Effects of exogenous ABA application on post-anthesis dry matter redistribution and grain starch accumulation of winter wheat with different staygreen characteristics

The objective of this study was to investigate whether and how exogenous abscisic acid(ABA)is involved in mediating starch accumulation in the grain and redistribution of carbohydrates during grain filling of two wheat cultivars with different staygreen characteristics.At blooming stage,plants of Wennong 6(a staygreen cultivar)and Jimai 20(control)were sprayed with10 mg L-1abscisic acid(ABA)for 3 days.The application of ABA significantly(P<0.05)increased grain filling rate,starch accumulation rate and content,remobilization of dry matters to kernels,and 1000-grain weight of the two cultivars.Exogenous ABA markedly(P<0.05)increased grain yield at maturity,and Wennong 6 and Jiami 20 showed 14.14%and 4.86%higher compared yield than the control.Dry matter accumulation after anthesis of Wennong 6 was also significantly(P<0.05)influenced by exogenous ABA,whereas that of Jimai 20 was unchanged.Application of ABA increased endogenous zeatin riboside(ZR)content 7 days after anthesis(DAA),and spraying ABA significantly increased endogenous indole-3-acetic acid(IAA)and ABA contents from 7 to 21 DAA and decreased gibberellin(GA3)content at 14 DAA,but increased GA3content from 21 to 35 DAA.The results suggested that increased yield of staygreen was due to greater starch assimilation owing to a higher filling rate and longer grain-filling duration.

Polyamines mediate the effect of post-anthesis soil drying on starch granule size distribution in wheat kernels

Polyamines(PAs) are important endogenous plant growth regulators responding to environmental stress and mediating many physiological processes including grain filling in cereals.This study investigated whether PAs mediate the effect of post-anthesis soil drying on starch granule size distribution,starch content,and weight of superior and inferior kernels of wheat(Triticum aestivum L.).Two wheat cultivars were grown in pots.Three treatments,well-watered(WW),moderate soil drying(MD) and severe soil drying(SD),were imposed from 9 days post-anthesis until maturity.PA levels in kernels and small,medium and large granules were measured.The results showed that superior kernels had much higher free spermidine(Spd) and free spermine(Spm) concentrations,larger volumes of medium starch granules,and smaller-sized large granules than did inferior kernels under all the treatments.Compared to WW,MD significantly increased the concentrations of free Spd and free Spm,activities of soluble starch synthase and granule-bound starch synthase,volume of medium granules,and starch content and kernel weight of inferior kernels,and decreased the size of large granules.SD produced the opposite effect.Application of Spd or Spm to spikes produced effects similar to those of MD,and application of an inhibitor of Spd and Spm synthesis produced effects similar to those of SD.These results suggest that PAs mediate the effect of post-anthesis soil drying on starch biosynthesis in wheat kernels by regulating key enzymes in starch synthesis and that elevated PA levels under MD increase the volume of medium granules and kernel weight of inferior kernels.

Preparation of Cationic Starch by Electromagnetic Dry Process (EMDP)

Introduction Cationic starches are a series of products of which various sorts with different properties and usages can all be produced via cationic reactions by using different types of etherification agents under different conditions. As an additive and strengthening agent,

APPLICATION OF CATIONIC STARCH BY DRY-PROCESS AS ANIONIC CHARGE NEUTRALIZING AGENTS TO IMPROVE FILLER RETENTION

This paper deals with the preparation of cationic starch with high degree of substitute by dry-process. The corn starch and the alkali catalyst are mixed in the mixer, then added the cationic etherifying agent (3-chloro-2-hydroxypropyltrimethylammonium chloride). The reacting time is for 5 hours at the temperature of 70℃. The cationic starch with high degree of substitution is used as anionic charge neutralizing agents to improve filler retention in wet-end section of papermaking machine.

