甘薯淀粉性质与其粉丝品质的关系

为了弄清不同品种甘薯淀粉所制粉丝品质差异的原因,该研究通过对各种甘薯淀粉的理化性质、热力学特性、分子结构与甘薯粉丝品质的测定,并以绿豆淀粉做对照,对三者与其粉丝品质进行了相关性分析。结果表明：淀粉理化性质对粉丝品质影响较大,按相关系数大小依次是：膨润力＞溶解度＞表观直链淀粉含量＞蛋白质含量＞颗粒大小。回生对粉丝品质的影响远远大于糊化对其的影响。快速黏度分析参数与粉丝品质有显著的相关性,可作为预测其相应的粉丝品质的重要手段之一。淀粉分子结构对粉丝品质影响更大,按显著程度依次是：直链淀粉（A _m ）含量＞支链淀粉（A _P ）短链量＞A_P长链量＞A_m分支数＞A_P短链长度＞A_m链长＞A_P长链长度。     

Comparison of physicochemical properties and starch structure of red rice and cultivated rice

Sixteen red rice accessions from the southern United States were studied for their physical, milling, pasting, and thermal properties, chemical composition, and starch fine structure relative to cultivated medium- and long-grain rice varieties. All red rice samples were medium-grain, but their physicochemical properties were different from those of Bengal, a cultivated medium-grain rice. Their apparent amylose and crude protein contents were generally higher, and their amylopectin structure consisted of a higher percentage of the shorter branch chains (DP6-24) and a lower percentage of the longer branch chains (DP25-65). Red rice starch pasting and thermal properties were similar to those of Wells, a long-grain rice cultivar. The red rice samples can be classified into two major clusters according to their kernel properties by hierarchical cluster analysis: one cluster with more resemblance to Wells and another cluster with more resemblance to Bengal. Starch structure and kernel physicochemical properties may offer an alternative way of classifying red rice in addition to phenotypic and genetic indices.     

Thermal and physicochemical properties of rice grain, flour and starch

Three types of rices, namely, Thailand rice (Indica), Nipponbare (Japonica), and Himenomochi (Japonica waxy), in grain, flour, and starch forms have been studied for their thermal and physicochemical properties. In grain form, Indica was slender and Japonica rices were bold and thick. Indica had the highest protein and amylose equivalent. Protein contents in isolated starches varied from 0.2 to 0.9%. Cooked Indica grain was hardest and waxy rice was softest; stickiness was highest in Japonica rice. Glass transition temperature (T(g)) was highest in Indica rice flour (approximately 222 degrees C) and almost the same in Japonica rice flours. Melting point was highest for Japonica (approximately 264 degrees C) and almost the same for Japonica waxy and Indica rice flours. T(g) values of starches were almost the same in Indica and Japonica waxy (approximately 237 degrees C); defatting caused reduction in this property in all of the starches. Highest melting point was shown by Indica starch (approximately 276 degrees C) and was almost the same for the other two starches. Protein and fats play a critical role in glass transition and melting points of rice flours and their respective starches. Viscosities of the cooked pastes of flour and starch during cooking in an RVA instrument and their gel and other properties have been discussed.     

Genetic variation in the physical properties of sweet potato starch.

Sweet potato starch, prepared from 44 genotypes adapted to Philippine conditions, showed wide variation and distinctly different pasting profiles in Rapid Visco-Analyzer (RVA) analysis at 11% and 7% starch concentration. At 11% starch concentration, the pasting profiles were type A, characterized by high to moderate peak with a major breakdown and low cold paste viscosity. At 7%, the pasting profile was generally type C, characterized by the absence of a distinct peak with none to very slight breakdown and high cold paste viscosity. However, differentiation among genotypes was better achieved from RVA pasting profiles at 11% starch concentration. Peak viscosity (PV) and hot paste viscosity (HPV) at 11% starch paste concentration had significant negative correlation with amylose content. PV, HPV, and setback ratio were significantly correlated to adhesiveness of the starch gel. Sweet potato starch generally had high swelling volume but low solubilities at 92.5 degrees C.     

