单甘酯对小麦淀粉凝胶冻融稳定性的影响

为了提高小麦淀粉凝胶的冻融稳定性,研究了单硬脂酸甘油酯对小麦淀粉凝胶晶体结构、热力学特性及质构特性的影响。结果表明,X-射线衍射图显示样品中含有V-型结晶结构,说明单甘酯与淀粉结合形成了淀粉-单甘酯复合物;差示扫描量热仪测定显示,淀粉凝胶样品含有直链淀粉重结晶的熔融峰和淀粉-单甘酯复合物的熔融峰,复合物熔融焓显著小于淀粉凝胶熔融焓;经过5次冻融循环,小麦淀粉凝胶中淀粉分子发生了重结晶,淀粉凝胶的结晶度从15.37%增大至18.75%,而添加单甘酯形成复合物的淀粉凝胶结晶度从13.98%增大至17.35%;随着冻融循环增加,小麦淀粉凝胶中支链淀粉重结晶的熔融焓增加显著大于含复合物淀粉凝胶中支链淀粉重结晶的熔融焓增加,并且小麦淀粉凝胶硬度显著大于含复合物淀粉凝胶硬度。说明单甘酯与淀粉形成复合物能提高小麦淀粉凝胶的冻融稳定性。     

不同乳化剂对米粉糊化和流变性质的影响

本文以大米粉为原料,研究了三种常用乳化剂分子蒸馏单甘酯、大豆卵磷脂和蔗糖脂肪酸酯对其糊化、凝胶和流变性质的影响。结果表明：分子蒸馏单甘酯和蔗糖脂肪酸酯使大米粉的崩解值、最终黏度、回生值和糊化温度显著升高。大豆卵磷脂使大米粉的峰值黏度、谷值黏度、最终黏度、回生值和糊化温度都显著降低,崩解值显著升高。分子蒸馏单甘酯、大豆卵磷脂和0.7%的蔗糖脂肪酸酯均会降低流体特征指数n,假塑性增强;0.5%～0.7%的分子蒸馏单甘酯和0.7%的蔗糖脂肪酸酯会增大稠度系数K值。三种乳化剂均会降低经高速剪切后的米粉糊表观黏度和触变环面积。     

分子蒸馏单甘酯含量对花生油基有机凝胶油性质的影响

以花生油为基料油,通过向其添加分子蒸馏单甘酯制备具有一定塑性的有机凝胶油。探讨了分子蒸馏单甘酯含量对有机凝胶油性质的影响。结果表明:分子蒸馏单甘酯含量对有机凝胶油的硬度、流变性、持油性、固体脂肪含量、热性质有很大影响,这些性质参数随分子蒸馏单甘酯含量的增加而增大,而分子蒸馏单甘酯含量对有机凝胶油的晶型影响不大。     

大米淀粉-单甘酯复合物的性质和结构研究

为了减缓大米淀粉在食品加工过程中的老化，采用加热糊化法制备大米淀粉-不同单甘酯复合物，研究甘油单月桂酸酯（GML）、甘油单棕榈酸酯（GMP）和甘油单硬脂酸酯（GMS）三种单甘酯对复合物的理化和结构特性的影响。采用RVA、DSC、FTIR、XRD等方法测定了复合物的糊化特性、热特性、短程有序性及结晶结构。结果表明，不同单甘酯对复合物的复合指数具有显著影响（P<0.05），复合指数为GMP>GMS>GML；与原大米淀粉相比，复合物的溶解度、析水率、回生值以及短程有序性均显著下降（P<0.05），且不同复合物之间也存在显著差异（P<0.05），其中大米淀粉-甘油单棕榈酸酯的析水率、回生值和短程有序性最低，分别为25.58%、281.7 cP和0.58；差式扫描量热和X-射线衍射分析发现，与单甘酯复合后，淀粉由A型结晶结构转变为V型结晶结构。上述结果表明单甘酯的加入在一定程度上可延缓淀粉老化，大米淀粉-甘油单棕榈酸酯复合物抑制淀粉老化效果更好。     

不同链长单甘酯-籼米淀粉复合物结构及体外消化特性

研究不同链长脂肪酸单甘酯添加量变化时,单甘酯-籼米淀粉复合指数和糊化性质双变量相关性,通过傅里叶变换红外光谱仪、差示扫描量热仪、X-射线衍射分析仪和扫描电镜,研究单甘酯链长、添加量及温度对籼米淀粉-单甘酯复合物结构和体外消化特性的影响。研究结果表明:单甘酯碳链越长,与籼米淀粉的复合程度越高,且越易在冷却过程中形成黏度峰。相比于月桂酸单甘酯和硬脂酸单甘酯,棕榈酸单甘酯与籼米淀粉形成的复合物具有更高的焓变值、结晶度。硬脂酸单甘酯-籼米淀粉复合指数和糊化特性显著相关(除最低黏度值外);不同链长脂肪酸单甘酯-籼米淀粉复合指数与快消化淀粉含量显著负相关。     

