采用不同方法制备豌豆抗性淀粉及其性质研究

以豌豆淀粉为原料,研究交联、湿热、脱支酶解3种不同方法处理后其抗性淀粉含量及其他性质的变化。实验表明:交联、湿热、脱支酶解处理均能增加豌豆抗性淀粉的含量,且脱支酶解处理>湿热处理>交联处理;交联处理后其溶解度降低,但湿热和酶解均使其溶解度增加,3种处理方式均使豌豆淀粉膨胀度降低;交联和酶解处理使豌豆淀粉的糊化温度和糊化焓增加,糊化变得困难,而湿热处理后其糊化峰变为2个;X射线衍射数据表明,交联处理不会改变豌豆淀粉的晶型,湿热处理和脱支酶解后豌豆淀粉的晶型分别由原来的C型变为A型和B型;体外消化模拟实验表明,经交联处理后豌豆淀粉消化性增加,而经湿热和酶解处理后其消化性能均降低。     

湿热处理对马铃薯淀粉-大豆肽复合物的理化和消化特性的影响

研究湿热处理(HMT)的水分条件对马铃薯淀粉与大豆肽复合物(PS-SPT)的理化和消化性质的影响。采用扫描电子显微镜和偏光显微镜研究复合物的形貌特征;利用差示扫描量热仪测定复合物的热力学特性;采用布拉班德粘度仪测定复合物的黏度特性;采用Englyst体外消化法测定复合物的体外消化性。结果表明:HMT后淀粉-大豆肽复合物偏光十字减弱,团聚现象增加。淀粉-大豆肽复合物糊化温度(To、Tp和Tc)显著升高,焓变(ΔH)显著降低,且To、Tp和Tc随HMT水分含量的增加呈逐渐升高的趋势。与物理混合样品相比,HMT后淀粉-大豆肽复合物的起糊温度升高,膨胀度、峰值黏度、热糊黏度和冷糊黏度均出现大幅下降。随着HMT水分含量的增加,淀粉的膨胀度和峰值黏度逐步降低。蒸煮后的体外消化性表明,HMT使马铃薯淀粉-大豆肽复合物的快消化淀粉含量(RDS)降低,而抗性淀粉(RS)含量升高。35%的HMT水分条件下,马铃薯淀粉-大豆肽复合物中RDS含量最低(81.53%±1.22%),RS含量最高(11.76%±0.62%)。这说明湿热处理显著改变了马铃薯淀粉-大豆肽复合物的理化和消化特性。HMT过程中直链/支链淀粉发生重组,大豆肽的物理包埋作用,以及马铃薯淀粉带负电荷基团与大豆肽侧链基团之间的相互作用均会降低淀粉的消化性。本研究为优化含慢消化淀粉和抗性淀粉的新型低GI食品的加工方法,提供理论参考。     

豌豆抗性淀粉的酶法制备及其性质研究

以豌豆淀粉为原料,经糊化、普鲁兰酶脱支和凝沉处理,使其分子结构发生改变,制备出高含量的抗性淀粉,并研究了其理化性质。结果表明,在加酶量为300 ASPU/g,脱支时间12 h,凝沉时间24 h时,抗性淀粉含量达到最高52.66%;经糊化、脱支和凝沉处理后的样品结晶结构由C型变为B+V型;随着抗性淀粉含量的增加,其溶解度逐渐降低且均高于原淀粉,但膨胀度均低于原淀粉;消化产物随抗性淀粉含量的增加而降低。     

食用交联甘薯淀粉制备与性质研究

以甘薯淀粉为原料,三偏磷酸钠为交联剂,对甘薯淀粉进行变性,制备食品用交联甘薯淀粉。以交联淀粉峰值粘度和结合磷含量为指标,以三偏磷酸钠用量、反应pH、温度、时间和硫酸钠用量为因素研究交联反应最优工艺;并研究系列食用交联甘薯淀粉粘度、溶解度、膨胀度、透明度、凝沉性、冻融稳定性等理化性质及形态学和结构性质,为其在食品中应用提供理论依据。     

