Synthesis and paste properties of octenyl succinic anhydride modified early Indica rice starch

Octenyl succinic anhydride （OSA） modified early Indica rice starch was prepared in aqueous slurry systems using response surface methodology. The paste properties of the OSA starch were also investigated. Results indicated that the suitable parameters for the preparation of OSA starch from early Indica rice starch were as follows： reaction period 4 h, reaction temperature 33.4℃, pH of reaction system 8.4, concentration of starch slurry 36.8% （in proportion to water, w/w）, amount of OSA 3% （in proportion to starch, w/w）. The degree of substitution was 0.0188 and the reaction efficiency was 81.0%. The results of paste properties showed that with increased OSA modification, the starch derivatives had higher paste clarity, decreased retrogradation and better freeze-thaw stability.

Electroneutral Quaternization/Sulfosuccination for Alleviating the Adverse Effect of Paste Aging on the Properties of Corn Starch Film

For the purpose of alleviating the adverse effect of paste aging on the properties of corn starch film, a series of electroneutrally quaternized/sulfosuccinylated starches（EQSS） with different degrees of substitution（DS） were synthesized via the quaternization/sulfosuccination of acid-thinned corn starch（ATS） by varying the amounts of N-（3-chloro-2-hydroxypropl） trimethylammonium chloride, maleic anhydride, and sodium hydrogen sulfite. The influence of paste aging on the properties of starch film cast from heat-induced starch paste was investigated and the properties were explored in terms of tensile strength, elongation, work at break, degree of crystallinity, and flex-fatigue resistance. The experimental results showed that the paste ageing generated adverse influence on the elongation, work at break, and flex-fatigue resistance of starch film. Further experiments showed that electroneutral quaternization/sulfosuccination of starch were able to alleviate the negative effect of paste ageing on the elongation, work at break, and flex-fatigue resistance, thereby obviously enhancing the elongation, work at break and flex-fatigue resistance, and thus reducing the drawback of brittleness. The enhancement depended on the amounts of the substituents introduced. With the increase in DS value, the elongation and work at break as well as flex-fatigue resistance continuously rose, whereas the tensile strength gradually reduced.

RVA and Farinograph Properties Study on Blends of Resistant Starch and Wheat Flour

Resistant starch （RS） is the undigested starch that passes through the small intestine to the large intestine. As a functional low calorie additive, it has special applications in the food industry. Rapid visco analysis （RVA） and the Brabender farinograph were used to study the pasting properties and the viscoelasticity of blends of RS （RS3 and RS2） and three wheat flours. The wheat flours represented strong gluten wheat （SGW）, intermediate gluten wheat （IGW）, and weak gluten wheat （WGW） flours, at different levels of RS substitution （0, 5, 10, 15, and 20%）. The influence of RS3 on the control wheat flours and RS-wheat flour blends were consistent with those of RS2. The peak, trough, and final viscosities of RS3-wheat flour blends were higher than those of the corresponding RS2-wheat flour blends. The peak, trough, breakdown, final, and setback viscosities ofwheat-RS blends decreased with an increase in resistant starch contents from 0 to 20% in the blends. The 0-20% RS-wheat flour blends were all able to form doughs. The dough development times, dough stabilities, dough breakdown times, and farinograph quality numbers for the RS-wheat flour blends decreased as the RS proportion in the blends increased. The values for RS-SGW flour blends were the highest, followed by RS-IGW and then RS-WGW flour blends. The water absorption values for RS-wheat flour blends and the mixing tolerance index for RS-WGW flour blends were found to increase significantly with an increasing proportion of RS from 0 to 20%, but the mixing tolerance index for RS-SGW and RS-IGW flour blends showed no significant differences amongst the different ratios. Correlation analysis showed that the Farinograph quality number was highly positively correlated with dough breakdown time, dough stability, and dough development time （r= 1.000, 0.958, 0.894）, and highly negatively correlated with the mixing tolerance index （r =-0.890）. Data from this study can be used for the development of dough-based products. It also provides a basis for RS-wheat flour blends and quality evaluation in the food industry.

