近年来,随着人们对于食品品质、货架期以及环境保护的日益重视,可食用性或可降解性高分子膜正受到越来越多研究者的关注。利用乳清分离蛋白(Whey Protein Isolate,WPI)制备可食用性膜。通过实验比较了不同乳清蛋白浓度,不同温度下进行...近年来,随着人们对于食品品质、货架期以及环境保护的日益重视,可食用性或可降解性高分子膜正受到越来越多研究者的关注。利用乳清分离蛋白(Whey Protein Isolate,WPI)制备可食用性膜。通过实验比较了不同乳清蛋白浓度,不同温度下进行加热处理,以及加入不同浓度的增塑剂甘油对于乳清蛋白成膜性和物理特性的影响。实验结果表明,浓度在12%以上的WPI溶液加热后凝固;浓度在12%以下的WPI溶液加热后不凝固,且WPI浓度越高,溶液成膜越厚。增塑剂甘油与乳清蛋白的容积比越高,成膜时间越长,形成的膜越厚越柔软。80℃下加热30min与90℃下加热30min,两种条件下成膜的物理特性差别不大。10%WPI溶液,甘油与WPI的容积比(v/v)为1∶1,在80℃加热30min为最佳成膜条件。展开更多
以壳聚糖(chitosan,CTS)和乳清分离蛋白(whey protein isolate,WPI)为成膜基质,制备壳聚糖-乳清分离蛋白复合膜(chitosan/whey protein isolate composite fi lm,CWF),并分析CWF的理化性质。通过测定CWF的拉伸强度、断裂延伸率、水蒸气...以壳聚糖(chitosan,CTS)和乳清分离蛋白(whey protein isolate,WPI)为成膜基质,制备壳聚糖-乳清分离蛋白复合膜(chitosan/whey protein isolate composite fi lm,CWF),并分析CWF的理化性质。通过测定CWF的拉伸强度、断裂延伸率、水蒸气透过率、透明度,优化CWF的成膜条件为CTS脱乙酰度90%、分子质量300 kD,成膜液pH 3,甘油添加量1.5%,WPI添加量0.5%。CWF的机械性能和剥离性比CTS膜显著改善,WVP和透明度有良好的改善。扫描电镜分析显示CWF的横截面更规则、均匀,且外观为均匀半透明膜。傅里叶红外光谱扫描结果显示CTS、WPI制备CWF时在其分子之间形成了强烈的相互作用,二者有良好的相容性。展开更多
The largest amount of dairy by-products, especially the whey, comes from the manufacture of cheese. The whey proteins are used in several different industry technologies. The forage production is used for animal feedi...The largest amount of dairy by-products, especially the whey, comes from the manufacture of cheese. The whey proteins are used in several different industry technologies. The forage production is used for animal feeding in the forms of various flours mixed in feeds, and the food industry uses whey proteins as human nutrition, such as different dry soups, infant formulas and supplements. The fat components of whey may inhibit the efficient processing and might impair the use of whey in these technologies. Thus, the aim of the experiment was to investigate a cheap and economical separation of the lipid fraction of whey. This separation method was made by microfiltration, which is an inexpensive, effective and energy efficient method for this task. During the measurements, 0.2 μm and 0.45 μm microfiltration membranes were used in a laboratory tubular membrane filtration module, and the membrane separation method was combined and modified by using astatic mixer and/or air insufflation. The same pore size membranes were used in a vibrating membrane filtration equipment （VSEP）, too. The two different membrane filtration devices allowed the comparison of the effect of vibration and the effect of the static mixer and/or air insufflation. The flux values above 0.2 MPa transmembrane pressures strongly decreased on using the tubular membrane. Therefore, it can be determined that the use of the lower transmembrane pressures gave better flux combined with air insufflation and the use of static mixer. The flux values increased three times higher with using vibration during the microfiltration process than that without vibration. Comparing these methods, it can be concluded that the separation made on tubular membrane （0.2 μm） combined with statics mixer gave sufficient result according to the degreasing, retentions and flux values of the other components.展开更多
文摘近年来,随着人们对于食品品质、货架期以及环境保护的日益重视,可食用性或可降解性高分子膜正受到越来越多研究者的关注。利用乳清分离蛋白(Whey Protein Isolate,WPI)制备可食用性膜。通过实验比较了不同乳清蛋白浓度,不同温度下进行加热处理,以及加入不同浓度的增塑剂甘油对于乳清蛋白成膜性和物理特性的影响。实验结果表明,浓度在12%以上的WPI溶液加热后凝固;浓度在12%以下的WPI溶液加热后不凝固,且WPI浓度越高,溶液成膜越厚。增塑剂甘油与乳清蛋白的容积比越高,成膜时间越长,形成的膜越厚越柔软。80℃下加热30min与90℃下加热30min,两种条件下成膜的物理特性差别不大。10%WPI溶液,甘油与WPI的容积比(v/v)为1∶1,在80℃加热30min为最佳成膜条件。
文摘以壳聚糖(chitosan,CTS)和乳清分离蛋白(whey protein isolate,WPI)为成膜基质,制备壳聚糖-乳清分离蛋白复合膜(chitosan/whey protein isolate composite fi lm,CWF),并分析CWF的理化性质。通过测定CWF的拉伸强度、断裂延伸率、水蒸气透过率、透明度,优化CWF的成膜条件为CTS脱乙酰度90%、分子质量300 kD,成膜液pH 3,甘油添加量1.5%,WPI添加量0.5%。CWF的机械性能和剥离性比CTS膜显著改善,WVP和透明度有良好的改善。扫描电镜分析显示CWF的横截面更规则、均匀,且外观为均匀半透明膜。傅里叶红外光谱扫描结果显示CTS、WPI制备CWF时在其分子之间形成了强烈的相互作用,二者有良好的相容性。
文摘The largest amount of dairy by-products, especially the whey, comes from the manufacture of cheese. The whey proteins are used in several different industry technologies. The forage production is used for animal feeding in the forms of various flours mixed in feeds, and the food industry uses whey proteins as human nutrition, such as different dry soups, infant formulas and supplements. The fat components of whey may inhibit the efficient processing and might impair the use of whey in these technologies. Thus, the aim of the experiment was to investigate a cheap and economical separation of the lipid fraction of whey. This separation method was made by microfiltration, which is an inexpensive, effective and energy efficient method for this task. During the measurements, 0.2 μm and 0.45 μm microfiltration membranes were used in a laboratory tubular membrane filtration module, and the membrane separation method was combined and modified by using astatic mixer and/or air insufflation. The same pore size membranes were used in a vibrating membrane filtration equipment （VSEP）, too. The two different membrane filtration devices allowed the comparison of the effect of vibration and the effect of the static mixer and/or air insufflation. The flux values above 0.2 MPa transmembrane pressures strongly decreased on using the tubular membrane. Therefore, it can be determined that the use of the lower transmembrane pressures gave better flux combined with air insufflation and the use of static mixer. The flux values increased three times higher with using vibration during the microfiltration process than that without vibration. Comparing these methods, it can be concluded that the separation made on tubular membrane （0.2 μm） combined with statics mixer gave sufficient result according to the degreasing, retentions and flux values of the other components.
