超声波对玉米淀粉成膜性能影响的研究

利用超声波对玉米淀粉糊进行处理,使其成膜,并对膜的抗拉强度、断裂伸长率、透光率、水蒸气透过系数、透油系数及表面微观结构进行分析。超声波处理的玉米淀粉溶液所成膜的机械性能、阻隔性以及表面微观结构都有所改善。其中1200 W处理15 s时效果最佳,抗拉强度达到最大13.68 MPa、断裂伸长率27.8%、水蒸气透过系数0.1098(g/cm2.d),透油系数0.0113(g.mm/cm2.d)。     

有机蒙脱土对热塑性氧化淀粉膜性能影响

以不同有机蒙脱土为增强剂,采用熔融挤出流延制膜工艺,研究不同有机蒙脱土对淀粉膜性能影响。结果表明,有机蒙脱土可有效提高淀粉膜拉伸强度和断裂伸长率、增加膜透明度、并降低膜的水蒸气透过率和水溶性。添加不同有机蒙脱土对膜性能有不同影响,DK_1和DK_5蒙脱土可有效提高膜断裂伸长率,DK_4蒙脱土可明显提高膜拉伸强度,DK_3蒙脱土可提高膜透明度,DK_2蒙脱土可有效降低膜的水蒸气透过率。     

大豆球蛋白-马铃薯淀粉可食膜的微观结构及机械性能

以不同质量比马铃薯淀粉(PS)和大豆球蛋白(11S)为原料制备PS-11S复合可食膜,通过X-射线衍射、傅里叶红外光谱、质构、光学性能、透气性、扫描电子显微镜对可食膜组分间作用力、微观结构和机械性能进行多尺度研究。结果表明,通过X-RD和FTIR光谱分析,11S和PS通过疏水作用和氢键相互交联,形成网状结构,促进可食膜的形成。随着11S含量的增加,可食膜机械性能出现先升高后降低的趋势。在11S和PS比例为2∶15时,可食膜断裂伸长率达到最大值46.69%,水蒸气透过率达到最小值5.63 mm/m²d·kPa,氧气透过率和二氧化碳透过率分别降低为8.48 g/d·m²和12.47 g/d·m²。当11S含量过大时,可食膜孔隙增加,甚至产生裂缝。结论:当11S和PS比例为2∶15时,可食膜软硬适中,空间结构紧密,机械性能优异,研究结果为蛋白-淀粉基复合可食膜的制备提供了研究数据。     

淀粉纳米晶提高大米淀粉可食用膜物理化学性能的研究（网络首发、推荐阅读）

采用溶剂蒸发法制备蜡质玉米淀粉纳米晶（SNC）/大米淀粉复合可食用膜,研究SNC添加量对大米淀粉复合膜力学性能、水蒸气阻隔性、热稳定性和微观结构的影响。结果表明,不同SNC添加量的复合成膜膜液在稳态剪切试验中均呈现剪切变稀的行为,为假塑性流体。随着复合膜中SNC含量的增加,其拉伸强度呈现出先增大后减小的趋势;而复合膜的水蒸气透过率则呈现出相反的变化趋势。通过扫描电镜形貌图可知,在5%SNC/大米淀粉复合膜中SNC分散均匀。随着SNC添加量增加至15%,SNC在复合膜中形成了较大的团聚体。基于X-射线衍射和热重分析,研究发现SNC的适量添加可有效提高大米淀粉复合膜的结晶度和热稳定性。     

淀粉质可食用膜性质研究

以马铃薯淀粉、玉米淀粉、木薯淀粉以及小麦淀粉作为基质制作可食用薄膜,通过优化薄膜中塑化剂含量降低可食用薄膜的水蒸气透过率(WVP)。检测马铃薯淀粉质、玉米淀粉质、木薯淀粉质、小麦淀粉质和果胶质5种可食用薄膜在相对湿度(RH)30%,50%,70%和90%环境下的水蒸气透过率。检测优化后的可食用薄膜拉伸强度和伸长率机械特性以及可食用膜溶解性,马铃薯淀粉质、玉米淀粉质和木薯淀粉质薄膜都随多元醇含量的增加先降低后升高。当多元醇添加量均为20%时,马铃薯淀粉质和玉米淀粉质可食用膜水蒸气透过率最低。当多元醇添加量均为35%时,木薯淀粉质可食用膜水蒸气透过率最低。玉米淀粉质可食用膜拉张强度最大,木薯淀粉质可食用膜延伸较果最佳。果胶质可食用膜溶解性达100%。     

蓝莓花青素智能指示膜的制备及应用

以蓝莓花青素(BA)作为新鲜度指示剂,以玉米淀粉(CS)、羧甲基纤维素(CMC)为成膜基材,采用流延法制备智能指示膜.分析不同质量分数花青素对复合膜在机械性能、含水率、水蒸气透过率、热稳定性、红外光谱、表面微结构以及灵敏度等的影响.结果表明:当BA质量分数为3％时,指示膜的断裂伸长率最高,含水率与水蒸气透过率最低,且灵...     

