Clean label food is a rising consumer trend in the food industry.Milk protein concentrate(MPC)and reduced-calcium milk protein concentrate(RCMPC)could serve as natural emulsifiers and increase the total protein conten...Clean label food is a rising consumer trend in the food industry.Milk protein concentrate(MPC)and reduced-calcium milk protein concentrate(RCMPC)could serve as natural emulsifiers and increase the total protein content of ice cream products.The objectives of this study were to determine and compare the effects of MPC and RCMPC on ice cream composition,mix viscosity,storage stability,meltdown rate,and texture.A base formulation with 3%non-fat dry milk(NFDM)and no added emulsifiers was set as the control.Three levels of MPC or RCMPC(each powder containing 85%protein)at 1%,2%,and 3%were incorporated by replacing equivalent amounts of NFDM and keeping other ingredients unchanged.All ice cream treatments were processed with a target overrun of 70%and hardened at−25℃in a blast freezer.Additions of MPC or RCMPC at 1%,2%,and 3%corresponded to increases in protein content of ice cream by 15%,30%,and 45%,respectively.The viscosity of the ice-cream mix increased with increasing levels of MPC or RCMPC.In general,higher protein samples had slower meltdown rate and higher values of hardness and adhesiveness,but the trends were inconsistent.No shrinkage in volume was observed in any ice cream stored at−25℃after 180 days.However,an additional storage stability study revealed that the control showed significant shrinkage after 60 days(−6.5%±1.5%),90 days(−7.1%±1.8%),and 180 days(−7.9%±1.1%)in a typical household-style freezer at−13℃.MPC at 1%also showed significant shrinkage after 180 days,while samples with RCMPC at any levels showed no shrinkage at all.Ice cream manufacturers may consider MPC and RCMPC natural alternatives to synthetic emulsifiers,with RCMPC being more effective than MPC in terms of ice cream storage stability.展开更多
常温再制干酪制品是指经超高温瞬时灭菌(Ultra-high temperature treated, UHT)处理后可常温贮藏的灭菌型干酪制品,是我国乳品工业的新热点。然而,干酪在UHT处理后易失稳发生凝胶结构重构,在贮藏期间出现析水等质构问题,影响产品品质。...常温再制干酪制品是指经超高温瞬时灭菌(Ultra-high temperature treated, UHT)处理后可常温贮藏的灭菌型干酪制品,是我国乳品工业的新热点。然而,干酪在UHT处理后易失稳发生凝胶结构重构,在贮藏期间出现析水等质构问题,影响产品品质。为阐明蛋白原料对常温再制干酪制品析水性的影响及机制,筛选了3种不同的蛋白原料:膜过滤酪蛋白胶束、浓缩牛奶蛋白、凝乳酶酪蛋白,分析其蛋白质含量、组成以及粒径、电位、水合性和钙离子分布等理化特性,进而分析了蛋白原料对常温再制干酪制品析水性和质构特性的影响规律,并从水分分布和微观结构层面解析蛋白原料对常温再制干酪制品析水性的影响机制。结果表明:3种蛋白原料的蛋白质含量和组成存在显著差异,浓缩牛奶蛋白的乳清蛋白占总蛋白质量分数比膜过滤酪蛋白胶束高7.81个百分点,而凝乳酶酪蛋白中不含乳清蛋白;在水合性方面,浓缩牛奶蛋白和膜过滤酪蛋白胶束相近,均显著高于凝乳酶酪蛋白。蛋白原料显著影响常温再制干酪制品析水性,贮藏90 d时,由凝乳酶酪蛋白制备的常温再制干酪制品析水率最高,而由浓缩牛奶蛋白制备的常温再制干酪制品的析水率最低,表面析水率和离心析水率分别为0.42%和1.10%。水分分布和微观结构结果显示,蛋白原料通过影响干酪制品中水分的存在状态和三维网络空间结构,从而影响常温再制干酪制品的析水性。研究解析了不同蛋白原料对常温再制干酪制品析水性的影响及机制,为常温再制干酪制品析水性的改善提供了理论依据。展开更多
