热处理对不同直链淀粉含量的玉米淀粉理化性质的影响

采用快速黏度分析法、离心法、差示扫描量热分析法、动态流变仪分析法等,研究了干热与湿热处理对3种不同直链淀粉含量的玉米淀粉糊化性质、膨润性质、热力学性质、流变性质的影响,为淀粉的物理改性研究和加工应用提供理论依据。结果表明,干热处理使淀粉更易糊化,表现为3种玉米淀粉糊化温度降低,溶解度、膨胀度增加。湿热处理加大糊化难度,使3种玉米淀粉的糊化温度升高,膨胀度降低。热处理使玉米淀粉糊稠度、糊化焓值降低。蜡质玉米淀粉经热处理后,溶解度和老化率增加。流变性质测定结果表明,湿热处理不利于高直链玉米淀粉黏弹性凝胶的形成。     

湿热处理对损伤淀粉理化性质的影响研究

以郑麦366小麦淀粉为原料对其进行脱脂处理和球磨处理,通过测定相关理化指标,研究湿热处理对脱脂前后损伤淀粉的改性作用.研究表明湿热处理可以降低损伤淀粉含量,降低淀粉糊黏度,降低溶解度和溶胀势,提高糊化温度,降低糊化焓,促进淀粉分子的重结晶.     

不同直链淀粉含量大米淀粉性质的研究

以4种不同直链淀粉含量的米淀粉为原料,采用扫描电镜（SEM）、全波长自动扫描仪,质构仪等对其颗粒形貌、淀粉-碘复合物性质、ATP指标及透明度性质进行观察研究。结果表明,不同直链淀粉含量的大米淀粉颗粒形貌差异不大,均呈现不规则多边形,表面不光滑;随着直链淀粉含量的增加,淀粉颗粒的平均链长和聚合度不断增大,优糯3号淀粉颗粒内部短链数量较多,随着直链淀粉含量的增加淀粉颗粒内部的长短链比率逐渐趋近于1;淀粉糊的质构性质测定显示出淀粉糊的硬度、胶着性和咀嚼性随着直链淀粉含量的增加呈现出明显的上升趋势,弹性随着直链淀粉含量的增加变化不大,而凝胶的粘聚性明显下降;糊透明度随直链淀粉含量的增大而不断降低。      

不同直链淀粉含量玉米淀粉研究进展

该文综述不同直链淀粉含量玉米淀粉的颗粒特性、淀粉糊性质及消化性差别,并简要分析引起这些差别原因;为今后玉米淀粉生产应用提供一定理论依据。     

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。     

损伤淀粉含量对米粉理化性质的影响

采用不同粉碎方法得到损伤淀粉含量不同的米粉,研究了损伤淀粉含量对米粉性质的影响。结果表明随着损伤淀粉含量的增加,米粉的总直链淀粉没有明显差异,可溶性直链淀粉和溶解度显著升高,溶胀度变化不大而透明度则显著降低。快速黏度分析(RVA)表明糊化温度由89.2℃降低到86.2℃,回生值由89.58 RVU降低到59.33 RVU,峰值黏度由139.29 RVU降低到85.08 RVU,谷值黏度由103.67 RVU降低到49.04 RVU,末值黏度由180.67 RVU降低到108.38 RVU。损伤淀粉含量9.05%米粉的衰减值最低。糊化后米粉凝胶的硬度和弹性显著降低。     

湿热处理制备豌豆抗性淀粉及其性质的研究

选用豌豆淀粉为原料,采用湿热处理制备抗性淀粉,用扫描电镜（SEM）、差示扫描量热仪（DSC）、X-射线衍射仪、红外光谱仪、Brabender粘度仪和In vitro体外消化模型研究了抗性淀粉的颗粒形貌、热力学性质、结晶结构、粘度性质和体外消化性质。结果表明,当湿热水分为35%,130℃处理12h时其抗性淀粉含量达到最大值26.36%;湿热处理后豌豆淀粉的糊化温度升高,糊化焓降低;豌豆淀粉仍保持颗粒形状,部分颗粒表面产生裂痕;豌豆淀粉的晶型均由原来的C型变为A型,其相对结晶度增加5.26%¹6.16%;随湿热处理温度的升高,豌豆淀粉的溶解度和膨胀度均增加;随抗性淀粉含量的升高,溶胀度出现先增加再降低的趋势。      

