高直链玉米淀粉络合体的慢消化性与结构鉴定

以单硬脂酸甘油酯（GMS）、硬脂酰乳酸钙（CSL）、月桂酸单甘酯（GML）等乳化剂为客体,高直链玉米淀粉（HACS）为主体原料,采用酒精碱法制备高直链玉米淀粉-乳化剂络合体。在淀粉∶无水乙醇∶水∶3 mol/L KOH=1∶2.8∶4.2∶5（w/v/v/v）条件下,制备的高直链玉米淀粉-单硬脂酸甘油酯络合体、高直链玉米淀粉-硬脂酰乳酸钙络合体和高直链玉米淀粉-月桂酸单甘酯络合体的络合率分别达到62.3%、52.1%和40.6%,慢消化淀粉含量分别达到47.4%、39.4%和32.9%。红外光谱技术和X-射线衍射技术研究结果表明,上述客体乳化剂与高直链玉米淀粉形成了络合物,呈现V-型晶体结构。此外,DSC结果表明,三种络合体热稳定性显著提高,峰值温度均在98℃以上。综上所述,酒精碱法制备的三种高直链玉米淀粉-乳化剂络合体中慢消化淀粉含量高、热稳定性好,可作为慢消化淀粉制备的重要途径。      

直链淀粉/大豆卵磷脂包合物的制备及其性质研究

目的:为了制备直链淀粉-大豆卵磷脂包合物并优化包合工艺以及对制得的直链淀粉包结络合大豆卵磷脂样品的结构性质进行分析研究。方法:本文以木薯淀粉为原料,加入普鲁兰酶酶解制备直链淀粉;在酶解后的淀粉中加入大豆卵磷脂溶液,制备直链淀粉-大豆卵磷脂包合物;通过单因素实验考察大豆卵磷脂的添加量、反应时间、反应温度对直链淀粉包结络合大豆卵磷脂反应效率的影响,采用X-射线衍射（XRD）、傅立叶变换红外光谱（FT-IR）、¹³C固体核磁共振谱(¹³C CP/MAS NMR)和差示扫描量热法（DSC）表征其结构。结果:直链淀粉-大豆卵磷脂包合工艺的最佳条件为:每克木薯干基淀粉添加0.16 g大豆卵磷脂,反应时间2 h,反应温度60℃。在最佳条件下得到包合物中大豆卵磷脂的含量为116.28 mg/g,包合率达到63.02%。XRD、FT-IR、DSC结果表明直链淀粉与大豆卵磷脂发生了包结络合作用,¹³C CP/MAS NMR结果表明是与大豆卵磷脂上的脂肪酸烃基发生了包结络合,大豆卵磷脂分子的其他基团位于直链淀粉螺旋空腔的外部。      

Structural factors governing starch digestion and glycemic responses and how they can be modified by enzymatic approaches: A review and a guide

Starch is the most abundant glycemic carbohydrate in the human diet. Consumption of starch-rich food products that elicit high glycemic responses has been linked to the occurrence of noncommunicable diseases such as cardiovascular disease and diabetes mellitus type II. Understanding the structural features that govern starch digestibility is a prerequisite for developing strategies to mitigate any negative health implications it may have. Here, we review the aspects of the fine molecular structure that in native, gelatinized, and gelled/retrograded starch directly impact its digestibility and thus human health. We next provide an informed guidance for lowering its digestibility by using specific enzymes tailoring its molecular and three-dimensional supramolecular structure. We finally discuss in vivo studies of the glycemic responses to enzymatically modified starches and relevant food applications. Overall, structure–digestibility relationships provide opportunities for targeted modification of starch during food production and improving the nutritional profile of starchy foods.     

