Gelatinization and Retrogradation Properties of Native and Hydroxypropylated Crosslinked Tapioca Starches with Added Sucrose and Sodium Chloride

The effects of sucrose and sodium chloride on the gelatinization and retrogradation of native and hydroxypropylated crosslinked tapioca starches were investigated by using Differential Scanning Calorimetry (DSC). Hydroxypropylated crosslinked tapioca starches showed low gelatinization temperature and enthalpy compared to the native tapioca starch. Sucrose and sodium chloride increased the gelatinization temperatures of all starch samples. The enthalpy to melt retrograded amylopectin of hydroxypropylated crosslinked tapioca starches were low, compared to that of the native starch. Sucrose did not have much effect on retrogradation of the starch, while sodium chloride decreased retrogradation of all starch samples.     

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。     

蕉藕淀粉与薯类淀粉特性对比研究

为探索蕉藕淀粉应用范围,选取木薯淀粉、马铃薯淀粉、红薯淀粉等薯类淀粉为对照,对蕉藕淀粉与常见薯类淀粉的组成、吸水(油)率、溶解度、膨胀度、透明度、凝沉性、凝胶强度、冻融稳定性及黏度等特性进行了对比分析。结果显示:蕉藕淀粉与常见薯类淀粉特性相比除吸水性差异不显著外,吸油率、溶解度、膨胀度、透明度、凝沉性、凝胶强度、冻融稳定性及黏度变化均存在显著差异,可利用蕉藕淀粉直链淀粉含量高、透明度好、凝胶强度高等特性,开发新型淀粉食品和增稠稳定剂。     

两种羟丙基淀粉对速冻饺子品质影响

研究两种不同原料(马铃薯和木薯)羟丙基淀粉对面粉溶剂保持能力及速冻饺子皮烹煮损失率、色泽、水分含量和微观结构影响.结果表明,随羟丙基淀粉添加量增加,配粉对乳酸保持能力(乳酸SRC值)逐渐降低,面筋强度弱化;随马铃薯羟丙基淀粉添加量增加,配粉对水保持能力(水SRC值)升高;而木薯羟丙基淀粉对面粉水SRC值无显著影响.添加...     

Starch Retrogradation: A Comprehensive Review

Starch retrogradation is a process in which disaggregated amylose and amylopectin chains in a gelatinized starch paste reassociate to form more ordered structures. Starch retrogradation has been the subject of intensive research over the last 50 years, mainly due to its detrimental effect on the sensory and storage qualities of many starchy foods. However, starch retrogadation is desirable for some starchy food products in terms of textural and nutritional properties. To better understand the effect of starch retrogradation on the quality of starchy foods, measurement methods of starch retrogradation and factors that influence starch retrogradation have been studied extensively. This article provides a comprehensive review of starch retrogradation including the definition of the process, molecular mechanisms of how it occurs, and measurement methods and factors that influence starch retrogradation. The review also discusses the effect of retrogradation on the in vitro enzyme digestibility of starch. Spectroscopic methods such as FTIR and Raman are considered to be very promising in characterizing starch retrogradation at a molecular level, although more studies are needed in the future.     

Physicochemical Properties and Food Uses of Starch from the New Sweetpotato Cultivar Konamizuki

Starch from the new sweetpotato cultivar Konamizuki (KM) was evaluated as a food material, and its basic properties were characterized. Change in elastic modulus during cold storage of KM starch gels and syneresis after freeze-thaw treatment were limited and indicated slow retrogradation properties. In addition, KM starch paste had higher and more stable storage modulus than other starches, suggesting desirable gel-forming properties. These KM gel properties reflected distinctive structural properties, including larger quantities of short unit chains with degree of polymerization 6-10 and amylose-like long chains of the amylopectin, as well as longer amyloses and longer amylose-like chains of the amylopectin compared with other starches. Finally, KM starch was used in the production of tapioca pearls and starchy noodles, and subsequent sensory analyses indicated highly desirable properties as a food material for starchy gel products.     

交联羟丙基木薯淀粉性质研究

本实验以木薯淀粉为原料,分别以环氧丙烷为醚化剂、三偏磷酸钠为交联剂制备了不同取代度和交联度的交联羟丙基木薯淀粉,并对其透明度、冻融稳定性、抗酸性、高温稳定性及流变学特性进行了分析,同时对其加入面条后对面条特性的影响进行了研究,结果显示糊液的透明度、冻融稳定性、抗酸性、耐高温性及耐剪切性方面都有显著的提高,加入面条后对面条的最佳烹煮时间和烹煮损失方面有较大改善。     

