大豆蛋白和羧甲基葡甘聚糖共混膜的制备和性能

为了提高大豆蛋白膜的机械和阻湿性能,制备了大豆分离蛋白/羧甲基葡甘聚糖共混膜。用红外光谱、透光率测试、扫描电镜测定表征了其结构,测试了共混膜的力学、抗潮、阻气等性能。结果表明,大豆分离蛋白与羧甲基葡甘聚糖有良好的相互作用,共混膜的力学性能、抗潮性能及阻气性能均有明显提高,其中拉伸强度较羧甲基葡甘聚糖提高了117.6%,吸湿增重较羧甲基葡甘聚糖下降了19.02%,透湿系数下降了40.97%。     

Physical‐Mechanical Properties of Agar/κ‐Carrageenan Blend Film and Derived Clay Nanocomposite Film

Abstract: Binary blend films with different mixing ratio of agar and κ‐carrageenan were prepared using a solution casting method with and without nanoclay and the effect of their composition on the mechanical, water vapor barrier, and water resistance properties was tested. The tensile strength (TS) of the κ‐carrageenan film was greater than that of agar film. The water vapor permeability (WVP) of the agar film was lower than that of κ‐carrageenan film, the swelling ratio (SR) and water solubility (WS) of κ‐carrageenan film were higher than those of agar film. Each property of the binary blend films varied proportionately depending on the mixing ratio of each component. The XRD result indicated that the nanocomposite with agar/κ‐carrageenan/clay (Cloisite^® Na⁺) was intercalated. Consequently, the mechanical strength, water vapor barrier properties, and water contact angle (CA) were significantly (P < 0.05) improved through nanocomposite formation.     

蜂蜡和甘油含量对大豆蛋白膜机械性能和阻隔性能的影响

研究添加蜂蜡(质量分数分别为1%、2%、3%、4%、6%、8%和10%)和甘油(质量分数分别为40%和50%)交互作用对大豆蛋白膜机械性能和阻隔性能的影响。结果表明,蜂蜡以固体小颗粒的状态分散于大豆蛋白膜中,能够提高大豆蛋白膜的抗张强度、氧气透过率、阻水性能和表面接触角,降低水蒸气透过率以及断裂延伸率。甘油浓度升高有助于蜂蜡与大豆蛋白分子相结合,提高大豆蛋白膜的综合性能。     

Effect of calcium and sodium caseinates on physical characteristics of soy protein isolate–lipid films

The effect of addition of caseinates to soy protein isolated (SPI) based films containing lipids (33% of oleic acid or 85:15 oleic acid (OA)–beeswax blend (BW)) on water vapour permeability (WVP), mechanical and optical properties was evaluated. SPI–lipids was combined with caseinates (sodium or calcium) in different SPI:caseinate ratios with the aim of improving water vapour barrier, mechanical and optical properties of SPI films containing lipids. Caseinate incorporation to SPI based films provoked an increase of elastic modulus and tensile strength at break, mainly for calcium caseinate. Both caseinates contributed to increase the water vapour barrier properties of soy protein-based films. Caseinates also provoked an increase of transparency of SPI based films and colour softening. The most effective combination was 1:1 sodium caseinate:SPI ratio, when film contains 85:15 oleic acid:beeswax ratio.     

Characterization of quinoa protein–chitosan blend edible films

Quinoa protein/chitosan films were obtained by solution casting of blends of quinoa protein extract (PE) and chitosan (CH). Films from a PE/CH blend were characterized by FTIR, X-ray diffraction, thermal analysis, and SEM. The tensile mechanical, barrier, and sorption properties of the films were also evaluated. The blend of PE with CH yielded mechanically resistant films without the use of a plasticizer. The film had large elongation at break, and its water barrier properties showed that they were more hydrophilic than CH film. The thickness and water-vapor permeability of PE/CH (v/v) 1/1 blend film increased significantly compared to pure CH films. CH films are translucent in appearance and yellowish in blend with PE. By blending anionic PE with cationic CH an interaction between biopolymers was established with different physicochemical properties from those of pure CH. Drying and sorption properties show significant differences between PE/CH blend film and CH film. The structural properties determined by XRD, FTIR and TGA showed a clear interaction between quinoa proteins and CH, forming a new material with enhanced mechanical properties.     

