大豆分离蛋白膜研究

以大豆分离蛋白(SPI)和甘油为成膜基质,研究多聚磷酸钠、羧甲基纤维素钠(CMC–Na)、微波及磷酸化对大豆分离蛋白膜性质影响。结果表明,多聚磷酸钠可显著提高膜的水溶性(ρ0.01)和抗拉伸强度(ρ0.05),显著降低膜的氧气透过性(ρ0.01)和水蒸气透过性(ρ0.05);CMC–Na能显著提高膜抗拉伸强度(ρ0.01)和氧气透过性(ρ0.05),显著降低膜的水溶性、透光率及水蒸气透过性(ρ0.01);微波处理可显著提高膜的抗拉伸强度(ρ0.05),降低膜的水溶性(ρ0.05);磷酸化可显著降低膜的氧气透过性(ρ0.05)、透光率及抗拉伸强度(ρ0.01)。     

微波改性大豆分离蛋白/壳聚糖可食膜工艺优化研究

为研究制备具有优良性能可食膜的方法,以大豆分离蛋白、壳聚糖为成膜基材共同制备可食膜,并利用微波技术对可食膜进行物理改性,研究成膜材料配比、微波功率和微波时间对可食膜断裂伸长率、抗拉强度、水蒸气透过系数影响。通过响应面法进行优化,建立二次多项式回归模型,得出如下结论:m (SPI)︰m (CS)=1.69︰1、微波功率222 W、微波时间9.06 min,此时SPI/CS可食膜各项性能较好,抗拉强度为21.32 MPa,断裂伸长率为27.12%,水蒸气透过系数为0.59×10~(-12) (g·cm~(-1)·s~(-1)·Pa~(-1))。由于微波处理作用,可食膜机械性能显著增加,膜的阻水性能也得到提高,研究结果为可食膜生产及应用提供参考。     

工艺条件对酶法改性大豆蛋白膜性能的影响（Ⅰ）

研究了酶浓度、成膜溶液的pH值、干燥温度等工艺参数对谷氨酰胺转移酶(TGase)改性大豆分离蛋白(SPI)膜性能的影响.SPI膜制好后裁切成所需要的样品形状,放在相对湿度为50%的环境中平衡48 h,测定抗拉强度(TS)、断裂伸长率(EB)、水分含量(MC)、总可溶性物质量(TSM)、表面疏水性(S0)及透光率等各项指标.研究表明低浓度的酶浓度改性可显著(P≤0.05)增加SPI膜的TS值和S0值,而降低TSM值.TGase改性使EB值下降,酶浓度越高,EB值下降得越多.TGase改性膜的S0值和TSM值随着酶浓度的增加而增加.成膜溶液的PH值显著影响TGase改性SPI膜的TS值和S0值.TGase改性SPI膜的TS值、EB值和S0值随着干燥温度从18℃增加到50℃而逐渐下降.     

青香蕉微波干燥中淀粉糊化行为及消化特性的研究

明确微波干燥（Microwave drying, MD）过程中青香蕉水分迁移与其淀粉糊化行为的关系及其对淀粉消化特性的作用,以青香蕉片为研究对象,设计不同微波功率密度,研究青香蕉MD干燥特性、淀粉糊化行为及消化特性的变化。结果表明微波功率密度和MD时间对青香蕉中淀粉糊化行为和消化特性影响显著。当青香蕉含水率高于45%,在MD过程中,高微波功率密度和高含水率可促进青香蕉中的淀粉糊化;当含水率降低到45%以下,含水率和微波功率密度对香蕉中淀粉糊化程度无显著影响（P>0.05）。当微波功率密度为2~8 W/g时,青香蕉中的抗性淀粉（Resistant starch, RS）含量与淀粉糊化程度、快消化淀粉（Rapidly digestible starch,RDS）含量呈极显著负相关（P<0.01）;而当微波功率密度为2 W/g和4 W/g时,慢消化淀粉（Slowly digestible starch,SDS）含量与淀粉糊化程度呈极显著正相关（P<0.01）,青香蕉中的淀粉糊化可显著促进SDS的形成,SDS含量最高可达53.90%。因此,微波干燥青香蕉可以通过调节MD微波输出功率和时间,调控青香蕉中淀粉的糊化程度,抑制RS向RDS转化,促进SDS的形成,降低RDS的含量。研究结果为MD高效保留青香蕉中抗性淀粉或提高慢消化淀粉提供理论基础及科学依据。     