Drying characteristics, functional properties and in vitro digestion of purple potato slices dried by different methods

The drying characteristics,physico-chemical and functional properties,as well as starch digestibility,of purple potato slices dried using different methods(such as,vacuum freeze-drying,VFD;hot-air drying,HAD;air-impingement jet drying,AIJD;and far-infrared assisted heat-pump drying,FIHPD)were investigated.Drying rate was the highest(3.0 g 100 g^-1 min^-1)using AIJD,followed by FIHPD and HAD,and the rate of VFD was the lowest one(0.3 g 100 g^-1 min^-1).Drying data were fitted to 12 thin-layer drying models,with the Midilli model giving the best predictions.Moreover,AIJD showed higher diffusivity(5.5×10^-10 m^2 s^–1)and energy efficiency(55 J g^-1)than any other drying method used in this study.With reference to the samples dried by VFD,the starch granules of the samples obtained by HAD,FIHPD,and AIJD exhibited different extent of disruption,which significantly increased their water absorption capacity,swelling power,and in vitro digestibility,but decreased the peak viscosity.The sample resulting from AIJD had the greatest water absorption capacity(7.9 g g^-1)and solubility(21.6%),but the smallest syneresis rate(48%).Good correlation coefficients(R^2>0.98)implied that the pseudofirst order kinetic model adequately described the rate and extent of starch digestion of dried potato flours.Samples from AIJD and FIHPD showed the highest digestibility percentages,reaching to 72.4 and 72.5%.Based on the drying rate,specific energy consumption,functional properties and digestibility,AIJD appeared to be quite effective and suitable to be transferred on the industry scale.

Modeling the Drying Kinetics of Earth Bricks Stabilized with Cassava Flour Gel and Amylopectin

Earth bricks could contribute to alleviate the housing shortage in the world, thanks to their low cost, easy production, and low environmental impact. However, to manufacture bricks with required properties, many raw soils must be ameliorated. In Central and Eastern Africa, the waste water of the cassava processing is used to improve earth brick mechanical properties. This technique is interesting, because it is sustainable, low-cost and easy to implement. But, studies on this stabilization method are scarce, in particular on the drying kinetics of these bricks. Now, it is important to know the drying duration, because the earth brick’s strength is strongly correlated to its moisture content. Thus, this study aims to quantify and to model the effect of adding cassava flour gel and amylopectin on the drying kinetics of earth bricks. Depending on the soil nature, the drying duration decreases from 7% to 25% for a stabilizer content of 20%. For the five models used, the coefficient of determination is superior to 0.997 and the chi square is inferior to 3 × 10&#8722;4. In average, the best model is Khazaei, followed in order by Avrami-Page, diffusion, Yong and Peleg. The effective coefficient of diffusion of water is about 4 × 10&#8722;5 m&#8901;s&#8722;2. The parameter T of the Khazaei’s model is strongly correlated to the drying duration and the stabilizer content, and their relationships have been deduced.

Microencapsulation by Spray Drying of Vitamin A Palmitate from Oil to Powder and Its Application in Topical Delivery System

Vitamin A palmitate (VAP) contains retinol and palmitic acid which is easily absorbed by body and widely used in skin care products. But, it is a hydrophobic and oxidation sensitive molecule which undergoes rapid degradation especially in an aqueous environment. The purpose of this study was to prepare microcapsules of VAP using combination maltodextrin and modified starches. Emulsion of VAP was prepared using cremophore RH 40 with Tween 80 in a homogenizer and formed emulsion was spray-dried. The spray process was optimized using a central composite design for two variables to obtain microcapsules with desirable characteristics. Microcapsules containing 30% of VAP were produced using different concentration of wall materials. The prepared microcapsules were evaluated for their physical, morphological, in-vitro drug release and SEM study. The results showed that obtained microcapsules are nearly spherical in shape with a particle size ranged from 1 to 12 μm. The drug content and encapsulation efficiency (53% - 63%) of different batches were found within acceptable range. These stabilized drug loaded microcapsules were incorporated into silicone cream based formulation for convenient topical application and evaluated for its physicochemical parameters. The drug release study showed 80.18% to 83.43% of drug release from VAP microcapsules while topical formulations prepared by VAP microcapsules showed 67.09% to 71.45% drug release at the end of 24 hrs. The formulations were kept for 3 months stability study as per ICH guidelines and found to be stable.