Structural, Pasting, and Thermal Properties of Ultra-high Pressure-treated Lotus Seed Starch

Lotus seed starch （15%, w/w） was subjected to ultra-high pressure （UHP） at 500 MPa for 10～60 min. The effects of UHP on the structural, pasting, and thermal properties of starch were investigated using solid-state 13C CP/MAS NMR, differential scanning calorimetry （DSC）, HPSEC-MALLS-RI, and a rapid visco analyzer. The 13C CP/MAS NMR results revealed a reduction in the relative crystallinity and peak intensity of the crystalline state with increasing the UHP time. The molecular weight of native starch was 1.433 × 107 Da, which was higher than that of the UHP-treated starch. Viscograms of UHP-treated starch revealed an increase in paste viscosity, peak time, and pasting temperature and a reduction in breakdown and setback viscosity compared to the native starch. Furthermore, the DSC results showed a reduction in gelatinization temperature and gelatinization enthalpy with increasing the UHP time.

Characterization of A-and B-type starch granules in Chinese wheat cultivars

Starch is the major component of wheat flour and serves as a multifunctional ingredient in food industry. The objective of the present study was to investigate starch granule size distribution of Chinese wheat cultivars, and to compare structure and functionality of starches in four leading cultivars Zhongmai 175, CA12092, Lunxuan 987, and Zhongyou 206. A wide variation in volume percentages of A- and B-type starch granules among genotypes was observed. Volume percentages of A- and B-type granules had ranges of 68.4–88.9% and 9.7–27.9% in the first cropping seasons, 74.1–90.1% and 7.2–25.3% in the second. Wheat cultivars with higher volume percentages of A- and B-type granules could serve as parents in breeding program for selecting high and low amylose wheat cultivars, respectively. In comparison with the B-type starch granules, the A-type granules starch showed difference in three aspects：（1） higher amount of ordered short-range structure and a lower relative crystallinity,（2） higher gelatinization onset（To） temperatures and enthalpies（ΔH）, and lower gelatinization conclusion temperatures（Tc）,（3） greater peak, though, and final viscosity, and lower breakdown viscosity and pasting temperature. It provides important information for breeders to develop potentially useful cultivars with particular functional properties of their starches suited to specific applications.

A plastidic ATP/ADP transporter gene, IbAATP, increases starch and amylose contents and alters starch structure in transgenic sweetpotato

A plastidic adenosine triphosphate（ATP）/adenosine diphosphate（ADP） transporter（AATP） is responsible for importing ATP from the cytosol into plastids. In dicotyledonous plants, increasing ATP supply is a potential way to facilitate anabolic synthesis in heterotrophic plastids. In this study, a gene encoding the AATP protein, named Ib AATP, was isolated from sweetpotato（Ipomoea batatas（L.） Lam.）. Transcripts of Ib AATP were predominantly detected in the storage roots and leaves and were induced by exogenous sucrose and subjected to circadian rhythm. Transient expression of Ib AATP in tobacco and onion epidermal cells revealed the plastidic localization of Ib AATP. The overexpression of Ib AATP in sweetpotato significantly increased the starch and amylose contents and led to enlarged starch granules. The IbA ATP-overexpressing plants showed altered fine structure of amylopectin, which contained an increased proportion of chains with a degree of polymerization（DP） of 10–23 and a reduced number of chains with a DP of 5–9 and 24–40. In addition, starch from the transgenic plants exhibited different pasting properties. The transcript levels of starch biosynthetic genes, including Ib AGP, Ib GBSSI, Ib SSIIV, and Ib SBE, were differentially regulated in the transgenic plants. These results revealed the explicit role of Ib AATP in the starch biosynthesis of sweetpotato and indicated that this gene has the potential to be used to improve starch content and quality in sweetpotato and other plants.