直链淀粉含量对淀粉-脂肪酸复合物形成及理化特性的影响

本研究以不同直支比的玉米淀粉和硬脂酸为原料制备了三种不同的淀粉-脂质复合物,并采用扫描电镜、X射线衍射、傅里叶红外光谱等分析方法对淀粉-脂质复合物外部形态、晶体结构、抗消化性、缓释性等进行了表征与测定。结果表明:在扫描电镜下观察,与原淀粉相比,复合物的体积增大,同时表面凹凸不平。红外光谱证明淀粉-脂质复合物的形成,同时氢键的增加可能会导致抗性淀粉含量增加。复合物的形成使得晶体构象变为V型结构。普通玉米淀粉（normal）及高直链玉米淀粉（G60）在处理后快消化淀粉（RDS）含量减少,慢消化淀粉（SDS）含量增加,抗性淀粉（RS）含量增加,其中抗性淀粉含量分别达到52.0%和52.4%。硬脂酸在复合物内的释放分为两个阶段呈现先快后慢的趋势,并且直链淀粉含量的增加能够显著提高复合物对于硬脂酸的缓释能力。本文可为进一步提高直链淀粉的应用范围提供参考依据。     

直链淀粉含量对抗性淀粉形成的影响

考察不同直链淀粉含量的高直链玉米淀粉形成抗性淀粉的能力。结果表明:随着直链淀粉含量的增加抗性淀粉含量增大,最高可达20.74%,普通玉米淀粉的抗性淀粉得率仅为9.09%。     

盐对不同直链含量玉米淀粉理化特性及流变学特性的影响

分析了盐对不同直链含量玉米淀粉的理化特性及流变学特性的影响。结果表明,盐抑制了淀粉颗粒的膨胀,盐浓度越大,抑制作用越强。盐质量浓度为0 g/100 mL的蜡质淀粉和普通淀粉膨胀势在65℃到75℃迅速增加,2.0 g/100 mL时膨胀势在75℃到85℃迅速增加且幅度最小。蜡质淀粉和普通淀粉DSC图谱呈G峰和M2峰,高直链淀粉呈G峰。盐提高了凝胶化起始温度,蜡质淀粉从50.1℃增加到90.2℃,普通淀粉从56.6℃增加到99.6℃,高直链淀粉从98.8℃增加到105.7℃。盐也抑制了淀粉的糊化进程,盐浓度越大,糊化温度越高。普通淀粉的储存模量G',损耗模量G"和表观黏度η大于蜡质淀粉。普通淀粉和蜡质淀粉在低盐浓度(0.6g/100 mL)下的G'、G"和η值均大于高盐浓度(2.0 g/100 mL)。     

Heat-moisture treatment effects on sweetpotato starches differing in amylose content

Sweetpotato starch from two genotypes, Taiwan (15.2% amylose) and 93-006 (28.5% amylose), were exposed to heat-moisture treatment (HMT) of 25% moisture at 110°C for various exposure times at ‘as-is’ (pH 6.5–6.7) and alkaline pH (pH 10) conditions. In both starch samples at ‘as-is’ pH, there was a shift from a Type A pasting profile (characterized by a high to moderate pasting peak, major breakdown after holding time at 95°C and low cold paste viscosity) to a Type C pasting profile (characterized by lack of a pasting peak and no breakdown, with high cold paste viscosity in 93-006; and a slight breakdown in Taiwan). With HMT at pH 10, the pasting peak viscosity was increased and low hot paste viscosities and high cold paste viscosities were observed. Under both pH conditions after HMT, there were marked increases in gelatinization temperatures and broadening of the DSC gelatinization endotherms, and considerable decreases in swelling volume and solubilities. Gel textures of HMT starch samples appeared to be related to amylose content. Taiwan starch gel had a marked increase in hardness and adhesiveness, while that of 93-006 did not show significant differences in hardness after HMT. Both starch samples showed a marked reduction in resilience, indicating a shift from a long stringy nature to short paste consistency. Starch gels exposed to HMT under alkaline conditions showed a high degree of syneresis.     