以脱脂乳为原料,通过超滤、洗滤、离子交换和喷雾干燥制备了脱钙率为0%、11%、19%、27%和37%的浓缩乳蛋白(milk protein concentrate,MPC),并在35℃加速贮藏4个月,采用聚丙烯酰胺凝胶电泳、激光共聚焦、激光粒度仪等方法分析了MPC中可...以脱脂乳为原料,通过超滤、洗滤、离子交换和喷雾干燥制备了脱钙率为0%、11%、19%、27%和37%的浓缩乳蛋白(milk protein concentrate,MPC),并在35℃加速贮藏4个月,采用聚丙烯酰胺凝胶电泳、激光共聚焦、激光粒度仪等方法分析了MPC中可溶性蛋白的含量、组成及其溶解液的微观结构和粒径分布,旨在探讨脱钙程度对MPC溶解性和贮藏稳定性的影响。脱钙MPC的初始溶解度都在95%以上,且随脱钙程度的增加而略有提高。在贮藏过程中,0%脱钙MPC的溶解度显著降低;11%脱钙MPC的溶解度随贮藏时间增加而显著降低;19%~37%脱钙MPC的溶解度在贮藏期内几乎不变。MPC溶解度的降低,主要是由酪蛋白聚集所致。MPC的脱钙率越高,其在水中的分散程度越高,且分散程度随贮藏时间降低的速度越慢。综上所述,当脱钙率达到19%及其以上时,MPC具有良好的溶解性和贮藏稳定性。展开更多
研究了一种由浓缩乳蛋白粉(Milk Protein Concentration Powders,MPC Powders)和难溶性钙盐制备得到的新型钙增强剂(Ca-MPC),通过激光共聚焦扫描显微镜、ζ-电位等表征手段证实了此钙增强剂是蛋白质和难溶性钙盐通过分子间弱相互作用形...研究了一种由浓缩乳蛋白粉(Milk Protein Concentration Powders,MPC Powders)和难溶性钙盐制备得到的新型钙增强剂(Ca-MPC),通过激光共聚焦扫描显微镜、ζ-电位等表征手段证实了此钙增强剂是蛋白质和难溶性钙盐通过分子间弱相互作用形成的复合物,并进一步分析了蛋白质的不同组分与钙盐之间相互作用的差异性。另外,对此类钙增强剂在纯水和蛋白溶液中的分散稳定性进行了考察,结果表明,该钙增强剂在水溶液和蛋白溶液中的悬浮稳定性都有所改善,可作为良好的食品外源性钙补充剂。展开更多
乳蛋白浓缩物(Milk protein concentrate,MPC)是近年来新兴的牛乳蛋白制品,在食品加工中有着广泛的应用。本试验采用薄膜蒸发浓缩牛乳超滤截留液至固形物含量为15.55%,18.17%和26.12%,研究了不同浓缩程度对MPC粉末的粒径,溶解性,流动性...乳蛋白浓缩物(Milk protein concentrate,MPC)是近年来新兴的牛乳蛋白制品,在食品加工中有着广泛的应用。本试验采用薄膜蒸发浓缩牛乳超滤截留液至固形物含量为15.55%,18.17%和26.12%,研究了不同浓缩程度对MPC粉末的粒径,溶解性,流动性和喷流性指数等性质的影响。结果表明,浓缩至超滤截留液固形物含量为26.12%时,MPC具有较好的加工特性。展开更多
文摘Clean label food is a rising consumer trend in the food industry.Milk protein concentrate(MPC)and reduced-calcium milk protein concentrate(RCMPC)could serve as natural emulsifiers and increase the total protein content of ice cream products.The objectives of this study were to determine and compare the effects of MPC and RCMPC on ice cream composition,mix viscosity,storage stability,meltdown rate,and texture.A base formulation with 3%non-fat dry milk(NFDM)and no added emulsifiers was set as the control.Three levels of MPC or RCMPC(each powder containing 85%protein)at 1%,2%,and 3%were incorporated by replacing equivalent amounts of NFDM and keeping other ingredients unchanged.All ice cream treatments were processed with a target overrun of 70%and hardened at−25℃in a blast freezer.Additions of MPC or RCMPC at 1%,2%,and 3%corresponded to increases in protein content of ice cream by 15%,30%,and 45%,respectively.The viscosity of the ice-cream mix increased with increasing levels of MPC or RCMPC.In general,higher protein samples had slower meltdown rate and higher values of hardness and adhesiveness,but the trends were inconsistent.No shrinkage in volume was observed in any ice cream stored at−25℃after 180 days.However,an additional storage stability study revealed that the control showed significant shrinkage after 60 days(−6.5%±1.5%),90 days(−7.1%±1.8%),and 180 days(−7.9%±1.1%)in a typical household-style freezer at−13℃.MPC at 1%also showed significant shrinkage after 180 days,while samples with RCMPC at any levels showed no shrinkage at all.Ice cream manufacturers may consider MPC and RCMPC natural alternatives to synthetic emulsifiers,with RCMPC being more effective than MPC in terms of ice cream storage stability.
