高粱淀粉-多酚复合物与高粱淀粉的理化性质比较分析

为探究高粱中内源性多酚对高粱淀粉理化性质的影响,分别对高粱淀粉-多酚复合物与高粱淀粉进行理化性质（溶解度、膨润力、凝沉性、冻融稳定性、黏度特性和热力学特性）研究。结果表明高粱淀粉-多酚复合物溶解度较高粱淀粉溶解度高0.37%～5.25%,而膨润力、析水率和凝沉性均低于高粱淀粉,分别下降0.14%～1.63%、1.18%和13%～27%;与高粱淀粉的糊化相比,高粱淀粉-多酚复合物峰值黏度、谷值黏度、最终黏度和回生值分别下降128 、73 、97 和24 cP,高粱淀粉-多酚复合物成糊温度较低。高粱淀粉-多酚复合物与高粱淀粉理化性质存在差异,说明高粱中内源性多酚对高粱淀粉的理化性质具有一定的影响。     

Physicochemical Properties and Starch Digestibility of Autoclaved-Cooled Water Yam (Dioscorea alata L.) Flour

Water yam (Dioscorea alata L.) is suitable for resistant starch high flour because of its high amylose content. The purple, yellow, and white water yams were treated by autoclaving and cooling with one, two, and three cycles to obtain resistant starch. Water yam tubers were cooked in an autoclave for 15 min, and then cooled prior to drying. Autoclaving–cooling of water yams decreased protein, fat, dietary fiber, water soluble polysaccharide, dioscorin, and diosgenin but increased amylose and sugar. The treatments significantly raised resistant starch and reduced in vitro starch digestibility that depended on water yam types, and affected starch granule morphology.     

山西不同品种高粱淀粉特性

为探究不同品种间高粱物化特性和品质特性的差异,并探究两者之间的内在联系。本研究选取6个品种高粱,研究不同品种高粱淀粉的直链淀粉和支链淀粉含量、粒度、X-射线衍射图谱、核磁共振图谱、糊化特性、热特性,分析不同品种的高粱淀粉在微观结构和理化性质方面的差异以及导致这些差异的可能原因。研究结果表明,6个不同品种的高粱淀粉直链淀粉含量范围在4.42%～43.63%之间,不同品种的高粱淀粉的颗粒形状整体呈不规则状,大多数为多面体,少数为球体,淀粉颗粒表面有凹痕和孔隙,高粱淀粉的平均粒径在15～20 μm。X射线衍射图谱和核磁共振波谱均表明高粱淀粉属于A-型淀粉。6个品种高粱淀粉糊化温度在67.94～69.96℃之间,晋夏2842糊化温度最低,晋杂38号糊化温度最高,回生值范围在240.14～1666.78 cP之间,其中金糯梁6号回生值最大,较易老化,晋杂22号回生值最小,不易老化。6个品种高粱淀粉糊化温度的峰值温度在68.88～71.74℃范围内。     

四种元麦淀粉粒形态结构与理化性质的比较

为探明不同品种元麦淀粉粒形态结构与理化性质的差异,以通麦6号、苏裸麦2号、青元麦、黑元麦为实验材料,采用扫描电镜观察、X-射线衍射、傅里叶变换远红外光谱等方法研究了这四类元麦淀粉粒形态特征及其理化性质,结果表明:青元麦,苏裸麦2号和通麦6号淀粉颗粒比较光滑,大小比较均匀,大颗粒多为圆饼形,小颗粒多为圆球形。黑元麦颗粒大小不均匀,差异较大。4类元麦的表观直链淀粉含量不同,其中黑元麦的直链淀粉含量显著高于其他品种;黑元麦和苏裸麦2号的B-型淀粉粒较多,通麦6号和青元麦的A-型淀粉粒较多。黑元麦的淀粉相对结晶度和表层结构有序度最高,溶解度最高、膨胀势最低。在淀粉葡萄糖苷酶水解过程中,青元麦水解程度最高,苏裸麦2号水解程度最低;在猪胰腺α-淀粉酶水解过程中,通麦6号水解程度最高,青元麦最低;在HCl水解过程中,青元麦水解程度最高,黑元麦水解程度最低。     

