四川地方大米品种特性对方便米粉品质的影响

以四川省农业科学研究院试验区筛选出的7种优质杂交水稻为研究对象,米粉工业常用大米作对照,通过测定原料基本成分、米粉感官品质、蒸煮品质和质构特性等指标,研究不同品种四川地方大米原料对方便米粉品质的影响,通过相关分析建立大米原料品种指标与米粉品质间的相关性。结果表明:原料米品种对方便米粉感官品质、蒸煮品质、质构特性的均有显著影响。米粉的劲道、爽滑、风味等感官指标及其综合评分,质构特性与大米直链淀粉含量均呈显著的正相关性。米粉的断条率、复水时间与大米的直链淀粉含量、蛋白质含量呈显著的负相关性,与大米的支链淀粉含量、粗脂肪含量呈显著的正相关性(P0.05或P0.01)。当大米直链淀粉含量在21.40%～25.61%时,米粉感官品质、硬度、拉伸长度和断条率均最优。采用本实验方法制作米粉时,4#、5#、6#这3种大米加工的米粉品质较好,为进一步确定四川方便米粉原料标准化提供了参考依据。     

东北大米食用品质的调查分析

本试验主要研究了 5 2种东北大米的食用品质特性 ,与河北省大米相比 ,东北大米蛋白质含量普遍较高 ,直链淀粉含量较低 ,适合于加工米粉和方便米饭等米制食品 ,而且米饭光泽度好。     

东北大米食用品质的调查分析

本试验主要研究了52种东北大米的食用品质特性，与河北省大米相比，东北大米蛋白质含量普遍较高，直链淀粉含量较低，适合于加工米粉和方便米饭等米制食品，而且米饭光泽度好。     

大米及其衍生食品风味物质的研究进展

大米作为我国主要成品粮,风味及品质备受关注。不同品种和产地的大米,具有其独特的风味。对比目前提取大米风味物质的方法（溶剂萃取法、同时蒸馏法、固相微萃取法、吹扫捕集法、超临界萃取法等）;探讨大米风味物质的产生机制,不同稻谷品种、生长环境、储存条件、直链淀粉含量、蒸煮方法、浸泡时间等都会对大米风味产生影响,目前尚未明确挥发性物质与香气的关系,但普遍认为2-AP是区别香型和非香型大米的标志性物质;阐述一些大米衍生食品的风味物质、加工方式及其产生机制等。为大米风味物质的回收及应用提供一定参考及理论基础。     

大米淀粉结构组成与其品质特性关系的研究进展

淀粉是大米的主要组成成分,其含量及性质直接影响了大米的食用和加工品质。研究表明,通过对大米淀粉的结构组成进行分析可以推断大米原料的品质及加工特性。通过对大米淀粉的结构组成、直/支链淀粉协同互作作用、淀粉颗粒大小及淀粉陈化作用等方面的研究成果进行综述,提出大米淀粉加工过程中需要考虑的与品质改变相关的关键控制点,归纳大米淀粉结构变化影响机制,为进一步系统了解大米淀粉结构变化对其品质特性的影响提供研究思路。     

直链淀粉分子螺旋对风味化合物包埋的研究进展

综述了直链淀粉分子螺旋结构对风味化合物包埋的研究进展,探讨了直链淀粉复合物的形成、结构特性和分子模拟,以及影响直链淀粉复合物释放的因素和直链淀粉复合物对食物体系的影响,最后展望了直链淀粉复合物在食品应用中的巨大潜力。综合研究结果表明,在风味化合物存在的情况下,直链淀粉由双螺旋结构转变为单螺旋结构,形成具有疏水空腔和亲水性的螺旋结构,使其能够形成包合物。风味分子包括在腔内或在螺旋之间,或在这两个位置,取决于分子的结构。直链淀粉包合物具有良好的耐高温性能,可以防止不稳定风味物质在加工和贮存过程中的损失,在食品工业中具有广阔的应用前景。此外,复合物的释放还可以通过α-淀粉酶的水解以及水分和温度的变化来控制。     