非糯性大米淀粉和非糯性玉米淀粉性质比较

以非糯性大米和玉米淀粉为研究对象,比较分析了淀粉的化学组成、结晶特性、浊度、热性质、质构及回生性质。试验结果表明非糯性玉米淀粉浊度、淀粉糊化熔点和峰值温度、凝胶硬度、咀嚼性、弹性和凝聚性值高于非糯性大米淀粉,但其膨润力和回生焓变值低于非糯性大米淀粉。此外,在4℃贮藏过程中,非糯性玉米淀粉凝胶的熔点、峰值温度、回生焓变和回生度均高于大米淀粉。试验非糯性大米淀粉和玉米淀粉理化性质比较的试验数据结果,可为玉米淀粉改性加工及其相关产品的开发提供依据。     

单甘酯对马铃薯淀粉物化特性的影响

考察分子蒸馏单甘酯(MON)对马铃薯淀粉(PS)糊的流变特性、淀粉凝胶析水特性及其硬度的影响,并借助差示扫描量热仪(DSC)和扫描电子显微镜(SEM)方法,分析PS与PS-MON的热特性和凝胶微结构的变化。结果表明:添加MON可显著提高PS的起始糊化温度、最大黏度值下的温度和糊化过程的焓值;显著降低淀粉糊的最大黏度值和凝胶老化过程的析水率(P<0.05);并增强凝胶内部结构的致密性,提高淀粉老化凝胶的硬度(P<0.05)。     

挤压蒸煮加工米糠可溶和不溶膳食纤维对米淀粉性质的影响及其相互作用分析

研究未挤压、挤压蒸煮加工米糠可溶和不溶膳食纤维对米淀粉糊化性质、热性质、回生性质、结晶性质、微观结构的影响,并采用质构分析、核磁共振、傅里叶变换红外光谱等方法探究挤压蒸煮米糠膳食纤维与米淀粉之间的相互作用。结果表明：与未挤压蒸煮加工米糠膳食纤维相比,挤压蒸煮加工米糠可溶和不溶膳食纤维分别使米淀粉的崩解值显著增加了74.09%和128.36%,并均显著降低米淀粉的峰值黏度、谷值黏度、终值黏度、峰值时间、糊化温度。米糠经过挤压蒸煮加工后,米糠可溶膳食纤维使淀粉凝胶的自由水向强结合水转化,米糠不溶膳食纤维使淀粉凝胶的自由水向弱结合水转化。与未挤压蒸煮加工相比,挤压蒸煮加工米糠可溶和不溶膳食纤维分别使米淀粉的回生值降低了62.59%和44.81%,也均降低了米淀粉凝胶的回生率、相对结晶度、硬度、内聚性、回复性、胶黏性、咀嚼性、1 047 cm－1与1 022 cm－1处吸收峰的峰高比,添加挤压蒸煮米糠可溶、不溶膳食纤维的淀粉凝胶表面较光滑,凝胶结构出现较大的裂缝,说明挤压蒸煮加工米糠提高了米糠膳食纤维对米淀粉回生的抑制效果,且挤压蒸煮可溶膳食纤维比挤压蒸煮不溶性膳食纤维效果好。     

魔芋葡甘聚糖水解物对淀粉消化性及糊化热力学性质的影响

研究魔芋葡甘聚糖(KGM)水解物对小麦淀粉、玉米淀粉、马铃薯淀粉消化性质及糊化热力学性质的影响。添加KGM水解物的小麦、玉米、马铃薯粒度分布变宽;添加KGM水解物后,小麦、玉米、马铃薯淀粉的消化率显著降低。小麦淀粉-KGM水解物复合物、马铃薯淀粉-KGM水解物复合物的热焓值均低于原淀粉,玉米淀粉-KGM水解物复合物热焓值高于原淀粉。淀粉-KGM水解物复合物的峰值黏度、谷值黏度、最终黏度以及破损值均高于原淀粉。     

富硒杂粮营养速溶粉的研制

以多种杂粮为主要原料,经蒸煮预熟化处理和挤压膨化技术制备富硒杂粮营养速溶粉。采用单因素和正交试验确定了富硒杂粮营养速溶粉的加工参数:挤压机的挤压温度140℃、物料水分35%、螺杆转速300 r/min。结果表明:富硒杂粮营养速溶粉的焓值增加,淀粉与脂肪形成淀粉脂复合物。在该参数条件下制备的富硒杂粮营养速溶粉的溶解度得到明显改善,口感细腻,色泽和风味均达到较佳水平。     