Mechanical properties and water vapor permeability of edible films made from fractionated soy proteins with ultrafiltration

Soy protein isolates (SPI) were fractionated by ultrafiltration unit equipped with 100 and 300 kDa cutoff size membranes. Glycerol-plasticized fractionated soy protein films were developed by casting methods. Mechanical, moisture barrier and physical properties of films, as affected by molecular weight of soy protein fraction, were investigated. Tensile strength and percent elongation at break of films increased with molecular weight of soy proteins. However, molecular weight variation did not influence the water vapor barrier properties of films. Protein solubilities of fractionated films were in the range of 3.5-4.6 g/100 g of dry film, whereas 11.9 g of proteins were solubilized from 100 g of dry SPI film. Hunter b value of fractionated protein films decreased with molecular weight of soy protein.     

热压成型工艺对黄麻／大豆分离蛋白复合材料降解性能的影响

采用热压成型工艺制备黄尉大豆分离蛋白完全可降解复合材料,利用正交试验以质量损失率和拉伸强度损失率为优化指标,研究热压成型工艺因素——成型温度、成型压强和成型时间对复合材料降解性能的影响。试验结果表明,黄彬大豆分离蛋白复合材料的成型温度对其降解性能影响最大,成型压强和成型时间影响较小;在成型温度100℃、成型压强9MPa...     

Effect of glycerol on the physicochemical properties of films based on legume protein concentrates: A comparative study

The overall goal of this research was to examine the mechanical, water vapor barrier properties and opacity of films prepared using legume protein concentrates (faba bean, pea, lupin, lentil, and soy) as a function of glycerol concentration (50, 75, or 100% [wt/wt]—relative to the protein weight). Overall, tensile strength (TS) decreased with increasing glycerol concentration, whereas tensile elongation (TE) and water vapor permeability (WVP) increased with increasing glycerol concentration. Film opacity was independent of glycerol concentration. The effect of protein‐type varied considerably depending on the functional property of the film being measured; TS was greatest with faba bean and lowest with lupin, whereas TE was highest for pea, and lowest for soy. Lentil protein films had considerably higher WVP, at the 100% glycerol concentration, as compared to the other protein concentrates. Findings from this study indicate that legume protein concentrates are capable of forming biodegradable, edible films. Overall, pea protein concentrate films showed the most promise for application in terms of strength, elongation, and moisture barrier properties.     

pH和AOT添加物对大豆分离蛋白基生物可降解膜机械性能的影响

运用响应面分析法分析了pH和AOT(琥珀酸二异辛酯磺酸钠)添加物对大豆分离蛋白(SPI)基生物可降解膜机械性质的影响,确定了影响该种膜机械性能的最优工艺参数。测试的膜的机械性质包括抗拉强度、穿刺强度、断裂伸长率。分析结果表明,在pH为8.795,AOT的添加量为13.00%时,膜的综合机械性能达到最优。     

Physical and Mechanical Properties of Pea-Protein-based Edible Films

ABSTRACT: Edible films produced from denatured pea protein concentrate (PPC) solution possessed the strength and elasticity to resist handling. Increasing the concentration of the plasticizer (glycerol) in the film decreased tensile strength and elastic modulus, and increased elongation and water vapor permeability (WVP). Very strong and stretch-able films were obtained from 70/30 and 60/40 of PPC/glycerol composition, respectively. The low WVP value was maintained over a range of glycerol concentration from 20% to 40%, in the dry film. Film solubility was not affected significantly by the amount of the plasticizer. The physical and mechanical properties of the PPC films were comparable with those of soy protein and whey protein films.     

Sorption Characteristics of Soy Protein Films and their Relation to Mechanical Properties

Effects of plasticizers (glycerol, sorbitol, and 1:1 mixture of glycerol and sorbitol) on moisture sorption characteristics of hydrophilic soy protein isolate (SPI) films were investigated at three levels of plasticizer concentration (0.3, 0.5, and 0.7 g plasticizer/g SPI). The combined effects of relative humidity and plasticizer on mechanical properties of soy protein films were also examined. Moisture affinities of soy protein films were affected by hydrophilicity of plasticizer and its concentration. Under given RH conditions, films with higher glycerol ratio absorbed more moisture with higher initial adsorption rate, and films with higher plasticizer contents exhibited higher equilibrium moisture contents. Monolayer moisture contents of SPI films increased as glycerol ratio in a plasticizer mixture and plasticizer concentration increased. Plasticizer and absorbed water loosened the film synergistically, resulting in higher elongation but lower tensile strength. RH effects on mechanical properties of SPI films were varied with plasticizers and their concentration. Films of lower glycerol contents were more sensitive to RH variation as compared to the higher glycerol samples, whereas sorbitol concentration affected the RH region where a sharp decrease in TS value occurred.     