Effect of Gluten on Pasting Properties of Wheat Starch

The effect of gluten on pasting properties of wheat starch was studied to provide a scientific basis for the application of gluten in food production and quality improvement in wheat breeding. The pasting properties of blends were analyzed using PH 1391 wheat starch mixed with five different additions of three kinds of gluten （strong-, medium-, and weak-gluten） and the structures of network were observed with microscope. The significant downtrends of peak viscosity, trough viscosity, final viscosity, area of viscosity, setback, and peak time were observed with the increase in the addition of gluten. In general, the average value of them decreased respectively by 3.6, 4.8, 3.4, 3.8, 4.0, and 1.18% of those corresponding indexes of pure starch for every 2% increase in gluten. The decreasing rate of the indexes mentioned above exceeded more than 2% except peak time, but there were no significant influence of gluten addition on breakdown, pasting temperature and pasting time. The inter layer composed of gluten was not observed when the addition of gluten was 10%, as the compound formed of gluten inlaid in the paste of starch, but obvious inter layer was detected when the addition of gluten was 18%. There was significant or remarkable difference among the effects of three different kinds of gluten on the peak viscosity, trough viscosity, area of viscosity, setback, and peak time, but it had no significant difference among the effects of different glutens on pasting temperature and pasting time. The descending order of the effect of different glutens on peak viscosity, trough viscosity, and area of viscosity was strong-, medium-, and weak-gluten, but the order of them for setback was opposite. Both addition and types of gluten significantly affected peak viscosity, trough viscosity, area of viscosity, setback, and peak time, but there were no significant effects of it on peak time and peak temperature.

Rheological properties of sweet potato starch before and after denaturalization

Based on the sweet potato starch,cationic starch,acetic starch and cationic-acetic compoundedly modified starch were made through chemical denaturalization.The above three kinds of static rheological parameter and dynamic rheological parameter were measured,respectively.The experimental result reveals that the thermal stability of starchy viscosity increases after chemical denaturalization.Under the condition of identical shearing rate,the shear stress of cationic-acetic ester compoundedly modified sweet potato starch paste is the largest among these kinds of sweet potato starch.This attributes to a phenomenon of shearing thinning.Furthermore,raw sweet potato starch has a larger gel intensity than that of modified starch.

Influence of Gum Arabic from <i>Acacia Senegal</i>var. <i>kerensis</i>on the Modifications of Pasting and Textural Properties of Cassava and Corn Starches

The use of hydrocolloids to modify the properties of native starches has been on the rise in the recent times due to the market demand for natural, safe and economical food ingredients. The objective of this study was to investigate the effect of gum Arabic from Acacia senegal var. kerensis to modify pasting and textural properties of corn and cassava starches, as an alternative to chemical and enzymatic modification. Blends were prepared by substituting the starches with gum at different levels (0%, 0.5%, 2.0%, 4.0%, 6.0% and 8.0%), whereas native corn and cassava starches were used as control. The pasting properties of the starch-gum mixed systems were determined using the Brabender viscograph while the textural properties (firmness, consistency, cohesiveness and work of cohesion) were determined using Texture Analyzer. Results showed that the gum Arabic significantly decreased all the viscosity parameters (peak viscosity, final viscosity, break down and setback values) of both starches at all levels of substitution. However, there was no significant effect of gum Arabic on the pasting temperature (72.05°C - 71.85°C) for corn starch and (68.90°C - 68.65°C) for cassava starch. The degree of gel firmness and consistency was higher in corn starch than in cassava starch and the effect of gum addition differed with each starch. The findings from this study indicate that gum Arabic significantly modified the pasting and textural properties of corn and cassava starches due to strong interaction between the gum and the starches. Hence, this property of gum Arabic could be useful in controlling starch retrogradation and determining starch end use functionality.

超声处理时间对莲藕淀粉理化和结构特性的影响

以莲藕淀粉(lotus root starch,LS)为对象,探究不同超声时间(0、10、20、30、40、50 min)对LS糊化特性、流变特性以及片层结构、结晶结构、短程有序结构、微观结构等的影响。结果表明,不同超声时间处理后LS分子链溶胀和缠结增加,糊化黏度最大增至(6059±31)mPa·s;淀粉颗粒表面出现裂缝、塌陷及坑洞,利于水分子进入,黏弹性增加。在超声作用下LS的α-1,6-糖苷键被破坏,部分支链断裂,形成淀粉短链,重新排列成有序的结构,短程有序结构增多,R_(1047/1022)值升高了3.20%;较短时间的超声处理(30 min)增强了淀粉分子间的相互作用,双螺旋结构变得有序和紧密,使T_p和ΔH值分别增大了11.09%和89.21%。长时间超声处理(40~50 min)不利于这种有序结构的形成。本研究结果可为超声技术在淀粉理化特性及多尺度结构调控中的应用提供理论参考。

