直链淀粉-脂质复合物的形成及其结构性质研究进展

直链淀粉-脂质复合物的形成赋予淀粉抗消化、包埋有益脂质、改善食品质地等优良特性,同时还可以调控淀粉的糊化、老化等性质,已逐渐成为淀粉改性领域的研究热点。文中综述了近年来直链淀粉-脂质复合物的研究进展,概括了国内外主流及新兴的制备方法,探讨了复合物的结构性质、形成机理,并介绍了复合物对淀粉理化和功能特性的影响,最后展望了其在食品行业中的应用前景。     

月桂酸添加方式对甘薯淀粉及膜性能的影响研究

采用甘油为增塑剂制备淀粉膜,研究了月桂酸添加方式对甘薯淀粉及膜性能的影响。结果表明：对淀粉进行方法 I (加热后添加月桂酸)处理时,直链淀粉-脂质复合物分布在淀粉颗粒表面和内部,而对淀粉进行方法 II (加热前添加月桂酸)处理时,直链淀粉-脂质复合物主要分布在淀粉颗粒表面;方法 I 和方法 II 处理后的淀粉在热分析图中均出现了直链淀粉-脂质复合物的熔融峰;随着月桂酸的加入,淀粉糊各特征点黏度值均出现不同程度的改变;加入月桂酸后,淀粉结晶度降低,在 2θ = 20.15° 处均出现了直链淀粉-脂质复合物的特征衍射峰;加入月桂酸后,淀粉膜表面变得平整,断裂伸长率降低,而抗拉强度和接触角变大;与方法 I 相比,方法 II 更适宜制备淀粉膜。     

淀粉-脂质复合物的形成及其性质的研究进展

淀粉中的直链淀粉由线性分子组成,具有螺旋结构,在适当的条件下脂质等小分子客体可以进入疏水螺旋空腔内,进而形成复合物.此复合物能够改善淀粉的一些功能性质,如可以降低淀粉在水中的溶解度、提高淀粉的稳定性、延缓淀粉的老化、减缓淀粉的消化、制备新型淀粉等.目前,对淀粉-脂质复合物的研究为淀粉基物料提供新的应用平台.该文主要介绍...     

基于分子动力学模拟研究淀粉与脂质和蛋白质的相互作用：现状分析与未来趋势

淀粉、脂质和蛋白质在热加工中的相互作用会显著影响最终食品的风味、口感、质构、营养特性以及货架期,近年来受到了学术界和工业界的广泛关注。理解淀粉与其他组分在加工过程中的相互作用机制对于食品加工过程品质控制具有重要的理论意义。分子动力学模拟作为一种重要的理论计算分析手段,对于深入揭示淀粉与其他食品组分之间的相互作用机制起着至关重要的辅助作用,近年来引起了人们的广泛关注。作者在简要介绍了淀粉-脂质及淀粉-脂质-蛋白质复合物的形成及结构的基础上,系统综述了分子动力学模拟技术的基本原理、概念和操作流程及其在研究淀粉与脂质和蛋白质相互作用中的应用方面的最新进展,并对未来的发展趋势进行了展望。     

直链淀粉含量对淀粉-脂肪酸复合物形成及理化特性的影响

本研究以不同直支比的玉米淀粉和硬脂酸为原料制备了三种不同的淀粉-脂质复合物,并采用扫描电镜、X射线衍射、傅里叶红外光谱等分析方法对淀粉-脂质复合物外部形态、晶体结构、抗消化性、缓释性等进行了表征与测定。结果表明:在扫描电镜下观察,与原淀粉相比,复合物的体积增大,同时表面凹凸不平。红外光谱证明淀粉-脂质复合物的形成,同时氢键的增加可能会导致抗性淀粉含量增加。复合物的形成使得晶体构象变为V型结构。普通玉米淀粉（normal）及高直链玉米淀粉（G60）在处理后快消化淀粉（RDS）含量减少,慢消化淀粉（SDS）含量增加,抗性淀粉（RS）含量增加,其中抗性淀粉含量分别达到52.0%和52.4%。硬脂酸在复合物内的释放分为两个阶段呈现先快后慢的趋势,并且直链淀粉含量的增加能够显著提高复合物对于硬脂酸的缓释能力。本文可为进一步提高直链淀粉的应用范围提供参考依据。     

