Starch Properties of a Waxy Mutant Line of Hull‐less Barley (Hordeum vulgare L.)

Endosperm starch isolated from an amylose‐free waxy mutant hull‐less barley line, Shikoku Hadaka 97, had an amylose content of 0.3% and higher swelling power than ordinary waxy barley cultivars/lines with amylose contents of 2.2—6.5%. A highly significant correlation was observed between amylose content and swelling power among waxy barley starches. No clear differences were detected in the chain‐length distribution profiles or thermal properties between the amylose‐free starch and ordinary waxy starch. The chain‐length distribution profile of waxy barley starch was slightly different from that of normal barley starch. Gelatinization temperatures and gelatinization enthalpy of waxy barley starch were higher than those of normal barley starch. Significant correlations were observed between amylose content and thermal properties of starch samples analyzed. Waxy barley starch stained with a concentrated iodine‐potassium iodide solution showed a ghost‐like appearance.     

Zur genaueren Kenntnis durch Temperatureinfluß modifizierter Wachsmais- und Amylosestärke

Contribution on Waxy Maize Starch and High Amylose Starch Modified under the Influence of Temperature. The starches of the two genetic varieties of the corn grain, waxy maize starch and high amylose starch, were subjected to the influence of different temperatures. Subsequently, the physico-chemical properties of the modified starches were examined. Waxy maize starch which mainly consists of amylopectin, and high amylose starch which contains a high portion of linear chains of polymerized glucose units are interesting test materials because of their properties which are different by nature. Waxy maize starch with its high viscosity values, great swelling power and good solubility in hot water shows no tendency to settle or retrograde. While the process of freezing the starch granules hardly changes the properties mentioned, the influence of a temperature of 100°C causes morphological changes of a small proportion of grains, including the loss of birefringence. These changes are particularly pronounced after treatment of native starch at 120°C. The properties of the starch pastes were also strongly changed. The native high amylose starch characterized by unusual, oblong starch granules without birefringence, a low viscosity, low swelling power and low solubility showed only minor changes after freezing, whereas a temperature of 100°C resulted in reduced values of solubility and aggregation of the starch granules. A temperature treatment at 120°C and at 125°C brought about changes in the swelling properties, the viscosity and limiting viscosity, settling, swelling power, and solubility of the starch pastes. Attempts were made to conform the changes in the different properties observed with the expected influence of temperature treatment on the intermolecular forces (hydrogen bonds, crossbonding).     

Morphological,Thermal, Pasting,and Rheological Properties of Barley Starch and Their Blends

Native barley starch, as well as its blends with corn, wheat, and rice starch at different ratios of 75:25, 50:50, 25:75 were examined in terms of morphology, thermal, pasting, rheological, and retrogradation properties. Amylose content varied between 10.9–41.4% in rice, corn, wheat, and barley while it ranged from 18.02–38.40% in blends of barley starch with rice, corn, and wheat. A rapid visco analyzer showed that barley starch and its blends having low amylose content exhibited higher peak viscosity, breakdown, and setback than the high-amylose-containing starches and their blends. Amylose content was found to be negatively correlated with swelling power while it exhibited nonlinear relationship with solubility index. The transmittance of starch suspension stored at 4°C decreased during storage up to 6 days. Barley starch granules were largest (<110 μm) in size followed by wheat (<30 μm), corn (<25μm) and rice (<20μm) starches. Gelatinization temperatures (To, Tp, Tc) and enthalpies of gelatinization (ΔHgel) of starches from different sources also differed significantly. Corn and rice starches showed higher transition temperatures in general than those from wheat and barley; however, they showed higher ΔHgel values. Barley starch showed a higher tendency towards retrogradation than the cereal starches. Barley starch showed highest peak G′, G″ and lower tan Ð than corn, rice and wheat starches during the heating cycle. This study showed that the magnitude of changes in their properties during blending depends on the amylase content and morphological characteristics.     

Steeping of Barley Starch. Effects on Physicochemical Properties and Functional Characteristics

Starches isolated from 3 barley varieties (Glacier, High-amylose Glacier, Waxy Compana) were steeped at 25°, 40° and 50°C for 1 and 3 days. Enzyme susceptibilities, water binding capacities, swelling powers, solubilities and gelatinization temperatures were determined. The extent of change in physicochemical properties due to steeping varied with type of barley starch. Generally, gelatinization temperature increased and the range narrowed as the temperature and the duration of incubation at a specific temperature increased. Swelling power was inversely related while solubility was directly related to amylose content. The treatment had little effect on swelling powers but restricted solubilities. Steeping of Glacier and Highamylose Glacier barley starches produced a more pronounced V-pattern indicating increased amylose-lipid interaction. Cakes baked with Glacier barley starches treated at 25° and 40°C up to 3 days were acceptable; starch treatment at 50°C caused collapse of cakes. Starch treatment caused high initial consistencies of fillings which were reduced during storage.     