大米基本成分与米发糕品质间相关性探讨

对10种大米的基本成分及其所加工成的米发糕品质进行分析,并对大米基本成分与米发糕的感官品质、质构特性之间相关性进行探讨。结果表明:影响米发糕品质的主要因素是大米直链淀粉含量、蛋白质含量、水分含量,其中直链淀粉含量对米发糕品质的影响最大;大米的直链淀粉含量与米发糕的比容、结构、回复性呈极显著正相关,与米发糕的外观形状、硬度、咀嚼性呈显著正相关;大米的蛋白质含量与米发糕的外观形状、硬度和咀嚼性呈显著负相关;大米的水分含量与米发糕的弹性呈显著负相关。     

大米淀粉特性与米线品质关系的研究

文章分析了14个稻米品种的淀粉特性,探讨了大米淀粉特性与米线品质的关系,并分别建立了米线品质各指标与直链淀粉含量、淀粉的溶解度、膨胀力和老化特性之间的回归模型。结果表明:直链淀粉含量对米线品质影响最大;直链淀粉含量、淀粉的溶解度、膨胀力和老化特性4个因素对米线煮沸损失、复水时间、断条率和口感都有显著影响;而对加工效果影响显著的只有直链淀粉含量。     

淀粉精细结构与大米蒸煮食味品质相关性的研究进展

稻米是我国最重要的粮食作物之一，作为食物时需要完全熟化，蒸煮食味品质是决定消费者对大米接受程度的关键因素。淀粉是大米最主要的成分，其精细结构是具有相似表观直链淀粉含量的水稻品种之间食味品质差异的主要原因之一，研究淀粉精细结构对大米蒸煮食用品质的影响具有重要理论意义和实用价值。该文综述了淀粉精细结构(淀粉分子大小分布、链长分布、支链淀粉的平均链长、分支化度等)与大米蒸煮食味品质相关性的研究进展，通过分析淀粉分子精细结构与糊化、回生、质构特性等重要蒸煮食味品质指标的关系，揭示了具有优质食味品质稻米的淀粉结构基础，以期为优质大米的育种和评价提供参考。     

大米品种特性与面窝品质的相关分析

对大米的品种特性及其加工的面窝的感官品质和质构特性进行研究,并对二者的相关性进行探讨,确定面窝生产用原料大米的选择标准。结果表明：大米中蛋白质含量、直链淀粉含量和垩白度是评价大米品种的主要指标;大米直链淀粉含量与面窝品质呈显著正相关关系,可以作为面窝生产用原料大米的选择指标。     

Study of starch-lipid complexes in model system and real food produced using extrusion-cooking technology

The formation of starch-lipid complexes during extrusion of model system (rice starch added with oleic acid) and real food (rice starch added with pistachio nut flour) was evaluated. Both formulas were extruded at the same processing conditions (temperature profiles, screw speed and water feed content).The formation of starch-lipid complexes in real food, is strongly dependent on water feed content. In fact, at barrel temperature of 128 °C, the highest melting enthalpy of real food (6.7 J/g) was obtained only at 21% of water feed content whereas in the model system it was obtained both at 16 and 21%.These results point out the importance to consider all components present in the extruded food in order to study biopolymers modifications that occur during processing.

Industrial relevance

Additions of lipids alter the physical and chemical properties of starchy foods. The changes brought about by them in starchy foods have been attributed to the formation of complexes between amylose and lipids. These changes in the functionality of starch are of interest to the food industry and for human nutrition. Lipid complexation with starch is a very important reaction in extrusion cooking that affects structure formation and texture of the extruded products. Most studies on the starch-lipid complex formation during extrusion of model systems like starch and free fatty acids have been carried out, instead very little is known about starch-lipid complex formation during extrusion of flour blends containing fatty meal. This paper points out the importance to consider all components present in the food extruded in order to study biopolymers modifications that occur during processing. For this reason it is very important to use model systems that are not very different to real food and anyhow it would be advisable to verify the obtained results on real food, above all when a relation between macromolecular modifications and quality characteristics of extruded products would be studied.     

