Influence of Cassava Storage Root Development and Environmental Conditions on Starch Granule Size Distribution

Among starch producing crops, cassava has a higher carbohydrate production than others under suboptimal conditions, more than 163×10⁶ t of cassava starch are produced world‐wide each year and are used for direct human consumption, animal feeds and as raw material for a wide range of industrial products. A basic knowledge of starch characteristics and storage process is required to improve cassava starch quality and quantity. This report describes a comparative study of morphology, starch granule size distribution and amylose content in cassava storage roots grown under different conditions. Microscopic evaluation reveals that storage roots contain larger starch granules than fibrous roots. The study on three Asian cassava cultivars demonstrates the increment of starch granule size from outermost to innermost layers of storage root, while no significant change is observed in amylose content. The effects of developmental stage and growing season on cassava starch reveals that granule size is significantly influenced by both factors, while the amylose contents only fluctuate in a narrow range. The size of the starch granules increases particularly in the first six months after cultivation. Planting cassava in the beginning of the wet season in Asia yields larger granule sizes than planting in the dry season. The significance of this study lies in better understanding optimal growing conditions for improved starch characteristics and production, leading to a better quality agricultural production of this important food and materials crop.     

马铃薯块茎干物质、淀粉及还原糖含量的检测及相关性分析

本文以来自全国13个省(14个地区)46个品种的马铃薯为实验材料,采用国家标准方法或国标方法稍有改动,检测马铃薯的干物质、还原糖和淀粉含量。再通过SPSS 20.0对不同样品中还原糖和淀粉含量差异的显著性进行了分析,并采用矩阵散点图、一元线性回归研究了干物质、还原糖和淀粉含量之间相关性。结果表明:马铃薯中干物质含量为15.43%~29.67%,还原糖含量为0.09%~1.84%,淀粉含量为9.11%~22.30%(均为湿基);大部分样品的还原糖含量差异都很显著(p0.05),淀粉含量差异也很显著(p0.05);通过矩阵散点图发现马铃薯中还原糖含量与干物质含量无相关性,与淀粉含量也无相关性;马铃薯中干物质含量和淀粉含量呈正相关,服从一元线性方程:y=9.626+0.708x,即马铃薯中干物质含量越高,淀粉含量也就越高。     

糖型与淀粉型木薯后代块根品质与发酵特性

为了研究糖型与淀粉型木薯后代块根品质与发酵特性,测定了28个木薯品系块根的干物质、淀粉、总糖、还原糖、粗蛋白和灰分等主要品质性状。结果表明,淀粉型木薯后代块根的淀粉（14.52%）、总糖（27.48%）、干物质（41.24%）、粗蛋白（1.67%）和灰分（0.25%）含量,总体上比糖型木薯后代块根高;糖型木薯后代块根还原糖含量（2.01%）显著高于淀粉型木薯后代块根（0.61%）（P＜0.05）,而其淀粉含量仅6.62%。相关分析表明,还原糖与淀粉、总糖、干物质和粗蛋白等性状均呈显著负相关（P＜0.05）。通过杂交改良克服负相关,新品系SM03块根的乙醇转化率达到53.7 mL/100 g干质量,产酒精34.73 L/hm2。SM03和SC16只糖化、不经过糊化预处理,酵母发酵分别产酒精31.13 L/hm2、27.80 L/hm2,均是很有推广价值的能源木薯新品种。     

不同杀菌剂防治对马铃薯主要营养成分的影响

目的 以喷施4种杀菌剂防治马铃薯Y病毒病的样品为试验原料,研究防效与干物质、淀粉、还原糖和维生素C含量之间关系,分析各营养成分之间的相关性。方法 在国家标准基础上稍加改动测定营养成分,采用矩阵散点图、标准化残差P-P图、一元线性回归分析防效与营养成分及各营养成分之间的相关性。结果 防效与干物质、维生素C和淀粉含量之间呈正相关,干物质含量与淀粉含量、维生素C呈正相关,维生素C含量与淀粉含量呈正相关,还原糖含量与维生素C含量、淀粉含量、干物质含量和平均防效四者之间无显著相关性。结论 4种杀菌剂中防效最好的为喷施5%氨基寡糖素水剂中剂量,且采收该小区马铃薯干物质含量、淀粉含量和维生素C含量最高。研究结果可为种植马铃薯防治Y病毒病筛选最佳药剂,为马铃薯病害防治与营养成分之间相关性提供数据支撑。     

Stability of native starch quality parameters,starch extraction and root dry matter of cassava genotypes in different environments