不同直链淀粉含量大米淀粉性质的研究

以4种不同直链淀粉含量的米淀粉为原料,采用扫描电镜(SEM)、全波长自动扫描仪,质构仪等对其颗粒形貌、淀粉-碘复合物性质、ATP指标及透明度性质进行观察研究。结果表明,不同直链淀粉含量的大米淀粉颗粒形貌差异不大,均呈现不规则多边形,表面不光滑;随着直链淀粉含量的增加,淀粉颗粒的平均链长和聚合度不断增大,优糯3号淀粉颗粒内部短链数量较多,随着直链淀粉含量的增加淀粉颗粒内部的长短链比率逐渐趋近于1;淀粉糊的质构性质测定显示出淀粉糊的硬度、胶着性和咀嚼性随着直链淀粉含量的增加呈现出明显的上升趋势,弹性随着直链淀粉含量的增加变化不大,而凝胶的粘聚性明显下降;糊透明度随直链淀粉含量的增大而不断降低。     

Effect of annealing on the structure and physicochemical properties of barley starches of varying amylose content

Starch from normal (CDC McGwire, SR 93102), waxy (CDC Fibar, HB 364), and High amylose (SB 94897, SB 94893) hull-less barley cultivars was isolated and its structure, morphology, and properties were studied before and after one-step annealing (50 °C for 72 h at a moisture content of 75%). The amylopectin structure of all starches was nearly identical. The X-ray pattern of CDC Fibar, HB 364, and CDC McGwire starches was of the ‘A’-type. Whereas, SR 93102, SB 94897, and SB 94893 starches exhibited a mixed ‘A + B’-type pattern. The relative crystallinity (RC), swelling factor (SF), amylose leaching (AML), gelatinization temperature range (GTR), enthalpy of gelatinization (ΔH), amylose–lipid complex melting temperature (Tp_CX) and the enthalpy of melting of the amylose–lipid complex (ΔH_CX) ranged from, 37.0% to 44.3%, 41.0–54.2% (at 90 °C), 4.0–31.0% (at 90 °C), 11.4–22.5 °C, 6.0–13.0 J/g, 84.9–89.1 °C and 0.4–1.8 J/g, respectively. The RC of CDC Fibar, HB 364, SR 93102 and CDC McGwire starches increased on annealing. Whereas, it remained unchanged in SB 94897 and SB 94893 starches. The ‘A’-type X-ray pattern of CDC Fibar, HB 364, and CDC McGwire starches remained unchanged on annealing. However, the ‘A + B’-type X-ray pattern of SR 93102, SB 94897 and SB 94893 starches resembled more closely the ‘A’-type pattern on annealing. In all starches, the X-ray intensity of the V-amylose–lipid complex peak increased on annealing. Annealing increased the gelatinization transition temperatures and decreased the GTR in all starches. The ΔH of SB 94893 starch increased on annealing, whereas it remained unchanged in the other starches. Tp_CX of SR 93102 and SB 94897 remained unchanged on annealing, whereas Tp_CX of CDC McGwire increased slightly. ΔH_CX of native and annealed CDC McGwire, SR 93102 and SB 94897 were similar. Tp_CX and ΔH_CX were not detectable in annealed SB 94893 starch. In all starches, SF decreased on annealing. Annealing decreased AML in SR 93102, SB 94897 and SB 94893 starches in the temperature range of 50–90 °C, but increased AML in HB 364 and CDC McGwire starches at higher temperatures. The effect of annealing on acid hydrolysis was marginal.     

Influence of acid hydrolysis on thermal and rheological properties of amaranth starches varying in amylose content

BACKGROUND: The granules of amaranth starch are very small compared with starches from other sources. In the current work, amaranth starches with different amylose contents were treated with hydrochloric acid as a function of time in order to study the effect of acid treatments on starches. Differential scanning calorimetry and dynamic oscillation in shear were employed to analyse the thermal and rheological properties of acid‐modified amaranth starch. RESULTS: Results showed that gelatinisation temperatures and enthalpy change of gelatinisation (ΔH) decreased steeply initially, and had a slight increase with further treatment up to 12 h then decreased, an outcome that reflected distinct resistance to acid with various amylose contents. Rheological parameters of storage and loss moduli during heating, cooling and frequency sweep of modified starches reflected the differential scanning calorimetry results by decreasing in value as the time of acid hydrolysis increased. CONCLUSION: With amylose content increase, the effects of acid hydrolysis on gelatinisation temperatures became less pronounced. Nevertheless, prolonged acid hydrolysis decreased the storage and loss moduli, with the starch pastes becoming more liquid‐like. Copyright © 2012 Society of Chemical Industry     

