生物甘油基聚酯对大豆分离蛋白复合膜贮藏期间机械性能稳定性的影响

以大豆分离蛋白（soybean protein isolate,SPI）为主要原料,将甘油进行改性后制备的生物甘油基聚酯加 入到成膜液中制备SPI复合膜,通过对贮藏期间SPI复合膜机械性能、水分含量和甘油迁出率进行跟踪测定,比较分 析甘油经改性后制备的增塑剂对SPI复合膜的机械性能稳定性、保水性、甘油迁出率稳定性及微观结构的影响。研 究结果表明：与未改性甘油增塑的SPI复合膜相比,改性后制备的机械性能稳定性最高的SPI复合膜为生物甘油基聚 酯（生物聚甘油和脂肪酸的质量比为1∶1）增塑的复合膜,其拉伸强度稳定性提高了18.08%,断裂延伸率稳定性提高 了34.52%,水蒸气透过系数稳定性提高了14.68%,水分含量稳定性提高了17.02%,甘油迁出率稳定性提高了74.28%, 膜体系的紧密性和连续性增强,且其表面形成了致密的空间网状结构。生物甘油基聚酯的添加一定程度上提高了SPI 复合包装薄膜的机械性能稳定性,为其更广泛的实际应用提供了重要的理论参考和技术支持。     

不同增塑剂对结冷胶薄膜性能的影响

为开发新型食品包装材料，以结冷胶为成膜基质，以甘油、丙二醇和聚乙二醇400为增塑剂，采用流延法来制备生物可降解包装薄膜，研究膜的微观结构、热稳定性、力学性能、透光性能、水蒸气及氧气透过率。采用红外光谱、X-射线衍射和电镜扫描对3种增塑剂与结冷胶之间的相容性进行分析。结果表明：以甘油为增塑剂，成膜性能最佳，丙二醇次之。热重分析表明，3种基膜在0～100℃表现出良好、均一的热稳定性，热稳定性依次为：丙二醇、甘油、聚乙二醇400。物理学性能测试分析表明，3种增塑剂的添加均会提高基膜的厚度、断裂延伸率、抗拉强度、水蒸气和氧气透过率，降低膜的透光性能。采用甘油添加量为40%(质量分数，结冷胶基)来制备薄膜时，抗拉强度最大为32.46 MPa,断裂延伸率最大为8.33%,氧气透过率最大为2.11 cm³·mm/(m²·d·atm),水蒸气透过率最大为2.45×10^-10 g/(m·s·Pa),透光率最大为91.8%,满足包装薄膜的性能需求，为新型可降解包装膜的制备及应用提供理论基础。     

不同增塑剂对玉米醇溶蛋白膜机械性能的影响

本试验主要研究了几种不同增塑剂对玉米醇溶蛋白膜机械性能（抗拉强度、延伸率）的影响。结果发现：添加复合增塑剂的蛋白膜延伸率较大、抗拉强度差；甘油和乙二醇的延伸率都较其他两种小得多，但乙二醇的抗拉强度比甘油的大；添加油酸所制备的蛋白膜抗拉强度较低、延伸率较大，并且蛋白膜柔软、有光泽和富有弹性。     

马铃薯淀粉/海藻酸钠复合交联可食膜阻湿性影响因素研究

研究不同膜液配比、不同增塑剂及用量、不同油脂及用量对马铃薯淀粉/海藻酸钠复合交联可食膜阻湿性能的影响。马铃薯淀粉含量高的膜样比海藻酸钠含量高的膜样具有更低的水蒸气透过系数,但水溶性增加;增塑剂(甘油、山梨醇、甘油山梨醇混合物)用量提高,复合交联可食膜的水蒸气透过系数和水溶性均增加,以质量比为1∶1的甘油与山梨醇混合物为增塑剂的膜样具有较低的水蒸气透过系数和水溶性;油脂可以提高复合交联可食膜的疏水性,降低复合交联可食膜的水溶性,添加橄榄油的复合交联可食膜比添加硬脂酸具有更低的水蒸气透过系数。     