微波韧化辅助制备马铃薯抗性淀粉性质的研究

优化马铃薯淀粉制备工艺,采用微波、韧化辅助处理以增加抗性淀粉含量。并对淀粉增抗机制与增抗后淀粉的理化特性进行研究。结果表明,与原淀粉相比,增抗处理后的马铃薯淀粉颗粒表面受到严重侵蚀,相互粘连,呈簇状存在;结晶度比原淀粉显著提高,淀粉分子趋于有序化重新形成的晶体结构;To、Tp、Tc、△H增加,用热处理破坏结晶结构需要更多的能量;淀粉糊的黏度降低,糊化温度提高;抗消化性与抗性淀粉热稳定性增强;吸水性、乳化性与乳化稳定性低于原淀粉,持水能力略微增加。     

湿热交联甘薯抗性淀粉的制备及理化性质研究

以甘薯淀粉为原料,采用湿热交联协同处理,制备高含量抗性淀粉,探究最佳工艺条件并研究了其理化性质。结果表明,当交联剂质量分数为10%、pH11.5、水分20%及温度120℃时,制备的抗性淀粉质量分数达72.45%,结合磷质量分数为0.39%。通过31 P NMR检测,RS质量分数为72.45%产物中含有磷酸二淀粉酯(DSMP),而没有发现磷酸单淀粉酯(MSMP)。扫描电镜和偏光显微镜观测结果表明:在高水分下进行交联反应,淀粉颗粒易受水汽和热能的影响而部分糊化,表面发生部分破裂,从而影响淀粉的抗酶解性。X-射线衍射图谱显示,甘薯抗性淀粉的晶型仍为C型,但相对结晶度有稍许变化。糊化温度随水分增加而升高,糊化焓值则明显降低。     

交联糯玉米淀粉合成工艺及性能研究

以糯玉米淀粉为原料，以三氯氧磷为交联剂，氢氧化钠为催化剂，对交联淀粉合成工艺及其性能进行了研究。考察了反应pH值、交联剂用量、膨胀抑制剂用量、反应温度、反应时间对淀粉交联度的影响。结果表明，随着交联剂用量和反应时间的增加，交联度逐渐增加，pH值、反应温度对糯玉米淀粉交联反应的影响存在较佳值。糯玉米淀粉经交联后，其冻融稳定性提高，透光率降低，耐酸性增强。     

响应面试验优化交联马铃薯淀粉制备工艺及体外消化性质研究

以马铃薯淀粉为原料,三偏磷酸钠(STMP)和三聚磷酸钠(STPP)以质量比99:1的比例混合作为交联剂,制备交联马铃薯淀粉。以结合磷含量为指标,交联剂用量、反应pH值、反应温度和反应时间为因素,运用响应面法进行优化,确定最优工艺条件为交联剂用量为淀粉干质量的16%、反应时间4.5h、反应pH11.5、反应温度55℃;在最优工艺条件的基础上,通过改变交联剂用量制备一系列不同结合磷含量的交联淀粉并研究它们的体外消化性质。结果表明,随着交联马铃薯淀粉结合磷含量的增加,其所含的抗性淀粉也随之增加。     

蜡质玉米淀粉微晶的理化性质及其消化性研究

以蜡质玉米淀粉为原料,在酸醇介质中制备淀粉微晶。对制得的不同水解率的蜡质玉米淀粉微晶进行了颗粒形貌、X射线衍射、DSC热稳定性分析,溶解度和消化性能的测定。结果表明:随着酸醇水解程度的增加,淀粉颗粒形貌逐渐呈片晶状,最终为碎片;淀粉颗粒的无定形区先被水解,结晶区后被水解,进而导致颗粒破裂;晶体形态仍为A型。与原淀粉相比,淀粉微晶的Tp和Tc均增大,糊化温度范围也有很大提高;不同水解率的淀粉微晶的热焓(△H)先减小后增大。淀粉微晶的溶解度随水解率的增加不断增大。酸醇水解蜡质玉米淀粉的水解率越高,其在in vitro模型中的消化产物也就越多,消化速度也越快。对于同一水解率的淀粉微晶,其消化速度随时间的延长先上升后下降。     

