Gamma Radiolysis of Starches Derived from Different Foodstuffs. Part III. Study of Induced Hydrogen Peroxide

The foodstuff from which the studied starches (maize, waxymaize, amylomaize, manioc, bread-wheat, potato, rice and haricot bean) derive has only a little influence upon the quantities of gamma radioinduced hydrogen peroxide.     

Gamma Radiolysis of Starches Derived from Different Foodstuffs. Part IV. Study of Radiodepolymerization

The foodstuffs from which the investigated starches (maize, waxymaize, amylomaize, manioc, bread-wheat, potatoe, rice and haricot bean) derive has only little influence upon their radiodepolymerization, as previously stated by theory.     

Gamma Radiolysis of Starches Derived from Different Foodstuffs. Part 1. Study of Some Induced Carbonyl Derivatives

The foodstuff from which the studied starches (maize, amylomaize, waxymaize, bread-wheat, manioc, rice, potato, haricot bean) derive only has a little influence upon the quantities of gamma radioinduced carbonyl derivates: the ratio between the maximal and minimal values found is always lower than 5; the radio-induced quantities in maize starch do not vary for more than 30% around the average value found for the different starches; the different curves drawn – showing the influence of irradiation dose, atmosphere, water content – have similar shapes.     

Detection of Corn Starch Irradiated with Low Doses of Gamma Rays. Part II. Disappearance of Malonaldehyde from Starches of Various Moisture Contents

Using the thiobarbituric acid test for malonaldehyde, irradiated starch can be detected qualitatively for up to a year after irradiation. If the moisture content of the starch is known, the dose can be determined quantitatively, if below 75 krad, for up to four months after irradiation, and doses between 75 and 200 krad can be determined up to four weeks after irradiation. Decreasing production of malonaldehyde with increased moisture content is ascribed to preferential radilysis of the water rather than the starch, with formation of hydrogen peroxide. A possible route for the disappearance of malonaldehyde by reaction with hydrogen peroxide is suggested.     

几种不同品种淀粉及羟丙基产物糊液性质比较研究

以薯类淀粉(木薯,马铃薯)及禾谷类淀粉(普通玉米、蜡质玉米、高直链玉米及糯米)为原料,以环氧丙烷为醚化剂。制备了羟丙基变性淀粉。反应条件:淀粉乳质量分数40%、反应温度40℃、无水Na_2SO_4添加量12%(以淀粉干基计)、NaOH添加量1.2%、环氧丙烷添加量12%、反应时间18h。分别对原淀粉及在相同的反应条件下制备的羟丙基变性淀粉糊性质做了对比研究。不同品种淀粉糊性质存在很大差别。经过羟丙基改性。淀粉糊液粘度性质、冻融稳定性、透光率、都有不同程度的改善,但凝沉性质不能准确反映羟丙基化对蜡质玉米淀粉和糯米淀粉糊液性质的改善。     

Synthesis and Application of Reactive Carbohydrates. Part VI: Application of Reactive Carbohydrates Derived from Starch and Hydrolyzed Starches to Cotton Fabric

Native starch, 15 min, 30 min, 45 min and 60 min hydrolyzed starches were converted to reactive carbohydrates via graft polymerization with acrylamide followed by methylolation with formaldehyde. The reactive carbohydrates so obtained were applied to cotton fabric according to the conventional pad-dry-cure method under different conditions. The latter included the catalytic system and the curing conditions. The pad-cure and the pad-batch methods were also applicated. Examination of the treated fabrics for nitrogen content as a measure of the extent of reaction, occuring between the methylol groups of the reactive carbohydrate and the hydroxyl groups of cotton cellulose, as well as durability of the finish on the fabric indicated the dependance of the reaction and durability on nature of both reactive carbohydrate and catalyst as well as curing conditions. Reactive carbohydrate derived from 15 min hydrolyzed starch along with mixed catalyst, namely MgCl₂ · 6 H₂O/citric acid (20:80), constitute the most appropriate finish/catalyst combination provided that application is carried out according to the pad-dry-cure method; drying is effected at 100°C for 2.5 min while curing is expedited at 130°C for 30 s.     

不同品种大米淀粉的流变学特性研究

以不同品种大米淀粉为材料,研究淀粉糊的流变学特性,温度、淀粉糊浓度对黏度系数、流变指数的影响,为淀粉质食品的原料选择和加工提供参数。结果表明,大米淀粉糊呈假塑性流体的特性。不同品种大米淀粉湖的流变特性有较大差异,金优和放心米的热稳定性较差,大米淀粉糊的黏度系数为0.1~11。黏度系数和流变指数对温度和浓度对有较大的依赖性。大米淀粉的流动能约为1.66×106J/mol~20.53×106J/mol。     

Properties of Sweet Potato Starches from Different Tissue Zones

Sweet potato starches prepared from the peel ( P ), cambium ( C ), and inner-tissue ( IT ) were tested for physicochemical properties. The average granule sizes of the IT starches were tended to be larger than those of the P and C starches. Amylose contents of starches from the different tissue zones did not differ significantly. The onset and peak temperatures ( T _o, T _p ) of the P starches determined by differential scanning calorimetry (DSC) were somewhat high. The C starches were readily digested by the four glucoamylases.     