大豆低聚肽对小麦淀粉理化性质的影响

为改善小麦粉的品质,提升小麦食品的蛋白质含量,将具有营养价值和生物活性的大豆低聚肽添加到小麦淀粉中,对小麦淀粉糊化特性、流变学特性、热力学特性和结构特性进行研究。结果表明,大豆低聚肽的添加(0%~40%)使复合物的峰值黏度、低谷黏度和终值黏度降低,糊化温度显著升高(P<0.05)。复合物表现为弱凝胶性质,具有假塑性剪切稀化行为。与对照组相比,大豆低聚肽添加量为40%时,复合物的峰值黏度最小,糊化温度最大,分别为396 cp和77.5℃,焓变下降了79.6%,Zeta-电位的绝对值下降了89.6%,粒径增加至924.1 nm。大豆低聚肽增加了复合物氨基酸含量和热稳定性,降低了复合物的凝胶特性,为功能性谷物食品的开发和加工提供了参考。

抛光色选工艺过程对香稻米2-AP含量和糊化特性的影响

抛光色选工序是生产食用大米的重要步骤,会影响稻米品质和香气2-乙酰基-1-吡咯啉(2-AP)含量。以香稻品种19香和软华优金丝为材料,研究了工业生产中抛光色选工艺过程对香米2-AP含量和糊化特性的影响。结果表明,在稻米抛光阶段增加抛光色选程序会导致19香和软华优金丝2-AP含量分别损失51.66%和38.10%,蛋白质含量分别降低7.31%和1.49%,水分含量、淀粉峰值黏度、最低黏度、最终黏度和消减值都有上升,而回冷值降低。

种植密度对沿淮玉米籽粒淀粉粒度分布与糊化特性的影响

分析不同种植密度对沿淮玉米籽粒中淀粉粒度分布与糊化特性的影响。以豫单132、京科968等13个玉米杂交品种为材料,设置56 250株/hm^(2)、67 500株/hm^(2)、77 250株/hm^(2)等3个种植密度,分析不同种植密度对玉米籽粒品质、淀粉粒度分布与糊化特性的影响。结果表明,在种植密度56 250~77250株/hm^(2)范围内,随着种植密度的增加,玉米籽粒的蛋白质和脂肪含量呈递减趋势,淀粉含量呈递增趋势,即淀粉/蛋白质比率增加。玉米籽粒大型淀粉粒体积和表面积百分比显著增加,小型淀粉粒却显著降低。增加种植密度后玉米淀粉的峰值黏度、低谷黏度、最终黏度和稀懈值等黏度参数均呈显著升高。相关分析表明,玉米籽粒峰值黏度等黏度参数与小、大型淀粉粒体积百分比呈正相关,与中型淀粉粒体积百分比呈显著或极显著负相关。说明种植密度影响玉米籽粒淀粉粒度分布、淀粉黏度参数和组分含量。

乳酸菌发酵芋泥的制备及其对面包品质的影响

为拓宽芋泥资源的应用,提升其营养价值,以芋泥为发酵基质,经TR22型植物乳杆菌发酵后,将其添加进面团制作面包。在考察发酵过程中芋泥基质营养成分变化的基础上,测试不同添加量(0%、5%、10%、15%,w/w)的发酵芋泥对面团粉质特性、流变特性及面包品质的影响。结果表明,经乳酸菌发酵的芋泥,其乳酸菌菌落总数最高可达8.39×10^(6) CFU/mL,乳酸和乙酸分别达到5.21 mg/g和4.96 mg/g,胞外多糖由1.43 g/kg增长为2.38 g/kg,氨基酸含量也有不同程度提高。发酵芋泥的添加可以增强面团的吸水性、弹性和柔软性,在一定程度上会增大面包比容和持气性,使其组织状态变得柔软,瓤芯气孔个数减少。综上可知,添加乳酸菌发酵的芋泥可提升面包品质,为发酵芋泥在面包产品中的应用提供了理论依据。