Variation in the Composition and Physical Properties of Barley Starches

Amylose and lysophospholipid contents, swelling factor, and dimensions of large A-type and small B-type granules were measured in 21 waxy, normal and high-amylose starches. Amylose and lipid contents were highly correlated, and both were inversely related to swelling factor. Susceptibility of the starch granules to amyloglucosidase was a function of specific surface area, and was not affected by amylose or lipid content. Environmental (climatic and edaphic) effects seen in 16 samples of Triumph barley starch were generally small (coeff. variation < 10%) and not related to weather statistics, except for lysophospholipid content which was positively correlated with accumulated temperature and solar radiation during the grain-filling period and inversely related to swelling factor.     

Rice Starch Diversity: Effects on Structural,Morphological, Thermal,and Physicochemical Properties—A Review

Abstract: Rice starch is one of the major cereal starches with novel functional properties. Significant progress has been made in recent years on the characterization of rice starches separated from different rice cultivars. Studies have revealed that the molecular structure and functional properties are affected by rice germplasm, isolation procedure, climate, agronomic conditions, and grain development. Morphological studies (microscopy and particle size analysis) have reflected significant differences among rice starch granule shapes (polyhedral, irregular) and in granule size (2 to 7 μm). Nonwaxy and long‐grain rice starches show greater variation in granular size than the waxy starches. Rice starch granules are smaller than other cereal starches with amylose contents varying from virtually amylose‐free in waxy to about 35% in nonwaxy and long‐grain rice starches. Amylose content appears to be the major factor controlling almost all physicochemical properties of rice starch due to its influence on pasting, gelatinization, retrogradation, syneresis, and other functional properties. Waxy rice starches have high swelling and solubility parameters, and larger relative crystallinity values than nonwaxy and long‐grain starches. However, nonwaxy rice starches have a higher gelatinization temperature than the waxy and long‐grain starches. The bland taste, nonallergenicity, and smooth, creamy, and spreadable characteristics of rice starch make it unique and valuable in food and pharmaceutical applications. This review provides recent information on the variation in the molecular structure and functional properties of different rice starches.     

不同植物来源淀粉之间的理化性质的比较

本研究比较了绿豆淀粉、马铃薯淀粉、红薯淀粉、大米淀粉及玉米淀粉的理化性质,结果如下：绿豆淀粉具有最高的直链淀粉渗滤和胶凝值,并且这两个指标均与表观和总直链淀粉含量呈高度的相关关系。尽管绿豆淀粉具有最高的直链淀粉含量,但它并不显示出热糊稳定性。红薯淀粉在加热过程中具有高的膨润力和峰值黏度、高的崩溃值以及低的离水率,这表明红薯淀粉颗粒在加热时能够自由膨胀,糊的热稳定性差,淀粉的老化速率较低,而大米淀粉则与红薯淀粉相反。五种淀粉具有不同的胶稠度,马铃薯淀粉最高,而大米淀粉最低。离水率与直链淀粉含量不呈现明显的相关关系,因此其值的大小可能受其他因素的影响。     

Preparation and Physicochemical Properties of Starches and Their Fractions from Finger Millet (Eleusine coracana) and Foxtail Millet (Setaria italica)

The isolation and physicochemical properties of starches and their fractions from different varieties of finger millets and foxtail millets have been studied. Starches from all the millets exhibited single stage swelling and low solubility. The Brabender viscosities decreased considerably during cooking. Purna starch had the tendency to retrograde considerably during cooling. Native millet starches were susceptible to glucoamylase attack. Amylose content of the millet starches ranged from 15,5 to 17,5%. Successive leeching of starches with water and alkali yielded different amylose components having different molecular weights and β-amylolysis limit, suggesting the heterogeneity of total amyloses.     