Cassava is an important food and cash crop in Malawi. It is also becoming increasingly important for industrial use. The aim of this study was to investigate the native starch quality of different Malawi cassava genotypes. Trials were conducted at Chitedze and Makoka in Malawi in the 2000/01 season. Apart from root dry matter and starch extraction, starch quality parameters considered included protein, moisture and ash contents, pH and whiteness. Various stability measures were used to deal with the problem of genotype × environment interaction. The results showed that all the cassava genotypes produced starch with no protein and with colour as white as required by the industry. Moisture and ash contents and pH fell within the industry‐recommended ranges. This suggests that native cassava starch is suitable for use in various industries. Additive main effects and multiplicative interaction (AMMI) was strongly correlated with other measured stability parameters and is therefore recommended for stability analysis of starch quality parameters. Genotype had a larger influence than environment on root dry matter. This agrees with the hypothesis that one or a few major genes control root dry matter in cassava. Copyright © 2004 Society of Chemical Industry     

不同采收期不同品种莲藕的营养品质变化规律及评价

目的 探究不同采收期不同品种莲藕的营养成分和活性成分的变化规律。方法 选取5个采收期的4个品种莲藕,测定蛋白质、淀粉等指标。采用主成分分析和聚类分析进行综合评价,并建立莲藕品质评价模型。结果 在采收期内,莲藕淀粉含量呈现先上升后下降再上升的趋势,可溶性糖的变化趋势与其相反;总酚含量整体呈现先上升后下降的趋势;蛋白质、膳食纤维等指标呈现不同的变化规律。主成分分析法提取出PC1、PC2、PC3 3个主成分因子,特征值依次为2.274、1.933、1.023,累积方差贡献率达87.170%。不溶性膳食纤维、可溶性膳食纤维、可溶性总糖、淀粉、总酚和总黄酮6个指标可以用来综合评价莲藕营养品质。综合评价发现, 9月采收的八月粉,10月的鄂莲6号,2月的鄂莲10号和鄂莲11号,营养品质较好,优于其他采收期。3月采收的4个品种莲藕的综合营养品质较低。结论 在采收期内, 4个品种莲藕的营养物质动态规律存在一定差异。基于主成分分析和聚类分析的分析方法能够科学评价不同采收期莲藕的综合营养品质,为莲藕育种、加工等提供支撑。     

不同类型甘薯品种主要经济性状和营养成分差异

对20个主栽甘薯品种的经济性状和营养成分含量分析,表明不同类型间的差异很大,同一类型不同品种间差异达到显著或极显著水平。粗淀粉含量和鲜薯产量呈极显著正相关(ρ=0.967),粗蛋白与粗纤维含量呈极显著正相关(ρ=1.000);粗蛋白含量与鲜薯产量、薯干产量、粗淀粉含量均呈负相关。粗纤维的检测结果,基本符合专业技术人员肉眼判断结果。系统聚类分析结果与甘薯专业委员会的分类结果有差异,但甘薯品种经济性状突出,营养成分基本均衡,遗传距离远的品种基本自成一类。徐薯18和南薯88这两个品种各方面经济性状突出,遗传配合力高,仍然可以作为当前北方薯区甘薯育种的骨干亲本。     

Cassava root yields and culinary qualities as affected by harvest age and test environment

Five cassava genotypes were grown at five contrasting sites in Cameroon, and their roots were harvested 6, 8, 10, 12, 14 and 16 months after planting, to determine the effects of growing environment and harvest age on storage root yields and culinary qualities. The highest root yields were obtained at Ekona (26.3 t ha^?1), whereas the highest root counts were recorded at Bertoua (33 roots per 10 m²). Root yields were lowest (2.9 t ha^?1) when roots were harvested at 6 months, but continued to bulk up to 18.5 t ha^?1 at 16 months. The greatest root increase (9.3 t ha^?1) was observed between 8 and 12 months. Improved and local varieties had comparable dry matter contents (39%). All clones cooked when harvested at 6 and 8 months; thereafter, improved clones did not cook, and cooking duration continued to increase even for the local variety, accounting for the difficulty seen in disseminating these newly developed clones to growers. Cooking durations of roots were longer at Nkolbisson, Bertoua and Ebolowa than at Ekona and Yoke. Soil carbon content was negatively correlated (r = ?0.999***) with mealiness but not with cooking duration. Cooking quality appears to be under genetic and environmental control. Further studies to elucidate the role of the environment on cookability should concentrate on duration of the rainy and dry seasons, soil physical and chemical properties, and starch chemistry of the genotypes. Suggestions for further research are discussed. © 2003 Society of Chemical Industry     

Fried sweetpotato user preferences identified in Nigeria and Ghana and implications for trait evaluation

Fried sweetpotato quality is important for variety adoption in West Africa. To inform breeding efforts, the study developed a product profile for sweetpotato chunk fries using mixed qualitative and quantitative methods. Root characteristics, processing attributes, in-mouth attributes and appearance of fried product were critical to final product quality. Raw roots should be hard, have smooth skin and no off-odours. Peeled roots should be hard to slice and not sticky. Stickiness and moist surface indicate high moisture content, associated with excessive oil absorption during frying. Hard to slice roots connote high dry matter. Fried product should be crisp, slightly sugary and mealy, have a uniform colour with brown tint and not be soggy. Crispness, mealiness and short frying time with limited oil absorption may be functions of starch. Understanding starch characteristics and other attributes that contribute to quality fried sweetpotato is critical for breeding sweetpotato genotypes with superior quality for frying.     

