香蕉成熟度对抗性淀粉理化性能的影响

本文提取了大蕉和皇帝蕉两个品种的5个成熟度抗性淀粉,考察了香蕉成熟度对抗性淀粉持水性、溶解度、膨胀度、碘吸收曲线、黏度特性等理化指标的影响。结果表明:大蕉和皇帝蕉成熟度越高,抗性淀粉持水性呈现先增加后下降的趋势,温度升高时差异显著,皇帝蕉抗性淀粉的持水性优于大蕉抗性淀粉;大蕉和皇帝蕉的溶解度随着成熟度的增加而增加,膨胀度无显著变化;随成熟度的增加,大蕉和皇帝蕉抗性淀粉碘吸收曲线峰面积减小,前三级成熟度抗性淀粉峰值黏度和最终黏度随成熟度增加而降低,且大蕉抗性淀粉较皇帝蕉抗性淀粉不易老化。因此,香蕉抗性淀粉的溶解度、膨胀度较低,持水性和抗老化性均较好,作为一种新型淀粉资源,具有广阔的开发和应用前景。     

热处理对不同直链淀粉含量的玉米淀粉理化性质的影响

采用快速黏度分析法、离心法、差示扫描量热分析法、动态流变仪分析法等,研究了干热与湿热处理对3种不同直链淀粉含量的玉米淀粉糊化性质、膨润性质、热力学性质、流变性质的影响,为淀粉的物理改性研究和加工应用提供理论依据。结果表明,干热处理使淀粉更易糊化,表现为3种玉米淀粉糊化温度降低,溶解度、膨胀度增加。湿热处理加大糊化难度,使3种玉米淀粉的糊化温度升高,膨胀度降低。热处理使玉米淀粉糊稠度、糊化焓值降低。蜡质玉米淀粉经热处理后,溶解度和老化率增加。流变性质测定结果表明,湿热处理不利于高直链玉米淀粉黏弹性凝胶的形成。     

压热法结合反复冻融制备小麦抗性淀粉及其理化性质研究

以小麦淀粉为原料,利用压热法制备抗性淀粉,再经过反复冻融,以期提高产品的抗性淀粉含量。对产品的颗粒形貌、碘吸收曲线、持水力、膨胀度、溶解度等理化性质进行了测定。结果表明,反复冻融次数为6次时得到的小麦抗性淀粉含量最高,为18.31%,经过反复冻融处理的小麦抗性淀粉,颗粒呈不规则形,且在碘吸收曲线中稍微偏向直链淀粉吸收峰,表明其可能含有较多的直链淀粉。与小麦原淀粉相比,经反复冻融处理的小麦抗性淀粉的持水力与膨胀度显著增加,而溶解度显著降低。     

微波湿热处理对马铃薯抗性淀粉含量及性质的影响

在湿热条件下,采用不同微波条件对马铃薯淀粉进行处理,运用扫描电子显微镜、布拉本德粘度仪,对微波处理前后的物化性质进行了研究.结果表明,经微波辐射处理后,淀粉颗粒表面会出现小孔和凹坑;马铃薯淀粉中抗性淀粉和直链淀粉的含量、糊化转变温度及其范围、热糊稳定性和凝沉性得到提高;马铃薯淀粉的膨胀度、溶解度和粘度降低.     

马铃薯淀粉介电处理理化性质研究

以马铃薯淀粉为原料,研究射频和微波加热对马铃薯淀粉的颗粒形态、内部结构、直链淀粉含量、溶解度和膨胀度、热特性和黏度特性的影响。结果发现:淀粉经微波处理比经射频处理使淀粉表面更粗糙,压痕凹陷也更多。射频处理后直链淀粉含量高于微波处理后的淀粉。而微波处理后淀粉颗粒的体积平均粒径均大于射频处理后的体积平均粒径。射频处理改变了淀粉的晶型且结晶度降低,微波处理晶型不变,但结晶度增加。射频处理后淀粉溶解度和膨胀度高于微波处理。淀粉糊化温度:微波处理过的淀粉原淀粉射频处理过的淀粉。射频处理过的淀粉峰值黏度始终高于微波处理过的淀粉。射频处理的淀粉崩解值高于微波处理。     

