阿魏酸对可食性大豆蛋白膜理化特性的影响

用大豆分离蛋白制备可食性包装膜时，在成膜溶液中添加阿魏酸能增加膜的抗拉强度和断裂伸长率，降低膜的水蒸气透性，并减少甘油用量、提高膜的抗氧化性能。阿魏酸的最适添加量为100mg／100g。其主要机理是阿魏酸与蛋白质的某些氨基酸反应而增加了蛋白质的交联度。由于阿魏酸与蛋白质反应后吸收峰红移，暗示阿魏酸的添加有利于膜防止短波辐射，延长食品保质期。     

Water Vapor Permeability and Mechanical Properties of Soy Protein Isolate Edible Films Composed of Different Plasticizer Combinations

Water barrier and mechanical properties were measured for soy protein isolate (SPI) films plasticized with glycerol (GLY) and 1 of the plasticizers (propylene glycol [PG], polyethylene glycol [PEG], sorbitol [SOR], or sucrose [SUC]) at a ratio of 25:75, 50:50, 75:25, and 0:100. Plasticizer type as well as the plasticizer ratio in the GLY: plasticizer mixtures affected the film water barrier and mechanical properties. An addition of as little as 25% of a less hygroscopic plasticizer in the mixture induced significant reduction in water vapor permeability (WVP) of SPI films. However, at least 50% of the mixture needs to be GLY to show significant improvement in tensile strength (TS). From our experimental design, 50:50 GLY:SOR was the recommended combination because of its comparatively low WVP value and relatively high flexibility and strength. Incompatibility of GLY:PEG plasticizer mixture in SPI film was observed by surface migration of PEG from the film matrix.     

可食性大豆复合蛋白膜的研究

可食性大豆蛋白膜是指以大豆分离蛋白为主要原料,添加增塑剂、交联剂等物质,通过不同分子间的相互作用而形成的复合薄膜。与合成包装材料相比,可食性膜能被生物降解,无污染,还可以作为食品风味料、营养强化剂的载体。文中以大豆分离蛋白、瓜尔豆胶、硬脂酸为基质,制备复合型可食性膜。研究结果表明:水与乙醇的体积比、瓜尔豆胶含量、硬脂酸含量对复合膜的性能有较大影响,制备大豆蛋白复合膜技术条件为,大豆分离蛋白浓度为5.0%,水与乙醇体积比为80∶20,瓜尔豆胶加量为0.25%,硬脂酸加量为0.3%。     

可食性大豆分离蛋白膜的研究进展

随着人们对环境保护和食品安全的日益重视，在食品包装材料的开发上正发生较大变革，其中，可食性包装材料的研究特别引人注目。本文简单介绍了可食性大豆分离蛋白(SPI)膜的成膜机理、营养特性、机械特性、透气特性等，并综述了国内外在改善膜的应用特性方面取得的积极进展。     

大豆分离蛋白膜的DSC分析

采用差示扫描量热法(DSC),研究不同相对湿度(RH)条件下,大豆分离蛋白(SPI)膜的热特性以及谷氨酰胺转移酶(TGase)改性对热特性的影响。对于SPI膜,无论是对照膜还是TGase改性膜,蛋白膜的热稳定性随着RH的增高而下降。TGase改性改变了SPI膜吸热峰出现的位置与数量。在同一RH条件下,TGase改性膜更易失去水分。TGase改性使SPI膜的耐热特性基本未变。     

大豆分离蛋白可食膜的生产工艺及性能表征

选用大豆分离蛋白为原料,以卡拉胶添加量、甘油添加量、pH值和料液比为影响因素做正交试验,得到大豆分离蛋白膜的最佳配方。结果表明：以大豆分离蛋白为基数,卡拉胶添加量8%,甘油0.4mL/g,料液比1:15(g/mL),调节pH值到7.0时大豆分离蛋白膜的性能最佳。最佳工艺条件下测得大豆分离蛋白膜的水溶性为32.7%,水蒸气透过系数为2.348g ·mm/(m2 ·h ·kPa),抗拉强度为7.192MPa,断裂伸长率为128.1%。最佳膜的电镜分析结果：大豆分离蛋白分子在膜上的分布较均匀,一定程度上影响了膜的阻水性能,可以采用均质等方法加以改进,使大豆分离蛋白分子更好的分散在膜的表面,从而使膜具有更强的阻水性。     