颗粒状冷水可溶淀粉糊性质的研究

在常压下,用醇解法制备了不同溶解度的颗粒状冷水可溶淀粉系列,并对玉米、木薯和马铃薯原淀粉及其不同溶解度的颗粒状冷水可溶淀粉糊的性质进行了研究。试验证明,相对于原淀粉糊,醇解法制备的颗粒状冷水可溶玉米淀粉糊的表观粘度和冻融稳定性有所提高,凝沉性降低;颗粒状冷水可溶木薯和马铃薯淀粉糊的表观粘度、凝沉性和冻融稳定性均降低。三种颗粒状冷水可溶淀粉糊的透明度大大提高,且随着溶解度提高其透明度增大。     

绿豆淀粉抗老化技术及在冰淇淋中的应用

为抑制绿豆淀粉在冰淇淋贮藏期间老化而产生的淀粉味感,以绿豆淀粉为原料,经过α-淀粉酶酶解处理,通过正交试验研究不同酶解条件对绿豆淀粉抗老化性质的影响。结果表明：用α-淀粉酶处理绿豆淀粉,使其适度的水解,保持了绿豆特有的口感风味,且保水力较大,糊化性好,老化度明显低于未经过α-淀粉酶处理的绿豆淀粉。酶解最佳工艺为pH6.5、酶解温度70℃、添加0.0008%的α-淀粉酶、酶解8min。在绿豆冰淇淋制作中添加不同量的酶解绿豆浆、CMC-Na、明胶、单甘酯对绿豆冰淇淋膨化率及融化率和口感有不同的影响,酶解豆浆、CMC-Na、明胶、单甘酯的添加量分别为60%、0.1%、0.1%、0.15%时,绿豆冰淇淋的风味口感明显改善。     

高透明度氧化蜡质玉米淀粉性质研究

研究氧化蜡质玉米淀粉颗粒形态、偏光性质、透明度、凝沉性等性质,并与其原淀粉相比较;结果表明,在相同氧化条件下,氧化蜡质玉米淀粉羧基含量要比氧化普通玉米淀粉低;其颗粒外观形状与蜡质玉米淀粉相似,偏光十字清晰,氧化作用发生在无定型区;氧化蜡质玉米淀粉颗粒表面更为粗糙,微孔洞量增加,氧化反应在淀粉颗粒表面和内部进行,颗粒表面发生降解;比其原淀粉显示更高透明度,而凝沉效果相差不大。     

颗粒冷水可溶亲脂性玉米淀粉的制备及性质研究

该研究以玉米淀粉为原料,首先利用酒精-碱法对其α-化,在此基础上,以辛烯基琥珀酸酐(octenyl succinic anhydride,OSA)为酯化剂,在干法条件下制备出颗粒冷水可溶亲脂性淀粉,所得产品取代度最高可达0.0192。通过分析试验制备的颗粒冷水可溶玉米淀粉和颗粒冷水可溶亲脂性玉米淀粉的透明度、冻融稳定性、凝沉性、黏度、流变学特性,并进一步探索这些特性与产品取代度之间的关系。结果表明:这两种淀粉的性质比原淀粉有显著的改善,后者又比前者具有良好的性质,随着取代度的增大,颗粒冷水可溶亲脂性玉米淀粉的透明度增强,冻融稳定性提高,凝沉性降低,表观黏度增加;流变学分析显示两种淀粉呈现出假塑性流体的性质,表观黏度随着剪切速率的增加而降低。     

Retrogradation of Potato Starch as Studied by Fourier Transform Infrared Spectroscopy

Retrogradation kinetics for a potato starch-water system (10% w/w gel) was monitored by Fourier Transform Infrared spectroscopy and compared with waxy maize starch. The spectra showed the C-C and C-O stretching region (1300-800 cm⁻¹) to be sensitive to the retrogradation process. A multi-stage process was observed during the retrogradation of potato starch and characterized as the formation of short- and long-range order. The first stage was characterized as the formation of helices and the fast formation of crystalline amylose regions. The second stage was described as the induction time for amylopectin helix aggregation. Stage three was described as the helix-helix aggregation and the crystallization of amylopectin. The overall-first order calculated rate constant of potato starch was (9.6±1.4) 10⁻ 3h⁻¹. The calculated rate constant were in agreement with the known difference in retrogradation kinetics of waxy maize and potato starch. The effects were explained by the differences in retrogradation rate of amylopectin and amylose. Potato starch consists of amylose as well as amylopectin. Whereas amylose crystallization occurs within a few hours, amylopectin crystallization is slow and takes a few weeks.     