4 种改性方式对明胶膜性能的影响

研究了共混改性、增塑改性、交联改性和乳化改性对明胶膜性能的影响。结果表明,明胶分别与壳聚糖、海藻酸钠共混溶解性较好,成膜均匀透明,同时具有较低的水蒸气透过率和透氧率,阻隔性增强;添加甘油作为增塑剂可提高明胶膜的断裂伸长率,机械性能增强;与柠檬酸钠交联改性后降低了明胶膜的水蒸气透过率,增强阻隔性能,提高抗拉强度,增强力学性能,但是膜的透光率下降;添加质量分数为0.1%的乳化剂吐温-80可以降低可食膜的水蒸气透过率,增强膜的阻隔性能,同时增大抗拉强度,改善机械性能。研究认为,共混、增塑、交联、乳化4 种改性方式均能不同程度地影响明胶膜的阻隔性能和机械性能,改善明胶膜的综合性能以满足其在不同领域的应用。     

L-阿拉伯糖、增塑剂复合改性鱼皮明胶可食用膜制备工艺研究

以鱼皮明胶为成膜基质,L-阿拉伯糖、甘油和山梨醇为改性剂,采用浇铸法制备可食用膜,以拉伸强度和断裂伸长率为目标优化指标,通过单因素试验及正交试验确定薄膜最佳制备工艺。结果表明：在L-阿拉伯糖和鱼皮明胶质量比2 ∶8、增塑剂（甘油∶山梨醇）质量比为2 ∶1、增塑剂浓度20%、水浴温度60 ℃、水浴时间40 min 条件下,可食用膜机械性能最佳,拉伸强度和断裂伸长率分别达到（17.46±2.59）MPa、（116.95±13.05）%。     

增塑剂对乳清蛋白-丝胶复合可食用膜性能的影响

本实验研究了甘油、山梨醇、聚乙二醇200以及甘油,聚乙二醇400(3/1)的混合物作为增塑剂对乳清蛋白-丝胶复合膜性能的影响.结果表明:增塑剂对乳清蛋白-丝胶复合膜的性能有显著影响.同一种增塑剂随着添加量的升高,膜的拉伸强度和透明度降低,断裂拉伸率、水蒸气透过性、含水量和溶解性升高.含有山梨醇和含有聚乙二醇200的膜的拉伸强度和溶解性比含有甘油和含有甘油/聚乙二醇400(3/1)的膜大,但前两者的拉伸率均较小.不同增塑剂制成的膜的水蒸气透过性和水分含量排列顺序为:含有甘油的膜＞含有甘油,聚乙二醇400(3/1)的膜＞含有乙二醇200的膜＞含有山梨醇的膜.甘油和甘油,聚乙二醇400(3/1)的膜相比,后者在一定添加量下拉伸性和阻水性都要优于前者.     

十二烷基磺酸钠对大豆分离蛋白膜性能的影响

本文研究了以甘油为增塑剂时,十二烷基磺酸钠（SDS）对大豆分离蛋白（SPI）膜功能特性的影响。结果表明：SDS可改善SPI膜的功能特性．显著提高了膜的延展性和阻水能力。当膜液中SDS的添加量为SPI的20％时,膜的断裂伸长率最大,为221％,比对照提高了301％;透光率最大,为43．6％,比对照提高了98％;膜的水分含量为22．2％,比对照降低了7．5％;膜的水蒸气透过率为7．8gmm/／m^2 hkPa,比对照降低了23％。但添加SDS也使膜的抗拉强度有所降低,膜的厚度、膨胀率、总可溶性物含量增加。     

十二烷基磺酸钠对大豆分离蛋白膜性能的影响

本文研究了以甘油为增塑剂时,十二烷基磺酸钠（SDS）对大豆分离蛋白（SPI）膜功能特性的影响。结果表明：SDS可改善SPI膜的功能特性．显著提高了膜的延展性和阻水能力。当膜液中SDS的添加量为SPI的20％时,膜的断裂伸长率最大,为221％,比对照提高了301％;透光率最大,为43．6％,比对照提高了98％;膜的水分含量为22．2％,比对照降低了7．5％;膜的水蒸气透过率为7．8gmm/／m^2 hkPa,比对照降低了23％。但添加SDS也使膜的抗拉强度有所降低,膜的厚度、膨胀率、总可溶性物含量增加。     

