荞麦淀粉糊特性的研究

以小麦、玉米和马铃薯三种淀粉为参照，研究了荞麦淀粉糊性质，结果表明：荞麦淀粉糊化温度与小麦淀粉糊化温度相当，但比玉米淀粉、马铃薯淀粉难糊化；其粘度热稳定性显著高于小麦、玉米和马铃薯淀粉；冷粘度稳定性大于小麦、玉米和马铃薯淀粉；凝胶性和凝沉性均高于马铃薯淀粉；透明度低于小麦、玉米和马铃薯淀粉；冻融稳定性强于小麦和玉米淀粉。     

韧化处理对甘薯淀粉糊化特性的影响

本文采用差示扫描量热分析、快速粘度分析等现代仪器分析方法研究了不同韧化时间、韧化温度和含水量等韧化处理方法对甘薯淀粉糊化特性的影响。结果表明,不同韧化温度处理后,甘薯淀粉的起始糊化温度、峰值糊化温度和终止糊化温度均呈升高趋势,其中起始糊化温度升高趋势明显,由甘薯淀粉的62.47℃升高到70.37℃,糊化温度范围变窄,糊化热焓值增加;其峰值黏度呈下降趋势,55℃时为1342 cp比甘薯淀粉下降了321 cp,破损值降低、回生值升高。不同韧化时间处理后,甘薯淀粉To升高,糊化温度范围变窄,由甘薯淀粉的21.35℃减少到60 h的15.09℃,回生值上升了29.89%。不同水分含量韧化处理后,85%时糊化热焓值提高了36.20%,峰值黏度比甘薯淀粉下降了378 cp。甘薯淀粉经韧化处理后糊化温度、热焓值升高,黏度下降,回生值增加。     

淀粉种类对甘薯膨化食品品质的影响

纯甘薯制品膨化质量差，适量添加淀粉可显著提高膨化度、改善产品质构。本研究以常用的高温膨化方式，考察了马铃薯、木薯、甘薯及玉米淀粉对甘薯制品膨化度和感官质量的影响。结果表明，淀粉添加量在40％左右甘薯膨化质量最佳；不同淀粉对膨化度的影响不同，马铃薯淀粉＞木薯淀粉＞甘薯淀粉＞玉米淀粉。     

常用淀粉对甘薯食品膨化质量的协同作用研究

纯甘薯制品膨化质量差，适量添加淀粉可显著提高膨化度、改善产品质构。本文以常用的高温膨化方式，考察了马铃薯、木薯、甘薯及玉米淀粉对甘薯制品膨化度和感官质量的协同作用。结果表明，以鲜甘薯质量为基准计的最佳工艺配方为：马铃薯淀粉20％、木薯淀粉5％、玉米淀粉10％。淀粉对甘薯膨化食品的影响显著性顺序为，马铃薯淀粉＞木薯淀粉＞玉米淀粉。其中马铃薯淀粉的影响极显著，而木薯、玉米淀粉的影响相对不显著。     

几种不同淀粉的物性分析研究

以玉米淀粉、蜡质玉米淀粉、马铃薯淀粉、马铃薯酯化变性淀粉、木薯淀粉和木薯醋酸酯淀粉为原料,比较研究了激光粒度仪和X-射线衍射仪测定的淀粉的颗粒大小和结构,快速粘度仪测定糊化特性,差示扫描量热仪和热重分析仪测定淀粉的热特性。结果表明,淀粉的平均粒径大小顺序为马铃薯类淀粉玉米类淀粉木薯类淀粉,且湿法和干法测定有差异;玉米淀粉、木薯淀粉和木薯醋酸酯淀粉为A型结构,蜡质玉米淀粉经过变性处理无双峰结构,马铃薯及其酯化变性淀粉为B型结构;马铃薯淀粉峰值粘度最大,热焓值最高,持水力最强,玉米淀粉的糊化温度最高,峰值粘度和衰减值最小,马铃薯酯化淀粉的起始糊化温度最低,综合持水力最弱。     

蜡质玉米淀粉的性质及其在食品加工中的应用

本文研究了蜡质玉米淀粉的品质特性，结果表明蜡质玉米淀粉糊液的粘性比马铃薯淀粉低，但明显高于普通玉米淀粉，蜡质玉米淀粉糊化后不易老化，其糊液抗凝沉、透光度都优于普通玉米淀粉和马铃薯淀粉。用Brabender粘度计测定了蜡质玉米淀粉糊在不同pH值及添加物条件下粘度曲线的变化情况。     