Non‐contact Atomic Force Microscopy of Starch Granules Surface. Part II. Selected Cereal Starches

Atomic Force Microscopy (non‐contact method) was used to examine the surface of starch granules of selected cereals. Depressions which might be typical surface pores or ends of penetrating channels were observed in case of all examined granules. The size and shape of these depressions depended on the botanical origin of the starch. Regions of relatively flat surface without visible structures, pores and protrusions could be detected on the granules studied.     

不同品种鹰嘴豆淀粉糊与凝胶特性研究

以不同品种的鹰嘴豆Kabuli和Desi为原料,采用快速黏度仪、质构仪和流变仪研究淀粉糊与凝胶特性的差异。研究表明:Kabuli淀粉在糊化过程中的峰值、谷值、最终黏度等特征值均高于Desi淀粉,而降落值、回值及成糊温度却低于Desi淀粉。Kabuli淀粉的品质优于Desi淀粉,但这2种鹰嘴豆淀粉糊的糊丝均属于短糊系列。在不同热过程中Desi淀粉形成凝胶速度快,强度大;Kabuli淀粉的凝胶强度随温度的变化是可逆的。Kabuli淀粉凝胶破裂强度、弹性模量均小于Desi淀粉凝胶。     

Studies on Sago Starch. Part I: Characterization and Comparison of Sago Starches Obtained from Metroxylon sagu Processed at Different Times

This paper reports on a study undertaken to determine some of the factors responsible for the variability shown by sago starch, which at present severely limits the commercial value of this material. Two batches of sago starch extracted from Metroxylon sagu species were characterized physicochemically and structurally. One batch was white in colour while the other was reddish-brown. The latter contained significantly more protein (0.06%) than the former (0.015%). Non-proteinaceous material constituted 40% of the total nitrogen in the former. The ionic contents of the two batches of starch exhibited a similar ion profile except for the following striking differences. The white batch contained 20-fold more phosphorus and 15-fold more aluminium whilst the reddish-brown batch contained double the quantity of iron and calcium. The solubility and swelling capacity of both batches were also different. Amylographic representation was used to reveal the strength of starch granules during pasting. Scanning electron microscopy disclosed different degrees of pitting between the two batches, the morphology of which were also shown to be disparate. Flow curves also displayed significant differences in the rheological behaviour.     

Properties of Starches from Australian Wheats. Part 1: Separation of Starch and Gluten

Starch and gluten were isolated from flours milled from 21 Australian wheat varieties. Relative yields of starch and gluten varied in general accord with flour protein content. Recoveries of total solids (starch plus gluten) ranged from 67.6% to 85.1% amongst the varieties. Significant differences in proximate composition and amylose content were observed between the isolated starches. This was especially so for starch protein content which was significantly correlated with wheat hardness. Potential benefits exist for the starch/gluten industry in selecting wheats on the basis of minimal loss of total solids during the process, and for purity and amylose content of the isolated starch.     

Studies on the Gelatinization of Starches. Part 2. Effect of Lower Alcohols on the Gelatinization of Cereal Starches

The effect of lower alcohols (methyl to amyl alcohol) on the gelatinization of cereal starches was studied by means of amylography and the determination of degree of gelatinization by glucoamylase digestion and iodine affinity. The straight chain primary alcohols other than methyl alcohol considerably decreased the transition temperature of the amylograms of these starches with the increase of molecular weight. The characteristic modification of the amylograms by these alcohols was inferred to be due to the exchange of the alcohols for the lipids in the amylose-lipids complex of starch.     

不同品种苦荞麦淀粉的主要理化性质

研究了不同种类苦荞淀粉的性质。采用扫描电镜(SEM)拍摄了苦荞淀粉颗粒的形态;用X-射线衍射仪测定了X衍射图样及结晶结构;用快速黏度分析仪(RVA3)对各个淀粉黏度进行了测定;并与玉米淀粉进行了比较。同时测定了淀粉糊的透明度、凝沉曲线等性质。     