Physicochemical properties of pearled hull-less barley cultivars with normal and low amylose content

Five different hull-less barley cultivars of Korea, including normal and low amylose content, were examined both from a chemical and physical perspective. The barley cultivars showed a large variation in whiteness (28.8?C39.2), fat (0.69?C1.28%), ash (0.77?C1.12%), protein (10.1?C12.1%), ??-glucan (5.2?C8.4%), starch (59.9?C68.9%), and amylose (5.3?C22.7%) contents. Amylose content was positively correlated with starch content (r=0.723) and negatively correlated with ??-glucan (r= ?0.959), ash (r= ?0.796), and fat (r= ?0.682) content. Among the chemical components of barley, amylose and ??-glucan contents are the most important factors influencing physical properties. Amylose content was related with hardness (r=0.855), adhesiveness (r= ?0.642), initial pasting temperature (r=0.924), and setback viscosity (r=0.835). ??-Glucan content was related with water absorption (r=0.581), hardness (r= ?0.767), initial pasting temperature (r= ?0.947), and final viscosity (r= ?0.909). Hardness was highly correlated with setback (r=0.925) and adhesiveness was correlated with final viscosity (r=0.866). The results obtained in this study indicate that there are interesting correlations between chemical composition and physical characteristics of barley cultivars and could be used to predict the physicochemical properties of barley based food products.     

Neuere Untersuchungen über die Lipide der Getreidestärken. Teil II. Die Lipide verschiedener Stärkearten und ihre Bindung an die Amylose

Recent Studies on Lipids of Cereal Starches. Part 2. Lipids of Various Types of Starch and their Bond to Amylose. By means of butanol/water (65 : 35) the lipids have been extracted from various cereal starches at 70°C. 1.0 respectively 1.3 %. lipids could be obtained from barley resp. oat starch. In every case lysolecithine was the main part (50–60 %). Apart from that, other lysophosphatides as well as free fatty acids were isolated and identified. The lipids bound to starch remain unchanged for a longer term. Apparently, the inclusion into the amylose helix acts as a protection against autoxidation. The amylose-lysolecithine-inclusion compound was prepared in pure form with a lysolecithine content of 10.2%. Processes for the determination of amylose so far proposed do not take into consideration the special bonding circumstances of lipids in cereal starches. Thus, amylose contents having been determined by these processes are too low.     

不同直链淀粉含量对羟丙基氧化玉米淀粉性质的影响

本文采用蜡质玉米、普通玉米和高直链玉米淀粉为原料,改变有效氯添加量,制备羟丙基氧化淀粉,通过XRD、DSC、Brabender粘度仪等测定手段,研究不同直链淀粉含量对羟丙基氧化淀粉理化性质的影响。实验表明,直链淀粉含量对羟丙基化和氧化程度影响显著,其中直链淀粉含量高有利于羟丙基化,而不利于氧化;X-射线衍射分析发现,改性淀粉没有改变晶型,随氧化程度增加,淀粉分子结晶度下降,直链淀粉含量越高,下降趋势越缓;DSC测试和Brabender粘度分析表明,直链淀粉含量直接影响到羟丙基氧化淀粉糊化特性,糊化温度:高直链普通蜡质,糊粘度:蜡质普通高直链,糊化焓:蜡质普通高直链;通过观察淀粉的偏光特性和颗粒表面形态,发现直链淀粉含量越高,羟丙基氧化淀粉的偏光十字越弱,颗粒越不易破碎。     

Buffalo Gourd Root Starch. Part I. Properties and Structure

The structural and physico-chemical properties of starch isolated from three genetically different populations of buffalo gourd (Cucurbita foetidissima HBK) were explored. The proximate composition of this starch was found to be similar to that of other starches. Granules were depicted to vary in shape (round, oval, truncated) and to resemble maize starch in size. A change in X-ray diffraction behavior from a B- to a C-type pattern was observed upon autoclaving raw gourd starch. Average physico-chemical values were reported as follows: amylose content, 23.1%; water binding capacity, 112; and gelatinization temperature range, 61–69°C. Variation in alkali numbers among samples of this starch was extensive. A highly ordered internal structure of the granule was suggested by low values of swelling power and solubility and high initial pasting temperatures. Pasting curves of buffalo gourd starches were developed which revealed stable gel viscosities throughout the temperature cycle. Amylose fractions were found to be resistant to β-amylase attack and exhibited an average DP η of 1915. Amylopectins were shown to have an average DP η of 2000, and an OCL to ICL of 1.3 to 1.     