Biopolymer interactions affect the functional properties of edible films based on agar, cassava starch and arabinoxylan blends

Edible films based on the binary combination of agar (AG), cassava starch (CAS) and arabinoxylan (AX) were studied with regard to their microstructure, moisture barrier and mechanical properties. Though the films appear macroscopically homogeneous, electron microscopy observations reveal a phase separation and dispersion, respectively, in AG–CAS and AG–AX blend film structures, whereas the structure of CAS–AX blend films seems homogeneous. In case high moisture (84% and 99% RH), neither the combination of AG and CAS nor the addition of AX into CAS can improve film moisture barrier properties, except at a lower RH (57%). Conversely, water vapor permeability (WVP) of AG based film is significantly reduced when AX is used as an “additive”. On the other hand, blending AG with CAS increases the surface wettability of AG films but not that of CAS films. Adding AG into CAS induces an improvement in elongation and tensile strength of CAS based films. Mechanical properties of agar based films are degraded when CAS or AX was added. The results suggest that AG is able to provide a very good cohesive matrix, which contributes to enhance the mechanical properties of other polysaccharide based films.     

钛酸酯偶联剂在碳酸钙填充SF/PVA共混膜中的应用

为解决碳酸钙粉体表面与SF/PVA共混体系的结合能力较差,易形成聚集体,造成在有机共混体系中分散不均匀等问题,使用钛酸酯偶联剂处理碳酸钙填充的SF/PVA共混溶液,制备出以碳酸钙为填充物的SF/PVA共混膜,探讨钛酸酯偶联剂对碳酸钙填充共混膜的力学性能和湿态稳定性的影响。结果表明,钛酸酯偶联剂的质量分数为0.5%时,成膜性能较好,对共混膜的力学性能及湿态稳定性的改善均具有明显的效果,共混膜的拉伸强力和断裂伸长率可分别达到49.7 MPa和873.4%,溶失率为1.03%,之后随着偶联剂用量的增加,力学性能反而逐步减小,溶失率逐渐增大。     

Effect of glycosylation on the mechanical properties of edible soy protein packaging film

In this paper, we explore the glycosylation conditions (glucomannan content, reaction time, temperature and humidity) to probe the relationship between glycosylation and mechanical properties of soy protein isolate (SPI) film. The mechanical properties were characterized by studying the tensile strength (TS) and elongation at break (EB). Furthermore, degree of glycosylation, free glucomannan content, surface hydrophobicity, sulfhydryl groups content, lysine and arginine content of glycosylation soy protein with different reaction time were investigated to certify the significant effect of glycosylation on mechanical properties of soy protein film. What is more, the comparison of TS and EB, contact angle values and water vapor permeability of glycosylation SPI (GSPI), SPI and mixture of SPI and glucomannan films showed the excellence of GSPI. At the end, the analysis of scanning electron microscope was applied to reveal the effect of glycosylation on the structure of films. These results suggested that glycosylation with glucomannan is an ideal method to enhance the mechanical properties of soy protein isolate film.     

月桂酸酯化淀粉/聚乙烯醇(PVA)共混膜的制备及其性质研究

本文将原玉米淀粉和制备的月桂酸酯化淀粉与聚乙烯醇(PVA)共混,延流法制备淀粉/PVA共混膜,对膜的部分结构和性质进行研究,探讨月桂酸酯化改性对共混膜的性质和结构的影响。结果表明：酯化淀粉共混膜的表面比原淀粉更平滑,酯化改性提高了淀粉与PVA的相容性,使得透明度增大,断裂伸长率增加;但酯化改性对淀粉耐水性的改善不显著;抗拉伸强度改善不显著;热重分析结果表明酯化淀粉共混膜与原淀粉共混膜相比,其热分解更不完全。     