玉米直链淀粉的酶法制备及其性质的研究

以市售玉米淀粉为原料,糊化后采用异淀粉酶进行酶解脱支实验,以制备酶解玉米直链淀粉。该文通过单因素和正交试验,最终确定,在淀粉乳浓度为10%,酶解温度为50℃,酶解p H为6,异淀粉酶添加量为25 U/g(干淀粉),酶解时间为2 h时,得到的直链淀粉含量最高,为60.26%。理化性质表明,在酶解过程中没有产生新的基团,酶解过后淀粉颗粒遭到破坏,呈不规则层状结构。     

Starch fraction profiles of milled,nonparboiled rice varieties from Nigeria

This study determined the levels of nutritionally important starch fractions in selected milled, nonparboiled rice cultivated in Nigeria. Five improved varieties (FARO 52, FARO 57, FARO 44, FARO 60 and FARO 61) and four local varieties (Kwandala, Yardass, Jeep and Jamila) were evaluated. There were significant differences in starch fractions among varieties. Resistant starch (RS) ranged between 1.43% and 3.13%. Rapidly digestible starch (RDS) was lowest in Jamila (27.70%) and highest in FARO 61 (39.26%). Generally, the local varieties had significant higher RS (2.71%) with a lower RDS (32.82%) compared with improved varieties (RS; 1.88% and RDS; 36.07%). RS was inversely related to RDS and starch digestion index (SDI). The SDI had a highly significant positive correlation with RDS (r = 0.879, P < 0.01). These results highlight the need for further work in the identification of milled, nonparboiled rice varieties with less rapid digestion for its associated health benefits to consumers.     

直链淀粉——风味分子包合物制备及结构表征

直链淀粉系由葡萄糖以α–1,4糖苷键聚合,分子内氢键作用使链卷曲成线性螺旋状分子,每个环圈含6~8个葡萄糖残基,其螺旋状结构能与食品中多种风味分子形成包合物,可对风味分子释放具有重要影响。该文对直链淀粉―风味分子包合物制备及其结构表征方法研究状况进行综述,并根据国内外研究进展,对直链淀粉在食品、化妆品和药品中应用加以叙述。     

退火处理对慢消化淀粉形成及性质影响

以蜡质玉米淀粉为原料,研究退火处理方法对慢性消化淀粉(SDS)形成影响,并对性质和机理进行研究。结果表明,淀粉样品在水分含量60%、温度55℃、处理时间24 h条件下SDS含量达8.01%;经退火处理后淀粉颗粒整体结构变化不大,但在淀粉颗粒表面出现不同程度凹坑、裂纹和碎片,偏光十字依旧清晰,结晶晶形为A形;由于热量和水分长时间作用,使淀粉颗粒内部结晶结构更完美,提高SDS含量,降低淀粉消化性。     

食品制造方法对膳食淀粉消化性能的影响(Ⅱ)——热加工

研究了3种不同的加热方式(煮沸、加压蒸煮、微波加热)对不同植物来源膳食淀粉消化性能的影响。结果表明:相比普通煮沸处理,加压蒸煮与微波加热对淀粉的消化性能影响较显著。加压蒸煮与微波加热使淀粉颗粒中直链淀粉浸析出来,淀粉糊化度增加,淀粉营养片断慢消化淀粉(SDS)与抗性淀粉(RS)大部分转化成易消化淀粉(RDS),消化指数指数达到80%左右,可降解淀粉营养片断与直链淀粉含量成负相关,与糊化度成正相关。不同热加工方法会影响淀粉中营养片断的比例。     

不同配方饼干中慢消化淀粉含量的研究

为了考查不同配方饼干中慢消化淀粉含量的差异,研究了淀粉脂质复合物、高链玉米淀粉、小麦淀粉、低筋面粉和高筋面粉在烘烤前后淀粉消化性的变化;考查了饼干加工中水油配比对淀粉消化性的影响;将淀粉脂质复合物、高链淀粉和小麦淀粉添加到高筋面粉中制成饼干,考查了添加原料对饼干中淀粉消化性的影响。结果表明,淀粉脂质复合物在烘烤后慢消化淀粉和抗消化淀粉含量变化很小,分别为38.75%和17.27%,其他几种原料在烘烤后慢消化淀粉和抗性淀粉含量降低显著;当用水量为45%,用油量为20%时,制成的饼干中慢消化淀粉达到最高为12.78%;以淀粉脂质复合物为添加原料制备的饼干慢消化淀粉含量最高,达到23.56%。     