马铃薯全粉虾片加工技术的研究

为提高马铃薯的利用率，丰富虾片品种，该文对马铃薯全粉虾片的加工技术进行了研究，结果表明,加工马铃薯全粉虾片的最佳工艺参数是:马铃薯淀粉与马铃薯全粉两者质量比为65∶35，粉团含水率为40%，老化时间16 h，50℃下干燥4.5 h，坯料含水率9%左右；油炸温度190～200℃。按此最佳工艺参数，加工过程中成型、蒸煮容易，所得产品马铃薯风味浓郁、口感细腻、膨胀度为362%。     

磷肥用量对马铃薯淀粉理化性质及产量的影响

[目的]研究不同磷肥用量对马铃薯淀粉理化性质及产量的影响,为不同用途马铃薯的磷肥科学管理提供参考.[方法]以早熟马铃薯'尤金'和中晚熟马铃薯'克新13号'为供试品种,在黑龙江省开展了两年田间试验.分别设置P2O5用量为0(CK)、45(低磷Low P,LP)、90(中磷Middle P,MP)和135(高磷High P...     

马铃薯糊化过程中介电特性和热特性的分析(简报)

该文采用介电特性测定仪(DES100)和示差扫描量热仪(DSC120)对马铃薯片(含水率80.7%,淀粉含量16.5%)介电特性和热特性进行了比较研究,以确定马铃薯淀粉糊化过程中各特征参数值之间的关系。由介电特性曲线得出:在1～100kHz频率范围内的,65～80℃温度范围内,介电常数e′随温度的升高出现跃变型变化,67℃时变化速率最大,之后逐渐下降;由热吸收曲线得出热焓值的变化与e′变化规律相同,其糊化的3个特征温度(糊化起始、峰值、结束)分别是65、67和80℃,从两曲线得到的各特征值基本一致,说明利用马铃薯的介电特性和热特性的综合分析可以更准确地掌握其糊化过程,为进一步利用和控制马铃薯的糊化作用提供参考。     

Effect of location on starch content and tuber texture characteristics in potato breeding lines and cultivars

The texture of boiled potato tubers is one of the most important quality traits. The variation of tuber texture is usually examined in relationship with dry matter or starch content. The objective of the work was to examine variation and stability of texture and starch content in tubers grown in various environments. Both traits were evaluated for the set of potato breeding lines and 10 table potato cultivars. The lines were developed in the program of parental lines carried out in M?ochów Research Center, Poland. The environments were represented by three locations, which differed in cultivation system as well as climatic and soil conditions. The traits were influenced by the effects of genotype, location and their interactions. The effect of location on texture was not explained by the changes in starch content. The calculated stability parameters indicated that unstable expression of both traits was more pronounced and more frequent in breeding lines than in the cultivars. The short period of selection used in the development of the parental lines is not conducive to select potato genotypes with stable expression of quality traits. The starch content was at most moderately related with various characteristics of tuber texture.     

Host-status of sweet potato cultivars to South Africa root-knot nematodes

Globally, most of the crop-related developmental projects collapsed due to the existence of aggressive plant-parasitic nematodes. Intensive South African biofortification efforts using exotic and local sweet potato (Ipomoea batatas) cultivars have hardly considered the inclusion of nematode resistance in plant breeding, despite the withdrawal of most nematicides from agrochemical markets. The objective of this study was to screen 12 selected biofortification sweet potato cultivars for host-status to South Africa tropical root-knot (Meloidogyne species) nematodes. Three exotic orange-fleshed, three local orange-fleshed and six cream-fleshed cultivars were used in three separate experiments of M. javanica and races 2 and 4 of M. incognita. In each experiment, 6000 eggs and second-stage juveniles/plant were used for inoculation, with nematode assessment performed at 56 days after inoculation. All tested biofortification exotic (except for cv. ‘W-119’) and local cultivars were hosts to Meloidogyne species and races, whereas three non-biofortication local cultivars, namely, ‘Bosbok’, ‘Blesbok’ and ‘Mvuvhelo’ were non-hosts. In conclusion, the findings suggested the likelihood of the existence of non-host-status in certain exotic and local sweet potato cultivars for use in plant breeding programmes against South African Meloidogyne species and races.     