还原剂影响可食性大豆分离蛋白膜性能的研究

研究了还原剂对可食性大豆分离蛋白 (SPI)膜性能的影响。结果表明 ,还原剂可明显提高SPI膜的抗拉强度 (TS) ,降低水蒸气迁移系数 (WVP) ,但伸长率 (E)有所下降。添加还原剂的SPI膜在 pH 7时机械强度和阻隔性最好 ,其中添加半胱氨酸的SPI膜 TS最大 ,为14.4 8MPa ,WVP最小 ,为 4 .6 1g·mm/m2 ·d·kPa     

Properties of Edible Films from Total Milk Protein

The mechanical properties and water vapor permeability of edible films made from various total milk proteins (TMPs) were investigated. Two TMPs obtained from nonfat dry milk (NDM) by removing lactose and three TMPs obtained from a commercial source were studied. Lactose was extracted from NDM by ultrafiltration or suspension in ethanol followed by filtration. TMP concentrate obtained by ultrafiltration (UF) produced films with the lowest water vapor permeability (WVP) and the highest tensile strength at break. Commercial TMP concentrates produced films more ductile than those from the UF-TMP or retentate from ethanol extraction. Further research is needed to improve mechanical properties of UF-TMP films without increasing the WVP.     

大豆分离蛋白食品包装薄膜的制备条件研究

以大豆分离蛋白为主要原料,在一定条件下与增塑剂、还原剂等发生共价交联反应,通过单因素试验和正交试验对成膜配方、成膜条件的研究,及薄膜理化指标的测定和微观结构分析,制备出可以降解,并具有一定机械强度、弹性、阻气性、阻水性的复合蛋白薄膜。结果表明：采用亚克力材质板槽制膜,干燥温度60℃,时间2h,成膜配方是大豆分离蛋白质量浓度4.0g/100mL、增塑剂2.0g/100mL、还原剂0.1g/100mL;抗拉强度可达61.892N,透H2O 性16.204mg/(cm2·d),透O2 性0.313mg/(cm2·d),透CO2 性2.899mg/(cm2·d)。该产品可部分替代塑料用于食品包装领域,减少环境污染,是一种具有开发前景的绿色包装材料。     

可食性大豆分离蛋白膜的制膜工艺研究

以大豆分离蛋白为成膜主料,添加增塑剂甘油、还原剂Na 2SO3制备大豆分离蛋白膜,研究了其实验室和工业化制膜工艺及其参数.结果表明,大豆分离蛋白膜的实验室制膜工艺参数为:大豆分离蛋白加水溶解,加热,同时采取桨式搅拌,搅拌速度为180r/min,加0.06%食用消泡剂对膜液进行消泡,在涂有0.05ml/100cm 2吐温80的不锈钢板上刮板成膜,在60℃下热风干燥2.0h,均湿,揭膜,贮存.工业化制膜工艺参数为:大豆分离蛋白在夹层锅中加水溶解,加热,同时搅拌,搅拌速度为30r/min,在紫铜带上成膜,紫铜带转速为1.5r/min,烘缸中通入蒸汽加热,蒸汽压力为0.25MPa(表压),卷膜,包装,贮存.该工艺已中试成功,可扩大生产.     

乳化剂提高大豆分离蛋白可食性膜性能的研究

比较11种乳化剂对大豆分离蛋白膜抗拉伸强度、断裂伸长率、水蒸气透过率和O_2透气量的影响效果,结果显示蜂蜡和斯潘20对大豆分离蛋白膜具有最佳改善效果.进一步研究这两种乳化剂单一添加及复合使用时对膜综合性能的影响,同时测定膜表面接触角、成膜溶液中巯基及二硫键数量优化乳化剂使用量,最终获得复合使用两种乳化剂时,大豆分离蛋白膜性能改善效果明显,其添加量为蜂蜡0.0845%,斯潘200.506%,甘油1.335%.     

豆渣蛋白质的提取

本文在测定豆渣化学组成及豆渣蛋白等电点的基础上，采用简单工艺提取豆渣蛋白，粗蛋白得主继９０％以上，蛋白中必需氨基酸齐全，可以替代部分动物蛋白，具有营养高，成本低，价格廉等优点。     

谷氨酰胺转移酶对大豆分离蛋白成膜性能的影响

研究了谷氨酰胺转移酶（TGase）对大豆蛋白膜特性的影响。研究表明：在成膜溶液中加入TGase（4U／g）可以使膜的抗拉强度增加16．79，6，表面疏水性增加39．2％，同时也明显降低了膜的断裂伸长率、水分含量、总可溶性物质量及透光率，但是对水蒸气转移速率几无影响。扫描电镜（SEM）显示，酶法交联膜的表面比对照膜略为粗糙，断面却更为均匀致密。SDS-PAGE分析表明，TGase催化SPI产生了共价交联。     