普通玉米杂交种间原淀粉与羟丙基淀粉糊化性质关系的研究

本文采用湿法在实验室的条件下提取了17种普通玉米杂交种淀粉，并制取了羟丙基淀粉。采用快速粘度测定仪（RVA）测定了所有淀粉的糊化性质参数。结果表明：羟丙基淀粉提高了所有原淀粉的峰值和破损值；降低了所有原淀粉的谷值、终粘度、回生值、出峰时间和成糊温度；原淀粉和羟丙基淀粉的糊化性质参数在普通玉米杂交种间均达到了极显著相关水平，表明了羟丙基淀粉并没有改变原淀粉在普通玉米杂交种间的糊化性质差异性。羟丙基淀粉的糊化性质参数间的相关性显著水平发生了明显的变化，表明了不同的普通玉米杂交种的羟丙基淀粉的糊化性质参数的变化幅度是不同的。但是，羟丙基和原淀粉的相同糊化性质参数间的相关性都达到极显著的正相关水平，说明了羟丙基淀粉与原淀粉的糊化性质参数间存在密切关系，二者的糊化性质又存在着一致性。     

超声波辅助韧化改性甘薯淀粉的结构及理化特性

为研究超声波辅助韧化对甘薯淀粉特性的影响，在其韧化处理不同阶段施加超声波，并对其表观直链淀粉含量、相对分子质量、支链淀粉链长分布、淀粉颗粒形态、结晶结构、糊化、流变、凝胶性质等理化特性进行表征。结果表明，在韧化处理中施加超声波对支链淀粉侧链分布和淀粉颗粒形态特征无显著影响；超声波辅助韧化在一定程度上改变了甘薯淀粉的结晶结构，韧化中间阶段施加超声波使其相对结晶度从31.98%减少至25.71%；与单独韧化相比，超声波辅助韧化使甘薯淀粉具有更高的回升值（1220 cp）和更低的崩解值（1594 cp），同时使甘薯淀粉凝胶的G″与G′值升高，大幅提高了甘薯淀粉凝胶的弹性和黏性；超声波辅助韧化使甘薯淀粉的凝胶硬度、胶黏性和咀嚼性增加。     

预糊化变性淀粉在麻糬面包中的应用

本文研究了预糊化木薯变性淀粉、预糊化马铃薯变性淀粉、预糊化玉米变性淀粉和预糊化大米粉对麻糬面包的感官评价、比容、弹性的影响,分析了预糊化变性淀粉的布拉班德粘度曲线,结果表明,预糊化木薯变性淀粉与预糊化马铃薯变性淀粉制作的麻糬面包口感及外观较好,而预糊化玉米变性淀粉与预糊化大米粉制作的产品口感不佳、比容小,预糊化木薯变性淀粉与预糊化马铃薯变性淀粉质量比为1:1时,麻糬面包加工性能好、口感清爽、弹性强、比容较大、保型性佳。     

食盐对普通玉米杂交种淀粉糊化性质的影响

采用快速粘度分析仪（RVA）研究了食盐对18种普通玉米杂交种淀粉糊化性质的影响。结果表明：食盐显著降低了所有普通玉米杂交种淀粉的峰值、破损值和回生值;提高了谷值、终粘度、出峰时间和成糊温度。但对不同的普通玉米杂交种淀粉的糊化性质的影响程度有显著差别。随着食盐溶液质量分数的增加,普通玉米杂交种淀粉的谷值、终粘度、出峰时间和成糊温度也逐渐增加,破损值和回生值则显著降低,峰值受食盐溶液质量分数的影响很小。     

凉粉草胶与不同淀粉混合体系糊化和质构性质的研究

凉粉草胶(MBG)与淀粉作用可以形成凝胶。为比较不同淀粉与MBG混合体系糊化和凝胶性质的差异,选取玉米等八种常见淀粉,利用Brabender糊化仪、质构仪、对MBG与不同淀粉混合体系的糊化和质构性质进行了研究。结果发现,MBG对谷类淀粉(大米、小麦、玉米)和豆类淀粉(绿豆、豌豆)的糊化性质的影响都比较显著,对薯类淀粉(木薯、马铃薯、甘薯)的不显著,但MBG与薯类淀粉混合体系的黏度远高于MBG与豆类和谷类淀粉的;MBG与大米淀粉形成的凝胶硬度最大,与马铃薯淀粉形成的凝胶硬度次之,与豌豆淀粉形成的凝胶硬度最小。淀粉与MBG之间相互作用的强弱可以从Brabender糊化曲线上的特征点值E-D来比较。     