Regulatory effect of amino acids on the pasting behavior of potato starch is attributable to its binding to the starch chain

The binding of an amino acid, glycine (Gly), alanine (Ala), epsilon-aminocaproic acid (-AC), monosodium glutamate (GluNa), or lysine (Lys), to starch was examined by a biomolecular interaction analyzer (IAsys). A starch sample (ATS) hydrolyzed to an extent of 1% hydrolysis rate with 15% sulfuric acid was used as a model starch for the binding examination. The reducing end of ATS was oxidized by the Somogyi reagent, and the conversion of the reducing end to the carboxyl group of ATS was confirmed by a carboxylic acid fluorescence labeling reagent. The oxidized ATS was immobilized to the amino group of a sensor cuvette by using water-soluble carbodiimide and N-hydroxysuccinimide through an amide bond. The IAsys examination showed that Gly, Ala, and epsilon-AC scarcely bound to the immobilized starch chains but that GluNa and Lys favorably bound with their increasing concentrations. The relative binding index (RBI) of each amino acid was defined by the ratio of the slope of the linear regression equation between the binding response and the concentration for each amino acid to that for Gly. Because the relationships between the RBI and the pasting characteristics (pasting temperature, peak viscosity, breakdown, and swelling index) could each be expressed by a linear regression equation with a high correlation coefficient, it is concluded that the regulation of the pasting behavior of starch with an amino acid is caused by binding of the amino acid to the starch chains.     

甘薯淀粉产量及相关性状的遗传多样性和关联度分析

甘薯[Ipomoea batatas(L.)Lam.]是加工淀粉和燃料乙醇的重要原料,是目前我国最具开发前景的非粮食类新型能源作物。选育高淀粉产量的能源型甘薯新品种是甘薯育种的重要目标。为了获得准确筛选高淀粉产量育种材料的性状指标,提高甘薯高淀粉产量育种效率,缩短育种周期,本研究利用不同甘薯品种(系)的自然变异,根据淀粉产量、不同生长发育阶段的5个主要农艺性状和3个淀粉合成关键酶活性测定结果,利用相似系数和遗传距离矩阵,以类平均法对国内48份不同淀粉产量甘薯种质资源进行了遗传多样性分析,通过关联度分析研究了淀粉产量与不同时期农艺性状、淀粉合成关键酶活性的相关性。结果表明:48份甘薯种质资源材料在不同时期农艺特征差异较大;不同时期农艺性状的聚类结果中,栽后100 d的农艺性状与淀粉产量关联度最大,淀粉产量与该时期的基部分枝数呈极显著负相关(r=0.428),与干率呈极显著正相关(r=0.423),而与最长蔓长、单株结薯数和单株鲜薯重相关性不显著。48份甘薯种质材料在不同时期的酶活聚类结果差异明显。不同时期的甘薯淀粉合成关键酶活性聚类结果中,栽后50 d酶活聚类与淀粉产量聚类结果关联度最大,淀粉产量与该时期测得的ADPG焦磷酸化酶(ADPG-PPase)活性呈负相关关系(r=0.163),与蔗糖合成酶(SS)活性(r=0.101)、蔗糖磷酸合成酶(SPS)活性(r=0.016)呈正相关,但相关性均未达到显著水平。加之淀粉合成关键酶活性测定步骤繁琐,不适宜作为甘薯高淀粉产量育种早期选择的生理指标。在高淀粉产量育种材料筛选时可于栽后100 d对农艺性状进行综合考察,重点考虑干率较高及分枝数较少的品系。本研究可为甘薯高淀粉产量育种提供一定的理论依据。     