不同品种玉米淀粉的理化性质及相关性研究

通过研究10个玉米品种淀粉的理化性质及其相关性,结果表明,淀粉的平均粒径与终黏度存在极显著负相关(r=-0.789,P<0.01),与回凝值存在显著负相关(r=-0.760,P<0.05).淀粉的糊化温度与淀粉熔融起始温度、熔融峰值温度具有正相关关系(r=0.656,P<0.05;r=0.862,P<0.01).淀粉的糊化峰黏度与崩解值呈极显著正相关(r=0.948,P<0.01),与熔融峰值温度、熔融终止温度呈极显著负相关(r=-807;r=-O.770,P<0.01).崩解值与淀粉的熔融峰值温度、熔融终止温度具有显著负相关关系(r=-740;r:-0.683,P<0.05).淀粉的终黏度与回凝值存在高度正相关(r=0.968,P<0.01).淀粉的熔融起始温度、熔融峰值温度和熔融终止温度两两之间存在显著正相关.淀粉的熔融起始温度与淀粉的黏着性存在显著正相关(r=0.752,P<0.05).淀粉的熔融终止温度与粘聚性存在显著正相关(r=0.646,P<0.05).淀粉的凝胶硬度与黏着性存在极显著相关性(r=0.793,P<0.01).     

Physicochemical and Functional Properties of Sour Starches from Different Cassava Varieties

This article reports our investigation on the effect of cassava varieties on the physicochemical and functional properties of sour starches. There were significant differences (P < 0.05) in the ash, pH, amylose, amylopectin, starch damage, total titratable acidity (TTA), sugar, and starch content but not moisture contents of various cassava sour starches. There were no significant differences (P > 0.05) in Water Absorption Capacity (WAC), swelling power, and solubility index, while significant differences were recorded in Least Gelation Concentration (LGC) and color at 5% level and granule size at P < 0.0001 for cassava sour starches. Peak viscosity values ranged from 333.17RVU (clone 4(2) 1425) to 380.75RVU (clone TME 1). There were significant differences (P < 0.05) in pasting properties except for pasting temperature and breakdown.     

Xerophytic Cucurbit Root Starches. Part VI: Preliminary Investigation of Starches from Apodanthera undulata Gray,Marah gilensis Greene and Maximowiczia lindheimeri Gray

The root starches of Apodanthera undulata Gray, Marah gilensis Greene and Maximowiczia lindheimeri Gray were quantified, isolated and characterized to expand knowledge concerning potentially useful products from xerophytes. Apodanthera roots contained relatively high levels of starch (20.5%) whereas starch levels in the other two species were 8.2 and 9.5%, resp. Starch isolated from Apodanthera manifested physical, physico-chemical and rheologic properties which closely resembled those of the potentially commercial Cucurbita foetidissima and Cucurbita digitata root starches. Granules were composed of approximately 26% amylose, were of medium size, were round, oval, or truncated in shape; and were moderately resistant to gelatinization, swelling and solubilization. Suspensions displayed high initial pasting temperatures. The pastes were resistant to collapse and developed only a modest level of set-back upon cooling. Starch from Maximowiczia also resembled Cucurbita starches for most parameters but exhibited a higher resistance to granule hydration and disintegration than any of its counterparts. Granules of Marah starch were somewhat larger than those of other starches within this group and their equilibrium moistures were high. They offered little resistance to gelatinization, were more free-swelling and soluble than other subject materials, and in suspension they displayed a relatively low initial pasting temperature. Furthermore, Marah pastes were more highly viscous than those of other subject materials during the pasting cycle and suffered regain as they cooled.     

Properties of Starches from Australian Wheats. Part 3: In vitro Digestibility and Hydroxypropyl Derivatives

The in vitro digestibilities of starches isolated from 21 Australian wheat varieties were measured after gelatinisation, using porcine pancreatic α-amylase. The starches were also converted into their hydroxypropyl derivatives and levels of substitution, and freeze-thaw stability of the products assessed. Digestibilities varied between samples and were significantly correlated negatively with fat content of the starches. No significant correlations between digestibilities and any of amylose content, grain hardness or granule crystallinity were found. Efficiency of reagent usage during derivatisation and freeze-thaw stability also varied between starches. Levels of substitution were not reflected in relative freeze-thaw stabilities of the starch derivatives.     

采用不同方法制备豌豆抗性淀粉及其性质研究

以豌豆淀粉为原料,研究交联、湿热、脱支酶解3种不同方法处理后其抗性淀粉含量及其他性质的变化。实验表明:交联、湿热、脱支酶解处理均能增加豌豆抗性淀粉的含量,且脱支酶解处理>湿热处理>交联处理;交联处理后其溶解度降低,但湿热和酶解均使其溶解度增加,3种处理方式均使豌豆淀粉膨胀度降低;交联和酶解处理使豌豆淀粉的糊化温度和糊化焓增加,糊化变得困难,而湿热处理后其糊化峰变为2个;X射线衍射数据表明,交联处理不会改变豌豆淀粉的晶型,湿热处理和脱支酶解后豌豆淀粉的晶型分别由原来的C型变为A型和B型;体外消化模拟实验表明,经交联处理后豌豆淀粉消化性增加,而经湿热和酶解处理后其消化性能均降低。