不同链淀粉含量玉米微晶淀粉理化性质研究

分别以蜡质玉米淀粉、玉米淀粉及高直链玉米淀粉为原料,在酸醇介质中制备不同水解率微晶淀粉,测定不同微晶淀粉水解性能并研究其颗粒形貌、结晶结构、溶解度及消化性。结果表明:淀粉颗粒内部结构致密性依次减弱,支链淀粉含量高的淀粉较易被试剂进攻;经酸醇处理后,三种微晶淀粉均保留原来晶型,颗粒形态没明显变化,没破碎和膨胀出现,但颗粒表面变粗糙;随直链淀粉含量增加,相似条件(水解率和温度)淀粉溶解度逐渐降低;in-vitro消化体系中三种淀粉及其微晶淀粉消化速度依次降低。     

Dielectric barrier discharge and radio-frequency plasma effect on structural properties of starches with different amylose content

The effect of the dielectric barrier discharge atmospheric (DBD) and radio-frequency (RF) cold plasma treatment on the morphology, helical order, and structural stability of starches with different amylose content (30, 50, & 70%) was investigated. The cavities formed after RF plasma treatment allowed the active species to modify the internal structure of the granule, probably reaching its center and expanding to the periphery, where the amorphous regions were damaged and gradually removed by the treatment, increasing the amylose helix order and thermal stability of starch molecule as suggested by the SEM, FTIR, DSC, and TGA analysis. In contrast, DBD treatment promoted a thicker coating deposition and HMDSO functional groups inclusion, which increased both the granular interaction and the decomposition temperature. Overall, active species of HMDSO plasma generated in RF and DBD reactors modified mainly the amylose chains in a distinctive way, favoring the ordering or stability of starch molecules, respectively. These findings could be useful when looking for potential applications in the food industry or in other fields like semiconductors.Industrial relevanceAtmospheric pressure dielectric barrier discharge (DBD) and radio-frequency (RF) plasma are sustainable and quick methods to modify the structural properties of corn starch. After short-time treatments (10 min) both reactors change the granule surface (HMDSO coating and holes), which resulted in structural changes at different extent, such as increase of helical order and high thermal stability.These results showed that the DBD and RF treatments are suitable methods to obtain starches with high resistance to gelatinization (≈91 °C), especially those with high amylose content; however, due to their distinctive properties, they could have different end uses. DBD treated starch with HMDSO chemical group incorporation could be used in the paper, packaging, and electronic industry.Although HMDSO plasma is not yet approved for food industry, the results of FTIR confirmed that RF plasma treatment does not incorporate new elements in the starch molecules but only promoted interactions between them. Therefore, HDMSO plasma treatment could be considered as a safe and chemical-residue free technique useful to modify starches, which can be explored in food matrices development. Furthermore, they could be employed in an industrial food process that involves the use of high temperature.     

Gel texture and rheological properties of normal amylose and waxy potato starch blends with rice starches differing in amylose content

This study characterised the textural and rheological behaviour of blends of rice (waxy, low- and high-amylose) and potato (waxy and normal) starch. Blends of potato starch with rice starch in the ratios of 100:0, 80:20, 60:40, 40:60, 20:80 and 0:100 were tested. Addition of rice starch (except high-amylose rice starch) greatly increased the swelling of rice–potato starch mixtures. Addition of rice starch decreased gel firmness for most starch mixtures and increased gel adhesiveness for blends containing waxy potato starch. For rheological measurements, storage modulus was much higher than loss modulus of blends, indicating solid-like behaviour. Starch blends with 20%/40% proportion of rice starch showed a greater thickening effect, whereas with further increase in rice starch proportion, a pseudoplastic, shear-thinning behaviour was observed. This study may provide a basis to develop blends of potato and rice starch for potato noodle production without use of chemical additives.     

Effect of heat-moisture treatment on rice starch of varying amylose content

The effect of heat-moisture treatment (HMT) on the properties of rice starches with high-, medium- and low-amylose content was investigated. The starches were adjusted to 15%, 20% and 25% moisture levels, and heated at 110 °C for 1 h. The swelling power, solubility, pasting properties, morphology, enzymatic susceptibility and X-ray crystallinity of the starches were evaluated. HMT reduced the swelling power and solubility of the starches. The strongest effect of HMT occurred on the high-amylose starch; the pasting temperature was increased and the peak viscosity, breakdown, final viscosity and the setback were reduced. HMT increased the starch’s susceptibility to α-amylase and promoted a reduction in the starch relative crystallinity.