不同脱涩处理对中田大山楂采后贮藏品质的影响

为研究不同脱涩处理对中田大山楂采后贮藏品质及脱涩效果的影响。以清水浸泡+20 ℃恒温贮藏为对照组,以40%酒精溶液浸泡+30 ℃恒温贮藏、0.25%乙烯利溶液浸泡+30 ℃恒温贮藏和清水浸泡+30 ℃恒温贮藏为3个不同的处理组,通过测定中田大山楂硬度、可溶性固形物、可滴定酸、总糖、类黄酮、单宁含量等指标的变化来分析山楂采后贮藏品质的变化。结果表明: 不同脱涩处理中,40%酒精溶液浸泡+30 ℃恒温贮藏处理在不明显破坏山楂果实贮藏品质的条件下（硬度、可溶性固形物和可滴定酸等变化虽然快于对照组,但显著慢于其他两个处理组）,加速了果实中可溶性单宁向不可溶性单宁转化且效果最明显（15 d可溶性单宁含量显著低于对照组（P<0.05）,为对照组的9.5%）,进而达到良好的脱涩效果,为乙醇脱涩在水果加工中提供了良好的应用前景;相关性分析中,单宁与硬度、可滴定酸和可溶性固形物呈极显著正相关（P<0.01）,与总糖、固酸比、糖酸比呈极显著负相关（P<0.01）,与类黄酮呈显著负相关（P<0.05）,说明实验设计中的指标不仅可以反映山楂的贮藏品质,也可在一定程度上从侧面反映山楂可溶性单宁的变化。主成分分析中,40%酒精溶液浸泡+30 ℃恒温贮藏处理组,脱涩效果最佳。     

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。     

微波处理对植物蛋白基可食膜特性改善效果的研究

通过微波处理以谷朊粉（WG）、大豆分离蛋白（SPI）为主要成膜原料的可食保鲜膜，研究其对可食膜特性的改善作用，结果表明微波处理能有效改良三种膜的机械性能、感官性能及通透性，特别是对WG／SPI膜的改良效果最好。利用扫描电子显微镜对微波处理前后蛋白膜的微结构进行研究，微波处理对膜的微结构有明显的改善作用，可使膜表面更光滑平整，使膜的横截面更均匀、规则、致密，其中对WG／SPI膜的改善效果最明显。经微波处理后WG膜、SPI膜、WG／SPI膜的横截面微结构接近。微波处理后膜的结构改善效果与膜的外观、机械性能、通透性的改善效果一致。     

成膜介质和还原剂对大豆分离蛋白膜性能的影响

研究了成膜介质和还原剂对大豆分离蛋白膜(SPI)性能的影响。结果表明,大豆分离蛋白在自制玻璃板上成膜效果最好;亚硫酸钠可明显提高SPI膜的抗拉强度,对透气度和透光率影响不显著;添加0.1%亚硫酸钠的SPI膜抗拉强度最大,超过0.1%,抗拉强度下降明显。     

冷冻蛋糕的微波烘焙技术特性

文中对冻藏时间(0、2、4、6周)、冻融循环次数(0、1、2、3次,数字代表冻融循环次数)、微波烘焙功率(40%和100%)和储藏时间(0、1、3、6和24h)对冷冻面糊微波烘焙蛋糕含水量、硬度、比容、水分损失及可溶性淀粉含量等进行了研究。结果发现:随冻藏时间延长,蛋糕含水量和比容显著降低,硬度显著增大,冻融循环过程明显加剧了这些影响;微波烘焙功率越大,蛋糕含水量显著降低,比容和硬度显著增大。在储藏过程中,蛋糕硬度和水分损失都显著增加,可溶性淀粉含量显著减少;微波烘焙功率较大时,硬度和水分损失增加的明显更快,可溶性淀粉含量降低的明显更迅速;储藏过程中蛋糕硬度变化与水分损失、可溶性淀粉含量均成正相关,相关系数分别为0.93和0.86。结果说明:(1)较小的微波烘焙功率(40%)比较高的微波烘焙功率(100%)会生产出更好的冷冻面糊蛋糕,且其老化速率相对较低,(2)冷冻面糊微波蛋糕的老化主要是由于水分损失和淀粉重结晶引起的。     