不同基材复配紫薯花青素制备智能指示膜及其应用

以马铃薯淀粉（starch,S）、羧甲基纤维素钠（carboxymethyl-cellulose sodium,CMC）以及魔芋葡甘露聚糖（konjac glucomannan,KMG）两两互配为成膜基材,紫薯花青素（P）作为新鲜度指示剂,制备智能指示膜,比较KMG/S/P（KSP）、S/CMC/P（SCP）、KMG/CMC/P（KCP）3 种智能指示膜的力学性能、水分质量分数、水溶性、微观结构、相容性及稳定性等的差异,并运用鱼肉进行初步应用评价。结果表明：SCP膜的抗拉伸强度最高（（15.39±1.15）MPa）、水溶性最低（（24.17±1.21）%）,且颜色稳定性好;而KCP膜断裂伸长率最大（（44.79±1.43）%）;扫描电子显微镜观察结果表明不同智能指示膜微观结构差异明显,其中SCP膜横切面光滑紧密。利用SCP检测鱼肉新鲜度,25 ℃下鱼肉贮藏24 h后挥发性盐基氮含量达15.2 mg/100 g,已经开始腐败,此时智能指示膜显示出浅红色,48 h后变为浅蓝色。因此,SCP膜适合新鲜度检测,且运用紫薯花青素开发稳定的指示膜有良好的应用前景。     

马铃薯淀粉及其7种变性淀粉糊液特性的比较研究

通过对马铃薯淀粉(PS)及其7种变性淀粉(醋酸酯淀粉、羟丙基淀粉、磷酸酯双淀粉、乙酰化二淀粉磷酸酯、羟丙基二淀粉磷酸酯、氧化淀粉、氧化羟丙基淀粉)在糊化温度、峰值黏度、热稳定性、凝胶性、抗剪切、耐酸性、冻融稳定性和透明度等性能差异的研究,探讨了不同改性方式对马铃薯淀粉糊特性的影响。结果表明:⑴羟丙基和醋酸酯改性均可降低马铃薯淀粉的糊化温度,提高淀粉峰值黏度,增加糊液透明度和冻融稳定性,但淀粉糊的热稳定性和凝胶性差;⑵交联改性提高了马铃薯淀粉的糊化温度和凝胶性,增强了糊液热稳定性和耐酸性,但透明度降低;⑶氧化处理降低了马铃薯淀粉的糊化温度和峰值黏度,提高淀粉糊透明度;(4)双重改性处理的复合变性淀粉同时兼有二种单一变性淀粉的共同特性,其中:氧化羟丙基淀粉的透明度最好,羟丙基二淀粉磷酸酯的冻融稳定性最好。     

挤压吹塑法制备淀粉基可食膜及其性能表征

以甘油为增塑剂,普兰多糖为黏合增强剂,采用熔融共混挤出技术制备热塑性淀粉,再挤出吹塑制备淀粉基可食膜。研究甘油对热塑性淀粉流变性、玻璃化转变温度、相变焓和微观形貌的影响;并研究了湿度环境对可食膜力学性能的影响及甘油对淀粉可食膜力学性能及热稳定性的影响。结果表明:甘油能有效的改善了热塑性淀粉的流变性和微观结构,降低热塑性淀粉的玻璃化转变温度,使淀粉结晶熔融焓变减小。实验制备的热塑性淀粉膜适宜在湿度40%的环境下使用;且在该湿度条件下,甘油添加量28%时,淀粉可食膜的纵向拉伸强度为5.26 MPa,断裂伸长率达到137.9%,横向拉伸强度为4.92 MPa,断裂伸长率为118.0%。     