乳化剂与直链淀粉相互作用及其对蛋糕品质影响的研究

通过差示扫描量热分析仪(DSC)和蓝值测定几种乳化剂与淀粉的络合能力,并对其对蛋糕的品质和老化特性的影响进行研究,结果表明,与淀粉络合能力强的乳化剂生产出来的蛋糕的品质和抗老化性要比络合能力弱的乳化剂好。研究和探讨了乳化剂对浆料比重、蛋糕比容和蛋糕质构的影响,结果表明,乳化剂的加入使浆料比重降低,蛋糕比容增加,使得保存1d的蛋糕的硬度降低,弹性和咀嚼性提高,乳化剂对蛋糕的回复性也有一定的影响。      

制备工艺对高直链玉米淀粉—硬脂酸复合物性质的影响

[目的]优化高抗性淀粉（RS）含量的淀粉—脂质复合物制备工艺,探究工艺参数对复合物抗消化性的影响。[方法]采用单因素试验和正交设计研究了高直链玉米淀粉（HA）预处理及其与硬脂酸（SA）络合过程中温度和时间参数对复合物RS含量的影响,分析最优工艺制备的HA-SA复合物的理化性质、抗消化性及水合特性。[结果]在糊化温区继续升高预处理温度、延长预处理时间、络合温度高于75 ℃均导致RS含量显著降低（P＜0.05）;HA-SA复合物最优制备工艺为：HA经85 ℃的退火温度预处理12 h后,在75 ℃与SA络合90 min;所制备的HA-SA具有V型晶体特征、完整的淀粉颗粒,为Ⅰ型淀粉—脂质复合物;与HA相比,其热稳定性、抗消化性显著升高,但膨胀力显著降低（P＜0.05）。[结论]退火温度预处理和适宜的络合温度有利于HA-SA中RS组分的形成;预处理过程中加热强度的增加使淀粉过度糊化,阻碍了直链淀粉与脂质的络合,络合过程中过高的温度也导致复合物中RS组分的解离,使RS含量降低;退火预处理使HA保留了完整的颗粒结构,是HA-SA抗消化性高的原因之一。     

不同加工方式对淀粉性质的影响

淀粉作为食品尤其是谷物制品的主要成分,在人类日常饮食中占有十分重要的地位。超高压、油炸、发酵、挤压和微波作为食品领域5种常用的加工手段,能显著地改变淀粉的糊化、老化、结晶等理化性质,影响其与食品其他组分之间的相互作用,进而影响食品的品质。作者主要综述了这5种加工技术在淀粉类食品中的应用,分析它们对淀粉性质的影响及作用机理,以期为淀粉类食品的深入开发提供一定的参考。     

反复/连续湿热制备淀粉-脂质复合物及其性质分析

为了解决目前制备淀粉-脂质复合物存在的复合率低、工艺复杂、产生工业废液污染物等问题,本研究利用反复/连续交替湿热技术制备高复合率的高直链玉米淀粉-大豆卵磷脂复合物,并对优化的复合物进行结构、理化和预测血糖指数的测定。结果表明,通过单因素实验和正交试验确定最高复合率条件为:湿热处理温度140 ℃,连续湿热处理时间4 h,反复湿热处理6次,交替周期为2周期,得到复合率最大(59.05%)的淀粉-卵磷脂复合物。傅里叶红外光谱测定表明大豆卵磷脂特有的2个吸收峰(2 710 cm-1和2 680 cm-1)在复合物中未出现,验证了此改性技术成功地将大豆卵磷脂复合在淀粉的螺旋空腔中,通过X-射线衍射图谱观察到复合物在衍射角20°时衍射峰强度明显增加。此外,复合物冻融稳定性明显提升,预测血糖指数显著降低。结论:反复/连续交替湿热技术作为一种绿色安全、操作简单的物理改性技术,提高了淀粉-卵磷脂复合物的复合率,并显著降低了淀粉的预测血糖指数,为淀粉复合物的发展提供了新思路。     

