热塑性可降解木薯淀粉的研究(Ⅱ)--改性木薯淀粉的性能

采用接枝技术使醋酸乙烯酯单体及丙烯酸甲酯单体在木薯淀粉分子链上进行了接枝共聚反应,碱化后制得改性木薯淀粉材料。结果表明,改性木薯淀粉材料的加工性能得到良好改善,并具有较好的力学性能及降解性能     

木薯淀粉—聚乙烯醇生物降解薄膜的研究

研究了木薯淀粉与聚乙烯醇（ＰＶＡ）的接枝反应工艺、反应机理和所得薄膜的生物降解性。结果表明：当反应温度高于淀粉糊化温度时，才能获得较好的接枝效果；接枝后，淀粉交联能获得较高强度的薄膜；ＰＶＡ接枝发生在淀粉的Ｃ２羟基上，Ｃ２羟基具有比Ｃ６羟基更高的反应活性；所得的木薯淀粉－聚乙烯醇薄膜具有较好的生物降解性。     

正交试验优选木薯淀粉接枝醋酸乙烯酯的工艺条件

以过硫酸铵引发木薯淀粉与醋酸乙烯酯接枝共聚反应,对影响淀粉与醋酸乙烯酯接枝反应的4个因素:原料配比、引发剂浓度、反应温度及反应时间进行了研究.以转化率、接枝率及接枝效率为考查对象,利用SAS软件统计分析得到适宜的工艺条件:引发剂浓度18.0 mmol/L,反应温度60℃,反应时间3 h,原料配比为2.0.并用Srectrum One红外光谱对接枝物的化学结构进行分析,证实了木薯淀粉-醋酸乙烯酯接枝共聚物的存在.     

超声活化淀粉与丙烯酸反相乳液聚合动力学研究

以油酸失水山梨醇酯Span80和壬基酚聚氧乙烯醚OP-10为混合乳化剂,环己烷为连续介质,过硫酸铵-硫代硫酸钠作为氧化还原引发剂,研究了经超声波活化的木薯淀粉与丙烯酸在反相乳液体系中的接枝共聚反应动力学,分别考察了反应温度、引发剂浓度、单体浓度、淀粉浓度、乳化剂用量对接枝共聚速率的影响。结果表明,在本实验考察的范围内的活化能为29.85 kJ/mol,动力学关系式为:Rp∝[I]0.88[M]1.47[St]0.945[Ws]0.586。     

氮磷钾配施对木薯产量和淀粉含量的效应研究

以华南8号木薯为研究对象,通过311三元二次D-最优饱和试验设计试验,探讨N、P、K配施对木薯产量和品质的影响。在此立地条件下,可获得最大的鲜薯产量为46.62 t/hm2,此时对应氮、磷、钾施肥量分别为167.13、26.51、179.82 kg/hm2。单因子效应分析表明,氮、磷、钾对木薯产量的影响以钾肥最大,氮肥次之,磷肥最小。双因子互作效应分析结果表明,N、K双因子之间的交互效应最大,N、P二因子之间的交互效应不明显,P、K与木薯产量的效应小于N、K效应,大于N、P效应;按三元二次D-最优饱和试验设计氮、磷、钾配施对木薯淀粉含量和干物率的影响不显著。     

木薯MeCML24与MeSAUR1互作调控MeAGPS1a表达的功能验证

木薯是华南地区重要的经济作物,其块根富含淀粉。解析木薯块根淀粉合成调控机理将有助于木薯高产、高淀粉分子改良。AGPase由大亚基和小亚基构成,催化1-磷酸葡萄糖和ATP形成腺苷二磷酸葡萄糖和焦磷酸,其中腺苷二磷酸葡萄糖为淀粉生物合成的底物。AGPase酶是植物淀粉合成的限速酶,提高AGPase酶活性,有利于作物淀粉的积累及产量的提高。木薯MeAGPS1a基因编码的小亚基是AGPase的催化中心,前期研究表明生长素响应因子MeSAUR1作为转录因子正调控MeAGPS1a基因表达,酵母双杂交筛选木薯cDNA文库显示钙调素类似蛋白（CaM-like, CML）成员MeCML24为MeSAUR1的候选互作蛋白。为了确定MeCML24和MeSAUR1的互作关系,本研究从‘SC8’木薯品种基因组克隆了MeCML24基因,该基因的CDS区长度为492 bp,编码163个氨基酸。MeCML24蛋白的理化性质及二级结构分析显示,该蛋白理论等电点pI值4.38,属于亲水性蛋白,α-螺旋占52.76%,无规则卷曲占30.06%,β-转角结构占11.04%。构建酵母双杂交载体BD-MeCML24,自激活实验表...     