增塑剂对卡拉胶可食用膜性能的影响

以卡拉胶为成膜物质,以甘油、山梨醇及丙二醇为增塑剂,制备卡拉胶基多糖可食用薄膜,研究了增塑剂的种类和添加量对卡拉胶薄膜机械性能、水蒸气透过性、厚度、透明度及色差的影响。结果表明,与对照组(无增塑剂)卡拉胶薄膜相比,随着增塑剂添加量从0. 5%增加至2. 5%(质量分数),卡拉胶薄膜的断裂伸长率、水蒸气透过性、厚度均呈现上升趋势,尤以添加2. 5%甘油对薄膜的影响最为显著,3项指标分别增加到68. 13%、10. 528 0 (g·mm)/(m~2·d·k Pa)和0. 176 mm;拉伸强度及不透明度均呈下降趋势,其中0. 5%丙二醇增塑剂下降最为缓慢;薄膜亮度略有下降、黄度增加。本实验可为卡拉胶在食品包装薄膜制备及应用方面提供一定的科学参考。     

Effects of various plasticizers and nanoclays on the mechanical properties of red algae film

To manufacture red algae (RA) film, we used various plasticizers such as glycerol, sorbitol, sucrose, fructose, and polypropylene glycol (PPG), and then determined the mechanical properties of the RA films. The tensile strength (TS), elongation at break (E), and water vapor permeability (WVP) of the films containing various plasticizers ranged between 0.43 to 9.10 MPa, 10.93% to 47.17%, and 1.28 to 1.42 ng m/m2sPa, respectively. RA films containing fructose as a plasticizer had the best mechanical properties of all the films evaluated. Incorporation of nanoclay (Cloisite Na+ and 30B) improved the mechanical properties of the films. RA film with 3% Cloisite Na+ had a TS of 10.89, while RA film with 30B had a TS of 10.85 MPa; these films also had better E and WVP values than the other RA films evaluated. These results suggest that RA/nanoclay composite films are suitable for use as food packaging materials. PRACTICAL APPLICATION: Edible RE/nanoclay composite films prepared in the present investigation can be applied in food packaging.     

Mechanical and Barrier Properties of Egg Albumen Films

Films were cast and dried from heated, alkaline aqueous egg albumen solutions containing glycerin (GLY) at 30, 40, or 50% w/w of protein, polyethylene glycol (PEG) at 50 or 60%, or sorbitol (S) at 50 or 60% as plasticizers. PEG-plasticized (60%) films also were prepared by substituting 10, 30, 50, or 70% of albumen with yolk solids. Film tensile strength (TS), elongation at break (E), water vapor permeability (WVP), and Hunter color values were measured. At a plasticizer content of 50%, films with S had the lowest WVP while films with PEG had the greatest E. S- and PEG-plasticized films had greater TS than GLY-plasticized films. Yolk solids decreased film TS, E, and WVP while increasing film yellowness.     

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.     

Water Vapor Permeability, Mechanical Properties and Antioxidant Effect of Mexican Oregano–Soy Based Edible Films

ABSTRACT:  Water-soluble extracts from Mexican oregano ( Lippia graveolens ) were incorporated into soy protein isolate (SPI) films. Water vapor permeability, mechanical properties, and antioxidant ability were evaluated. All the extracts were capable of scavenging DPPH radicals in a concentration-dependent fashion; the IC₅₀ values were obtained. Oregano extracts were incorporated into SPI films plasticized with sorbitol, glycerol, and glycerol–sorbitol 1:1. The addition of the extracts resulted in an increase in the water vapor permeability values and provided a dark reddish film appearance. Changes in tensile strength as well as elongation values were observed. The oregano SPI films exhibited antioxidant properties in a concentration-dependent fashion.     