Quinoa (Chenopodium quinoa) Starch — Physico-chemical Properties and Functional Characteristics

Starch was isolated from quinoa (Chenopodium quinoa) for a study of physico-chemical properties, functional characteristics and a comparison with starches from wheat, barley, wild rice, amaranth and potatoes. Quinoa starch granules range in size from 0.6 to 2.0 μm and are found within the cells of the seed as single entities or as compound structures of spherical or oblong aggregates. Quinoa starch exhibited a higher Amylograph viscosity, a greater waterbinding capacity and a greater swelling power compared to wheat- or barley starch. The gelatinization temperature range of quinoa starch was slightly higher than that of wheat- or barley starch. Amylose content was lower. As a thickening agent for fillings, quinoa starch performed better than other starches in the study. However, breads and cakes baked with quinoa starch were of poor quality. Volumes were lower, the grain non-uniform with thick cell walls and the texture dense and compact. The overall performance of quinoa starch in baked goods was similar to that of other non-cereal starches (amaranth- and potato starch).     

Amylose Content and Chain Profile of Amylopectin from Normal,High Amylose and Waxy Barleys

The amylose content and the chain profile of amylopectin from normal, waxy and high amylose barley starches were determined after enzymatic debranching and gel permeation chromatography and the degree of branching of the amylopectin was analysed by 1H-n.m.r. spectroscopy. The normal barley starch contained around 30%, the high amylose around 40% and the waxy starch 9% amylose. The amylopectin of the high amylose starches had longer chains than those of the normal or waxy starches, especially in the molecular weight interval 5,400-8,000, but less of those below 2,400 in molecular weight. The chain length of amylopectin from high amylose barley was on average 5 units longer than those of normal or waxy barleys.     

PHYSICOCHEMICAL CHARACTERISTICS OF YAM STARCHES

Starch from tubers of Dioscorea alata, Dioscorea cayenensis, Dioscorea dumetorum, and Dioscorea rotundata was isolated and some of the important characteristics determined. Amylose and amylopectin fractions were obtained by aqueous leaching technique. All the starches appeared to have definite but minor differences in iodine binding capacity, swelling power, solubility, intrinsic viscosity, and amylose/amylopectin ratio. Brabender amylogram of each starch showed no distinct peak viscosity, and the general amylograph pattern was distinctly different from typical amylographs of cereal starches. Amylose fractions from each starch variety exhibited variable degree of β-amylolysis limits ranging from 92–97.5%, and an average molecular weight for amylose triacetate of 210,000 to 265,000. Amylopectin fractions subjected to debranching by pullulanase gave essentially two chain populations of polysaccharides with degree of polymerization of approximately 13–27 and 47–65, respectively. Average unit chain length of the amylopectins ranged from 19 in Dioscorea rotundata to 24 in Dioscorea dumetorum.     

Morphological,thermal and rheological properties of starches separated from rice cultivars grown in India

Morphological, thermal and rheological properties of starches separated from five rice cultivars (PR-106, PR-114, IR-8, PR-103 and PR-113), varying in amylose content, were studied. Amylose contents of starches separated from PR-103, IR-8, PR-106, PR-114 and PR-113 were 7.83, 15.62, 16.05, 16.13 and 18.86%, respectively. The granular size, measured using a Scanning Electron Microscope, varied from 2.4 to 5.4 μm in all rice starches. PR-103 starch, with lowest average granular size, amylose content and solubility, had the highest swelling power, while PR-113 starch, with the highest average granular size and amylose content had the lowest swelling power. PR-103 starch showed highest transition temperatures, enthalpies of gelatinization, peak height index, range and enthalpies of retrogradation. The retrogradation (%) was observed to be highest in PR-113 starch and lowest in PR-103 starch. The changes in rheological parameters of rice starches during heating were measured using a Dynamic rheometer. PR-113 rice starch showed the highest G′, G″ and breakdown in G′ values, whereas PR-103 starch showed the lowest values for these parameters. Turbidity value of gelatinized pastes from all rice starches progressively increased up to the 3rd day during refrigerated storage, PR-103 starch paste showed the lowest turbidity value and PR-113 starch showed the highest value. The syneresis (%) of starch pastes, from different rice cultivars during storage at 4 °C, was also measured. The syneresis of starch pastes from all rice cultivars, except PR-103, increased with storage. PR-103 starch paste showed negligible syneresis during storage.     