Ultraviolet Radiation Affects Physical and Molecular Properties of Soy Protein Films

Films were cast from heated, alkaline aqueous solutions of soy protein (5 g/100 mL water) and glycerin (50% w/w of protein). Control and ultraviolet (UV) irradiated (13.0, 25.9,38.9, 51.8, 77.8, or 103.7 J/m²) films were evaluated for tensile strength (TS), elongation at break (E), water vapor permeability (WVP), and Hunter L, a, and b color values. TS increased (p<0.05) linearly while E decreased linearly with UV dosage. WVP was not affected (P>0.05) by UV irradiation. UV treatment intensified the yellowish coloration of films (increased +b values). SDS-PAGE patterns for UV-treated samples revealed bands of aggregates, increasing in intensity with UV dosage, which were absent in control samples. These changes suggested UV-induced cross-linking in films.     

增塑剂对大豆蛋白可食膜特性的影响

研究了增塑剂对大豆分离蛋白膜(热法成膜和酶法成膜)成膜特性的影响。增塑剂的种类(甘油、山梨醇或甘油山梨醇的等量混合物)对大豆分离蛋白膜的性能有明显影响。无论是否添加谷氨酰胺转移酶(TGase)，以山梨醇为增塑剂的膜都具有最高的抗拉强度、表面疏水性和总可溶性物量，最低的断裂伸长率、水分含量和透光率。TGase处理SPI(4U／g．蛋白)，可显著改善蛋白膜的抗拉强度和表面疏水性，抗拉强度和表面疏水性分别比对照膜增加10％～20％和17％～56％(P≤0.05)；同时也明显降低了(P≤0.05)膜的断裂伸长率、水分含量、总可溶性物量及透光率。     

大米蛋白的可食用膜

研究了大米蛋白可食用膜的工艺条件，并测定了膜的抗拉强度、延伸率和透水率．实验表明，大米蛋白的质量浓度为5g／dL，甘油的添加量为3g／dL，谷氨酰胺转胺酶的添加量为质量浓度0．2g／dL，反应时间为90min，膜液在80℃处理40min后能得到性能比较好的膜。     

Lipid Addition to Improve Barrier Properties of Edible Starch-based Films and Coatings

ABSTRACT: Effects of formulation (lipid presence, type of starch, and plasticizer) on microstructure, water vapor (WVP) and gas (GP) permeabilities of films and coatings were analyzed. Plasticizer was necessary to maintain film and coating integrity and to avoid pores and cracks. Films made from high amylose starch showed lower WVP and GP than regular corn starch films; permeabilities of films with sorbitol (20 g/L) were lower than those with glycerol. The addition of 2g/L sunflower oil to the formulations decreased WVP of starch-based films; X-ray diffraction and Differential Scanning Calorimetry experiments demonstrated that films with plasticizer and lipid showed lower crystalline-amorphous ratio compared to films without additives. Microstructural observations helped explain the decrease of the film permeabilities during storage.     

不同pH下阿魏酸对大豆分离蛋白膜性能的影响

本文报道了阿魏酸、pH及碱液等对大豆分离膜的的影响。以大豆分离蛋白为主要基质的成膜溶液调pH、热处理后铺板干燥，揭膜，在相对湿度为52％的室温环境下平衡48h后测定膜的抗拉强度、断裂伸长率、水蒸气透性、颜色等。结果表明，大豆蛋白膜的断裂伸长率随pH的升高而增加，抗拉强度在中性pH以上时也是随pH升高而增加；阿魏酸的添加可显著增加膜的拉伸张力和断裂伸长率，但也使膜的颜色变深；阿魏酸还使我们可以在成膜溶液pH为中性时制备具有较强抗拉强度的膜：加阿魏酸100、200、300mg(此用量分别相当于大豆分离蛋白的2％、4％、6％)将成膜溶液pH调为7．0,与对照相比，可使断裂伸长率提高24．2％～54．4％，抗拉强度提高62．5％～94．3％。     

Stable Clouding Agent from Isolated Soy Protein

In a dilute suspension the stability of soy protein particles equalled or surpassed that of orange juice prepared from concentrate during short-term storage at 4°C. Soluble soy protein produced a stable cloud only when soluble pectin was present in the incubation medium as the particles were forming. In the absence of soluble pectin the nascent soy protein particles rapidly aggregated. This soy protein based clouding agent may provide a natural and healthy alternative to oil-derived clouding agents. The stabilization of such suspended soy protein particles also provides a model system that may be comparable to orange juice cloud for stability studies.