大米淀粉老化特性的研究进展

概述了近几年国内外对大米淀粉老化特性的研究。简要阐述了大米淀粉的老化机理,表明大米淀粉的老化可以划分为短期老化(short-term retrogradation)和长期老化(long-term retrogradation)两个阶段。然后介绍了直、支链淀粉、糖类、蛋白质、脂质、水分含量及温度等影响因素对大米淀粉老化的作用原理,其中重点介绍了直链淀粉含量的多少、支链淀粉结构及蔗糖、魔芋葡甘露聚糖(KGM)、β-葡聚糖、β-环糊精等糖类的食品添加剂对大米淀粉老化的影响机理。最后展望了大米淀粉老化性质未来的研究和应用方向。     

Effect of Hydroxypropylation on the Properties of White Yam (Dioscorea rotundata) Starch

Starch isolated from white yam (Dioscorea rotundata) was subjected to hydroxypropylation under different conditions. Corresponding increases were observed between the molar substitution (MS) and the volume of propylene oxide added to the reaction mixture. After hydroxypropylation, a slight reduction in the intensity of the peak at 2θ = 19.6° was observed and the doublet peak at 23.8°, which was present in native starch, was no longer seen. Hydroxypropylation enhanced the free swelling capacity (FSC) and solubility. Setback and retrogradation of native starch declined after hydroxypropylation. Turbidity of native starch paste and syneresis were higher with storage time. The results also indicate that enzymatic digestibility improved as the MS increased, while the reverse was observed for starch paste turbidity, syneresis, setback and retrogradation. This study presents relevant information that could strategically position D. rotundata starch and its hydroxypropylated derivatives for industrial applications.     

Bread quality of frozen dough substituted with modified tapioca starches

Rheological properties of dough and bread quality of frozen dough-bread containing 18.4% of hydroxypropylated (HTS), acetylated (ATS), and phosphorylated cross-linked (PTS) tapioca starch with different degrees of modification and 1.6% of dried powdered gluten were compared to the same amount of native tapioca starch (NTS) or wheat flour-bread. Doughs substituted with native or modified tapioca starches had the same mixing tolerance as 100% wheat flour. The dough was frozen and stored for 1 week at −18°C, and thawed (one freeze-cycle). The amount of freezable water in the dough substituted with native or modified tapioca starches was not significantly different from that of wheat flour. Frozen dough-bread substituted with highly modified HTS (degree of substitution; DS 0.09–0.11) retarded bread staling, while lowly modified HTS (DS 0.06–0.07) or ATS (DS 0.02–0.04), and PTS (0.004–0.020% phosphoryl content) substitution fastened bread staling as compared with frozen dough-bread baked from wheat flour. The breadcrumbs containing HTS and ATS felt tacky, whereas the bread containing PTS was dry feel. HTS and ATS swelled and collapsed easily during heating, while PTS was difficult to swell and disperse as compared with NTS, therefore the gelatinization properties seemed to affect the texture of bread. Breadcrumb containing HTS showed small firmness during storage, and highly modified HTS-h (DS 0.1) was the smallest. This means highly hydroxypropylated tapioca starch significantly retards bread staling. Staling properties and texture of frozen dough-bread with various tapioca starches were the same as conventional bread baked with the same amount of tapioca starches. These results suggest that a one freeze–thaw cycle and a 1-week frozen period do not change characteristics of starch, gelatinization and retrogradation properties as compared with the conventional method, and the highly modified HTS-h is prominent anti-staling food-stuff in frozen dough.     

青香蕉抗性淀粉含量测定及特性研究

为香蕉的深加工及青香蕉淀粉在食品中进一步应用提供有价值的理论基础。采用AOAC 2002.02酶消化法测定植物性基质中抗性淀粉含量。用沉淀物体积随时间变化来表示淀粉糊的凝沉性质;分光光度法测定样品的透明度;NDJ-8s数显黏度计测量粘度随温度和浓度的变化关系。结果显示,样品青香蕉抗性淀粉含量为49.24%。青香蕉淀粉糊在较高浓度时凝沉迅速,较低浓度时凝沉缓慢;反复冻融次数越多,糊化的冻融稳定性越高;淀粉糊的透明度随质量分数的增加而降低;淀粉糊黏度随温度升高呈现先下降后上升,浓度越高黏度越大。     

淀粉基脂肪替代物的研究应用概况

综述了淀粉为基质的脂肪替代物的研究进展及其应用。淀粉为基质的脂肪替代物包括以玉米淀粉、马铃薯淀粉、大米淀粉、木薯淀粉为原料的脂肪替代物,用于替代食品中的脂肪,可以安全有效地降低食品中的脂肪含量,从而减少总膳食能量和脂肪的过多摄入所带来的不利影响。     

变性淀粉对速冻水饺质量的影响

分析不同原料(蜡质玉米淀粉、木薯淀粉和马铃薯淀粉)制备的羟丙基淀粉的性能,并将羟丙基蜡质玉米淀粉,羟丙基木薯淀粉和羟丙基马铃薯淀粉分别添加到面粉中,研究其对速冻水饺品质的影响。实验表明:变性淀粉添加量为3%～4%(以面粉干基计),面团含水量为44%～45%时,速冻水饺的冷藏稳定性最好。其中添加羟丙基蜡质玉米淀粉在减少速冻水饺的冻裂率,改善速冻水饺的透明度、光泽和色泽方面效果最明显。     