甘薯全粉加工中无硫复合护色工艺优化

为了优化甘薯全粉无硫复合护色工艺,该文通过考察柠檬酸、柠檬酸亚锡二钠、植酸、亚硫酸氢钠和抗坏血酸5种护色剂对甘薯全粉色泽的影响,优选出柠檬酸和抗坏血酸作为甘薯全粉加工合适的护色剂;通过正交试验,得到柠檬酸-抗坏血酸无硫复合护色剂的最佳护色工艺为:将10 mm厚的甘薯切片在质量分数为0.3%的柠檬酸和0.1%抗坏血酸的复合护色液中护色处理30 min,可使制得的甘薯全粉亮度值L*达90.58,多酚氧化酶的抑制率达88.13%.研究发现柠檬酸的添加能显著提高抗坏血酸的热稳定性;酶促褐变产物紫外-可见光谱扫描显示,加入复合护色剂后410 nm处吸收峰明显减弱,表明复合护色剂能有效抑制酶促褐变反应的发生;圆二色谱研究表明多酚氧化酶经复合护色剂处理后,酶蛋白二级结构中α-螺旋减少,而β-折叠结构增多,酶蛋白的分子构象被改变,从而降低多酚氧化酶活力.该文为甘薯全粉加工中的无硫复合护色工艺提供了参考.     

甘薯淀粉糊与绿豆淀粉糊流变行为的共性与区别

淀粉糊在粉丝加工中作为黏结剂，它的流变特性是粉团搅拌、形成、漏粉和定型的关键因素。本研究通过对甘薯淀粉糊和绿豆淀粉糊在不同浓度、温度、剪切速率和升温扫描过程中的流变行为的考察和分析比较，表明两种淀粉糊有触变共性，在流变曲线图上都呈现出不同滞后面积大小的开口型滞后回路，用Cross方程拟合精度比幂律方程高；用Arrhenius方程描述两者都具有温度敏感性。两者的区别在于：甘薯淀粉糊在各条件下的滞后面积比绿豆淀粉糊小，说明在粉团形成中甘薯淀粉糊的持续增黏效果高于绿豆淀粉糊；虽然绿豆淀粉糊的零剪切黏度值比甘薯淀粉糊要低，但在浓度较低(≤8%)时，两者差别不大，因此用甘薯淀粉糊替代绿豆淀粉糊是可行的。     

Molecular properties and activities of tuber proteins from starch potato cv. Kuras

Potato starch production leaves behind a huge amount of juice. This juice is rich in protein, which might be exploited for food, biotechnological, and pharmaceutical applications. In northern Europe cv. Kuras is dominant for industrial starch production, and juice protein of freshly harvested mature tubers was fractionated by Superdex 200 gel filtration. The fractions were subjected to selected activity assays (patatin, peroxidase, glyoxalases I and II, alpha-mannosidase, inhibition of trypsin, Fusarium protease, and alcalase) and protein subunit size determination by SDS-PAGE and mass spectrometry. Proteins present in SDS-PAGE bands were identified by tryptic peptide mass fingerprinting. Protein complexes such as ribosomes and proteasomes eluted with the void volume of the gel filtration. Large proteins were enzymes of starch synthesis dominated by starch phosphorylase L-1 (ca. 4% of total protein). Five identified dimeric patatin variants (25%) coeluted with four monomeric lipoxygenase variants (10%) at 97 kDa. Protease inhibitor I variants (4%) at 46 kDa (hexamer) inhibited alcalase. Fourteen Kunitz protease inhibitor variants (30%) at 19 kDa inhibited trypsin and Fusarium protease. Carboxypeptidase inhibitor variants (5%) and defensins (5%) coeluted with phenolics. The native sizes and molecular properties were determined for 43 different potato tuber proteins, several for the first time.     

In vitro protein digestibility and physicochemical properties of dry red bean (Phaseolus vulgaris) flour: effect of processing and incorporation of soybean and cowpea flour

A study was carried out to determine the effect of germination and drying temperature on the in vitro protein digestibility and physicochemical properties of dry red bean flours. A 2 x 3 factorial experiment with two treatments (germination and nongermination) and three drying temperatures was used for this purpose. The effect of particle size on water absorption capacity of bean flour was investigated. In addition, the effect of incorporating soybean and cowpea into the red bean flour on functional properties was equally investigated. Results reveal that protein digestibility increased with germination and also with drying temperature. Drying at 60 degrees C produced flours of optimum functional characteristics, although the hydrophilic/lipophilic index was high and the solubility index reduced. Germination and particle size as well as drying temperature all affected the water uptake properties of bean flours. Incorporation of soybean and cowpea flour into germinated bean flour at levels of 10 and 30%, respectively, produced a composite with higher functional properties.     