木薯AGPase及其同工酶活性与淀粉积累的关系

采用高淀粉木薯品种辐选01和低淀粉木薯品种华南124作为试验材料,研究木薯块根的腺苷二磷酸葡萄糖焦磷酸化酶(AGPase)及其同工酶活性与淀粉积累的关系。通过对比研究可知:木薯块根的AGPase对淀粉积累可能有着至关重要的促进作用,并且木薯块根的AGPase具有四种同工酶,分别为AGP a、AGP b、AGP c、AGPd,其中AGP a、AGP b、AGP c可能是决定AGPase活性和影响块根淀粉积累的关键同工酶。     

遮荫对木薯块根淀粉含量和品质的影响

以2个木薯主栽品种(SC124、SC8)为材料,自盛暑期开始遮荫(植后70 d至植后160 d),对植后160 d木薯块根进行淀粉含量及相关酶活性分析,结合扫描电镜观察遮荫处理与正常光照下木薯块根淀粉结构的变化,探讨弱光对木薯贮藏淀粉含量和品质的影响。结果表明,遮荫处理改变了木薯光合产物在"源"与"库"之间的分配,造成茎叶变长,茎干细弱,块根减重,根冠比显著降低。弱光显著影响淀粉含量及其组成,遮荫处理提高或显著提高了SC124和SC8块根直链淀粉含量,降低了2个品种块根的总淀粉含量和支链淀粉含量,以及支链淀粉与直支链淀粉的比率。遮荫处理后木薯块根AGPase活性均降低;GBSS活性增加(SC8)或无显著变化(SC124);而遮荫处理对SSS和SBE活性影响不一致。扫描电镜观察表明,遮荫处理形成许多直径较小的淀粉粒,影响淀粉充实程度而造成淀粉含量降低。     

不同种茎种植角度对木薯产量性状的影响

为探讨平地种植木薯不同种茎种植角度对木薯产量性状的影响,以华南8号木薯种茎为试材,比较种茎的0°平放(CK)、30°斜插、60°斜插、90°竖插和270°倒插5种处理对木薯产量的影响。结果表明,5种处理的薯干率和鲜薯淀粉含量之间存在较小差异,鲜薯产量、薯干产量和淀粉产量均表现60°斜插>30°斜插≈竖插>倒插≈平放,其中,60°斜插比30°斜插和竖插增产11.1%~13.4%的鲜薯、薯干和淀粉,60°斜插比倒插和平放增产18.0%~20.3%的鲜薯、薯干和淀粉。在平地种植木薯时,建议以60°斜插种茎为优,其次是30°斜插和竖插,不宜倒插。     

木薯地膜覆盖种植模式的技术探索与总结

通过对木薯地膜覆盖种植试验的技术探索,对照露地种植,比较农艺性状、产量及淀粉含量等三种性状表现。结果表明:木薯地膜覆盖种植比露地种植模式农艺性状更好、产量更高、单位面积淀粉含量更高,鲜薯产量增加1.36 t/666.67m~2,差异达极显著水平,增收662元/666.67m~2,对农民增产、增收具有重要意义,是一种值得推广与实践的种植技术。     

