粳性和糯性糜子淀粉的理化性质

为揭示粳性、糯性糜子淀粉的理化特性及其差异,本文选用2个粳性糜子、2个糯性糜子品种为试验材料,以玉米淀粉、马铃薯淀粉为对照,研究比较了其淀粉的颗粒形态与大小、晶体结构、直链淀粉含量、透明度、冻融稳定性等理化性质。结果表明：粳性、糯性糜子淀粉颗粒形态均呈棱角圆滑的多面体形或球形,平均粒径分别为7.18 μm、6.04 μm,结晶构型均为A型;粳性糜子淀粉直链淀粉含量、冻融析水率高于糯性糜子淀粉,而透光率较低;粳性、糯性糜子淀粉的溶解度与膨胀度均随温度升高而增大,前者的溶解度、膨胀度较低;粳性糜子淀粉破损值低,热糊稳定性好,而糯性糜子淀粉的回生值低,冷糊稳定性好。因此,糜子淀粉可作为一种新型的淀粉资源应用于不同领域。     

小米淀粉与玉米淀粉糊性质比较研究

对小米淀粉和玉米淀粉糊性质进行较详细比较研究,包括透明度、冻融稳定性、凝沉性、膨胀力、酸解、酶解,和介质对糊粘度性质影响。结果表明,小米淀粉与玉米淀粉相比,糊的凝胶稳定性好、持水力强、膨胀力高、糊化温度高、热焓变值大、但透明度较差、冻融稳定性不佳、热稳定性差;且氯化钠及糖溶液对小米淀粉糊粘度性质影响较大。     

Granular Structure and Physicochemical Properties of Starches from Amaranth Grain

The granular structure and physicochemical properties of starches isolated from grain amaranth cultivar K112 (Amaranthus cruentus L.) were studied in this study. Detailed physical and chemical analyses were performed by determining the granular morphology, crystallinity, particle size, thermal characteristics, blue value, enzyme susceptibility, and pasting properties. Results showed polygon-shaped A. cruentus L. K112 starch granules. The average diameter was 1.38 μm, in which half of the diameter was <2.91 μm. An A-type X-ray diffraction pattern was revealed with intense peaks of 15.2°, 17.5°, and 23.2°. The peak viscosity was 181 BU and the breakdown value was 2 BU. Amaranth starch obtained the highest pasting temperature (70.7°C) and enzymatic digestibility (absorbance value = 0.41 ± 0.013) compared with corn, cassava, and sweet potato starches.     

Gelatinization and Pasting Properties of Waxy and Non‐waxy Rice Starches

Gelatinization and pasting properties of diverse rice types grown in two locations were examined by differential scanning calorimetry (DSC) and rotational rheometry, respectively. The data were compared to previously reported molecular starch properties for these samples: specifically, amylose content, starch molecular weight (M_w), and amylopectin side‐chain‐length distributions. Significant correlations were observed between amylose content, starch M_w, and the weight degree of polymerization of the long side chains of amylopectin F₁(DP_w) and many of the gelatinization and pasting properties measured. Higher amylose content corresponded with increased gelatinization onset (T_o) and peak temperatures (T_p), pasting onset and peak temperatures, and decreased peak and trough viscosity. Starch M_w correlated negatively with T_o, T_p, pasting onset, and peak temperature and positively with peak, trough, final, and breakdown viscosity. Amylopectin with DP_w 59‐78 of F₁(DP_w) correlated with increased T_o, T_p, pasting onset and peak temperature, and decreased peak, trough, final and breakdown viscosity. Pasting properties were also somewhat related to DP_w 21 of shorter side chains of amylopectin (F₂(DP_w)). Significant correlations between F₂(DP_w) and peak, final, and breakdown viscosity were observed (r = −0.447*, −0.391*, −0.388*, peak, final, and breakdown viscosity, respectively).     

不同品种小米淀粉理化性质的比较研究

以碱法提取的10种小米淀粉为原料,通过与玉米和马铃薯淀粉对比,对其理化性质进行研究,旨在为小米及其淀粉的深加工利用提供参考。结果表明,小米淀粉的直链淀粉含量在19．77％-35．69％之间,品种之间存在显著性差异;溶解度显著低于马铃薯及玉米淀粉,其中九谷11号的溶解度最高;膨胀度在12．43％-18．77％之间,介于马铃薯淀粉和玉米淀粉之间;透明度显著低于马铃薯淀粉,品种之间存在显著性差异;冻融稳定性显著优于玉米淀粉,比马铃薯淀粉差;凝沉性试验表明其稳定性显著优于玉米淀粉。     