微波间歇干燥对玉米籽粒中淀粉理化特性的影响

为提高玉米干燥的速率,明确微波间歇干燥对玉米中淀粉的影响,以"吉农玉719"为研究对象,对比自然干燥和不同微波功率密度条件下微波间歇干燥对玉米中淀粉加工和结构特性的影响。结果表明:与自然干燥的玉米相比,玉米经微波干燥,其淀粉的性质发生明显变化,微波功率密度在0.9~3.6 W/g范围内,玉米淀粉的峰值黏度和溶解度均呈先升高后降低的趋势,当微波功率密度为1.8 W/g时,淀粉的峰值黏度最高,溶解度最高。静态流变学结果表明:玉米经自然干燥和微波干燥,其淀粉凝胶均为假塑性流体。动态流变学结果表明:微波功率密度在0.9~1.8 W/g范围,微波作用可明显改善玉米淀粉凝胶的黏弹性,当微波功率密度为1.8 W/g时,淀粉凝胶的黏弹性最好;当微波功率密度高于1.8 W/g时,玉米淀粉凝胶的硬度显著增加;玉米经微波干燥,其淀粉的膨胀度、热焓值和有序度均降低,粒径增加。结论:在微波功率密度1.8 W/g、微波时间2 min、缓苏时间4 min条件下干燥得到的玉米淀粉特性最佳。

干燥方式对热水可溶性淀粉的复溶性质和乳化能力的影响

热水可溶性淀粉(HWS)是一种新型天然乳化剂。为了便于储运,HWS需要干燥。研究了热风、冷冻、醇沉和喷雾干燥对HWS复溶性质和乳化能力的影响。4种干燥方式所得的HWS粉末,在100℃下均能完全复溶。以复溶后的HWS为水相,制备O/W乳液,比较其离心和储藏稳定性。结果表明,热风干燥的HWS所构建的乳液的稳定性最高,原因是能够更充分地吸附在油水界面上,产生更低的界面张力和更小的乳液粒径。此外,由于热风干燥的HWS在界面上的充分吸附,抑制了HWS分子的回生和网络结构的形成,使得构建的O/W乳液的黏度在90 d的储藏过程中几乎保持不变。热风干燥的HWS不仅能有效稳定O/W乳液,而且不改变乳液在储藏过程中的流变性质,有利于在食品中的广泛应用。

玉米糁品质特性研究

玉米糁是玉米籽粒经除杂、脱胚、研磨、筛分等系列工序加工而成的不同大小颗粒状产品,深受消费者的喜爱。为了解玉米糁的品质特性,本研究以玉米全粉为对照,以大玉米糁、粗玉米糁、细玉米糁和脱胚玉米粉为实验材料,对其基本组分、理化特性、糊化特性、热学特性、流变学特性等进行分析。结果表明,不同玉米糁、脱胚玉米粉与玉米全粉的品质特性存在显著差异。所有玉米糁的淀粉质量分数在72.27%~73.64%之间,高于玉米全粉(62.36%),低于脱胚玉米粉(74.57%),溶解度(6.67%~6.93%)与膨胀度(7.82~8.61 g/g)更低,糊化后形成最终黏度更大(1275~1524 cP)、更稳定的弹性凝胶。傅里叶红外光谱分析表明大玉米糁的淀粉结构更紧密,细玉米糁的淀粉晶体松散,糊化焓值更低(6.06 J/g),机械加工导致3种玉米糁蛋白质的二级结构受到破坏。与玉米糁相比,脱胚玉米粉更白、更亮,且吸水性好,但其双螺旋度低,糊化形成的凝胶稳定性较弱。玉米全粉的蛋白质、脂肪含量最高,吸水性较弱,峰值黏度最低,糊化焓值最高。

清洁标签常温酸奶的配方优化研究

以生牛乳、干热改性淀粉、海藻糖、蔗糖和柑橘纤维为主要原料研究开发一款清洁标签常温酸奶。以感官评分为指标,通过单因素和正交实验对清洁标签常温酸奶的配方进行优化。结果表明,清洁标签常温酸奶的最佳配方为生牛乳90.3%、干热改性淀粉1.5%、蔗糖4%、海藻糖4%、柑橘纤维0.2%,在此配方下制作的常温酸奶组织良好,口感细腻爽滑,发酵乳香浓郁,标签清洁化。