慢消化淀粉的研究与分析

慢消化淀粉是一种新型的食品资源,因其特殊的功能性质而日益成为食品科学和现代营养学领域研究的热点。文中综述了近年来国内外慢消化淀粉的研究进展,并简要介绍了其保健功效、制备及体外检测方法的研究状况,展望了其在食品领域中的应用前景。     

抗性、慢消化淀粉的制备及其控血糖机理的研究进展

抗性淀粉（RS）与慢消化淀粉（SDS）因其良好的抗消化性和功能特性得到了广泛关注,研究已证实其在调控血糖方面具有显著效果,成为近年来兴起的新型功能性食品原料。本文介绍了RS与SDS在物理、化学、生物方面主要制备方法及其形成机制,对RS与SDS在不同动物模型体内可能存在的血糖调控机理进行了整合,例举了它们在功能性食品中的应用,并对现存的问题作了展望,为未来RS与SDS的研究与应用提供参考。     

Gluten‐Free Snacks Using Plantain–Chickpea and Maize Blend: Chemical Composition,Starch Digestibility,and Predicted Glycemic Index

An increase in celiac consumers has caused an increasing interest to develop good quality gluten‐free food products with high nutritional value. Snack foods are consumed worldwide and have become a normal part of the eating habits of the celiac population making them a target to improve their nutritive value. Extrusion and deep‐frying of unripe plantain, chickpea, and maize flours blends produced gluten‐free snacks with high dietary fiber contents (13.7–18.2 g/100 g) and low predicted glycemic index (28 to 35). The gluten‐free snacks presented lower fat content (12.7 to 13.6 g/100 g) than those reported in similar commercial snacks. The snack with the highest unripe plantain flour showed higher slowly digestible starch (11.6 and 13.4 g/100 g) than its counterpart with the highest chickpea flour level (6 g/100 g). The overall acceptability of the gluten‐free snacks was similar to that chili‐flavored commercial snack. It was possible to develop gluten‐free snacks with high dietary fiber content and low predicted glycemic index with the blend of the 3 flours, and these gluten‐free snacks may also be useful as an alternative to reduce excess weight and obesity problems in the general population and celiac community.     

微波制备淀粉-油酸复合物及其消化特性的研究

目的微波制备淀粉-油酸复合物,降低大米淀粉消化速率,调控其消化特性。方法在微波作用下,将油酸引入淀粉体系使其与直链淀粉相互作用形成复合物,分析比较复合物的短程有序度、结晶结构、晶粒大小、热稳定性与消化特性的关系。结果相比于原淀粉,油酸的引入提高了淀粉的抗消化性,淀粉与油酸形成的复合物呈典型的V型结晶结构,并显示出比原淀粉更好的热稳定性。淀粉油酸复合物的短程有序度、相对结晶度、晶粒尺寸与微波处理温度呈负相关,且较低温度下制备的复合物具有更好的抗消化性。结论淀粉和油酸复合后消化速率降低,较低微波处理温度下制备的淀粉油酸复合物结晶结构更好,因而赋予其更好的抗消化性。     

双酶协同制备玉米慢消化淀粉及其性质研究

以普通玉米淀粉为原料,利用β-淀粉酶和葡萄糖苷转移酶协同处理制备慢消化淀粉,并研究其理化性质。试验表明,原淀粉在β-淀粉酶加酶量为20 mL、反应时间为4 h,葡萄糖苷转移酶加酶量为20 mL、反应时间为12 h时,慢消化淀粉含量最高可达16.37%;所有经过双酶处理后的样品的淀粉-碘吸附结合物的最大吸收峰位置,随着慢消化淀粉含量的增加而偏移增大;差示扫描量热仪结果表明慢消化淀粉样品的糊化起始温度、峰值温度、终止温度、起始与终止温度差均有显著的升高,淀粉热稳定性增强,糊化变得困难;与玉米原淀粉A型结晶结构相比,所有样品的晶型消失,仅在2？=19.8°附近出现尖锐的衍射峰,2？=13.1？附近有一弥散峰;扫描电镜结果显示,酶解后的样品变成不规则碎片,不再具有原淀粉的颗粒结构。     