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。     

Charakteristik der Stärke ausgewählter Kartoffelsorten Teil 1. Änderung des Stärkegehalts und der Stärkekorngröße während der Lagerung

Characteristics of Starch of Selected Potato Varieties. Part 1. Change of Starch Content and Starch Granule Size During Storage . Selected varieties of potatoes of the Czechoslovakian assortment were tested as to their contents of dry matter and starch, as well as to quality of their starch in three-years storage tests. Potatoes were stored in airconditioned boxes at temperatures of + 2 and + 10 °C. Analyses were carried out after harvesting and after storage. It was found that the content of dry matter was higher near the end of storage time. This increase was depending on temperature. Yet, related to dry matter the starch content had not diminished near the end of storage time. During storage of potatoes changes in the share of individual starch granule sizes do also occur. Larger granules were degraded to smaller ones, thereby increasing the latter's share. Higher temperature would also lead to an increase in these changes. The tests were supposed to show, wether during potato storage a change in size of starch granules takes place, and wether storage temperature may influence this change. Work on this problem will be continued.     

Short‐duration cassava genotypes for crop diversification in the humid tropics: growth dynamics,biomass, yield and quality

BACKGROUND: Short‐duration (6–7 months) cassava provides opportunities to smallholder farmers for effective utilisation of resources such as land, moisture and nutrients as well as diversification of enterprise and income. The variation in biomass production and partitioning, seasonal course of growth indices, yield, quality and nutrient uptake of ten short‐duration/early‐bulking genotypes of cassava and their impact on nutrient contents in soil in a lowland situation akin to rice fallow were examined in this study. RESULTS: Triploid 2–18 gave the highest yield (38.34 t ha^?1), followed by triploid 4‐2, Sree Vijaya, Sree Jaya and Vellayani Hraswa, which were on a par (30–32 t ha^?1). Vellayani Hraswa, Sree Vijaya and triploid 4‐2 had significantly higher tuberous root dry matter content (370–380 mg g^?1) and fairly higher starch content (270–280 mg g^?1). All genotypes except triploid 4‐2, triploid 2–18 and H‐165 had low cyanogen content (29.2–43.8 µg g^?1), well within the tolerable limit. Tuberous root dry matter and total dry matter production, crop growth rate, tuberous root bulking rate and harvest index at the last phase, number of tuberous roots, mean weight of tuberous roots and nutrient uptake showed significant positive correlations with tuberous root yield. Principal component analysis also showed a similar trend. CONCLUSION: The diploids Sree Vijaya, Sree Jaya, Vellayani Hraswa and Kalpaka are ideal for cultivation in rice fallow for food use owing to their high yield, good cooking quality and low cyanogen content. The triploids are better suited for industrial use owing to their high tuberous root dry biomass production. Copyright © 2009 Society of Chemical Industry     

Spezielle Probleme bei der Chips-Herstellung

Special Problems of Chips Manufacturing. This investigation deals with the problems manufacturing potato chips referring to the quality. A manufacturer of chips has realized some experiments in order to enlarge the spectrum of potato varieties, which are suitable for producing chips of good quality. Beside the results of these experiments some other problems have been solved, for example the degree of damage. Two of the most important characteristics of chips quality are the colour and the oil content. It is reported about tests showing that within the single classes of specific gravity the dry matter content, and depending on this dry matter content, the reducing sugar content is spreading very much within one potato variety. The data from these experiments show a correlation between dry matter content and chips colour within one variety. The increasing of dry matter content implies brightening up of the chips colour. Furthermore it is reported about the important correlation between dry matter content and relation of starch to nonstarch material and the quality characteristics like oil content and yield of chips. The influence of the manufacturing process on the quality characteristics has been examined.     