玉米抗性淀粉的制备及其对肌原纤维蛋白凝胶特性的影响

为探讨玉米抗性淀粉在肉制品中的应用,以玉米淀粉为原料,分别利用湿热超声法、湿热酶法、微波湿热法、二次循环湿热法4种工艺制备玉米抗性淀粉,确定玉米抗性淀粉制备方法并对其理化性质进行测定。再将玉米抗性淀粉添加至肌原纤维蛋白中,研究其对鸡胸肉肌原纤维蛋白凝胶特性的影响。结果表明:4种处理方法均能提高玉米抗性淀粉得率,其中微波湿热法和二次循环湿热法制备的抗性淀粉得率相近(分别为9.1%、9.4%),湿热酶法和湿热超声法得率相近(分别为10.7%、10.4%)。在65℃~85℃范围内,湿热超声法抗性淀粉的膨胀度随温度升高而增大,溶解度有降低趋势;持水性在45℃~85℃范围整体呈增大趋势;粒度增大。将湿热超声法制得的抗性淀粉添加至肌原纤维蛋白中发现,抗性淀粉的添加量影响肌原纤维蛋白凝胶性质,添加适量的抗性淀粉可增强蛋白凝胶强度与持水性,但蛋白的硬度、弹性、黏聚性等有不同程度的降低趋势。     

水热处理大米粉制备抗性淀粉研究

以大米粉为原料,考查了压热法、湿热法、韧化法处理大米粉对其抗性淀粉含量、基本成分、RVA黏度、透明度、溶解度和膨胀能力的影响。结果表明:压热、湿热、韧化处理均能提高大米粉中抗性淀粉含量。其中压热处理大米粉的抗性淀粉含量最高,可达12.70%。米粉乳浓度、处理温度、处理时间对不同水热处理有不同程度的影响。水热处理前后脂质含量的显著降低说明:在水热处理过程中,脂质参与形成了具有淀粉酶抗性的复合物。压热和湿热大米粉的RVA、透明度变化与大米粉、韧化大米粉差异较大,表明这2种水热处理后淀粉发生老化;压热后大米粉溶解度、膨胀度明显高于湿热、韧化处理,分析压热处理可能对大米粉结构造成影响。     

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。     

蚕豆、豌豆淀粉特性研究

本文以蚕豆、豌豆为对象,研究了两种豆类淀粉的各种性质:总淀粉含量,直链淀粉含量,淀粉的糊化特性,淀粉糊的膨胀度和溶解度,淀粉-碘复合物的可见光谱,淀粉糊的透明度,冻融稳定性,凝沉性以及沉降体积。结果表明:通过对淀粉的溶解度、膨胀度、黏度等性质进行研究,对蚕豆和豌豆淀粉性质有了初步的了解。实验发现温度和放置时间对两种豆类淀粉的性质有不同程度的影响。两种淀粉在进行加热、糊化时,随着温度的变化,都将不同程度地影响粉糊的溶解度和膨胀度等。两种淀粉的膨胀度和溶解度均随温度的升高而增加。放置的时间的不同,对淀粉糊的沉降体积、透明度等性质有不同程度的影响。并且淀粉碘复合物可见光光谱的最大吸收波长均在620 nm左右。     

颗粒态绿豆抗性淀粉的制备及性质研究

以绿豆淀粉为原料,采用湿热处理制备颗粒态抗性淀粉,并研究其颗粒形貌、直链淀粉含量、溶胀度、黏度及结晶性质等。试验表明:淀粉经过湿热处理后,抗性淀粉含量显著提高;湿热处理淀粉仍保持完整的颗粒外观,属于颗粒态抗性淀粉,部分淀粉颗粒表面出现了裂纹和凹坑,偏光十字强度有所减弱;湿热处理淀粉的直链淀粉含量明显增加,而溶解度、膨胀度和峰值黏度下降,淀粉糊化变得困难;X-射线衍射图谱表明原淀粉和湿热处理淀粉都为"A"型结晶,且湿热处理淀粉在15.2°、17.4°、22.9°左右的衍射峰强度有所加强。     

Extrusion of banana starch: characterization of the extrudates

Extrusion of banana starch was carried out for obtaining extrudates with functional and digestibility characteristics. Experimental design with temperature, screw speed and moisture content as independent variables produced 20 experiments that were studied using response surface methodology to discover the effect of these variables on resistant starch content, water absorption index and water solubility index. The amylose content was 37.4% with high resistant starch (RS) content in the ungelatinized sample, which decreased when banana starch was gelatinized (1.9%). Extrudate samples had a higher RS content than the gelatinized native starch, showing that the extrusion process increased RS content of native starch due to starch depolymerization and during cooling of extrudates those linear chains form an arrangement that cannot be hydrolyzed by α‐amylase. The response surface regression model fitted to experimental results of resistant starch showed good determination coefficient (84%). During model validation for RS, the model explains the experimental results up to 90%. Response surface showed that water absorption index values were high when the temperature, moisture content and screw speed were also high; water solubility values were not affected by screw speed, and both temperature and moisture content had a quadratic effect. Cylindrical structures were observed in powders where RS was present and as RS level increased the cylinders became coarser. Copyright © 2006 Society of Chemical Industry     