Starch Structure Influences Its Digestibility: A Review

Twenty‐five years ago, it was found that a significant fraction of the starch present in foods is not digested in the small intestine and continues to the large intestine, where it is fermented by the microbiota; this fraction was named resistant starch (RS). It was also reported that there is a fraction of starch that is slowly digested, sustaining a release of glucose in the small intestine. Later, health benefits were found to be associated with the consumption of this fraction, called slowly digestible starch (SDS). The authors declare both fractions to be “nutraceutical starch.” An overview of the structure of both fractions (RS and SDS), as well as their nutraceutical characteristics, is presented with the objective of suggesting methods and processes that will increase both fractions in starchy foods and prevent diseases that are associated with the consumption of glycemic carbohydrates.     

挤压和酶解挤压对豌豆粉淀粉体外消化率、蛋白质结构和流变特性的影响

目的:研究挤压和酶解挤压处理对豌豆粉理化性质的影响.方法:采用挤压和酶解挤压的方法改性豌豆粉,利用扫描电子显微镜、X射线衍射仪、傅里叶变换红外光谱、快速黏度分析仪、流变仪分析原料、挤出物和酶解物3种样品的结构变化,并测定体外淀粉消化特性.结果:挤压处理能部分破坏豌豆的结构,表现为相对结晶度下降,I1045cm-1/I1...     

湿热处理法制备慢消化淀粉及其性质研究

以蜡质玉米淀粉为原料,采用湿热处理法制备慢消化淀粉,并研究了其性质。研究出湿热处理制备慢消化淀粉的优化工艺为:淀粉体系的水分含量35%(w/w),温度120℃,时间为10h,慢消化淀粉含量达9.25%。扫描电镜照片显示,湿热处理后淀粉颗粒表面出现了裂纹和凹坑,淀粉糊化温度升高,峰值粘度降低。     

韧化处理条件下缓慢消化玉米淀粉的形成机理

探讨韧化处理条件下,缓慢消化玉米淀粉的形成过程。分别采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、差示扫描量热仪(DSC)研究韧化处理前后玉米淀粉颗粒形貌、结晶特性、热焓特性的变化情况。结果表明,韧化处理对玉米淀粉的颗粒形貌基本无影响,处理后基本保持原来的A型结晶结构,但结晶结合更为紧密,韧化玉米淀粉和去除快速消化玉米淀粉(RDS)的韧化玉米淀粉相比,DSC图谱的To、Tp、Tc以及Tc－To均较原玉米淀粉有所提高。这表明,韧化处理过程促进缓慢消化玉米淀粉的形成主要是通过调整玉米淀粉的结晶结构,使其结合更为紧密,从而对酶的抵抗作用增强而实现的。     

环糊精包合物的制备方法

环糊精是由6～12个葡萄糖基构成的环状化合物,主要有α、β和γ环糊精(分别由6、7和8个葡萄糖基构成)。它们具有亲水的外围及疏水的内腔,可与许多种物质形成包结物而改变物质的物理和化学特性,因而被广泛应用于各个领域。为了更好地研究环糊精包结物,本文总结出环糊精包合物的各种制备和检测方法。      

淀粉的慢消化性能与酶水解速率研究

研究了体外模拟条件下不同淀粉中营养片断,同时建立了酶水解动力学方程来探讨慢消化性能与酶水解速率的关系。结果表明,相比马铃薯与绿豆淀粉,玉米、蜡质玉米、小麦、糯米、大米等谷物淀粉属于理想的慢消化淀粉,它们的酶动力学水解速率小于1h-1,而马铃薯与绿豆淀粉的水解速率大于1h-1。淀粉的水解过程的反应动力学速率比Englyst法更能准确反映淀粉的消化性能。