玉米淀粉-脂质复合物对曲奇饼干体外消化和血糖生成指数的影响

目的 探究玉米淀粉-脂质复合物的结构和消化特性以及对曲奇饼干的体外消化特性与血糖生成指数的影响。方法 利用水热法制备了制备不同脂质(包括饱和脂肪酸与不饱和脂肪酸)与玉米直链淀粉的复合物, 通过傅里叶红外光谱仪(fourier transform infrared spectroscopy, FT-IR)与X-射线衍射(X-ray diffractometer, XRD)探究了淀粉分子短程和长程有序性。结果 研究表明, 淀粉-脂质复合物的形成使快消化淀粉含量显著降低, 慢消化淀粉和抗性淀粉含量显著增加。水热法制备中通过疏水相互作用得到的淀粉-脂质复合物利用氢键链接使其结构更加稳定, 体外消化速率呈降低趋势。其中玉米淀粉-卵磷脂复合物、玉米淀粉-硬脂酸复合物与玉米淀粉-肉豆蔻酸复合物为 V+B 型晶体结构, 玉米淀粉-大豆油复合物与玉米淀粉-玉米油复合物的晶型结构未发生改变。在五种淀粉-脂质复合物中, 玉米淀粉-卵磷脂复合物的水解率最低, 水解指数预估血糖指数分别为44.65%、64.22%, 所对应的曲奇饼干的水解指数与预估血糖指数也最低, 分别为51.68%、68.08%。结论 表明玉米淀粉-卵磷脂复合物适合作为新型淀粉-脂质复合物用于开发具有低血糖指数的饼干食品。     

稻米中脂质对淀粉性质影响的研究进展（网络首发、推荐阅读）

脂质是稻米中除淀粉、蛋白质以外的一种重要组分,不仅具有独特的营养价值,且对淀粉的功能特性有很大影响。概述了稻米中脂质的种类、结构、分布及含量,讨论了淀粉与脂质的相互作用机理、结构特征与影响因素,及淀粉与脂质相互作用对淀粉特性的影响,包括溶胀、糊化、流变、回生和消化特性,为进一步研究稻米中淀粉与内源性脂质的相互作用及其对稻米淀粉性质的影响提供参考,有助于稻米品质改良及功能性稻米的开发。     

绿豆微孔淀粉酶法制备工艺优化研究

以水解率为指标,研究α-淀粉酶与糖化酶复合水解绿豆淀粉制备微孔淀粉工艺条件,通过单因素和正交试验确定酶解最佳工艺条件：α-淀粉酶：糖化酶=1：3,酶用量2．0%,时间20 h,温度42℃,pH4．2。经吸水、吸油率测试,对酶解前后绿豆淀粉进行性质分析表明,微孔淀粉吸水、吸油能力明显大于原淀粉。     

Structural characterizations and digestibility of debranched high-amylose maize starch complexed with lauric acid

Structural characterizations and digestibility of debranched high-amylose maize starch complexed with lauric acid (LA) were studied. The cooked starch was debranched by using pullulanase and then complexed. Light microscopy showed that the lipids complexed starches had irregularly-shaped particles with strong birefringence. Gel-permeation chromatograms revealed that amylopectin degraded to smaller molecules during increasing debranching time, and the debranch reaction was completed at 12 h. Debranching pretreatment and prolonged debranching time (from 2 h to 24 h) could improve the formation of starch lipids complex. X-ray diffraction pattern of the amylose–lipid complexes changed from V-type to a mixture of B- and V-type polymorphs and relative crystallinity increased as the debranching time increased from 0 to 24 h. In DSC thermograms, complexes from debranched starch displayed three separated endotherms: the melting of the free lauric acid, starch–lipid complexes and retrograded amylose, respectively. The melting temperature and enthalpy changes of starch–lipid complex were gradually enhanced with the increasing of debranching time. However, no significant enthalpy changes were observed from retrograded amylose during the starch–lipid complex formation. Rapidly digestible starch (RDS) content decreased and resistant starch (RS) content increased with the increasing of debranching time, while the highest slowly digestible starch (SDS) content was founded at less debranching time of 2 h. The crystalline structures with dense aggregation of helices from amylose-LA complex and retrograded amylose could be RS, while SDS mostly consisted of imperfect packing of helices between amylopectin residue and amylose or LA.     

Preparation of resistant starch from starch–guar gum extrudates and their properties

Mixtures of starch, guar gum and citric acid were extruded at a temperature of 150 °C and screw speed of 180 rpm. Properties of the extrudates such as bulk density, expansion ratio, apparent viscosity and resistant starch content were measured with different concentrations of guar gum. Extrusion with citric acid influenced the physical properties and resistant starch content of the extrudate. Expansion ratios were lower for samples extruded with citric acid, and decreased as starch–gum concentration increased. The apparent viscosity of the extrudate increased with increasing guar gum concentration; however, citric acid at 2.0% concentration was found to lower the viscosity of the extrudate. Resistant starch content increased from 6.23% for extruded starch only to 14.21% for starch–gum extrudate, and further enhanced to 16.19% with the addition of 2.0% citric acid to the starch–gum extrudate. Resistant starch increased with increase of gum concentration and decreased with increase of starch–gum concentration from 7.5% to 12.5%.     