燕麦营养成分与燕麦片加工品质相关性研究

以56份燕麦原粮为研究对象,检测了燕麦主要营养成分及燕麦片加工品质指标,分析了它们之间的相关关系。结果表明燕麦的a~*值、直链淀粉含量和脂肪含量及燕麦片a~*值、黏度和汤汁可溶性固形物等指标受品种影响较大。皮燕麦脂肪含量和β-葡聚糖含量显著低于裸燕麦(P<0.05),皮燕麦片常温吸水率和b~*值显著高于裸燕麦片(P<0.05),但L~*值显著低于裸燕麦片(P<0.05)。燕麦片色泽与燕麦色泽呈极显著正相关(P<0.01)。燕麦中蛋白质含量、直链淀粉含量、灰分和纤维素含量越高,燕麦片的吸水率、汤汁可溶性固形物含量和黏度就越高。脂肪和总淀粉含量越高,燕麦片的吸水率、汤汁可溶性固形物含量和黏度就越低。蛋白质的含量不仅明显影响燕麦片的高温吸水率和黏度,对其冲泡性也有明显影响。     

Mechanical and barrier properties of biodegradable soy protein isolate-based films coated with polylactic acid

Polylactic acid (PLA)-coated soy protein isolate (SPI) films were prepared by dipping SPI film into PLA solution. The effects of coating on improvements in mechanical and water barrier properties of the film were tested by measuring selected film properties such as tensile strength (TS), elongation at break (E), water vapor permeability (WVP), and water solubility (WS). TS of SPI films increased from 2.8±0.3 up to 17.4±2.1 MPa, depending on the PLA concentration of the coating solution, without sacrificing the film's extensibility. In contrast, the extensibility of SPI film coated with solution containing more than 2 g PLA/100 ml solvent, increased. WVP of PLA-coated SPI films decreased from 20 to 60 fold, depending on the concentration of PLA coating solution. Water resistance of SPI films was greatly improved as demonstrated by the dramatic decrease in WS for PLA-coated films. The improvement in water barrier properties was mainly attributed to the hydrophobicity of PLA.     

Heat Curing of Soy Protein Films at Selected Temperatures and Pressures

Vacuum and temperature effects on moisture content, water vapor permeability (WVP), color (L, a, b, and ΔE), tensile strength (TS), elongation (E), and total soluble matter (TSM) of soy protein isolate (SPI) films were examined. SPI films were cured at 60, 72.5, or 85 °C and at 101.3, 81.32, or 61.32 kPa for 24 h. As a result of heat-curing moisture content, WVP, E, and TSM decreased, and total color difference and TS increased. Pressure, individually and interactively with temperature, significantly affected film moisture content, TS, and TSM.     

Physical and mechanical properties of water resistant sodium alginate films

Properties of sodium alginate films were modified using two different methods of CaCl₂ treatment, i.e. the direct addition of CaCl₂ into film making solution (mixing films) and the immersion of alginate films into CaCl₂ solutions (immersion films), and their treatment effects on tensile strength (TS), percentage elongation at break (E), water vapor permeability (WVP), and water solubility (WS) of the films were investigated. TS and E of the mixing films were not changed considerably, but those of the immersion films changed considerably with significant (P<0.05) increase in TS and decrease in E. WVP of the immersion films decreased significantly (P<0.05), but that of the mixing films did not decreased. Water resistance measured by WS was not improved with the mixing films, but the alginate films became water resistant when they treated by immersing in higher than 2 g/100 ml CaCl₂ solutions. Water adsorption by the films also decreased in the immersion films. Swelling ratio (SR) of the immersion film decreased with temperature without affecting WS of the films.     