株行距和施肥量对木薯产量及生长的影响

采用裂区试验设计方法,研究株行距和施肥量对华南5号木薯产量和生长的影响.结果表明:在本试验株行距和施肥量条件下,施肥量对木薯产量和生长的影响比株行距大.密植(0.6～0.8 m)有利于提高淀粉产量、鲜薯产量和鲜薯淀粉含量,以0.8m株行距最佳,而疏植(1.2～1.4m)有利于提高单株薯数、单株鲜薯重、单株鲜茎叶重、收获指数和茎径.施肥有利于提高淀粉产量、鲜薯产量、单株鲜薯重、单株鲜茎叶重、茎径、株高和单株薯数,但降低鲜薯淀粉含量和收获指数.丰产栽培技术要兼顾单位面积株数、单株鲜薯重和鲜薯淀粉含量.建议在土壤肥力差和少施肥时,用0.6 m株行距;土壤肥力中等且较高施肥时.采用0.8 m株行距;土壤肥力中上且优越水肥管理,采用1.0 m株行距.     

我国木薯产业的发展趋势与市场分析

对我国的木薯种植，木薯淀粉(变性淀粉)，木薯酒精行业的发展现状进行阐述，展望其发展趋势。     

木薯采后生理性变质与淀粉特性研究

以华南系列的SC205、SC5、SC6、SC8和SC10五个木薯品种为材料,于采收后不同时间分析其块根生理变质程度、干物质含量、淀粉含量、支链淀粉比例和淀粉透明度等指标,探讨木薯生理变质与块根淀粉特性的关系。研究结果表明：采后生理变质对块根淀粉特性有明显影响,所有品种淀粉特性指标在采后均呈下降趋势,其中下降最快的是SC205。对各指标的相关分析表明,支链淀粉分别与淀粉含量和淀粉透明度呈显著正相关和极显著正相关。可见,生理变质可导致淀粉透明度的下降,影响淀粉的商品品质。     

Biodegradable foam tray from cassava starch blended with natural fiber and chitosan

This work developed biodegradable foam trays from cassava starch blended with the natural polymers of fiber and chitosan. The kraft fiber at 0, 10, 20, 30 and 40% (w/w of starch) was mixed with cassava starch solution. Chitosan solution at 0, 2, 4 and 6% (w/v) was added into starch/fiber batter with 1:1. Hot mold baking was used to develop the cassava starch-based foam by using an oven machine with controlled temperature at 250 °C for 5 min. Results showed that foam produced from cassava starch with 30% kraft fiber and 4% chitosan had properties similar to polystyrene foam. Color as L^*, a^* and b^* value of starch foam tray was slightly increased. Density, tensile strength and elongation of the starch-based foam were 0.14 g/cm³, 944.40 kPa and 2.43%, respectively, but water absorption index (WAI) and water solubility index (WSI) were greater than the polystyrene foam.     

Selection of cultivars for minimization of waste and of water consumption in cassava starch production

When considering the sustainability of a business, deciding on the industrial use of starchy raw materials requires more than just the information on their agricultural productivity and starch yield. The main goal of this work was to investigate ten different cultivars to select for industrial applications seeking to minimize residue generation and water consumption in the production of cassava starch. The cassava cultivars that are richer in starch (22.61-22.89 g 100 g⁻¹) generated the smallest amounts of residues (420.63-423.52 kg ton⁻¹ of cassava roots) and required the smallest amounts of water for processing. There is an inverse relationship between the dry matter content in cassava roots and the amount of solid residues generated. One of the cultivars stood out for showing the following features: high starch yield, little tendency for generation of residues, low requirement of water for processing, easiness in the peeling process, and high content of total solids; therefore such features can suggest its use for starch extraction with wastes minimization.     