5种干燥方式对木薯酸淀粉性能的影响

为探究不同干燥方法对木薯酸淀粉性能的影响,本研究以木薯淀粉为原料,经乳酸菌发酵后,采用热风干燥、热泵干燥、真空冷冻干燥、喷雾干燥和太阳光晒干5种干燥方法制备木薯酸淀粉,对其性能进行测定分析,并采用变异系数法对性能进行综合评分。结果表明,热风干燥的木薯酸淀粉粒径跨度最大,为2.36,透明度、碘蓝值和持油性最小,分别为21.57%、8.96和1.74 g/g;热泵干燥的木薯酸淀粉比表面积最小,为351.83 m2/kg,堆积密度、析水率和凝沉性最高,分别为0.87 g/mL、33.02%和74.89%;真空冷冻干燥的木薯酸淀粉堆积密度、休止角和析水率最低,分别为0.73 g/mL、37.49°和4.64%,透明度、碘蓝值和持水性最高,分别为27.03%、19.64和1.43 g/g,溶解性最高;喷雾干燥的木薯酸淀粉比表面积、休止角和持油性最高,分别为407.43 m2/kg、54.11°和2.33 g/g,凝沉性最低,为67.00%;晒干的木薯酸淀粉跨度和持水性最低,分别为1.73和1.08 g/g。综合评分结果显示,真空冷冻、喷雾、晒干、热风和热泵干燥的木薯酸淀粉性能综合评分分别为0.60、0.38、0.18、-0.50和-0.64。综合分析,真空冷冻干燥制备的木薯酸淀粉性能最好,其次为喷雾干燥,晒干次之,热风和热泵干燥的最差。

不同淀粉添加和老化时间对干米粉品质的影响

为研究不同淀粉添加和老化时间对干米粉品质的影响,以干米粉复水率、断条率、质构特性、感官特性品质为考察指标,研究干米粉加工过程中不同比例玉米淀粉、木薯淀粉和不同老化时间处理对其品质的影响。结果表明,添加适量淀粉可明显改善干米粉的复水率和断条率;随着老化时间的延长,米粉的硬度、弹性逐渐增大,黏性降低,淀粉链的结构呈现有序化的趋势。因此,添加20%玉米淀粉或40%木薯淀粉老化6 h,干米粉品质较好。

植物乳杆菌TH103喷雾干燥制剂的制备工艺优化

以抗性淀粉及乳清分离蛋白为主要壁材,采用喷雾干燥法制备植物乳杆菌TH103微胶囊,以包载率为指标,探究壁材配比、进风温度、进气量及抗热保护剂种类对益生菌微胶囊包埋率的影响。结果表明,该植物乳杆菌微胶囊的最佳工艺为进风温度120℃,进气量30%,壁材配比10%,复合壁材(RS3∶WPI为1∶5),海藻糖添加量6%。在此条件下,所得到的微胶囊活菌数为(8.48±2.83)×109 CFU/g,包埋率为(61.52±2.05)%。

稻米淀粉、蛋白质和脂质与蒸煮食味品质关系研究进展

蒸煮食味品质是消费者选择稻米的重要评价标准。淀粉、蛋白质和脂质作为稻米的三大主要物质成分,与其蒸煮食味品质关系密切。为进一步探索稻米蒸煮食味品质形成机制及水稻优质栽培技术,本文综述了稻米三大主要物质的组成与分布、合成代谢特点及其与蒸煮食味品质关系的研究进展,总结了干湿交替灌溉技术对稻米三大主要物质及其蒸煮食味品质的影响,并提出了研究存在三大主要物质互作与稻米蒸煮食味品质关系不清楚以及干湿交替灌溉对蒸煮食味品质的调控机制不明确等问题。建议今后基于淀粉、蛋白质和脂质累积与合成代谢的关系深入研究稻米蒸煮食味品质形成机制以及轻-干湿交替灌溉对稻米蒸煮食味品质的调优机制。