辽宁省主栽品种马铃薯块茎和马铃薯全粉的品质分析

以辽宁省主栽的11个品种马铃薯块茎为原料,采用捣碎制泥工艺生产马铃薯颗粒全粉,测定其原料品质指标(总淀粉、蛋白质、还原糖、脂肪、粗纤维和氨基酸)和颗粒全粉功能性指标(碘蓝值、透光率、冻融稳定性、持水和持油性)。结果表明:11个马铃薯品种的淀粉含量为67.9%~73.4%,其中大西洋、919淀粉含量高,早大白和克23淀粉含量低;蛋白质含量差异较大,其中富金、尤金蛋白质含量高,中5蛋白质含量最低;还原糖含量差异也较大,BQ25和大西洋含量较低,克23还原糖含量较高;脂肪含量差异不大;大西洋粗纤维含量较低,克23粗纤维含量较高。异亮氨基酸、苯丙氨基酸+酪氨酸含量11个品种均高于世界卫生组织(WHO)的“必需氨基酸模式标准”,相对其他氨基酸,33、大西洋、夏波蒂和中5的氨基酸含量较高。11种马铃薯全粉的游离淀粉率差异不大。但是透光率差异很大,919的透光率最大,BQ25和大西洋的透光率较小。富金、克23和33的析水率较高,BQ25和大西洋析水率低。11种马铃薯全粉的持水能力为7.3~8.1 g/mL,持油能力为7.6~8.6 g/mL。     

A comparison of simple methods for estimating starch content of cassava roots

A comparison of simple methods for estimating starch content of cassava roots showed a strong relationship between root specific gravity and root dry matter content. In the absence of drying facilities a specific gravity balance appears adequate to separate root samples according to dry matter content. A strong relationship between root specific gravity and starch content was observed using a maceration/sieving technique. This relationship was close to a published relationship based on chemical analysis. Root dry matter content may be used as an indication of starch content but care should be exercised in using linear conversions until more information becomes available. Existing conversion tables from root specific gravity to starch content and the starch content calibrations on the Reimann balance used, grossly underestimated starch content of the samples analysed.     

不同烘烤湿度条件与烟叶淀粉含量变化关系

研究了不同烘烤湿度条件与烤烟烟叶干物质、淀粉、可溶性糖的变化关系.结果表明,随着烘烤湿度的提高,干物质损失量、淀粉降解量、可溶性糖的含量都有增大的趋势,不同部位的烟叶具有相似的规律.     

不同品种甘薯淀粉加工特性及其与磷含量的相关性研究

对24个甘薯品种的淀粉含量、干率、可溶性糖含量、淀粉的黏度特征谱和磷含量进行了比较研究。结果表明:试验品种薯块的平均淀粉含量为22.14%,以渝薯1号最高,达31.45%;平均干物质率为31.38%,品种之间的差异较小;平均可溶性糖含量2.32%,以秦薯5号最低,为0.42%;褐变指数7.00~20.01,最低的为渝薯27;淀粉糊化温度范围为66.8~77.1 ℃,秦薯9号、苏薯24、烟薯26和济薯25淀粉的糊化温度均低于70 ℃;淀粉峰值黏度最高的品种为运薯271,达1207 BU;崩解值最低的品种为桂粉3号,为381 BU;回生值最低的品种为秦薯5号,为241BU;淀粉磷含量82~231 mg/kg,与峰值黏度极显著正相关(p<0.01)。建议进行淀粉类产品加工时,根据产品所需的特征参数选择合适的品种,实现物尽其用。受试甘薯中,以渝薯1号、渝薯27、济薯25和苏薯24的综合加工特性较好,推荐作为育种亲本。     

Physicochemical properties of dry matter and starch from potatoes grown in Canada

In this study dry matter and starch were isolated from three potato cultivars (AC Stempede Russet, Russet Burbank and Karnico) grown at two locations (Fredericton and Benton) in New Brunswick, Canada. The chemical composition including total starch, dietary fibre, free glucose and protein content in potato dry matter and apparent amylose and total phosphorus content in potato starch were determined. Differential scanning calorimetry (DSC) was used to determine the thermal properties of gelatinization and retrogradation of potato dry matter and starch. The pasting properties of potato dry matter and starch were investigated by rapid visco analyzer (RVA). The resistant starch measurement method was employed to evaluate the digestibility in vitro of native and gelatinized potato starch. Molecular characteristics including chain length and chain length distribution of potato starch were also analyzed using high performance anion exchange chromatography (HPAEC). The analytical results suggest that differences in chemical composition and molecular chain length of potato starch may contribute to different functional properties of potato dry matter and starch of individual cultivars.     

Starch from Alberta potatoes: wet-isolation and some physicochemical properties

Starch content of six varieties of Alberta-grown potato tubers was more than 16% (wet basis). The tubers were wet fractionated in the laboratory and starch was recovered. The starch recovery ranged from 61 to 67%. The composition of the potato juice/fruit water (dry matter, protein, ash and mineral content) and starch isolations (moisture, starch, protein, lipid, ash, phosphorous and amylose content) was determined. The physicochemical characterization of the potato starch isolations were done in terms of granule size distribution, crystallinity (X-ray diffractometry), gelatinization (differential scanning calorimetry) properties, swelling factor and the changes in viscosity during heating and cooling of starch-water slurry (Brabender viscography). Substantial differences in the starch content of the tubers, fruit water composition and starch physicochemical properties were observed between potato varieties.     

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.