糜黍淀粉理化性质及消化特性

以黍子面和糜子面为原料,用碱法制备黍子淀粉和糜子淀粉,对其颗粒形态、红外光谱特性、透光率、溶解度、持水力、凝沉稳定性以及消化性等性质进行研究。结果表明：黍子淀粉中支链淀粉含量为91.78%,直链淀粉含量为8.21%;糜子淀粉中支链淀粉含量为65.28%,直链淀粉含量为34.72%。糜子面粉、黍子面粉及其淀粉中的抗性淀粉含量均超过50%,糜子面和糜子淀粉中的抗性淀粉含量均分别高于黍子面和黍子淀粉。黍子淀粉的透光率高于糜子淀粉。糜子淀粉凝沉稳定性强于黍子淀粉。糜子淀粉和黍子淀粉的溶解度、持水力随温度的升高,呈现上升趋势。     

Pasting Properties of Potato Starch and Waxy Maize Starch Mixtures

The pasting viscosity, morphological properties, and swelling properties of potato starch and waxy maize starch mixtures at different ratios were investigated. Pasting analysis of the starch mixtures (7% solids in water, w/w) using a Rapid Visco Analyser showed linear changes in peak viscosity and pasting temperature according to the mixing ratios of both starches, but not in breakdown and setback. The pasting profile revealed that the starches rendered mutual effects during pasting, more significantly when the amounts of potato and waxy maize starches were similar. The volume fraction of swollen granules and the presence of amylose appeared to be important parameters in the mutual effects of both starched during pasting. Under a light microscope, the swelling of potato starch granules was delayed by the presence of waxy maize starch. Overall results indicate that new pasting properties can be generated by mixing starches of different botanical sources.     

龙爪粟淀粉的提取及理化特性研究

以龙爪粟为原料,利用Box-Benhnken中心组合实验和响应面分析法,对龙爪粟淀粉的提取效果进行比较分析,并进一步通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)和差示扫描量热仪(DSC)等对龙爪粟淀粉的结构和特性进行研究。结果表明:龙爪粟淀粉提取的最佳工艺参数为料液比1∶6,酶解温度51.55℃,酶解时间4.23 h,pH 9.99,此条件下龙爪粟淀粉提取率为76.41%。龙爪粟淀粉颗粒较玉米淀粉小,平均粒径为7.7μm,属于C型淀粉晶型;其溶解度与膨胀度随温度的升高而增大,属于典型的二度膨胀淀粉;凝沉性及冻融稳定性较玉米淀粉差;龙爪粟淀粉的糊化起始温度及糊化焓变均显著高于玉米淀粉。     

我国不同地区特色品种小米淀粉性质

选取10 个不同地区、品种的特色小米作为研究对象,采用0.2 g/100 mL的NaOH溶液与1 g/100 mL的十二烷基硫酸钠溶液复合法提取小米淀粉,并对其基本成分、颗粒形态、黏度、透光率、溶解度和膨胀度等进行研究。结果表明：小米淀粉的直链淀粉含量为12.10%,平均粒径为6.49 μm,糊化温度为68.9～72.3 ℃。不同地区、品种的小米淀粉的直链淀粉、溶解度、峰值黏度、崩解值和老化值存在较大差异。     

山西不同品种谷子淀粉的理化特性研究

从谷子主产区山西省选取8个具有代表性的谷子栽培品种作为供试材料,分析研究了其淀粉的颗粒形态及粒径大小、直链淀粉含量、碘蓝值与淀粉糊的透光率、冻融稳定性、糊化特性、溶解度与膨胀度及凝沉特性等理化性状。结果表明：小米淀粉颗粒均为单粒,外形规整,多数为多角形,少数为卵圆形,具有清晰可见的偏光十字,不同品种间淀粉颗粒形态差异明显。小米淀粉小颗粒的粒径为0.42~2.25 μm,大颗粒的粒径为3.42~29.26 μm,小米淀粉的粒径分布特征呈现出“三峰”型。8个品种的直链淀粉含量变幅为2.22~17.96%,碘蓝值变幅为0.586~0.872,透光率变幅为2.4~29.2%,析水率变幅为3.67~49.85%,糊化温度变幅为67.6~78.8 ℃,各品种间具有显著差异。此外,各品种淀粉的糊化特性、溶解度、膨胀势及淀粉糊的凝沉特性也有着明显的差异。因此,应根据不同的加工目的采用相适宜的品种。     

荞麦、糜子与玉米淀粉理化性质比较研究

为阐明荞麦、糜子淀粉与生产常用玉米淀粉理化性质差异,以荞麦、糜子和玉米籽粒为原料,采用碱提法提取淀粉,比较研究电子显微镜(SEM)和X-射线衍射仪测定的淀粉颗粒结构,快速黏度测定仪(RVA)测定的糊化特性,差示热量扫描仪(DSC)测定的热特性,以及透明度和凝沉性。结果表明,荞麦淀粉颗粒为不规则多角形或球形,有微孔,粒径为3.5~12.6μm;糜子淀粉颗粒为多角形,表面塌陷,粒径为1.8~10.5μm。3种淀粉X-衍射图谱均属于A型。淀粉糊凝沉速度玉米荞麦糜子。荞麦淀粉峰值黏度和最终黏度最大,为1 692和2 265 cP,显著高于糜子、玉米淀粉(P0.05);糜子淀粉谷值黏度和回生值最小,为760和160 cP,显著低于荞麦、玉米淀粉(P0.05)。荞麦淀粉相变起始温度(T,)、峰值温度(T_p)、终止温度(T_c)为62.7、66.7和71.9℃,显著低于糜子、玉米淀粉(P0.05);荞麦、糜子淀粉热焓值(AH)分别为7.9和7.5 J/g,显著低于玉米淀粉(P0.05)。     