Potato starch edible films to control oxidative rancidity of polyunsaturated lipids: effects of film composition, thickness and water activity

The objective of this work was to study the effect of potato starch-based films acting as oxygen barrier on the oxidative rancidity of vegetable oil, as an example of a food rich in polyunsaturated fatty acids. The effect of glycerol (Gly) content (0%, 10%, 20%, 30%), film thickness (30, 60, 100 μm) as well as environmental relative humidity (RH) (50% or 75%) were analysed. Results obtained confirmed that potato starch films delayed the rancidity in vegetable oil. Films without Gly provided the same protection as films with 10% Gly. Films with higher Gly content were not as effective oxygen barrier. It is likely that the fact that film protective capability diminished with increased RH or Gly content was due to the increasing moisture content of the films. Despite that fact, potato starch films can be considered a very efficient oxygen barrier even at RH as high as 75%.     

Modification of pasting properties of wheat starch by cyclodextrin glycosyltransferase

The effect of cyclodextrin glycosyltransferase (CGTase) on wheat starch functionality was assessed by determining the pasting properties and the dynamic rheology. The addition of CGTase lowered the peak and final viscosity, increased breakdown and markedly decreased the total setback. The influence of CGTase on the ability of starch to form complex with lipids was explored in the presence of fatty acids (stearic and lauric) and an emulsifier (diacetyl tartaric acid ester of monoglyceride, DATEM). Further information about the effect of CGTase on the pasting properties of wheat starch was obtained by analysing the first derivative of the viscograph curves. The cyclodextrins formed in the starch as a result of the cyclization activity of the CGTase were quantified and it was observed that α‐cyclodextrin occurred in the highest concentration followed by β‐ and γ‐cyclodextrins. The starch obtained with CGTase after pasting exhibited better emulsifying properties as it contained the cyclodextrins. The CGTase treatment also modified the dynamic rheology of the starch slurry leading to a decrease in the elastic and viscous modulus. Copyright © 2004 Society of Chemical Industry     

Characterization of modified high-amylose maize starch-α-naphthol complexes and their influence on rheological properties of wheat starch

Amylose can form inclusion complexes with diverse small molecules. Modified starch has different and unique properties compared with its native counterpart. In this study, chemically/enzymatically modified high-amylose maize starches were used to make inclusion complexes with α-naphthol, and the physical properties of complexes and their influences on the rheology of wheat starch were characterized. The results showed that modification of starch had little influence on the wide angle X-ray diffraction pattern of complex (eightfold single helix), but did so on the complexation index and precipitation yield. Inclusion complexes with chemically modified starch showed a lower range of thermostability and recrystallization temperatures. Addition of complex considerably influenced the rheological properties of wheat starch, and the effect was dependent on the type of modified starch used. It may be concluded that starch inclusion complexes, with a range of properties and potential food applications, may be feasibly prepared by using diverse modified high-amylose maize starches.     

芋头淀粉提取工艺优化及淀粉特性研究

以NaOH为浸泡剂,探讨了料液比、pH、浸泡时间、浸泡温度对芋头淀粉提取率及色泽的影响,并对芋头淀粉特性进行了初步研究。结果显示芋头淀粉提取最佳工艺条件为:pH10.0、浸泡温度25℃、料液比1:3、浸泡时间80min。提取率可达84.82%,淀粉白度高达94.11,优于现有文献报道及市售其它常用淀粉;淀粉特性研究显示,芋头淀粉的体积平均粒度在10μm以下,d(0.5)为14.6μm,稍大于10μm;芋头淀粉具有优良的热稳定性、冷稳定性,凝胶强度和凝成特性等特性。      

豌豆淀粉与马铃薯淀粉、玉米淀粉理化性质比较

通过对豌豆淀粉、马铃薯淀粉和玉米淀粉的基本组成、颗粒形态、凝沉性、糊化特性、透明度及抗性淀粉含量的测定与比较表明:豌豆淀粉中直链淀粉和蛋白质的含量较高,但其颗粒直径小于马铃薯淀粉;与马铃薯淀粉和玉米淀粉相比,豌豆淀粉易于回生,但糊稳定性较好;豌豆淀粉糊的透明度低于马铃薯淀粉,但其淀粉组成中慢消化淀粉含量高于马铃薯淀粉和玉米淀粉。