共查询到19条相似文献,搜索用时 253 毫秒
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淀粉基可食膜是以淀粉或改性淀粉为主要原料,添加填充物和少量功能成分(抗菌剂/抗氧化物)通过干法或湿法等工艺制成的高分子薄膜,具有生物可降解性和可食性等优点。然而,由于淀粉膜力学性能、阻隔性能等相比传统塑料更差,因此探究淀粉膜性能的影响因素及优化工艺将成为重点研究方向。本文综述了淀粉基可食膜的性能、淀粉的结构性质、加工助剂、淀粉改性等对其性能的影响及机制,并概述了淀粉基可食膜应用前景及存在的问题,展望了其发展前景,为进一步开发具备优良性能的淀粉基可食膜提供参考。 相似文献
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淀粉是人类活动的主要能量来源和重要的工业原辅料。然而,传统淀粉来源的植物受种植环境影响较大,土地资源有限,产量增长困难,满足不了人口增长的需要;另一方面,传统植物来源的淀粉,其结构相对固定、性能存在局限性,不能完全满足应用的需求,往往要通过结构修饰来调控其性能。化学方法是常用的结构修饰和性能调控手段,但化学反应过程带来的试剂用量受限、化工辅料残留、副产物的产生和淀粉分子中新化学基团的引入等问题,使其作为食品添加剂的使用存在安全隐患。因此,传统淀粉资源已经不能够完全满足人类可持续发展的要求,有必要开发具有“未来特点”的淀粉新资源。未来淀粉来源根据其特点可分为三类:一是将传统淀粉来源植物通过遗传育种或者基因编辑改造,实现淀粉结构的定向或定点改造,使淀粉具有特殊的应用性能;二是能够克服土地和自然环境限制、或者富含淀粉而尚未被充分开发利用的新淀粉资源等;三是不以植物和微生物为载体合成的无细胞合成新型淀粉。本文阐述了未来淀粉发展的必要性、可行性和发展趋势,以高直链淀粉、蜡质淀粉、浮萍淀粉、微藻淀粉、CO2合成淀粉和多糖生物合成淀粉等为例,重点介绍了三类未来淀粉的研究现状和特点,将对未来淀粉的开发... 相似文献
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为改善微晶纤维素(microcrystalline cellulose,MCC)在淀粉膜中的分散性,通过对MCC进行阳离子醚化改性,制得改性微晶纤维素(modified-microcrystalline cellulose,MD-MCC),并对其化学结构、结晶性、热稳定性和微观形貌进行表征。采用溶液流延法制得淀粉-微晶纤维素复合膜(淀粉-MCC,淀粉-MD-MCC),分别研究MCC和MD-MCC添加量对淀粉膜结构和性能的影响。结果表明,与MCC相比,MD-MCC的基本化学结构未改变,仍然保持纤维素的基本结构,但其结晶度和热稳定性略有降低,表面呈多孔结构。随着MCC和MD-MCC添加量的增加,淀粉膜的表面粗糙度增大,透光率和断裂伸长率降低,水接触角、水分含量和厚度增大,抗拉强度和水蒸气渗透系数先增加后减小。MD-MCC在淀粉膜中的分散性优于MCC,淀粉-MD-MCC复合膜的力学性能和阻水性能优于淀粉-MCC复合膜,其中MD-MCC添加量为5%时,复合膜具有最大的抗拉强度和阻水性能。 相似文献
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淀粉是食品工业的重要主辅料,其分子结构制约着淀粉基产品的性能。淀粉包括高度分支的支链淀粉(amylopectin,AP)和近似线性结构的直链淀粉(amylose,AM)。随着对淀粉结构循序渐进和不断完善的认识,学者们意识到仅用目前普遍认可的直链淀粉和支链淀粉的相关理论已不足以解释在探讨淀粉功能与结构研究中所遇到的诸多实际问题。研究表明淀粉中可能存在介于AP、AM之间的第3种级分,即中间级分(intermediate material,IM)。IM被认为是影响淀粉特性的主要因素之一,但其分子结构尚不明确,以至于未能全面理解淀粉的结构与性质。本文主要对淀粉中IM理论的提出、分离及其结构与性质等方面展开论述,以期为淀粉及IM结构的研究提供参考。 相似文献
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目的 研究湿度对糙糯米发芽过程中淀粉结构及糊化性能的影响。方法 通过扫描电镜、X射线衍射仪、拉曼光谱、差示扫描量热仪、快速粘度测定仪等方法测定糙糯米淀粉结构和糊化性能。结果 发芽处理破坏了糙糯米淀粉的颗粒结构、结晶结构和螺旋结构, 使其淀粉颗粒表面出现凹坑和孔洞, 颗粒粒径减小, 淀粉结构无序化程度增加, 且随着发芽过程中湿度条件的改变, 趋势越加明显。此外, 由于发芽处理对淀粉结构的影响, 致使淀粉的糊化温度、热糊稳定性升高, 而降低了淀粉糊的黏度性能。结论 发芽湿度条件能够显著影响糙糯米发芽过程中淀粉结构特性及糊化性能。 相似文献
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为了解细菌纤维素对淀粉凝胶老化的影响,利用快速黏度分析仪、差示扫描量热仪、X-射线衍射和扫描电镜测定添加不同量细菌纤维素的大米淀粉凝胶糊化特性、热力学特性、结晶性和微观结构。结果表明,随细菌纤维素添加量的增加,大米淀粉糊化时崩解值、回生值、糊化焓值显著降低,显示细菌纤维素抑制了大米淀粉凝胶的短期老化;随细菌纤维素添加量的增加,大米淀粉凝胶老化焓值显著降低,而重结晶从13.26%降至7.93%,说明细菌纤维素抑制了大米淀粉中支链淀粉的重结晶;大米淀粉凝胶微观结构显示细菌纤维素的添加使大米淀粉凝胶的表面更加完整、结构更加致密。由此表明细菌纤维素对大米淀粉凝胶老化具有显著的抑制作用。 相似文献
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淀粉是人类饮食中重要的能量来源之一,也是食品工业中重要的原材料。天然淀粉易受外界环境影响,如温度、pH、剪切力等,加工不稳定,限制了淀粉在食品领域中的应用。因此,需要对淀粉进行改性以提高淀粉的功能性,淀粉常采用物理、化学和酶法改性。近年来,消费者对绿色健康食品的需求增大,研究者正在寻找一种安全、环保、高效的方法。超声改性淀粉具有绿色环保、处理简单、高效安全等优点,是一种很有潜力的物理改性方法,近年来成为了研究热点。采用超声改性淀粉的实验研究很多,但关于超声改性对淀粉影响的相关性综述较少,因此,本文综述了近年来有关超声改性淀粉的研究进展,主要阐述超声改性机理及超声对淀粉颗粒结构、糊化特性、流变特性、透明度的影响,讨论了超声与其它方法复合改性对淀粉理化性质的影响,对其在食品中的应用进展进行综述,为拓展改性淀粉深加工在食品领域中的应用提供理论依据。 相似文献
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脂质与淀粉相互作用及其对淀粉性质影响 总被引:3,自引:0,他引:3
淀粉是食品重要成分,在食品体系中起到提供热能与影响质构作用,在蒸煮、焙烤等加热过程中,淀粉粒开始吸水膨胀,淀粉性质发生变化。淀粉中脂质或外加入脂质在淀粉加热过程中,影响淀粉特性变化;脂质存在会使淀粉溶胀性和溶解性降低,改变糊化温度和热焓,对淀粉流变性质也会产生影响。 相似文献
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Form and functionality of starch 总被引:7,自引:0,他引:7