Microstructural and physicochemical properties of heat-moisture treated waxy and normal starches

Starches from normal rice (21.72% amylose), waxy rice (1.64% amylose), normal corn (25.19% amylose), waxy corn (2.06% amylose), normal potato (28.97% amylose) and waxy potato (3.92% amylose) were heat-treated at 100 °C for 16 h at a moisture content of 25%. The effect of heat-moisture treatment (HMT) on morphology, structure, and physicochemical properties of those starches was investigated. The HMT did not change the size, shape, and surface characteristics of corn and potato starch granules, while surface change/partial gelatinization was found on the granules of rice starches. The X-ray diffraction pattern of normal and waxy potato starches was shifted from B- to C-type by HMT. The crystallinity of the starch samples, except waxy potato starch decreased on HMT. The viscosity profiles changed significantly with HMT. The treated starches, except the waxy potato starch, had higher pasting temperature and lower viscosity. The differences in viscosity values before and after HMT were more pronounced in normal starches than in waxy starches, whereas changes in the pasting temperature showed the reverse (waxy > normal). Shifts of the gelatinization temperature to higher values and gelatinization enthalpy to lower values as well as biphasic endotherms were found in treated starches. HMT increased enzyme digestibility of treated starches (except waxy corn starch); i.e., rapidly and slowly digestible starches increased, but resistant starch decreased. Although there was no absolute consistency on the data obtained from the three pairs of waxy and normal starches, in most cases the effects of HMT on normal starches were more pronounced than the corresponding waxy starches.     

Comparative susceptibilities of sago,potato and corn starches to alkali treatment

The effects of steeping starch (sago, corn, and potato), in 0.025 M of sodium hydroxide for 0, 15, and 30 days at 30 °C, on its granular structure and other physicochemical properties were investigated. Changes in the morphology of starch granules indicated that the alkaline solution affected the granular structure of the starch. Pasting studies showed that the peak viscosity, breakdown, and setback of sago and potato starch decreased significantly, whereas that of corn starch increased significantly, when steeping time was prolonged. Swelling power increased significantly for treated potato and corn starches, but it decreased for sago starch. The amylose content of all alkali-treated starches also decreased significantly after treatment. Onset and peak temperatures of gelatinization (as analyzed with a differential scanning calorimeter) increased significantly, but the enthalpy decreased, for both gelatinization and retrogradation. The results showed that the physicochemical properties of starch of various botanical origins were affected to variable degrees when it was treated with alkaline solution.     

Physicochemical Properties of Sweet Potato Flour and Starch as Affected by Blanching and Processing

The effects of blanching on physicochemical properties of flours and starches prepared from two varieties of sweet potatoes (Mun‐Kai and Negro) were studied and compared. The pasting temperature and peak viscosity of starches, respectively, were 74 and 80 °C and 381 and 433 RVU. The pasting temperature (74.0‐94.8 °C) of flours was greater than that of starch, depending on the variety and blanching process. However, the peak viscosity (ca. 103‐120 RVU) of flours was lower than that of the corresponding starches. Partial gelatinization of starch granules was observed as a result of a 1‐min blanching. Composition of starch and flour was found to affect swelling power and solubility. The starch content of starches, flours from unblanched sweet potato and flours from 1‐min blanched sweet potatoes were 97; 66.3 and 74.9; as well as 36.6 and 40.4%, respectively. Amylose content of flours and starches varied from 17.2‐20.8%.     

淀粉种类对鲜湿面色泽及品质影响的研究

将小麦淀粉、马铃薯淀粉、红薯淀粉、豌豆淀粉及玉米淀粉添加到面粉中制作面条,从鲜湿面色泽、质构及感官三方面,研究淀粉种类对面条的影响规律。结果表明：不同淀粉均能改善鲜湿面的色泽,玉米淀粉效果最佳;质构影响方面,除红薯淀粉外,其他淀粉的添加使得面条的硬度下降,黏附性、回复性、粘聚性升高,坚实度和拉断力随添加量的增加呈先升后降的趋势;感官评价方面,玉米淀粉、小麦淀粉、马铃薯淀粉显著增大了面条的色泽得分,豌豆淀粉和红薯淀粉显著影响了韧性和粘性得分。     