马铃薯交联淀粉醋酸酯的制备工艺及特性

马铃薯原淀粉在水相体系、碱性条件下与醋酸酐作用，生成马铃薯淀粉醋酸酯，然后与交联剂进行交联反应，得到马铃薯交联淀粉醋酸酯。通过改变反应温度、反应时间、pH值和交联剂用量等条件，得出制取马铃薯交联淀粉醋酸酯的最佳工艺条件：反应温度35℃，pH值11，反应时间2 h，交联剂用量2%。所制取的马铃薯交联淀粉醋酸酯较原淀粉在糊液黏度的稳定性、抗老化性、抗分离性等方面均有较大的改善。     

甘薯收获期藤蔓茎秆的机械特性

为探明甘薯收获期藤蔓茎秆机械特性,以便提高甘薯藤蔓机械粉碎还田作业质量,该文农机农艺结合,以江苏南京地区鲜食紫甘薯宁紫1号、宁紫2号为试验对象,应用电子万能试验机、甘薯藤蔓粉碎还田试验机等仪器设备,研究了收获期甘薯藤蔓茎秆含水率和剪切强度的变化,揭示了茎秆含水率、剪切强度和机械碎蔓作业质量的内在关系,获得了含水率在86.92%~70.08%时,2个紫甘薯品种藤蔓茎秆剪切力与含水率之间变化的二次函数回归方程;明确了经验收获期开始时藤蔓茎秆含水率分别为81.5%和78.1%、剪切力分别为90.1和94.8 N;从提高机械作业质量角度出发,提出了收获期内最宜机械碎蔓作业时间约为6~8 d。研究结果为新型甘薯藤蔓粉碎还田机转速、切刀线速度等参数设计提供了直接依据,并为适宜的甘薯收获期选择和适宜机械作业的栽培农艺研究提供了参考。     

Comparison of volatile compounds isolated from the skin and flesh of four potato cultivars after baking

Four potato cultivars, Cara, Nadine, Fianna, and Marfona, were selected. Potatoes were baked in their skins prior to separating the skin and flesh and preparing extracts of the volatile flavor compounds using a modified Likens--Nickerson apparatus. The concentrated extracts were analyzed by gas chromatography--mass spectrometry. Volatiles were identified and classified according to their origin, that is, lipid, sugar degradation and/or Maillard reaction not involving sulfur amino acids, sulfur compounds, methoxypyrazines, and other compounds. Quantitative and qualitative differences were observed between isolates from flesh and skins and among cultivars grown at different sites. Strongest isolates from skin were obtained for Nadine. For flesh, Cara gave isolates approximately 10-fold more concentrated than the other three cultivars. For skin, sugar degradation and/or the Maillard reaction was by far the most important source in all cultivars except Nadine, for which 62% of the volatiles were accounted for by the sesquiterpene solavetivone. Lipid and sugar degradation and/or the Maillard reaction were the main origins of volatiles in flesh. Calculated aroma values for a selection of the key potato volatiles identified reinforce the effects of cultivar and growing site on baked potato flavor.     

不同抗性甘薯品种感染疮痂病后光合机理的研究

研究了田间栽培条件下感病薯种“金山1255”和抗病薯种“广薯88-70”染甘薯疮痂病后的光合机理。结果表明,染病后感、抗病品种叶绿素均被降解,叶片膜不饱和脂肪酸含量、不饱和指数、叶绿体膜流动性均降低,叶绿体Ca2 -ATP酶和Mg2 -ATP酶活性均下降,气孔导度、净光合效率、蒸腾速率均下降,但感病品种下降幅度比抗病品种大;胞间CO2浓度在抗病品种中下降,而在感病品种中略有上升;感、抗病品种的叶绿体超微结构都发生了变化,但感病品种受到的伤害程度远大于抗病品种。