Comparison of Starch Physicochemical Properties from Medium‐Grain Rice Cultivars Grown in California and Arkansas

The starch molecular structure and physicochemical properties of two medium‐grain rice cultivars from Arkansas (Bengal, Medark) and from California (M202, M204) were determined and compared when they were grown in their respective locations and grown together in Arkansas to better understand the impacts of genetics and environment on starch characteristics. Both M202 and M204 contained significantly higher amylose contents (13.2‐15.3%) compared with the Arkansas cultivars (11.6‐12.4%). Starch from the Arkansas rice cultivars exhibited higher pasting and gelatinization temperatures and higher enthalpy values. Rice amylopectin from the California cultivars consisted of a smaller proportion of intermediate chains (DP 13‐24), and had a lower molecular weight and a smaller radius of gyration. When the four cultivars were grown together in Arkansas, the ranges for amylose content narrowed (10.6‐12.4%), their differences in thermal and pasting properties became smaller, and the molecular characteristics of amylose and amylopectin changed for all four cultivars. This study demonstrated that genetics, location, and crop year all contributed to variations in rice starch fine structure and physicochemical properties.     

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%.     

Selected Physicochemical Properties of Flour from the Root of African Fan Palm (Borassus aethiopum)

Chemical composition of African fan palm (Borassus aethiopum) root and some physicochemical properties of the flour obtained from the root were investigated. It was found that the root was relatively high, on dry weight basis, in protein content (13.41%), starch (65.12%), crude fibre (7.72%), and total phenolics (1.94%). The processing characteristics of the root showed that the flour fraction obtainable from it ranged from 14.7–16.3% (on whole root basis) while the energy value of the flour (17.23 KJ/g) was relatively high. The elemental composition of Borassus aethiopum root revealed that it was high in potassium (812.21 ppm) and phosphorus (736.33 ppm), while it was low in iron (8.23 ppm) and manganese (4.41 ppm). Elements such as copper, zinc, aluminum, and silicon were not detected. The functional properties of the root flour showed that it had relatively high water absorption capacity (241.24%), moderate oil absorption capacity (192.42%), moderate bulk density (1.22g/cm³), and foaming capacity (2.31%). The maximum solubility and swelling power of the root flour were 15.7 and 18.9%, respectively, at the highest temperature of 95°C. The pasting characteristics of the flour revealed that the peak viscosities at different concentrations were 260 B.U. (5%), 340 B.U. (8%), and 520 B.U. (10%), and these peak viscosities were attained after reaching 95°C. Other pasting characteristics of flour from Borassus aethiopum root revealed that the flour could be used in such composite applications as those flours from other crops (i.e., maize, cocoyam, water yam, and plantain).     

Comparison of Endosperm Starch Granule Development and Physicochemical Properties of Starches from Waxy and Non-Waxy Wheat

Starch granule development and physicochemical properties of starches in waxy wheat and non-waxy wheat were investigated in this article. Starch granules in waxy wheat endosperm showed an early developmental process. Compared with non-waxy wheat starch granules (round-shaped), waxy wheat starch granules (ellipse-shaped) were larger and contained more B-type granules. According to the granule size, starch granules were divided into two groups in waxy wheat, but were divided into three groups in non-waxy wheat. Compared with non-waxy wheat starch, waxy wheat starch had higher swelling power, gelatinization temperatures (To, Tp, Tc), and relative degree of crystallinity. They showed similar ordered structures on external regions of starch granules. Additionally, waxy wheat starch had a higher proportion of double-helical components and a lower proportion of single-helical components than non-waxy wheat starch. Based on the previous results, it was concluded: (1) waxy wheat and non-waxy wheat not only differed in starch granule development, but also in physicochemical properties of starches; (2) waxy wheat had more potential value for producing traditional products than non-waxy wheat.     