Effects of cultivar,nitrogen fertilization rate and environment on yield and grain quality of barley

Ten barley cultivars, including covered and naked types, varying in their content of total starch, amylose, protein and β-glucan, were grown in different years, at various locations and nitrogen fertilization rates. The barley cultivars showed a large variation in yield (3250–6690 kg ha⁻¹), thousand kernel weight (40–50 g), bulk weight (660–815 g litre⁻¹), starch (51–67% of DM), protein (8–15% of DM), β-glucan (3·5–5·9% of DM) and ash (1·9–2·5% of DM). The naked cultivar SW 8775 had the highest starch content and the high amylopectin cultivar (SW 7142-92, waxy) had the lowest. The waxy starch barleys had the highest protein content, while the normal starch barleys (Golf and Lina) had the lowest protein content at each N-rate. Higher content of β-glucan was found in the waxy cultivars (5·0–5·9% of DM) and high amylose cultivars (5·6–5·9% of DM) than in the other barley cultivars (3·5–4·8% of DM). The results were evaluated by analysis of variance (ANOVA) and principal component analysis (PCA), and both confirmed that nitrogen fertilization rate was of great importance for the protein content. PCA revealed that protein and β-glucan were negatively correlated with starch and yield. The ANOVA showed that the cultivar factor was significant for all variables, but especially for the β-glucan content, which responded differently to the nitrogen fertilization rate during the 2 years. In this study, environmental effects were generally of less importance than the barley cultivars for the different variables. © 1998 Society of Chemical Industry.     

Calorimetric Determination of the Amylose Content of Starches Based on Formation and Melting of the Amylose-Lysolecithin Complex

Amylose-lysolecithin complexes, formed in an exothermic reaction when amylose or starches are heated with water and lysolecithin, melt at temperatures near 107°C. With excess lysolecithin present, formation of the maximum amount of amylose complex requires cooling after the first heating (during which gelatinization of starch takes place), and then reheating. An amylose with chain length of 300 glucose units took up 14% lysolecithin; the enthalpy of melting of this complex, observed by differential scanning calorimetry, was 5.9 cal/g amylose. Amylose content of a starch was calculated from the enthalpy of melting of its lysolecithin complex. Amylose contents for potato, tapioca, lima bean, wrinkled pea, amylomaize and waxy maize starches agreed with values obtained by iodine binding. Amylose contents of maize and wheat starches were larger than obtained by iodine binding, and in better agreement with amylose contents obtained by fractionation.     

Wheat starch production,structure, functionality and applications—a review

Starch is the main component of wheat having a number of food and industrial applications. Thousands of cultivars/varieties of different wheat types and species differing in starch functionality (thermal, retrogradation, pasting and nutritional properties) are grown throughout the world. These properties are related to starch composition, morphology and structure, which vary with genetics, agronomic and environmental conditions. Starches from soft wheat contain high amounts of surface lipids and proteins and exhibit lower paste viscosity, whereas that from hard cultivars contain high proportion of small granules and amylose content but lower gelatinization temperature and enthalpy. Waxy starches exhibit higher‐percentage crystallinity, gelatinization temperatures, swelling power, paste viscosities and digestibility, but lower‐setback viscosity, rate of retrogradation and levels of starch lipids and proteins than normal and high‐amylose starches. Starches with high levels of lipids are less susceptible towards gelatinization, swelling and retrogradation and are good source of resistant starch, while that with high proportion of long amylopectin chains are more crystalline, gelatinize at high temperatures, increase paste viscosity, retrograde to a greater extent and decrease starch digestibility (high resistant and slowly digestible starch and low rapidly digestible starch).     

Physicochemical and structural characteristics of starches from Chinese hull‐less barley cultivars

Fourteen hull‐less barley cultivars, collected from four major cultivated areas in China, were employed to investigate the structural and physicochemical properties of their starches in this study. Relatively wide variations in physicochemical properties of the starches were observed. Amylose content ranged from 23.1% to 30.0%, swelling power and water solubility index ranged from 12.8 to 19.9 g g^?1 and 12.7% to 23.7% respectively. Peak viscosity was from 170 to 346 Rapid Visco Unit (RVU), peak temperature (T_p) of starch gelatinisation was from 55.6 to 61.8 °C and enthalpy of starch retrogradation ranged from 0.3 to 3.1 J g^?1. Weight‐based chain‐length proportions of fa, fb₁, fb₂ and fb₃ in amylopectins ranged from 21.65% to 24.95%, 44.48% to 49.44%, 15.56% to 17.19% and 9.83% to 16.66% respectively. Correlation analyses showed that amylose content was inversely related to pasting parameters and enthalpy of gelatinisation. Pasting properties and amylopectin structures were the most important parameters to differentiate starch properties among different hull‐less barley cultivars in this study. This work will be useful for exploring applications of Chinese hull‐less barley starches in food and non‐food industries.