小麦纤维对绿豆淀粉理化特性影响

以绿豆淀粉为原料,研究添加不同量小麦纤维对绿豆淀粉溶胀度、可溶指数、糊化特性、凝胶质构、消化性等理化指标影响。结果表明,添加小麦纤维后,绿豆淀粉溶胀度和可溶指数增加;其峰值粘度、谷值粘度、末值粘度、衰减值也增加;绿豆淀粉凝胶硬度随小麦纤维添加量增加而增大;且添加小麦纤维绿豆淀粉,其快速消化淀粉含量和抗性淀粉含量明显低于对照组,但慢速消化淀粉含量高于对照组。     

乙酰化对红薯淀粉性质的影响

以红薯淀粉为原料,醋酸酐为乙酰化剂,制备低取代的乙酰化红薯淀粉.通过制备不同取代度乙酰化淀粉(DS 0.044～0.096),与红薯原淀粉进行比较,对乙酰化淀粉的透明度、凝沉性、溶解度、溶胀度、黏度和质构特性等进行深入研究.结果表明,与原淀粉相比,红薯淀粉经乙酰化作用后,凝沉性明显减弱,乙酰化红薯淀粉透明度、溶解度和溶胀度都随着取代度的增加而增加,且明显高于原淀粉.乙酰化红薯淀粉的糊化温度降低6～10℃,最终黏度和回生值显著降低,硬度显著降低.     

Effects of cross‐linking on the rheological and thermal properties of sweet potato starch

Sweet potato starches were modified with three different concentrations of phosphorus oxychloride (POCl₃) (0.01, 0.02, and 0.03%, based on dry weight of starch) as a cross‐linking agent. The effects of crosslinking on rheological and thermal properties of sweet potato starch (SPS) pastes were evaluated. Cross‐linking considerably reduced the swelling power, consistency index (K), apparent viscosity (η_a), and yield stress (σ_oc) values of SPS, which significantly decreased with increase in POCl₃ concentration. The gelatinization temperature (T_p) and enthalpy (ΔH) values of the cross‐linked SPS, which were determined using differential scanning calorimetry, were higher than those of native SPS. Storage modulus (G′), loss modulus (G″), and complex viscosity (η*) of the cross‐linked SPS pastes determined using small deformation oscillatory rheometry, were higher than native starch, and they also decreased with increase in POCl₃ concentration from 0.01 to 0.03%. The tan δ (ratio of G″/G′) values (0.15–0.19) of the cross‐linked SPS samples were much lower than that (0.37) of the native SPS, indicating that the elastic properties of the SPS pastes were strongly influenced by modifications from cross‐linking. Finally, Cox–Merz plots showed that η* was much higher than η_a for the cross‐linked SPS pastes.     

交联酯化甘薯淀粉特性研究

采用示差扫描量热仪(DSC)、扫描电子显微镜(SEM)和X-射线衍射仪(X-ray)研究了交联酯化甘薯淀粉的特性,结果表明,甘薯淀粉经过不同的交联酯化作用后,其糊化特性、颗粒形态外观特征和X-衍射图谱等发生明显的变化,并对其变化机理进行了分析。     

Physicochemical Properties of Starch Isolated from Bracken (Pteridium aquilinim) Rhizome

Bracken (Pteridium aquilinum) is an important wild plant starch resource worldwide. In this work, starch was separated from bracken rhizome, and the physicochemical properties of this starch were systematically investigated and compared with 2 other common starches, that is, starches from waxy maize and potato. There were significant differences in shape, birefringence patterns, size distribution, and amylose content between bracken and the 2 other starches. X‐ray diffraction analysis revealed that bracken starch exhibited a typical C‐type crystalline structure. Bracken starch presented, respectively, lower and higher relative degree of crystallinity than waxy maize and potato starches. Ordered structures in particle surface differed among these 3 starches. The swelling power tendency of bracken starch in different temperature intervals was very similar to that of potato starch. The viscosity parameters during gelatinization were the lowest in waxy maize, followed by bracken and potato starches. The contents of 3 nutritional components, that is, rapidly digestible, slowly digestible, and resistant starches in native, gelatinized, and retrograded starch from bracken rhizome presented more similarities with potato starch than waxy maize starch. These finding indicated that physicochemical properties of bracken starch showed more similarities with potato starch than waxy maize starch.     

