GOPs.展开更多
The emulsion polymerization of highly shear-stable copolymer dispersions of methyl methacrylate and butyl acrylate were carried out using poly （vinyl alcohol） with a thiol end group （PVA-SH） as protective colloid....The emulsion polymerization of highly shear-stable copolymer dispersions of methyl methacrylate and butyl acrylate were carried out using poly （vinyl alcohol） with a thiol end group （PVA-SH） as protective colloid. The dispersions can be transformed into corresponding redispersible powder via a spray dryingcooling process. On-line FT-IR monitoring shows that grafting polymer of PVA-g-PMMA was formed mainly at the stage-1 of the emulsion polymerization. TEM images show, the PVA-SH shell was fragmentary when adding SDS at initial stage and integrated when adding at particle growing or final stage. The particle size turns to be smaller when delayed adding SDS surfactant. Triethanolamine, a co-regulator of PVA-SH, controlled the M to 50 000-70 000 and reduced the PDI to 1.5-1.7. The acrylic dispersions with 0.8wt%-1.5wt% PVA-SH1 can be spray-dried into super dispersible polymer powder （SDPP）, which can easily disperse in water and form recon- stituted dispersions with an average particle size smaller than 1 micron.展开更多
该研究以猪皮蛋白粉(porcine skin protein powder,PSPP)为原料,以大豆油为油相制备乳液,研究了不同质量分数的PSPP(0.5%~3.0%)对乳液的理化性质、流变特性及稳定性的影响。结果表明,随着PSPP添加量的增加,更多的蛋白颗粒参与界面吸附...该研究以猪皮蛋白粉(porcine skin protein powder,PSPP)为原料,以大豆油为油相制备乳液,研究了不同质量分数的PSPP(0.5%~3.0%)对乳液的理化性质、流变特性及稳定性的影响。结果表明,随着PSPP添加量的增加,更多的蛋白颗粒参与界面吸附和连续相网络形成,导致乳液液滴尺寸降低(300~40μm),乳液持水力和流变学特性(表观黏度、模量)增加,进而提高了乳液的贮藏、离心、冻融稳定性。研究结果可为猪皮的高值利用拓展新途径,并为PSPP作为乳化型功能性组分在食品中应用提供理论依据和指导意义。展开更多
以猪皮蛋白粉(porcine skin protein powder,PSPP)为原料,大豆油为油相制备乳液,再经热诱导形成猪皮蛋白粉基乳液凝胶,研究PSPP的浓度和加热处理时间与次数对乳液稳定性、乳液凝胶质构及持水力的影响。结果表明,随着PSPP浓度的增加,加...以猪皮蛋白粉(porcine skin protein powder,PSPP)为原料,大豆油为油相制备乳液,再经热诱导形成猪皮蛋白粉基乳液凝胶,研究PSPP的浓度和加热处理时间与次数对乳液稳定性、乳液凝胶质构及持水力的影响。结果表明,随着PSPP浓度的增加,加热后乳液析出水层逐渐减小,乳液结构保持更加完整,液滴尺寸变化显著减小,乳液的表观黏度增大。质构和持水力分析显示,随着PSPP浓度的增加,乳液凝胶的硬度、黏聚性及持水力均显著增强。激光共聚焦显微镜显示,随着PSPP浓度的增加,乳液凝胶颗粒的直径明显减小,油水界面的蛋白覆盖率增大。当PSPP质量浓度为30 g/L时,随着热处理时间延长和次数的增加,乳液凝胶质构特性变化较小,这表明PSPP乳液凝胶可耐受长时间和反复加热处理。展开更多
文摘Lycopene is very susceptible to degradation once released from the protective chromoplast environment.In this study,oil-in-water(O/W)nanoemulsions coupled with spray drying technology were applied for the encapsulation and stabilization of lycopene extracted from tomato waste.Tomato extract was obtained by ultrasound-assisted extraction.Nanoemulsions were prepared by a high-speed rotor stator using isopropyl myristate as the oil phase and Pluronic F-127 as the emulsifier for the aqueous external phase.The effect of emulsification process parameters was investigated.Spray drying of the produced emulsions was attempted to obtain a stabilized dry powder after the addition of a coating agent.The effect of different coating agents(maltodextrin,inulin,gum arabic,pectin,whey and polyvinylpyrrolidone),drying temperature(120-170℃),and feed flow rate(3-9 ml·min^(-1))on the obtained particles was evaluated.Results revealed that the emulsion formulation of 20/80(O/W)with 1.5%(mass fraction)of Pluronic F-127 as stabilizer in the aqueous phase resulted in a stable nanoemulsion with droplet sizes in the range of 259-276 nm with a unimodal and sharp size distribution.The extract in the nanoemulsion was well protected at room temperature with a degradation rate of lycopene of about 50%during a month of storage time.The most stable emulsions were then processed by spray drying to obtain a dry powder.Spray drying was particularly successful when using maltodextrin as a coating agent,obtaining dried spherical particles with mean diameters of(4.87±0.17)μm with a smooth surface.The possibility of dissolving the spray dried powder in order to repristinate.The original emulsion was also successfully verified.