小米各级蛋白组分对淀粉糊化特性的影响

根据溶解度的不同,将4种蛋白组分从小米全粉体系中逐步去除,利用扫描电镜(SEM)、低场核磁共振(LF-NMR)、傅里叶变换红外光谱、快速黏度分析仪(RVA)探究样品结构及糊化特性的变化,并构建蛋白组分-淀粉重组体系进行反向验证。结果表明:整体而言,醇溶蛋白对淀粉糊化特性的影响最为显著,其次为谷蛋白;清、球蛋白的影响程度较小。SEM结果显示,醇溶蛋白对复粒淀粉无连接、包裹作用,对淀粉糊化不构成物理屏障,而谷蛋白则明显包围连接了淀粉颗粒。结合蛋白组分特性及RVA、LF-NMR试验结果,可知醇溶蛋白的高疏水性引发了憎水效应,增加了体系内水分子移动性,促进淀粉颗粒吸水溶胀,提高淀粉各项糊化特性值;谷蛋白降低淀粉糊化的峰值黏度及崩解值,延长糊化峰值时间,限制糊化进程。

拔节期渍水对软质小麦淀粉粒度分布与糊化特性的影响

为明确拔节期渍水对软质小麦淀粉粒度分布与糊化特性的影响。在大田条件下,于2021—2023年,选用软质小麦品种华成麦1688和荃麦725为试验材料,设对照(CK)和渍水(WL)2种处理,在小麦拔节期进行连续10 d的渍水处理,研究拔节期渍水对软质小麦淀粉粒度分布及黏度参数的影响及其相互关系。结果表明,与对照相比,拔节期渍水胁迫通过降低小麦穗数、穗粒数及千粒重,从而降低小麦产量,籽粒湿面筋含量、蛋白质含量显著降低,淀粉含量显著增加。拔节期渍水胁迫抑制了小麦胚乳B淀粉的产生和生长,使小麦B型淀粉粒体积、表面积及数目百分比显著降低,其中主要影响2.8~10.0μm的淀粉粒;A型淀粉粒体积、表面积百分比显著增加,以影响其中10.0~22.0μm的淀粉粒为主,渍水胁迫对A型淀粉粒数目百分比无显著性影响。渍水胁迫后,面粉峰值黏度、低谷黏度、最终黏度、稀懈值及回升值显著增加。可见,拔节期渍水胁迫改变了小麦淀粉粒度分布,通过降低B型淀粉粒占比,增加A型淀粉粒占比,进而增加峰值黏度等黏度参数,最终影响小麦籽粒品质。

监控施肥配施有机肥和生物炭对小麦产量及籽粒淀粉理化特性的影响

为了明确不同施肥措施对冬小麦籽粒淀粉结构、理化特性和小麦籽粒产量的影响,以小麦品种洛旱6号为材料,通过裂区试验(以农户施肥和监控施肥2种施肥方式为主区,以不配施有机物料、配施有机肥和配施生物炭为副区),分析不同处理下冬小麦籽粒淀粉结构、理化特征及产量的差异。结果表明,与农户施肥方式相比,监控施肥显著增加了小麦籽粒总淀粉含量、直链淀粉含量和直支比,提高了A型淀粉粒的体积和数目百分比,显著提升了平均低谷黏度、最终黏度、稀懈值和回升值。在同一施肥方式下,与不配施有机物料相比,配施有机肥对总淀粉含量、直链淀粉含量、淀粉直支比、A型淀粉粒体积百分比和淀粉黏度参数也均表现出正向效应,同时降低了B型淀粉粒的体积和数目百分比,而配施生物炭对淀粉含量及直支比、A型淀粉粒体积及表面积分布影响均不显著。施用生物炭对淀粉糊化特性影响在不同施肥方式下存在差异,农户施肥+生物炭处理显著降低了峰值黏度、低谷黏度和最终黏度,而监控施肥+生物炭处理显著增加了峰值黏度、最终黏度、稀懈值和回升值。监控施肥对产量影响不显著,但监控施肥+配施有机肥处理显著提高产量。在所有处理中,监控施肥+配施有机肥处理的小麦籽粒淀粉含量、直支比、淀粉粒分布、淀粉黏度参数综合表现最好,说明在监控施肥条件下减少施用化肥同时配施有机肥可改善小麦淀粉品质和增加产量,促进渭北旱地冬小麦高产优质生产。