Distinctive Sorghum Starch Granule Morphologies Appear to Improve Raw Starch Digestibility

Various factors, including starch granule channels, have been suggested to contribute to the control of sorghum starch digestibility for animal feed. Isolated starch from two normal sorghum lines (P721N, IS6986) and one high protein digestibility (HPD) mutant line (111) that differed in starch granule morphology were selected to study the influence of these factors on starch digestibility. Scanning electron micrographs were taken of raw and digested starches. Microscopy results confirmed that in all three sorghum lines channels in starch granules are the main route of enzyme penetration and the central cavity area is the starting point of enzyme digestion. Channel density was more pronounced in the HPD sorghum mutant line than in normal lines, which may have been responsible for its relatively high digestibility. Micrographs of IS6986 showed unique starch granule morphology with a collapsed ”doughnut‐shaped” structure in a portion of the granules. These unusual granules were rapidly digested and, unlike normal spherical granules, totally disappeared after 30 min of digestion. Amylases appeared to have fast access to the collapsed‐appearing starch granules. Digestion profiles, following incubation with pepsin and α‐amylase, showed that IS6986 and the HPD mutant (111) had the highest initial rate of starch digestion, followed by P721N. These findings provide insight as to how new sorghum cultivars might be developed with high starch digestibility for animal feed use.     

箭筈豌豆淀粉理化及消化特性研究

箭筈豌豆作为优良的绿肥和饲料作物,其食用开发价值受到愈发广泛的关注。本实验主要对箭筈豌豆淀粉的理化性质及消化特性进行探究。结果表明,箭筈豌豆淀粉具有较高的直/支链淀粉比值,在高温下具有较低的溶解度和膨润度;室温下透明度为 12.56%,并随着放置时间的延长而下降;淀粉糊静置 2 h 后上清液体积比高达 68.17%,凝沉速度快,易老化;冻融稳定性差,经过一次冻融后析水率便高达 62.17%;糊化温度高,具有良好的的热糊稳定性和冷糊稳定性。体外模拟消化结果显示,箭筈豌豆淀粉中可消化淀粉含量低于普通豌豆淀粉,具有更丰富的抗性淀粉含量。本实验结果为箭筈豌豆淀粉在功能性食品领域的开发利用提供数据支撑。     

Physicochemical and Biochemical Characterization of Starch Granules Isolated of Pigmented Maize Hybrids

In this study, the morphological and physicochemical of pigmented maizes as well as the initial characterization of the corresponding starch granule enzymes are described. Starch granules were isolated from blue, black, and white maize. They were analyzed using scanning electron microscopy, particle size distribution, pasting characteristics, sorption isotherms, differential scanning calorimetry, and two‐dimensional gel electrophoresis. The morphology of the starch granules of pigmented maizes was different from the granules of white maize; the pattern was related to the endosperm type of these varieties. The average starch granule size was higher for black than for white and blue maizes. The average gelatinization temperature was similar in the three starches, but the pigmented maizes had higher gelatinization enthalpy; black maize starch showed the lowest enthalpy of retrogradation. These results indicated that the starches from the three maizes analyzed had different organization level. Black maize starch showed the highest peak viscosity followed by white and blue maize starches. In the gel electrophoresis three starch granules presented one main spot at pI of 5 and MW of 60 kDa that corresponds to the granule‐bound starch synthase. Blue and white starches presented some spots near 97 kDa at pI of 5.3–5.7 (white maize) and 5.1–5.5 (blue maize), spots that were not observed for black maize starch. The morphological and physicochemical characteristics of maize starch are related to the enzymes involved in its biosynthesis.     