不同变性淀粉对冷冻面团热力学特性的影响

采用差示扫描量热法(DSC)研究4种不同种类变性淀粉对冷冻面团热力学特性(玻璃化转变温度、冰晶融化特性和可冻结水含量)的影响。结果表明,冷冻面团的玻璃化转变温度在-30℃左右,不同变性淀粉对冷冻面团玻璃化转变基本无明显影响;添加5%马铃薯羟丙基淀粉、木薯羟丙基淀粉和木薯醋酸酯淀粉可以显著降低冷冻面团冰晶融化范围,面团中形成的冰晶大小更加均匀;冷冻面团可冻结水含量随着马铃薯醋酸酯淀粉和马铃薯羟丙基淀粉添加量的增加呈降低趋势,添加10%木薯羟丙基淀粉时,面团可冻结水含量显著低于空白组,而木薯醋酸酯淀粉对面团可冻结水含量无显著影响。     

植物淀粉研究进展

淀粉是许多植物的重要储藏物质。衡量淀粉特性的指标较多，本文介绍了淀粉粒形状、大小、晶体特性、糊化特性、热特性和老化特性以及直、支链淀粉含量和分子结构等物理化学指标，简要分析了淀粉特性与品质的关系，综述了淀粉的生物合成途径及其关键酶的研究进展，介绍了种子储藏过程中淀粉的变化、酶的作用及食品加工中淀粉的变性，并展望了植物淀粉的研究前景。     

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。     

Cassava starch functional properties by etherification – hydroxypropylation

Starches are important food biopolymers with gelling properties that are well explored by the food industry for texture and physical food characteristic control. Brazil contributes to a large part of the starches produced world wide, but the modified starches used are imported and expensive. The objective of this work was to develop a hydroxypropylated starch from cassava starch, at a lower price and in conditions in accordance with Brazilian reality. Dihydroxypropylstarch (DHPS) was produced with a less expensive and less harmful substituting molecule, chloropropylene glycol. DHPS physical chemistry properties, retrogradation and micro structural characteristics were studied and compared with native corn, cassava starches and a commercial hydroxypropylated (HPS) cassava starch, with an extensive use in the food industry. DHPS showed the highest values for swelling power and viscosity, low retrogradation and higher freezing–thawing stability, compared with HPS, cassava and native corn starches. The microstructure of DHPS remained unmodified when compared with commercial HPS. Retrogradation and physical chemistry properties are superior to DHPS, which would indicate its use in industrial food production.     

Effect of modified tapioca starch and xanthan gum on low temperature texture stability and dough viscoelasticity of a starch-based food gel

This work investigated the effect of modified tapioca starch and xanthan gum on dough viscoelasticity and texture stability during storage at 4 °C of starch sheets for Chinese shrimp dumplings. Hydroxypropylated starch and hydroxypropylated-crosslinked starch were used to substitute for tapioca starch in the control formulation, and xanthan gum was added to adjust the formulation. During storage, texture of the control became firmer due to amylopectin retrogradation confirmed by differential scanning calorimetry and X-ray diffraction. Conversely, gel sheets containing modified starches showed less texture change. Dough viscoelasticity of the formulations substituted by hydroxypropylated starch were much softer and easier to deform than that of the control one. Dough with hydroxypropylated-crosslinked starch was, however, stiffer and more strain-resistant. Moreover, the formulation comprising the mixture of both types of modified starches and xanthan gum gave dough viscoelasticity similar to that of the control, and provided gel sheet the least texture change. Consequently, this modified formulation could be beneficial for the application of frozen/chilled dumpling wrappers.     

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。     

二氢杨梅素对大米淀粉回生的抑制作

淀粉是大米中的主要成分,其回生程度直接影响大米制品的品质与货架期。该研究将属于多酚类化合物的二氢杨梅素（Dihydromyricetin,DMY）添加到大米淀粉中,研究不同添加量的DMY与大米淀粉的相互作用以及DMY对大米淀粉的溶解度、膨胀度、回生焓值、微观结构的影响,以期改善大米淀粉的回生特性。结果表明,随着二氢杨梅素的添加,大米淀粉的溶解度从4.49%增加至12.83%,膨胀度11.41%降至10.12%;淀粉表面由原来的紧密结构变化为疏松多孔结构;红外光谱1 047 cm-1/1 022 cm-1的比值从0.87降至0.78。较未添加的DMY的大米淀粉相比,低浓度的DMY已经显著影响大米淀粉回生特性。当DMY的添加量为5%时,大米淀粉的回生焓值、回生率以及相对结晶度分别下降了68.75%、71.86%、59.07%。总体而言,二氢杨梅素可以抑制大米淀粉的回生。因此,在淀粉制品加工时,可考虑添加DMY来调控淀粉基食品的回生现象。