茶多酚对大米淀粉理化特性的影响

为研究茶多酚对大米淀粉理化特性的影响,以大米淀粉为原料,添加不同比例的茶多酚后考察大米淀粉溶解度、膨胀度、透光率、沉降率、冻融稳定性、糊化特性、热力学特性、流变学特性等的变化。结果表明,添加茶多酚会影响大米淀粉的溶解度和膨胀度,延缓淀粉糊透光率的降低,对沉降率和冻融稳定性影响较小。随着茶多酚添加量的增加,大米淀粉糊化温度、崩解值和糊化焓显著升高,最低粘度和最终粘度降低。添加茶多酚后,淀粉表观粘度、储能模量和损耗模量呈下降趋势,损耗因子tanδ有所增加。

武陵山区4种块根类淀粉的糊化特性和冲调性质分析

目的:探究葛根、蕨根、百合、凉薯4种块根类植物淀粉的糊化特性与冲调特性。方法:采用扫描电子显微镜(SEM)、快速黏度分析仪(RVA)、差式量热扫描仪(DSC)等分析淀粉的微观形态和糊化特性;对4种淀粉进行冲泡,并分析淀粉糊的透明度和表观形态等。结果:葛根、蕨根、凉薯淀粉的颗粒形态较为相似,大多为球形;百合淀粉颗粒较大,且形态为纺锤形。糊化特性表明,百合淀粉的峰值黏度最高,为(7.00±0.03) Pa·s;葛根和百合淀粉的回生值较大,表明其易于回生。热力学特性表明,蕨根淀粉的起始糊化温度最低,为59.4℃,表明其容易糊化;百合淀粉的糊化焓值最高,为15.64 J/g,表明其糊化时需要更多的热量。冲调特性表明,葛根淀粉糊的透明度最好,其透光率为29.11%;而百合淀粉糊的透光率仅为12.25%;冲调后,葛根淀粉糊和百合淀粉糊易于形成凝胶,但流动性较差;蕨根淀粉糊和凉薯淀粉糊凝胶能力较差,易于流动。结论:百合淀粉和葛根淀粉的冲调性质相似,具有冲调类食品的开发潜力;蕨根淀粉和凉薯淀粉回生值较低,糊的流动性较好,可用于抑制食品的回生。

不同种类淀粉与黑米粉复配体系的理化性质和分子结构特性研究

为了改善黑米粉的凝胶特性,分别将绿豆淀粉、马铃薯淀粉和玉米淀粉与黑米粉进行复配。对复配体系的糊化特性及凝胶质构特性进行测定,并结合低场核磁共振分析仪、傅里叶变换红外光谱和X射线衍射仪进一步分析复配体系的分子结构特性。结果表明:随着淀粉浓度的增加,淀粉-黑米粉复配体系的峰值黏度均显著增加,糊化时间和温度降低。绿豆淀粉和马铃薯淀粉显著增强了复配体系的持水力和膨润力,马铃薯淀粉和玉米淀粉显著降低了复配体系的溶解度。三种淀粉均可以促进复配体系凝胶网络结构的形成,改善凝胶的质构特性,包括凝胶的硬度、弹性、咀嚼性和回复性。此外,三种淀粉增强了复配体系淀粉链间的氢键相互作用,降低了凝胶的持水性,增强了体系的分子短程结构有序性和相对结晶度。上述研究表明,三种淀粉都可以改善黑米凝胶的品质,且绿豆淀粉的改善效果更佳。