文摘To investigate soapless emulsion copolymerization in the presence of a solid phase, copolymerization experiments were carried out for the styrene-butyl acrylate-K_2S_2O_8-water system by using barium sulfate powder,which is assumed to be chemically inert.Reaction conditions were varied with respect to barium sulfate powder quantity,initiator concen- tration and temperature.These factors were investigated with respect to the effect on reaction rate and conversion,polymer particle number and diameter,and latex stability.
基金the National Key R&D Program of China(2019YFD1101200,2019YFD1101204)Natural Science Foundation of China(51772150)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Jiangsu Provincial Key Research and Development Program(BE2018008-1).
文摘The graphene oxide powder(GOP)obtained from the spray drying process often exhibits poor redispersibility which is considered due to the partial reduction of GO sheets.The reduction of drying temperature can effectively increase the redispersibility of GOP,but result in a decreased drying efficiency.Herein,we found that the redispersibility of GOP is strongly affected by its microstructure,which is determined by the feed concentration.With the increase of feed concentration,the GO nanosheet assembly varies from the disordered stacking to relatively oriented assembly,making the morphology of the GOP transform from balllike(the most crumpled one)to flakelike(the least crumpled one),and the 0.8 mgml 1 is the threshold concentration for the morphology,structure,and redispersibility change.Once the feed concentration reaches 0.8 mg ml 1,the appearance of the nematic phase in droplet ensures the relatively oriented assembly of GO sheets to form the layered structure with a low crumpling degree,which greatly improves the polar parts surface tension of the solid GOP,making the GOP easier to form hydrogen bonding with water during the redispersion process,thus stabilizing dispersion.This work provides useful information for understanding the relationships between the morphology,microstructure,and final redispersibility of GOPs.
文摘The emulsion polymerization of highly shear-stable copolymer dispersions of methyl methacrylate and butyl acrylate were carried out using poly （vinyl alcohol） with a thiol end group （PVA-SH） as protective colloid. The dispersions can be transformed into corresponding redispersible powder via a spray dryingcooling process. On-line FT-IR monitoring shows that grafting polymer of PVA-g-PMMA was formed mainly at the stage-1 of the emulsion polymerization. TEM images show, the PVA-SH shell was fragmentary when adding SDS at initial stage and integrated when adding at particle growing or final stage. The particle size turns to be smaller when delayed adding SDS surfactant. Triethanolamine, a co-regulator of PVA-SH, controlled the M to 50 000-70 000 and reduced the PDI to 1.5-1.7. The acrylic dispersions with 0.8wt%-1.5wt% PVA-SH1 can be spray-dried into super dispersible polymer powder （SDPP）, which can easily disperse in water and form recon- stituted dispersions with an average particle size smaller than 1 micron.
文摘该研究以猪皮蛋白粉(porcine skin protein powder,PSPP)为原料,以大豆油为油相制备乳液,研究了不同质量分数的PSPP(0.5%~3.0%)对乳液的理化性质、流变特性及稳定性的影响。结果表明,随着PSPP添加量的增加,更多的蛋白颗粒参与界面吸附和连续相网络形成,导致乳液液滴尺寸降低(300~40μm),乳液持水力和流变学特性(表观黏度、模量)增加,进而提高了乳液的贮藏、离心、冻融稳定性。研究结果可为猪皮的高值利用拓展新途径,并为PSPP作为乳化型功能性组分在食品中应用提供理论依据和指导意义。
文摘以猪皮蛋白粉(porcine skin protein powder,PSPP)为原料,大豆油为油相制备乳液,再经热诱导形成猪皮蛋白粉基乳液凝胶,研究PSPP的浓度和加热处理时间与次数对乳液稳定性、乳液凝胶质构及持水力的影响。结果表明,随着PSPP浓度的增加,加热后乳液析出水层逐渐减小,乳液结构保持更加完整,液滴尺寸变化显著减小,乳液的表观黏度增大。质构和持水力分析显示,随着PSPP浓度的增加,乳液凝胶的硬度、黏聚性及持水力均显著增强。激光共聚焦显微镜显示,随着PSPP浓度的增加,乳液凝胶颗粒的直径明显减小,油水界面的蛋白覆盖率增大。当PSPP质量浓度为30 g/L时,随着热处理时间延长和次数的增加,乳液凝胶质构特性变化较小,这表明PSPP乳液凝胶可耐受长时间和反复加热处理。