低温储藏条件对大豆分离蛋白膜理化特性的影响

以大豆分离蛋白为原料制得可食性膜,研究在不同低温储藏条件下其功能特性,包括机械性能和阻隔性能的变化。结果显示:随冷藏温度的升高,其功能特性变化较为缓慢。而随冻藏温度的降低,断裂延伸率下降尤为明显,抗拉强度和脂质阻隔能力变化趋势次之,水蒸气透过率升高缓慢。冷藏时间与断裂延伸率呈显著正相关(p<0.05)。冷藏时间与水蒸气透过率和油脂渗透系数均呈极显著正相关(p<0.01)。冻藏时间与水蒸气透过率和油脂渗透系数呈显著正相关(p<0.05)和极显著正相关(p<0.01)。     

改性处理对大豆分离蛋白/壳聚糖/黑木耳多糖复合膜性质的影响

利用超声波、微波、紫外光及其协同改性制备大豆分离蛋白、壳聚糖、黑木耳多糖复合膜,研究不同改性方法对膜性质影响。结果表明：超声波、微波、紫外光改性处理可改善膜的机械性能、阻隔性能,其中超声波微波协同改性作用最明显,膜的抗拉强度和断裂伸长率达到最大值（21.67 MPa和78.02%）;水蒸气透过系数和氧气透过率达到最小值（1.34×10－12 g/（cm·s·Pa）、0.47×10－2 g/（m2·d））。超声波微波协同改性亦可显著增加膜的亮度和白度,提高膜的透光率。利用扫描电子显微镜、傅里叶变换红外光谱和热重分析对复合膜进行表征,表明经过超声波、微波、紫外光改性处理加强了膜分子间氢键作用,形成致密、稳定的网络结构,提高了复合膜热稳定性。     

Development and characterization of cassava starch and soy protein concentrate based edible films

The sensory attributes, mechanical, water vapour permeability (WVP) and solubility properties of cassava starch and soy protein concentrate (SPC)‐based edible films of varying levels of glycerol were studied. Addition of SPC and glycerol up to 30% and 20%, respectively, reduced stickiness and improved colour and appearance of the films. Tensile strength (TS), elastic modulus (EM) and elongation at break (EAB) of films increased, while film solubility (FS) and WVP decreased with SPC and glycerol up to 50% and 20% level, respectively, ranging from 20.33 to 26.94 MPa (TS), 41.33 to 72.76 MPa (EM), 7.90 to 12.28 MPa (EAB), 15.07 to 31.90% (FS) and 2.62 to 4.13 g H₂O mm m^?2 day kPa (WVP). The TS, EAB and WVP were higher for the biofilms than for low‐density polyethylene and cellophane films.     

Heat Curing of Soy Protein Films at Atmospheric and Sub-atmospheric Conditions

ABSTRACT: The effect of heat curing at atmospheric or subatmospheric conditions on selected properties (moisture content, water vapor permeability (WVP), color, tensile strength (TS), elongation (E), and total soluble matter (TSM) content) of cast soy protein isolate films was investigated. Films were heat cured at 85 °C for 6, 12, 18, or 24 h at absolute pressures of 101.3, 81.32, or 61.32 kPa. Heat-cured films had increased (P < 0.05) TS and decreased (P < 0.05) WVP and E compared to control, unheated films. Heat treatment under vacuum reduced the WVP of films faster than heat curing at atmospheric pressure. High TS values, low E values, and low TSM values were also reached within short heating time under vacuum. However, vacuum treatment increased the size and number of cavities in cured films as evidenced by scanning electron micrographs.     

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     

Water Solubility, Mechanical, Barrier, and Thermal Properties of Cross-linked Whey Protein Isolate-based Films

Water solubility, hermal properties, tensile strength, percent elongation, oxygen permeability (OP), water‐vapor permeability (WVP) of cross‐linked glycerol plasticized whey protein isolate films were studied to determine the effect of cross‐linkers (glutaraldehyde, formaldehyde, dialdehyde starch, carbonyldiimidazole, and UV irradiation) on film properties. With the exception of UV treatment, solubility of the films decreased (P>0.05) upon treatment of the film‐forming solutions with chemical cross‐linkers. Tensile strength increased (P>0.05), whereas percent elongation was not affected by cross‐linking. Chemical cross‐linking increased (P>0.05) WVP and decreased (P>0.05) OP of the films. UV treatment had no effect on WVP and O P. With the exception of UV‐treated films, both onset temperature and degradation temperatures, as determined by differential scanning calorimetry, were increased upon cross‐linking.