大豆蛋白-聚乙烯醇-层状硅酸盐粘土复合薄膜的性能研究

通过溶液流延法制备了大豆蛋白/聚乙烯醇/层状硅酸盐黏土(Laponite RD)共混物薄膜,研究了纳米黏土的添加量对薄膜的热性能、机械性能以及水蒸气阻隔性能的影响。随着Laponite RD的添加,薄膜熔融峰首先向低温方向偏移(0%~10%Laponite RD),然后随着Lapontite RD含量的继续增加,熔融峰又向高温方向偏移。Laponite RD的添加增强了薄膜的水蒸汽阻隔性能,对比不同相对湿度(RH)下的水蒸气透过性(WVP),75%RH下的WVP要高于50%RH下的WVP。随着Laponite RD添加量的增加,拉伸强度和断裂伸长率同样呈现先升后降的趋势。在较高的相对湿度下(75%RH),由于水分子的塑化作用,薄膜的拉伸强度和断裂伸长率相对50%RH下更低。     

Preparation and properties of rice starch–chitosan blend biodegradable film

Biodegradable blend films from rice starch–chitosan were developed by casting film-solution on leveled trays. The influence of the ratio of starch and chitosan (2:1, 1.5:1, 1:1, and 0.5:1) on the mechanical properties, water barrier properties, and miscibility of biodegradable blend films was investigated. The biodegradable blend film from rice starch–chitosan showed an increase in tensile strength (TS), water vapor permeability (WVP), lighter color and yellowness and a decreasing elongation at the break (E), and film solubility (FS) after incorporation of chitosan. The introduction of chitosan increased the crystalline peak structure of starch film; however, too high chitosan concentration yielded phase separation between starch and chitosan. The amino group band of the chitosan molecule in the FTIR spectrum shifted from 1541.15 cm⁻¹ in the chitosan film to 1621.96 cm⁻¹ in the biodegradable blend films. These results pointed out that there was a molecular miscibility between these two components. The properties of rice starch–chitosan biodegradable blend film and selected biopolymer and synthetic polymer films were compared; the results demonstrated that rice starch–chitosan biodegradable blend film had mechanical properties similar to the other chitosan films. However, the water vapor permeability of rice starch–chitosan biodegradable blend film was characterized by relatively lower water vapor permeability than chitosan films but higher than polyolefin.     

Preparation and characterization of bio-nanocomposite films based on soy protein isolate and montmorillonite using melt extrusion

The non-biodegradable and non-renewable nature of plastic packaging has led to a renewed interest in packaging materials based on bio-nanocomposites (biopolymer matrix reinforced with nanoparticles such as layered silicates). Bio-nanocomposite films based on soy protein isolate (SPI) and montmorillonite (MMT) were prepared using melt extrusion. Effects of the pH of film forming solution, MMT content, and extrusion processing parameters (screw speed and barrel temperature distribution) on the structure and properties of SPI–MMT bio-nanocomposite films were investigated. X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were used for structural characterization of the films. Properties of the films were determined by tensile testing, dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and water vapor barrier measurement. The arrangement of MMT in the soy protein matrix ranged from exfoliated at lower MMT content (5%) to intercalated at higher MMT content (15%). There was a significant improvement in mechanical (tensile strength and percent elongation at break) and dynamic mechanical properties (glass transition temperature and storage modulus), thermal stability, and water vapor permeability of the films with the addition of MMT. The results presented in this study show the feasibility of using bio-nanocomposite technology to improve the properties of biopolymer films based on SPI.     

直接溶解法制备新型纤维素／大豆蛋白生态复合纤维

利用研发的NaOH／硫脲／尿素复合溶剂直接溶解纤维素以及大豆分离蛋白（SPI）,然后采取湿法纺丝技术,在10wt．％H2SO4／12．5wt．％Na2SO4的凝固浴中凝固再生,成功制备出纤维素／大豆蛋白复合纤维。对所制备得到的再生复合纤维的结构与性质进行了红外光谱（FTIR）、扫描电镜（SEM）以及强伸性测试与表征。结果表明,蛋白含量为10wt．％的复合纤维其强度与伸长率分别达到了1．86cN／dtex和10．3％,具有较好的力学性能。