Effect of Acetylation on Some Properties of Corn and Potato Starches

Corn starch and starches separated from different potato cultivars were acetylated to evaluate the effect of plant source on the physicochemical, morphological, thermal, rheological, textural and retrogradation properties of the starches. Corn starch showed a lower degree of acetylation than potato starches under similar experimental conditions. The degree of acetylation for different potato starches also differed significantly. Morphological examination revealed that the granules of acetylated Kufri Chandermukhi and Kufri Sindhuri starches tended to appear as fused and less smooth than native starch granules. Acetylation of corn and potato starches decreased the transition temperatures and enthalpy of gelatinization and increased swelling power and light transmittance. However, the change in these was greater in the potato starches with higher percentage of small sized granules. Acetylated starches showed higher peak G', G'' and lower tan δ than their counterpart native starches during heating. Among the starches from different cultivars, the change in the rheological parameters after acetylation differed to a significant extent. The retrogradation was observed to be negligible in the acetylated cooked starch pastes. Results implied that the change in functional properties of starches with acetylation depends on source and granule morphology of native starch.     

湿热处理对不同晶型淀粉理化性质及消化性的影响

采用三种不同晶型淀粉即玉米淀粉(A型)、马铃薯淀粉(B型)、豌豆淀粉(C型)为原料,在水分含量为25%、温度120℃条件下湿热处理13 h,研究湿热处理对不同晶型淀粉的理化性质及消化性的影响。研究表明,与原淀粉相比,经湿热处理的三种淀粉的结晶结构均发生了改变,玉米淀粉由A型变为了A+V型,马铃薯淀粉和豌豆淀粉分别由B型和C型变为了A型;三种淀粉颗粒表面均出现了不同程度的破损;三种淀粉的部分颗粒的偏光十字的中心强度有所减弱;三种淀粉样品的糊化温度均升高,但A型和B型淀粉的焓值降低,而C型淀粉的焓值升高;三种淀粉的抗性组分含量均有所升高,抗消化性显著增强,其中C型淀粉变化最明显。     

交联淀粉性能与鲜粉丝耐煮性关系

本文以马铃薯淀粉、红薯淀粉和木薯淀粉为原料,三氯氧磷为交联剂,氯化钠为膨胀抑制剂,制备了不同交联度的交联淀粉,研究了交联对薯类淀粉性能及鲜粉丝耐煮性的影响。采用断条率、吸水率表征鲜粉丝的耐煮性,采用沉降积法测定淀粉的交联度。结果表明:交联淀粉用量和交联度对鲜粉丝耐煮性均有影响。淀粉经交联后,其蓝值、膨胀能力降低,但其冻融稳定性增加。     

Characterization of Phosphate Monoester Resistant Starch

The properties and structures of corn, wheat, and potato native starches and their phosphate monoester resistant starches were tested and compared. The results indicated that the resistant starch content, light transmittance, and freeze-thaw stability of the phosphate monoester resistant starch increased after modification. The native starches exhibited much higher peak viscosities compared with resistant starch (RS) and phosphate monoester resistant starches. The phosphate monoester resistant starch from corn and wheat starch exhibited a higher peak and final viscosity and lower gelatinization temperatures compared with the resistant starch, while the peak and final viscosity of the potato phosphate monoester resistant starch samples were lower than that of potato resistant starch. In the FT-IR graph, a new peak at 1244 cm^?1 (P=O bond) was observed for all kinds of phosphate monoester resistant starch.     

几种薯类与豆类抗性淀粉的抗消化性及其益生效应

采用压热法制备了木薯、红薯、马铃薯、豌豆和绿豆5种抗性淀粉,研究了它们对人工胃液和人工肠液的抗消化性,以及它们对肠道益生菌生长的影响。结果表明:人工胃液对木薯、红薯、马铃薯、豌豆和绿豆抗性淀粉的消化作用很小,人工肠液对它们有明显的消化作用;经人工胃液和人工肠液先后作用,它们的消化率都比单独人工肠液处理后的要高;各种抗性淀粉对双歧杆菌、嗜酸乳杆菌、保加利亚乳杆菌、乳链球菌都有不同程度的增殖作用。综合分析可知,对肠道益生菌增殖作用最强的是豌豆抗性淀粉,其次是红薯和绿豆抗性淀粉,再次是马铃薯抗性淀粉,最差的是木薯抗性淀粉。