Development and Characterization of Soy Protein Isolate Emulsion-Based Edible Films with Added Coconut Oil for Olive Oil Packaging: Barrier,Mechanical, and Thermal Properties

Emulsion-based edible films made of soy protein isolate (SPI), virgin coconut oil (VCO), and soy lecithin (SL) and plasticized with glycerol were prepared using the casting method. The effect of VCO and SL concentrations in SPI films and their in-between interaction were studied through the evaluation of physical (moisture and opacity), mechanical (elongation and tensile strength), water vapor permeability, and thermal properties. The response surface methodology was used to identify the most significant factors in the properties studied. The applicability of SPI emulsion-based films was evaluated as a package for olive oil to be used in small portions. The oxidative stability of the packaged olive oil was monitored by peroxide analyses during 28 days. The incorporation of VCO and SL decreased the moisture content and increased the elongation of the SPI emulsion-based films when compared to the SPI film without these components (control). The opacity of the films increased with the addition of VCO into the protein-based films, but not with the addition of SL or a combination of both constituents. By the other hand, the water vapor permeability was not improved by the incorporation of VCO, SL, or a combination of both. The peroxide value of the olive oil stored in SPI emulsion-based film sachets increased rapidly during the seven first days of storage. After this period, the peroxides increased relatively slow up to 28 days of storage. The peroxide values of the packaged olive oil did not reach the maximum limit recommended by the Codex Alimentarius. Based on these results, this work may be useful for the technological enhancement of emulsion-based films or for food packaging applications.     

大豆蛋白基明胶复合膜性能稳定性分析

以大豆蛋白和明胶为主要原料,采用戊二醛溶液交联方式和戊二醛饱和蒸汽交联制备大豆蛋白基明胶复合膜,通过对两种交联方式制备的复合膜机械性能稳定性和降解性测定,比较分析戊二醛不同交联方式对复合膜机械性能稳定性、降解性及微观结构影响。结果表明,在3个月贮藏期内,戊二醛溶液交联改性、蒸汽交联改性处理复合膜拉伸强度稳定性提高了20.58%、38.51%,延伸率稳定性提高了31.71%、54.49%,水蒸气透过系数稳定性提高了31.74%、52.19%,透氧率稳定性提高了0.24%、18.01%,降解实验中降解速率分别为未经改性处理大豆蛋白基明胶复合膜溶液交联改性处理复合膜蒸汽交联改性处理复合膜。同时,蒸汽交联复合膜表面及拉伸断面形成结构致密的三维立体网络结构。因此,戊二醛蒸汽交联制备的大豆蛋白基明胶复合膜机械稳定性能及微观结构均优于戊二醛溶液交联改性处理复合膜。     

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.     

Effect of Fatty Acid Addition on the Properties of Biopolymer Films Based on Lipophilic Maize Starch and Gelatin

In the presented work, composed layer films based on lipophilic starch and gelatin were produced containing different amounts of fatty acids (palmitic, lauric, myristic, capric, caproic and caprylic); i.e., 5, 15, 25 and 50%, using sorbitol as the plasticizer. All films were prepared by casting in an acrylic plate and their barrier properties (vapor permeability), as well as their mechanical (tensile strength and elongation), physicochemical (water solubility) and physical (opacity and thickness) properties were measured. The addition of fatty acids to the biopolymer films increased their thickness, opacity and elongation. On the other hand, the addition of fatty acids decreased the tensile strength and water vapor permeability of the biopolymer films for all formulations studied. The fatty acid concentration found to be effective in reducing the biopolymer film permeability varied between 15 and 25%.     

Effect of Sorbitol Plasticizer on the Structure and Properties of Melt Processed Polyvinyl Alcohol Films

Poly (vinyl alcohol) (PVA) possesses wide applications as food packaging materials, but is difficult to melt process for its strong inter/intra hydrogen bonding. In this work, flexible PVA films with different content of sorbitol plasticizers were prepared by melt processing with the assistance of water. And the influence of sorbitol plasticizer content on the crystallinity, optical transparency, water‐retaining capability, mechanical properties, thermal stability and oxygen and water permeability were investigated. The results indicated that sorbitol dramatically improved the melt processing ability of PVA. Sorbitol could interact with PVA to form strong hydrogen bonding interactions, which would decrease the original hydrogen bonding of the matrix, resulting in the decrease of crystallinity degrees. The glass transition, melting and crystallization peak temperatures decreased with the increase of sorbitol. All the films exhibited fine optical transparency. The water retaining capability were improved with the increase of sorbitol. Especially, an increase in elongation at break and decrease in Young's modulus and tensile strength were observed indicating good plasticizing effect of sorbitol on PVA films. In addition, the PVA films prepared in this work exhibited fine barrier properties against oxygen and water, suggesting wide application potential as packaging materials.     

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.