慈姑抗性淀粉的理化特性研究

采用酸解- 微波法制备慈姑抗性淀粉(resistant starch,RS),结果发现慈姑RS 形成了新的连续的致密结构,结晶以初级微晶为主,晶型转变为C 型,结晶度为23.62%;RS- 碘复合物的最大吸收波长为564.40nm;随着RS含量的增加,慈姑RS 的直链淀粉含量变化不大,大部分可溶性直链淀粉转变为不溶性直链淀粉,平均聚合度明显降低,提纯RS 的平均聚合度为22.94;红外光谱分析表明,慈姑RS 含有伯、仲醇羟基和α-D- 吡喃环结构特征,只较原淀粉形成了更多的氢键,说明其是物理改性淀粉。慈姑RS 的溶解度、透明度大大低于原淀粉,而持水力较原淀粉有明显的提高。     

不同干燥工艺对香蕉抗性淀粉的影响

本研究以绿色香蕉为原料,以香蕉抗性淀粉保留率、碘吸收曲线、颗粒形貌以及抗性淀粉的结晶结构、吸水指数、水溶性指数、L 值为衡量指标,系统分析和比较了各干燥技术(热风干燥、挤压干燥、真空冷冻干燥和喷雾干燥)对绿色香蕉功能因子--抗性淀粉的保留效果以及产品品质和特性的影响。结果表明：真空冷冻干燥、低温热风干燥(50℃)和喷雾干燥对香蕉抗性淀粉及其颗粒结构的保留效果以及产品品质均优于100℃热风干燥,而挤压干燥对香蕉抗性淀粉及颗粒结构的破坏效果最明显,产品色泽也最深。     

Stabilization of Paste Viscosity of Cassava Starch by Heat Moisture Treatment

Cassava starch has poor paste stability during prolonged cooking. The starch was modified by heat moisture treatment. A premoistured starch (18–24% moisture) was subjected to heat treatment for 3–16h to bring about paste stability. Different types of heat treatments like moist pressure heating, dry heating and microwave heating was tried. The optimum heat treatment to bring about the paste stability was found to be 18–21% premoistured starch, which was heated at 110°C per 16h. The modified starch granules were intact and had comparatively increased sedimentation volume, oil binding capacity, amylase susceptibility, and decreaced crystallinity, water binding capacity, solubility and paste translucency. The freeze - thaw stability was excellent with modified cassava starch. “Pie filling and Halwa” (an Indian sweetmeat) made from modified cassava starch had good organoleptic properites.     

Effect of baking method on some characteristics of starch in pound cake crumbs

BACKGROUND: The effect of the baking process (microwave versus conventional oven) on some starch characteristics of pound cake was evaluated. Proximal chemical analysis, total resistant starch (RS), retrograded resistant starch (RS3), differential scanning calorimetry (DSC), and X‐ray diffraction (XRD) were evaluated. Pound cake, one of the major products of Mexico's bread industry, was selected for analysis because the high moisture and fat content in the beaten dough might reduce the quality defects often associated with microwave baking. RESULTS: Crumbs from microwave‐baked pound cakes contained lower moisture than crumbs from conventionally baked pound cake. Lower RS was observed in fresh microwave‐baked than conventionally baked pound cake. RS3 increased significantly in conventionally baked products stored for 8 days at room temperature, whereas slightly lower changes in RS3 were observed in the microwaved product. DSC revealed less gelatinisation in microwaved pound cake which is related to limited water availability during the microwave heating process. The crystallinity peaks present in conventionally baked pound cake might be associated with RS3 content; the resistant retrograded starch formed during storage, is reflected in the XRD pattern. CONCLUSION: Microwave‐baked pound cake crumbs showed less gelatinisation than conventionally baked pound cake crumbs. Copyright © 2007 Society of Chemical Industry     

不同处理方式及粒径对小麦麸皮理化性质的影响

以小麦麸皮为原料,研究未处理、挤压、微波和蒸汽4种处理方式及粒径对小麦麸皮基本成分、吸水性、水溶性、持油性、膨胀力和色泽等理化性质的影响。结果表明:挤压处理对麦麸的灰分、粗脂肪和粗蛋白没有显著性影响,但会使总膳食纤维的含量提高,淀粉含量降低。挤压、蒸汽和微波处理均会使麦麸的平均粒度减小。挤压、蒸汽和微波处理对麦麸吸水性和膨胀力没有显著性影响;挤压处理对麦麸的水溶性和持油性没有显著影响,蒸汽和微波处理对其有显著性的影响。4种处理方式的麦麸吸水性先不变后随着粒径的增大而增大,水溶性随着粒径的增大而减小,持油性和膨胀力随着粒径的增大而增大。挤压处理对麦麸色泽的影响最强,蒸汽处理次之,微波处理最弱。     