自然发酵优势菌对小米淀粉物化性质的影响

小米自然发酵过程难控制,研究自然发酵液分离并鉴定出的优势菌(乳酸菌、酵母菌)对发酵小米淀粉物化性质的影响,可更好地剖析小米自然发酵的机理,为掌握并控制自然发酵提供理论依据。采用质量浓度为0.2 g/100 mL的NaOH溶液提取发酵后小米淀粉,并测定自然发酵、乳酸菌和酵母菌发酵小米淀粉溶解度、膨润度、透明度、热特性、黏度特性。结果表明,随发酵时间的延长,3种发酵方式所得小米淀粉的溶解度、膨润度和透明度均降低,且乳酸菌和酵母菌发酵小米淀粉的透明度较自然发酵下降1.4%和1.0%;乳酸菌和酵母菌发酵96 h时糊化温度较自然发酵下降1.84℃和1.13℃,峰值温度较自然发酵下降1.04℃和0.43℃;终止温度降低3.69℃和2.85℃;热焓值较自然发酵相比上升1.00 J/g和0.78 J/g;而乳酸菌和酵母菌的衰减值、回生值较自然发酵分别下降978 mPa·s和400 mPa·s、743 mPa·s和471 mPa·s,峰值黏度较自然发酵相比上升185 mPa·s和103 mPa·s。自然发酵的优势菌(乳酸菌、酵母菌)使小米淀粉发生改性,且发酵后的物化性质较自然发酵发生显著变化。     

Physicochemical Properties of Canna edulis Ker Starch on Heat-Moisture Treatment

Canna edulis Ker starch was modified by heat-moisture treatment at moisture levels ranging from 18 to 27 g/100 g starch and its physicochemical properties were investigated. Amylose content, swelling power, solubility as well as water and oil absorption capacity in native starch were higher than in all treated starches. However, alkaline water retention and acid susceptibility of native starch were lower, along with different extent of amylose leaching. The result in the X-ray diffraction measurement revealed that the crystalline type of the starch gradually changed from B-type to A-type, and the degree of crystallinity changed. Investigation on thermal properties showed that the gelatinization enthalpy decreased, whereas the onset temperature, peak temperature, concluding temperature and transition temperature range increased in modified starch than in native starch. In addition, all modified starches exhibited remarkably low values of peak viscosity, hot pasting viscosity and final viscosity, compared to those of native starch.     

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.     

A Rapid Method to Determine Starch Damage in Sorghum

As a major component of cereal grains, including sorghum, starch plays an important role not only in grain development but also in post-harvest processing and end-product quality. Since milling can lead to the inadvertent disruption of starch granules, negatively affecting dough rheology, monitoring of starch damage is an important part of flour formulation. As the existing methods for quantifying starch damage are time-consuming, an alternative non-enzymatic methodology was sought. This study described the use of SDmatic—an instrument developed for determining starch damage in wheat flour—for assessment of sorghum flour via generation of a standard calibration. The known starch damage values were integrated to the SDmatic Ai%, and the starch damage was calculated using the following equation: Starch Damage = aAi%² + bAi% + c. The following variables were developed for calibrating sorghum starch damage: a = 0.168, b = ?30.123, and c = 1349.648. Using this calibration developed specifically for sorghum flour increased our linear regression from initial R² = 0.38 to R² = 0.95.     

Endosperm Structure and Physicochemical Properties of Starches from Normal,Waxy, and Super-Sweet Maize