直链淀粉含量及检测方法与抗性淀粉增抗效应研究

直链淀粉含量及其品质对抗性淀粉的形成有着重要的影响,采用碱液分散法和碘吸光度法测量早米淀粉、葛根淀粉、青稞淀粉、绿豆淀粉、高粱淀粉、藕淀粉6种淀粉类原料的直链淀粉含量,采用循环老化工艺增抗并测定抗性淀粉含量,结果表明,抗性淀粉的得率与原料中的直链淀粉含量有密切的关系,同时,也与各淀粉中直链淀粉和支链淀粉的分子结构、平均聚合度有一定关系,与碘吸光度法相比,碱液分散法测得的直链淀粉含量能更好地预测原料淀粉增抗后的抗性淀粉得率.     

Form and functionality of starch

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.     

淀粉老化过程机理及淀粉抗老化剂应用的研究进展

淀粉老化是淀粉糊化过程中分解的直链淀粉和支链淀粉重新连接并形成更加有序结构的过程。淀粉老化是食品老化的主要原因,对淀粉质食品的感官、储存质量、风味等有不利影响。随着食品行业发展,延长食品货架期、保持食品原有风味及口感愈来愈重要。本文介绍了淀粉老化过程,并从老化动力学、热力学和淀粉晶体等方面探讨淀粉老化机理并综述淀粉老化机理研究方法,在此基础上,介绍抗老化剂在食品体系中的应用,为有效抑制淀粉老化,延长食品的货架期提供理论支持。     

食物中抗性淀粉的含量分析

对我国常见食品中可消化淀粉(DS)和抗性淀粉(RS)的含量进行分析,初步评价食品来源和加工方法对RS的影响。文中选择80种食物样品,依照AOAC 2002.2方法分析食物中DS和RS含量分析;并分析了不同直链淀粉比例、常规烹调加工方法下RS的含量。结果食物RS受来源和加工方法影响较大,豆类、生的薯类、饼干食品、含直链50%淀粉的玉米RS含量相对较高;淀粉中直链淀粉比例为50%时,RS含量较高;碾磨、蒸煮、膨化使RS含量降低,特殊工业加工的高RS产品蒸煮后RS不被破坏。     

Classification of Rice Starch Amylose Content from Rheological Changes of Starch Paste after Cold Recrystallization

Following storage at 4°C for 24 h (recrystallization) rice starch pastes with low and medium amylose content exhibited a lower increase in consistency index, shear stress and Casson plastic viscosities than pastes with high amylose content. On the other hand, high amylose rice starch showed a higher degree of retrogradation than rice starch of lower amylose content.     

压榨型干米粉专用米关键指标的研究

为确定压榨型干米粉专用米的特征指标,文章以17种籼米为原料,运用相关分析、主成分分析、聚类分析以及逐步回归分析法探讨大米原料品质和糊化特性对干米粉食用品质和质构品质的影响。结果表明:大米原料中的直链淀粉含量、淀粉含量、脂肪含量、脂肪酸值,糊化特性中的最低黏度、最终黏度、崩解值、回生值、胶稠度,与干米粉的蒸煮品质和质构品质存在显著(P<0.05)相关性;其中影响米粉综合品质的关键性指标为直链淀粉含量、最终黏度和胶稠度;聚类分析得出的适宜加工压榨型干米粉的原料大米的直链淀粉含量应大于22%,淀粉的最终黏度应大于3963 cP,胶稠度应小于46 mm。     

Physicochemical Properties of Starch and Flour from Different Rice Cultivars

The starches and flours from four different rice cultivars were evaluated for composition, crystallinity characteristics, blue value, turbidity, swelling power, solubility, pasting properties, and textural and retrogradation properties. The amylose content of starches and flours from different rice cultivars differed significantly. The results showed that the physicochemical properties of rice starch and rice flour were correlated to amylose content. The crystallinity degree of rice starch and flour depended on amylose content. The blue value, turbidity value, and gel hardness were positively correlated to amylose content; however, the swelling power, solubility, and gel adhesiveness were negatively correlated to amylose content. Furthermore, the pasting properties and gel textural and retrogradation properties of rice flours were related to the structure properties of rice starch. And the characteristics of starch, protein, and lipid significantly influenced the turbidity, pasting properties, and gel textural and retrogradation properties of rice flours.