明胶/普鲁兰酶改性淀粉膜的制备与性能研究

研究了普鲁兰酶对淀粉膜性能的影响及明胶对普鲁兰酶改性淀粉膜性能的影响。结果表明:与原淀粉膜相比,普鲁兰酶改性淀粉膜的表面更平滑;膜的热稳定性增大,热封性能增强;抗拉强度、水蒸气透过率和透光率分别增加了75%、18%和35%,断裂伸长率降低了53%。与未添加明胶的酶改性淀粉膜相比,添加明胶后,膜的表面变粗糙;膜的阻水性能与阻光性能增强,热封性能变差。当明胶添加量为10%时,膜的抗拉强度增加了17.6%;当明胶添加量为25%时,膜的断裂伸长率增加了54.3%;在明胶添加量为15%时,膜的热稳定性最大。     

Effects of virgin coconut oil on the physicochemical,morphological and antibacterial properties of potato starch-based biodegradable films

This study investigated the effects of adding different concentrations of virgin coconut oil (VCO) on the optical, mechanical, thermodynamic and antimicrobial properties, as well as water vapour permeability and morphology of potato starch-based biodegradable films. Increasing VCO concentrations caused a rise in the light transmittance of the films from 2.13 to 4.79 mm⁻¹ and a decrease in water vapour transmittance from 6.77 to 2.12 (10⁻⁵ GPa⁻¹ h⁻¹ m⁻¹). At a VCO concentration of 14 wt% (based on potato starch), the tensile strength reached its highest value (19.98 MPa). Scanning electron microscopy showed that the surface of the film became smoother as VCO concentration increased. The addition of VCO inhibited the growth of Listeria monocytogenes, Staphylococcus aureus and Escherichia coli. In conclusion, VCO supplementation improved the mechanical, antibacterial and water barrier properties of starch-based films. These results could expand the scope of the application of starch-based films in food packaging.     

Development of oxidised and heat-moisture treated potato starch film

This study investigated the effects of sodium hypochlorite oxidation and a heat-moisture treatment of potato starch on the physicochemical, pasting and textural properties of potato starches in addition to the water vapour permeability (WVP) and mechanical properties of potato starch films produced from these starches. The carbonyl contents, carboxyl contents, swelling power, solubility, pasting properties and gel texture of the native, oxidised and heat-moisture treated (HMT) starches were evaluated. The films made of native, oxidised and HMT starches were characterised by thickness, water solubility, colour, opacity, mechanical properties and WVP. The oxidised and HMT starches had lower viscosity and swelling power compared to the native starch. The films produced from oxidised potato starch had decreased solubility, elongation and WVP values in addition to increased tensile strength compared to the native starch films. The HMT starch increased the tensile strength and WVP of the starch films compared to the native starch.     

Paste viscosity of rice starches of different amylose content and carboxymethylcellulose formed by dry heating and the physical properties of their films

Starch modified by combination with sodium carboxymethylcellulose (CMC) has been reported to have improved film properties. In this study, rice starches with different amylose content were heat-treated in a dry state after being impregnated with low or medium-viscosity CMC. Noticeable change was found in pasting properties of the starches after dry heat treatment with CMC. It indicated that crosslinkage occurred between the starch and CMC. The waxy starch showed significant change in viscosity throughout pasting after dry heating with CMC, suggesting that the ester bonds were mostly formed between the hydroxyl groups in amylopectin branches of rice starch and carboxylate acid groups of CMC. Particle size also increased after heat treatment with CMC. The modified starch-based films showed improvement in the tensile strength. Both water vapor and oxygen permeability reduced for the modified starch-based films. Dynamic mechanical analysis (DMA) study showed that the values of G′ of modified starch-based film were higher than those of native starch-based film over the temperature range −40 to 60 °C. The heating process with CMC could be used as a modification method for starch and provide desirable properties of starch-based films.     

硼酸交联对挤出吹塑变性淀粉/聚乙烯醇复合膜性能的影响

为了提高淀粉基复合膜的阻水性,拓宽淀粉膜的应用范围,以羟丙基二淀粉磷酸酯与聚乙烯醇(PVA)为成膜原料,硼酸为交联剂,采用挤出吹塑工艺制备了淀粉/PVA复合膜。分析了粒料的流变性能,研究了淀粉膜的交联密度、力学性能、阻隔性能、疏水性能以及微观形貌等性质。结果表明,随着硼酸添加量的增加,淀粉/PVA复合材料的熔体流动性下降,淀粉/PVA复合膜的阻氧、阻水性能增强,而淀粉膜的抗拉强度和拉伸模量呈降低趋势,断裂伸长率先升高后降低。添加1%的硼酸,淀粉/PVA复合膜的表面更加均匀平整,疏水性最强,具有最小的溶胀度、最大的凝胶质量和最高的交联密度。     