冻融循环处理对玉米淀粉凝胶结构及颗粒理化特性的影响

本文研究了不同次数(0、1、2、3、4、5和6次)的冻融处理对糊化后的普通玉米和糯玉米淀粉凝胶理化性的影响。采用扫描电子显微镜对淀粉凝胶的微观结构进行分析,测定了凝胶化淀粉的碘蓝值、碘结合力、最大吸收波长、透明度、持水性、溶解度与膨胀力、水解特性和体外消化性。普通玉米淀粉凝胶呈孔状结构,糯玉米淀粉凝胶冻融2次后出现层状结构,二者孔径和层距都随冻融次数增加而减小。冻融循环处理对两种凝胶化玉米淀粉的碘蓝值、碘结合力、最大吸收波长和直链淀粉含量均无显著性影响。随冻融次数增加,普通玉米淀粉的透明度、持水性、RDS与SDS含量逐渐减小,而溶解度、膨胀力、水解率和RS含量逐渐升高;而糯玉米淀粉的透明度、持水性、溶解度和膨胀力逐渐减小,RDS、SDS和RS含量及水解率均无显著性变化。     

不同物理方法处理对碎米中淀粉特性的影响

采用挤压、微波、超声波三种物理方法对水分含量18%的碎米淀粉进行处理,研究分析碎米淀粉经物理方法处理前后的理化性质和结构变化。结果表明,碎米淀粉经微波和超声处理后酶解力增加,糊化黏度下降,而溶解度、膨胀力、糊化温度和直链淀粉含量变化不显著;两种淀粉颗粒表面棱角减少,淀粉颗粒晶型基本没有发生变化,淀粉结晶区降低。挤压后的碎米淀粉变化较大,颗粒形状为片状,凝沉性强,1.0 h后体积仅为3 mL,糊化温度明显降低至55.0 ℃,直链淀粉含量增长为30.75%,溶解度强,为0.59%,酶解力达到45%,X-射线主要衍射峰的强度降低。     

湿热及酶解处理对糯米粉体外消化特性和血糖生成指数的影响

目的 研究酶解处理、湿热处理和湿热复合酶解处理对糯米粉体外消化特性和血糖生成指数(glycemic index, GI)的影响。方法 采用体外消化法测定了不同处理糯米粉的水解度和血糖生成指数值, 并通过X-射线衍射和激光共焦拉曼光谱实验测定了不同处理糯米的淀粉晶体结构。结果 3种处理的水解度和抗性淀粉(resistant starch, RS)相对含量增加, 慢消化淀粉(slowly digestible starch, SDS)相对含量降低; 其中湿热复合酶解处理条件下, RS相对含量最高, 为71.31%; 酶解处理条件下, RS相对含量最低, 为67.66%。酶解处理、湿热处理和湿热复合酶解处理的GI值分别为79.1、76.0和70.6。3种处理后糯米淀粉的晶体结构发生改变, 3种处理均使分子短程有序度与结晶度增加, 其中湿热复合酶解处理条件下, 结晶度最高, 为34.41%。 结论 湿热复合酶解处理后的糯米粉抗消化特性增强且GI值降低, 湿热复合酶解工艺可能通过影响糯米粉的体外消化率来降低GI值。     

Resistant Starch‐rich Powders Prepared by Autoclaving of Native and Lintnerized Banana Starch: Partial Characterization

Powdered preparations enriched in resistant starch (RS) were obtained from native and lintnerized (prolonged acid treatment) banana starches by consecutive autoclaving/cooling treatments. The preparations were tested for indigestible starch content, swelling and solubility properties, thermal analysis and pasting profile. The autoclaved samples had higher RS content than their parental counterparts, but the chemical modification (lintnerization process) allowed development of higher RS proportions (19%, dry matter basis, dmb). The autoclaved samples (RS‐enriched products) showed similar swelling values (α = 0.05) at the temperatures assessed. These RS‐rich products exhibited a lower solubility in water than the corresponding raw materials. The peak temperatures of the thermal transition were 155.5 and 145.8°C for native autoclaved and lintnerized autoclaved starch, respectively. These values indicate that RS products have a marked thermal stability. The pasting behavior of the RS products was less pronounced than that of the raw counterparts. Hence, their potential use as processed food ingredients should not impact final product viscosity. These RS‐enriched products appear suitable for the formulation of functional foods.