Study on physicochemical characteristics of waxy potato starch in comparison with other waxy starches

The physicochemical properties of wx potato, wx corn, and wx rice starches were examined and compared. wx potato starch displayed the B‐type XRD pattern, whereas wx rice and wx corn displayed the A‐type. Shapes of wx potato starch were oval or slightly round, wx corn and wx rice starch granules were polygonal. AM contents of the three starches were between 1.0 and 1.5%. Rapid viscosity analyzer data showed initial pasting temperatures of wx potato, wx corn, and wx rice starches as 69.6, 75.4, and 76.8°C, respectively, peak viscosity, breakdown, and setback of wx potato starch were 2114, 1084, and 4 mPa s. Using DSC, onset temperature of gelatinization of wx potato starch was 5.5–7.2°C higher than those of wx rice and wx corn starches. The thermal enthalpies of the starches studied in our laboratory were in the range of 0.2268–1.9900 J/g with decreasing order of wx potato > wx corn > wx rice starch.     

Rheological Properties of Acidified and UV‐Irradiated Starches

This study evaluated the effect of added lactic acid and/or UV irradiation on the depolymerization and rheological properties of cassava and corn starches. Combination of lactic acid addition and UV irradiation decreased the intrinsic viscosity of corn and cassava starches. Lactic acid addition alone also decreased paste viscosity in both starches. The paste viscosity of cassava (but not corn) starch was also reduced after UV irradiation. Acidification and UV irradiation increased expansion volume during the baking of cassava (but not corn) starch dough. The baking expansion of cassava starch may be due to its high swelling capacity and solubility resulting from molecular degradation after acidification and irradiation. For corn starch, its high gelatinization temperature and internal lipids content could interfere in starch leaching and thus delay the decrease in viscosity and inhibit dough expansion.     

Changes in characteristics of sweet potato flour prepared by different drying techniques

The changes occurring in the characteristics of sweet potato flour as a result of processing were investigated. Pasting behaviour of drum dried and hot air-dried sweet potato flour was determined using Rapid Visco-Analyser. The pasting characteristics decreased due to gelatinization of starch during processing. The degradation of starch by amylases during hot air drying further lowered the water binding capacity/viscosity and total amylose and increased the digestibility compared to those of drum dried and native flour. Swelling power and solubility of the flours increased as a result of processing which subsequently increased with increase in temperature. Scanning electron micrographs of starch granules showed tendency of clustering, especially in drum dried samples. X-ray diffraction patterns showed alteration from Ca-type to V-type with a marked reduction in crystallinity index as a result of processing. The ¹³C NMR spectra of processed starches showed reduced peak intensities and line widths due to depolymerizing effects, and also pointing to their change in crystallinity.     

Viscosity and Gelatinization Characteristics of Hydroxyethyl Starch

Viscosity and gelatinization characteristics of corn and potato starches as well as their hydroxyethyl derivatives were investigated. The inherent viscosity increased from 164 in native corn starch to 209 in etherified one of DS 0.18. The etherified corn starch gelatinized at lower temperature than native corn starch due to their increase of DS. Maximum viscosity decreased from 93°C to 69°C for the modified corn starch. The retrogradation of starch was minimized by etherification as retrogradation ability of corn starch from its solution decrease from 22% to 6%. This is of great importance when starch is used as blood plasma volume expander. Variable results were obtained with etherified potato starch which might be due to its high contents of phosphorus.     

Effects of mucilage on the thermal and pasting properties of yam, taro, and sweet potato starches

This study investigates the effects of water-soluble mucilages (0, 2.5, and 5 g/100 g; w/w, dry basis) on the thermal and pasting properties of isolated starches from three root and tuber crops. The results show that yam tuber presents the greatest level of mucilage and also possess the largest amylose content of the three isolated starches. The addition of mucilage caused a remarkable increase in the temperature of gelatinization for the three tested starches due to the competition for water during starch gelatinization. Furthermore, adding mucilage increased the phase transition temperature range (Tc-To) of starches but decreased enthalpy (ΔH). However, although the pasting temperature increased with the addition of mucilage into tuber starches, it did not change that of taro starch. The peak viscosity of taro and sweet potato starches decreased significantly as their mucilages were added into each starch suspension system (p < 0.05). However, the addition of mucilage slightly increased the viscosity of yam starch. Furthermore, the addition of mucilage slightly increased the swelling power of yam and taro starches, but did not change that of sweet potato starch.