Maize is a main botanical source used for extraction of starch in the world market. New maize cultivars with different amylose contents and special starch metabolism characteristics have been generated. Three types of maize cultivars, namely, normal maize, waxy maize (wxwx homozygous mutant), and super-sweet maize (sh2sh2 homozygous mutant), were investigated to determine differences in endosperm structures, morphologies, and physicochemical properties of starches. Maize kernels exhibited significantly different contents of total starch, soluble sugar, and amylose. Normal maize kernels contained the largest proportion of floury endosperm, followed by waxy maize and then super-sweet maize. Normal maize starch and waxy maize starch were larger in size than super-sweet maize starch. Normal maize starch and waxy maize starch were spherical and polygonal in floury and vitreous endosperms, respectively. Super-sweet maize starch was spherical both in floury and vitreous endosperms. Waxy maize starch showed the strongest birefringence patterns, the highest crystallinity and the largest proportion of ordered structure in external region of granules, and the largest proportion of double helix components, followed by normal maize starch and then super-sweet maize starch. Waxy maize starch showed the highest peak viscosity, trough viscosity, breakdown viscosity, gelatinization temperatures (i.e., gelatinization conclusion temperature, gelatinization onset temperature, gelatinization peak temperature, and gelatinization enthalpy). By contrast, super-sweet maize starch showed the lowest corresponding values for these parameters.     

Physicochemical Properties of Different Types of Starch Phosphate Monoesters

Different types of starch were phosphorylated to different degrees of substitution using monosodium and disodium hydrogen orthophosphate at 160 °C under vacuum. Generally, phosphation enhanced the physicochemical properties of the modified starches compared to their native counterparts. Solubility and swelling power greatly increase when phosphorylation was carried out to a low degree of substitution, while the solubility and swelling power decreased gradually by increasing the degree of substitution. However, the values of the monoesters were still higher than those of the corresponding native polysaccharides. Viscosities of different starch types except corn amylose showed the highest values at the lowest degree of substitution, when the degree of phosphation increased the viscosity values decreased. Native potato starch formed a clear paste (96% transmittance) due to the presence of phosphate groups while the paste clarity of potato starch decreased gradually by increasing the degree of phosphation. Generally, phosphorylation increased the light transmittance of the other starches investigated at the lowest degree of substitution but the clarity decreased by increasing the degree of substitution.     

Processing Technology Comparison of Physicochemical and Functional Properties of Cassava Starch Extracted from Fresh Root and Dry Chips

Starch was extracted from dry chips of three varieties of cassava using wet milling and dry milling methods. The physicochemical and functional properties were compared with those from fresh root. The starch obtained exhibited lower peak viscosities, breakdowns and setbacks, and higher pasting and peak temperatures than that from fresh root. Most thermal properties (onset and peak temperatures of gelatinization and retrogradation; conclusion temperatures, enthalpies and peak height indices of retrogradation; and degree of retrogradation) were found to be higher than those of fresh‐root starch. Moreover, swelling power, paste clarity and freeze‐thaw stability of the former were inferior to those of the latter. Both types of starches exhibited increased rate of syneresis with increase in freeze‐thaw cycles. Differences observed in properties of starches derived from dry chips by wet and dry millings were very minimal. No indication of major change in granule structure was noted for dry‐chip starch that would alter the properties relative to fresh root starch. Higher fiber content and annealing due to exposure to heat and moisture of the former accounted for most of the variations of properties as compared to the latter. With the advanced technology used in starch manufacturing industry today it would be possible to obtain starch from dry chips with similar quality from fresh root. This would enable the industry to overcome the cycle of glut and low season, and allow them to remain open for longer period of time in a year.     

损伤淀粉含量对米粉理化性质的影响

采用不同粉碎方法得到损伤淀粉含量不同的米粉,研究了损伤淀粉含量对米粉性质的影响。结果表明随着损伤淀粉含量的增加,米粉的总直链淀粉没有明显差异,可溶性直链淀粉和溶解度显著升高,溶胀度变化不大而透明度则显著降低。快速黏度分析(RVA)表明糊化温度由89.2℃降低到86.2℃,回生值由89.58 RVU降低到59.33 RVU,峰值黏度由139.29 RVU降低到85.08 RVU,谷值黏度由103.67 RVU降低到49.04 RVU,末值黏度由180.67 RVU降低到108.38 RVU。损伤淀粉含量9.05%米粉的衰减值最低。糊化后米粉凝胶的硬度和弹性显著降低。