Impact of water stress on yield and quality of cassava starch

Cassava (Manihot esculenta Crantz) is an important source of industrial raw materials. Products obtained from cassava include chip/pellets for animal feed and starch. Important for major industrial uses are the amount and quality of starch obtained from this crop. Production efficiency, including yield and quality of starch, from cassava is markedly influenced by environmental conditions, especially water stress during early plant development and immediately before root harvest. In early plant development plants deprived of water for the first 6 months were characterized by a lower yield of starch compared to plants without water stress (starch yields of six varieties including Rayong 1, Rayong 5, Rayong 60, Rayong 90, Kasetsart 50 and CMR 33-57-81 were 0.1–0.2 and 5.0–8.7 t/ha for water-stressed and without water-stressed plants). Furthermore, starch from plants deprived of water for the first 6 months of growth, was functionally different to that laid-down under optimum growing conditions. Plants responded to subsequent rainfall and after 2 months contained significant amounts of starch, though this amount was less than was expected. Despite the fact that water-stressed plants responded to the availability of water by producing starch, most functional properties remained different. The portfolio of changes was sufficient as regards the starch of lower quality. Most effected were the hydration properties. Starch granules despite being smaller (mean size and distribution) than expected were morphologically normal. A second drought period further influenced some of the starch properties, but the sustained influence of the early drought seemed to dominate the response of the plant's starch metabolism. All varieties were similarly affected.     

干旱条件下不同种茎材料对木薯成活率及产量性状的影响

在干旱条件下,比较4种不同种茎材料对木薯成活率、农艺及产量性状的影响。结果表明：成活率(survival rate,SR)呈现SR1年生种茎(100.0%)＞SR2年生种茎(92.2%)＞SR60 d嫩茎(78.9%)＞SR老茎头(30.0%);鲜薯和薯干产量(root yield,RY)呈现RY1年生种茎＞RY60 d嫩茎＞RY老茎头＞RY2年生种茎;淀粉产量(starch yield,SY)呈现SY60 d嫩茎＞SY1年生种茎＞SY老茎头＞SY2年生种茎;薯干率和鲜薯淀粉含量呈现老茎头＞60 d嫩茎＞2年生种茎＞1年生种茎,且植株密度越小,则薯干率和鲜薯淀粉含量越高。     

不同木薯品种（系）块根淀粉特性研究

对79个木薯品种(系)块根淀粉的鲜薯含粉率、原淀粉水分、直链淀粉和支链淀粉含量、峰值粘度、糊化温度、透明度、恩氏粘度、淀粉粒直径和表面积等淀粉特性指标进行研究.结果表明,不同木薯品种(系)各淀粉特性指标存在很大的差异,不同指标间也有一定的相关性,利用主成分分析对各品种(系)各指标进行综合分析,认为E169、C766、E1424、E339、R72、E217、E344、E232、E316和桂热3号木薯淀粉的加工特性最好,更适合木薯淀粉的深加工.     

Some Nutritional Characteristics of Enzymatically Resistant Maltodextrin from Cassava (<Emphasis Type="Italic">Manihot esculenta</Emphasis> Crantz) Starch

Cassava (Manihot esculenta Crantz) native starch was treated with pyroconversion and enzymatic hydrolysis to produce a pyrodextrin and an enzyme-resistant maltodextrin. Some nutritional characteristics were quantified for both compounds. Pyroconversion was done using a 160:1 (p/v) starch:HCl ratio, 90 °C temperature and 3 h reaction time. The resulting pyrodextrin contained 46.21% indigestible starch and 78.86% dietary fiber. Thermostable α-amylase (0.01%) was used to hydrolyze the pyrodextrin at 95 °C for 5 min. The resulting resistant maltodextrin contained 24.45% dextrose equivalents, 56.06% indigestible starch and 86.62% dietary fiber. Compared to the cassava native starch, the pyrodextrin exhibited 56% solubility at room temperature and the resistant maltodextrin 100%. The glycemic index value for the resistant maltodextrin was 59% in healthy persons. Its high indigestible starch and dietary fiber contents, as well as its complete solubility, make the resistant maltodextrin a promising ingredient for raising dietary fiber content in a wide range of foods, especially in drinks, dairy products, creams and soups.     

木薯种质资源淀粉特性分析与评价

为了评价和筛选出淀粉品质优良的木薯资源,对212份国内外栽培木薯种质块根淀粉产量性状及淀粉含量、直链淀粉含量、支链淀粉含量、粘度峰值和糊化温度5个重要淀粉特性指标进行研究.结果表明,不同木薯资源各淀粉特性差异较大,不同指标间有一定的相关性,利用概率分级法将8个淀粉产量及特性性状分为5级,即极低、低、中、高和极高,推荐极...