文摘常温再制干酪制品是指经超高温瞬时灭菌(Ultra-high temperature treated, UHT)处理后可常温贮藏的灭菌型干酪制品,是我国乳品工业的新热点。然而,干酪在UHT处理后易失稳发生凝胶结构重构,在贮藏期间出现析水等质构问题,影响产品品质。为阐明蛋白原料对常温再制干酪制品析水性的影响及机制,筛选了3种不同的蛋白原料:膜过滤酪蛋白胶束、浓缩牛奶蛋白、凝乳酶酪蛋白,分析其蛋白质含量、组成以及粒径、电位、水合性和钙离子分布等理化特性,进而分析了蛋白原料对常温再制干酪制品析水性和质构特性的影响规律,并从水分分布和微观结构层面解析蛋白原料对常温再制干酪制品析水性的影响机制。结果表明:3种蛋白原料的蛋白质含量和组成存在显著差异,浓缩牛奶蛋白的乳清蛋白占总蛋白质量分数比膜过滤酪蛋白胶束高7.81个百分点,而凝乳酶酪蛋白中不含乳清蛋白;在水合性方面,浓缩牛奶蛋白和膜过滤酪蛋白胶束相近,均显著高于凝乳酶酪蛋白。蛋白原料显著影响常温再制干酪制品析水性,贮藏90 d时,由凝乳酶酪蛋白制备的常温再制干酪制品析水率最高,而由浓缩牛奶蛋白制备的常温再制干酪制品的析水率最低,表面析水率和离心析水率分别为0.42%和1.10%。水分分布和微观结构结果显示,蛋白原料通过影响干酪制品中水分的存在状态和三维网络空间结构,从而影响常温再制干酪制品的析水性。研究解析了不同蛋白原料对常温再制干酪制品析水性的影响及机制,为常温再制干酪制品析水性的改善提供了理论依据。
文摘以脱脂乳为原料,通过超滤、洗滤、离子交换和喷雾干燥制备了脱钙率为0%、11%、19%、27%和37%的浓缩乳蛋白(milk protein concentrate,MPC),并在35℃加速贮藏4个月,采用聚丙烯酰胺凝胶电泳、激光共聚焦、激光粒度仪等方法分析了MPC中可溶性蛋白的含量、组成及其溶解液的微观结构和粒径分布,旨在探讨脱钙程度对MPC溶解性和贮藏稳定性的影响。脱钙MPC的初始溶解度都在95%以上,且随脱钙程度的增加而略有提高。在贮藏过程中,0%脱钙MPC的溶解度显著降低;11%脱钙MPC的溶解度随贮藏时间增加而显著降低;19%~37%脱钙MPC的溶解度在贮藏期内几乎不变。MPC溶解度的降低,主要是由酪蛋白聚集所致。MPC的脱钙率越高,其在水中的分散程度越高,且分散程度随贮藏时间降低的速度越慢。综上所述,当脱钙率达到19%及其以上时,MPC具有良好的溶解性和贮藏稳定性。
文摘研究了一种由浓缩乳蛋白粉(Milk Protein Concentration Powders,MPC Powders)和难溶性钙盐制备得到的新型钙增强剂(Ca-MPC),通过激光共聚焦扫描显微镜、ζ-电位等表征手段证实了此钙增强剂是蛋白质和难溶性钙盐通过分子间弱相互作用形成的复合物,并进一步分析了蛋白质的不同组分与钙盐之间相互作用的差异性。另外,对此类钙增强剂在纯水和蛋白溶液中的分散稳定性进行了考察,结果表明,该钙增强剂在水溶液和蛋白溶液中的悬浮稳定性都有所改善,可作为良好的食品外源性钙补充剂。
文摘乳蛋白浓缩物(Milk protein concentrate,MPC)是近年来新兴的牛乳蛋白制品,在食品加工中有着广泛的应用。本试验采用薄膜蒸发浓缩牛乳超滤截留液至固形物含量为15.55%,18.17%和26.12%,研究了不同浓缩程度对MPC粉末的粒径,溶解性,流动性和喷流性指数等性质的影响。结果表明,浓缩至超滤截留液固形物含量为26.12%时,MPC具有较好的加工特性。