Effects of Fatty Acid Addition on the Physicochemical Properties of Corn Starch

The effect of addition of six fatty acids (stearic, palmitic, myristic, oleic, palmitoleic, and myristoleic acid) on the gelatinization, glass transition, and retrogradation properties of corn starch as well as their complexing abilities with amylose were determined. Differential scanning calorimeter studies reflected that addition of fatty acids caused a 73–89% decrease in the gelatinization enthalpy compared to that of the native starch. Besides amylose-lipid formation, exotherm was determined at the same temperature range with the gelatinization endotherm. As a result, it was suggested that fatty acids complexed with amylose during gelatinization. Fatty acid addition significantly increased the glass transition temperature of starch gel. This was attributed to two reasons: the first is due to the physical cross-linking action of amylose–lipid complexes in starch-water system; the second may be due to the effect of uncomplexed fatty acids on water distribution in the gel structure as a result of their amphiphilic character. Thermal properties of amylose-lipid complexes were compared in order to determine the effect of fatty acid properties. It was found that the shorter chain length and unsaturation favored the complex formation but the complexes formed by longer and saturated fatty acids were more heat stable. Addition of fatty acids resulted in 73–90% and 47–71% reduction in the retrogradation enthalpy compared to native starch gels at 5°C and 21°C, respectively. The reduction in the retrogradation enthalpy was inversely related to the amylose-lipid complexing abilities of the fatty acids and it might be explained by the hindrance effect of uncomplexed fatty acids to the water distribution in the starch gel matrix.     

Preparation and properties of RS III from waxy maize starch with pullulanase

Waxy maize starch was treated by pullulanase debranching and retrogradation at room temperature to produce resistant starch (RS). Physicochemical properties, crystalline structure and in-vitro digestibility of starch samples with different RS content were investigated. Compared with native starch, apparent amylose content of RS products increased. Based on Gel Permeation Chromatography (GPC) the Molecular Weight Distribution (MWD) of resistant starches significantly changed. Scanning Electron Microscopy (SEM) showed that upon pullulanase debranching and retrogradation treatment the granular structure of native starch was destroyed and all RS samples exhibited irregular shaped fragments. Crystal structure of samples changed from A–type to a mixture of B and V–type. The crystallinity of resistant starch also improved as compared with native starch. Moreover, samples with higher resistant starch showed higher relative crystallinity. Differential Scanning Calorimetry (DSC) determination showed that To、Tp、Tc and ΔH all increased which was in agreement with RS content. The resistance of waxy maize starch with Pullulanase treatment to α-amylase digestibility also increased, while the in-vitro digestibility of products decreased.     

油酸和麦芽糖醇混合物对玉米淀粉老化特性的影响

为探究油酸和麦芽糖醇混合物抑制玉米淀粉老化的效果,通过快速黏度分析、差示扫描量热分析、质构分析、动态流变分析、低场核磁共振分析、红外光谱分析和X射线衍射分析等方法比较不同复配比例的油酸和麦芽糖醇混合物对玉米淀粉糊化特性、老化特性、流变学特性、质构及结晶结构等的影响。结果显示：添加油酸和麦芽糖醇混合物后,玉米淀粉的糊化温度升高,回生值和老化速率降低,且当油酸和麦芽糖醇质量比为0.5∶1.5时,糊化温度最高（77.80 ℃）,回生值最低（1 218 cP）,老化速率比原淀粉降低了60%;油酸和麦芽糖醇混合物的添加能增大玉米淀粉的损耗角正切值和横向弛豫时间（T2）,形成较弱的凝胶结构,降低玉米淀粉凝胶的硬度、短程有序度和相对结晶度;当油酸和麦芽糖醇为0.5∶1.5质量比复配时,混合物对延缓玉米淀粉老化存在协同作用。这可能与麦芽糖醇能抑制淀粉体系中水分子运动、油酸能与淀粉形成淀粉-脂质复合物从而有效抑制淀粉重结晶有关。研究结果可为改善玉米淀粉加工特性、提高淀粉基食品品质提供一定的理论依据。     

机械活化对玉米乙酰化淀粉理化特性的影响

采用搅拌球磨机对玉米淀粉进行机械活化,以活化时间为60 min的玉米淀粉和原淀粉为原料制备乙酰化淀粉.研究了机械活化对玉米乙酰化淀粉理化特性影响.结果表明,机械活化预处理的玉米乙酰化淀粉的溶解度、糊透明度增大.冻融稳定性增强,凝沉性降低,糊黏度增大及其热稳定性提高.机械活化作用破坏了淀粉的结晶区,结晶程度降低,有效地改善了乙酰化淀粉的理化特性.     

十二烯基琥珀酸淀粉酯性质的研究

采用RVA快速粘度测定仪，研究了十二烯基琥珀酸淀粉酯(SSDS)糊的粘度性质。测定了糊的凝沉性质、糊的乳化性质、糊的冻融稳定性、并采用扫描电子显微镜对SSDS的微观结构进行了分析。结果显示：酯化后SSDS的颗粒形貌、糊粘度性质较原玉米淀粉糊有较显著变化、其抗凝沉性、乳化性都明显优于原玉米淀粉，而冻融稳定性比原玉米淀粉差。