Properties of cast films of vicilin-rich protein isolates from Phaseolus legumes: Influence of heat curing

The mechanical, hydrophobic and thermal properties of cast films of vicilin-rich protein isolates from three Phaseolus legumes were investigated and compared to that of soy protein isolate (SPI). The influence of heat curing at 85 °C on the properties of these films was characterized. The films of vicilin-rich protein isolates exhibited much less mechanical strength (TS) and elongation at break (EB) and similar film surface hydrophobicity, as compared with those of the SPI film. The heating remarkably improved the TS of these films, and the extent of the improvement much higher than that of the SPI film, while the EB was only slightly affected. The thermal properties of these protein isolate films were variable, and much distinctly affected by the heating of the films, to a various extent, depending on the type of protein isolates. Protein solubility analyses indicated strengthened hydrogen and hydrophobic bondings of these films by the heating. The results suggest that those vicilin-rich protein isolates have good potential to form cast films with mechanical strength comparable to that of SPI film.     

Mechanical Properties, Water Vapor Permeabilities and Solubilities of Highly Carboxymethylated Starch-Based Edible Films

ABSTRACT: Tensile strength (TS), elongation (E), water vapor permeabilities (WVP) and solubilities were determined for highly carboxymethylated starch (HCMS)-based edible films plasticized with sorbitol (S), xylitol (X), mannitol (M) and glycerol (G). TS and E of HCMS-based film increased as the concentration of plasticizer S, M or × increased. TS of the HCMS-based film containing combined plasticizers were higher than those of films containing single plasticizer. The WVP of HCMS-based films seemed to decreased as the concentration of M, X or G plasticizer increased. Increasing plasticizer concentrations in HCMS-based film resulted in decreasing solubility of the films.     

Classification,modeling and prediction of the mechanical behavior of starch-based films

The starch-based film properties database was created with 8 variables and 322 observations collected from the literature. The selected variables were: (1) the starch origin (potato, cassava (tapioca), corn (maize), wheat, yam), (2) the starch concentration, (3) the amylose content, (4) the glycerol concentration, (5) the ambient relative humidity during storage, (6) the aging time of films and two mechanical properties of the starch films at break, (7) tensile strength at break (s_b) and (8) strain at break (e_b). The main objective of this work was to classify the data set and to predict mechanical properties (tensile strength (s_b) and strain at break (e_b) of starch-based films using a Rival Penalized Competitive Algorithm to find the clusters and, for each class, an artificial neural network (ANN) model from 6 parameters (starch origin, starch concentration (%), amylose content (%), glycerol content, ambient relative humidity (RH) and the aging of films). Each ANN was optimized using a genetic algorithm. The root-mean square error (RMSE) and the coefficient of determination B allowed to choose the best ANN. The results showed that it was possible to distinguish five classes where the composition of each class C_i could be described accurately and connected with the mechanical behavior of the films. This work also showed that it was useful firstly to classify the database before attempting to predict the mechanical properties of the starch-based films.     

Physical and Mechanical Properties of High-amylose Rice and Pea Starch Films as Affected by Relative Humidity and Plasticizer

ABSTRACT: The tensile properties, water vapor permeability, oxygen permeability at different relative humidities (RH), and water solubility of edible films made of high-amylose rice starch (RS) or pea starch (PS) were measured and compared with the most commonly used edible films. Photomicrography of starch films shows amylopectin-rich gels and amylose-rich granules. The addition of glycerol into starch films made amylose-rich granules swollen and continuously dispersed between amylopectin-rich gels. Tensile strength of RS and PS films decreased when RH increased from 51% to 90%, whereas elongation-at-break (E) of both films increased when RH increased. Water vapor permeabilities of both films were similar, resulting in 130 to 150 g mm/m²/d /kPa. Oxygen permeability of RS and PS were very low (< 0.5 cm³μm/m²/d/kPa) below 40% RH, and 1.2 to 1.4 at 45% RH. Water solubility of PS film was 32.0%, which is lower than that of RS film (44.4%). Overall high-amylose rice and pea starch films possess an excellent oxygen barrier property with extremely high stretchability.     

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.