Starch is a macro-constituent of many foods and its properties and interactions with other constituents, particularly water and lipids, are of interest to the food industry and for human nutrition. Starch varies greatly in form and functionality between and within botanical species, which provides starches of diverse properties but can also cause problems in processing due to inconsistency of raw materials. Being able to predict functionality from knowledge of the structure, and explain how starch interacts with other major food constituents remain significant challenges in food science, nutrition, and for the starch industry generally. This paper describes our current understanding of starch structure that is relevant to its functionality in foods and nutrition. Amylose influences the packing of amylopectin into crystallites and the organization of the crystalline lamellae within granules, which is important for properties related to water uptake. Thermal properties and gel formation appear to be influenced by both amylose content and amylopectin architecture. While amylose content is likely to have an important bearing on the functional properties of starch, subtle structural variations in the molecular architecture of amylopectin introduces uncertainty into the prediction of functional properties from amylose content alone. Our ability to relate starch granule structure to suitability for a particular food manufacturing process or its nutritional qualities depends not only on knowledge of the genetic and environmental factors that control starch biosynthesis, and in turn granule morphology, but also on how the material is processed. 相似文献
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Corn starch was treated by a dielectric barrier discharge plasma, and the changes in the granule morphology, crystalline structure, and molecular structure, as well as the rheological properties, were investigated using diverse techniques. Dielectric barrier discharge plasma could change not only the granule surface but also the internal structures of the starch granule through its pinholes. Specifically, after the plasma treatment, as the pinhole diameter increased, the relative degree of crystallinity decreased, accompanied by molecular chain oxidation, i.e., the generation of carboxyl groups, and degradation, i.e., molecular weight reduction. Therefore, the rheological behavior changed from pseudo-plastic to Newtonian with a decrease in the paste viscosity. The results indicate that dielectric barrier plasma could be used to produce modified starch with low viscosity at a high concentration for food and non-food applications.Industrial relevanceAs an eco-friendly and non-thermal physical technique, dielectric barrier discharge plasma has attracted great attention in polymer modification due to the interest in reducing generated wastes during modification and producing polymer products with high safety. Starch is traditionally a main material for foods and has been widely used in food and non-food industries. For improving the properties of starch and thus widening its industrial applications using a specific technique, it is indispensible to understand how the technique affects starch's structure and property. The present work revealed that not only was the surface of starch granules altered by the dielectric barrier discharge plasma but also the internal structure was affected, since the pinholes promoted the penetration of the plasma into granule interior. In particular, along with a reduced degree of crystallinity, molecular chain oxidation and degradation occurred, as confirmed by the generation of carboxyl groups and the molecular weight reduction. Then, the rheological behavior of starch paste changed from pseudo-plastic to non-Newtonian, together with a decreased paste viscosity. These results have demonstrated that dielectric barrier discharge plasma could be used as a new physical method to modulate the structure and rheological properties of starch, for the production of starchy food products with relatively low viscosity at a high concentration. 相似文献