莲子热风干燥过程对其淀粉热特性及凝胶化的影响

为解决莲子干燥过程中淀粉形态结构变化造成莲子结壳、硬化,不利于干燥以及复水难、易返生问题,该文利用差示扫描量热技术(differential scanning calorimetry,DSC)对新鲜莲子以及不同热风干燥(70、80、90℃)莲子的淀粉热特性与凝胶化过程进行了研究。研究发现,莲子淀粉在低水分环境(42.2%,以质量比计)时存在2个明显的吸热峰,高水分环境(71.1%,以质量比计)时存在1个明显的吸热峰;莲子在干燥过程中不断失水,并伴随着淀粉凝胶化。方差分析(analysis of variance,ANOVA)表明,高温干燥显著影响莲子淀粉的热特性,其淀粉凝胶化温度(峰起温度To、峰顶温度Tp以及峰止温度Te)部分显著升高。相同干燥条件下,莲子淀粉糊化焓ΔH受水分显著影响,但干燥温度、升温速率对其影响不显著(P>0.01)。采用Kissinger、Crane方程获得了淀粉凝胶化动力学参数(活化能Ea、指前因子Z以及反应级数n)。莲子淀粉的非等温凝胶化反应可近似为一级反应,高温干燥后其Ea值出现增加,并随着水分增加呈现降低趋势。研究结果可为确定莲子高品质干燥工艺以及干莲子、莲子淀粉后续加工过程提供技术支持。

不同品种马铃薯贮藏期间干物质与淀粉含量之间的关系

针对10个栽培马铃薯品种贮藏期间干物质及其主要成分淀粉含量的变化和关系展开了研究。结果表明,在6个月的贮藏期中10个品种间马铃薯干物质含量有极显著差异(p<0.01),同品种马铃薯贮藏期间干物质含量无显著变化;不同品种间以及贮藏期间马铃薯的淀粉含量均有极显著地差异(p<0.01);马铃薯贮藏期间干物质含量和淀粉含量之间存在极显著地正相关关系;耐贮藏品种为斯诺登和甘农1号,较耐贮藏的品种为渭薯8号、大西洋、蝉内贝克、夏波蒂。

钾肥施用方式对高粱干物质积累及产量的影响

为了确定高粱最佳的钾肥施用方式,以吉杂305号和吉杂87号高粱品种为试验材料,设计4个施钾肥处理(K0:不施钾;K1:基施钾120 kg/hm^2;K2:基施钾90 kg/hm^2+追施钾30 kg/hm^2;K3:基施钾60 kg/hm^2+追施钾60 kg/hm^2),探讨钾肥施用方式对高粱干物质积累及籽粒产量的影响。结果表明,施用钾肥可提高高粱植株叶面积、干物质积累量、籽粒淀粉含量、产量及经济系数。2个高粱品种叶面积均表现为K0<K1<K2<K3,经济系数均表现为K0<K3<K2<K1,干物质积累量、籽粒淀粉含量、籽粒产量均表现为K0<K3<K1<K2。吉杂305号K2、K1、K3处理产量分别比K0处理显著提高15.6%、9.3%、8.9%,吉杂87号K2、K1、K3处理产量分别比K0处理显著提高12.5%、8.1%、7.8%。综合考虑,基施钾90 kg/hm^2+追施钾30 kg/hm^2为高粱钾肥的最佳施用方式。

阳离子淀粉干法制备研究进展

评述了近年来季铵型阳离子淀粉干法制备研究进展。阐明了干法制备阳离子淀粉的优点并与湿法进行了比较 ,还着重讨论了碱催化剂、反应温度。

干法制备高取代度高黏度羧甲基淀粉

以马铃薯淀粉和氯乙酸钠为原料,通过分阶段碱化和醚化方法,采用先进的干法工艺制备了高取代度、高黏度的羧甲基淀粉。并详细考察了氯乙酸钠用量、碱用量、反应温度及时间等条件对产品取代度和黏度的影响。实验结果表明,当淀粉、氯乙酸钠及氢氧化钠摩尔比为1:1:1．25时,在碱化和醚化反应温度、时间分别为35℃、 60 min和70℃、2．5 h条件下,可制备出取代度最高达0．73,反应效率为73％,黏度可达11 600 mPa·s的高取代度、高黏度羧甲基淀粉。