Structural and Physical Properties of Starches Isolated from Six Varieties of Millet Grown in China

This study investigated the structural and physical properties of starches extracted from six varieties of millet mainly grown in China. The amylose content of millet starches ranged from 17.6 to 28.4 g/100 g (dry weight basis, db), and a variety of waxy proso millet starch (0.38 g/100 g, db) was identified. These starches exhibited a majority of large polygonal granules with several indentations, few small spherical granules, and A-type crystallinity. Proso millet starch showed prominent paste clarity and freeze-thaw stability, whereas finger millet starch exhibited the highest solubility. Moreover, barnyard millet starch had the lowest sediment volume. The gelatinization enthalpy of proso millet starch was the highest (5.16 J/g). For non-waxy millet starch, the ratio of retrogradation (R%) was positively correlated with amylose content. Among all starches, the storage modulus (G′) was higher than the loss modulus (G″) during heating and cooling. The G′ and G″ of proso millet starch and barnyard millet starch pastes were significantly lower than other starches during cooling. The pasting properties of six millet starches significantly differed, had positive correlation with amylose content, and were affected by NaCl, sucrose, and pH values.     

高粱淀粉的研究进展

高粱是一种重要的杂粮作物,由于食用口感差,不易消化,主要用于酿酒、制糖及饲料。近年来,随着高粱品种的优化与改良,高粱的营养价值进一步改善,其应用价值也得到逐步的提高,但我国对高粱的营养和加工研究很少。淀粉是高粱的主要组分,国外对高粱淀粉的理化特性、改性以及加工利用已有较多研究,本文综述了高粱淀粉的组成特点,提取方法及其影响因素,高粱淀粉的膨胀性、凝胶性、淀粉改性等功能特性,并介绍了高粱淀粉的消化性,在食品工业中的应用以及今后的发展趋势。为指导国内高粱作物的品种选育和合理加工利用提供一定的参考。     

Comparison of Endosperm Starch Granule Development and Physicochemical Properties of Starches from Waxy and Non-Waxy Wheat

Starch granule development and physicochemical properties of starches in waxy wheat and non-waxy wheat were investigated in this article. Starch granules in waxy wheat endosperm showed an early developmental process. Compared with non-waxy wheat starch granules (round-shaped), waxy wheat starch granules (ellipse-shaped) were larger and contained more B-type granules. According to the granule size, starch granules were divided into two groups in waxy wheat, but were divided into three groups in non-waxy wheat. Compared with non-waxy wheat starch, waxy wheat starch had higher swelling power, gelatinization temperatures (To, Tp, Tc), and relative degree of crystallinity. They showed similar ordered structures on external regions of starch granules. Additionally, waxy wheat starch had a higher proportion of double-helical components and a lower proportion of single-helical components than non-waxy wheat starch. Based on the previous results, it was concluded: (1) waxy wheat and non-waxy wheat not only differed in starch granule development, but also in physicochemical properties of starches; (2) waxy wheat had more potential value for producing traditional products than non-waxy wheat.     

Structure,Physicochemical Properties,Modifications, and Uses of Sorghum Starch

Sorghum has great drought resistance and can be cultivated on marginal lands with minimal input costs. Thus, the supply of sorghum starch, the major component of the seeds, can be cheap and sustainable. This review summarizes the present knowledge of extraction, composition, granular and molecular structures, physicochemical properties, modifications, and uses of sorghum starch, and provides suggestions for needed research to improve our understanding and utilization of this starch.     

Physicochemical Properties of Waxy and Normal Maize Starches Irradiated at Various pH and Salt Concentrations

Waxy and normal maize starches of various pH values and salt contents were prepared, irradiated with gamma rays (5–20 kGy) and their molecular structure, pasting viscosity and rheological properties determined. Average molar mass and size of both waxy and normal maize starches decreased considerably by irradiation from >338.0×10⁶ to <39.4×10⁶ g/mol and from >237.5 to <125.2 nm, respectively. Adjustments of pH had little influence on the average molar mass and size of irradiated starch, whereas incorporation of salt greatly reduced the molar mass and size of irradiated waxy and normal maize starches. As the pH increased from 4 to 8, the pasting viscosity of the irradiated starches decreased from 1032 to 279 mPa s in waxy and from 699 to 381 mPa s in normal starches. Pasting viscosity of both irradiated waxy and normal starch decreased from 689 to 358 mPa s and from 327 to 184 mPa s as the salt concentration increased from 1 to 5%. The G′ of gels, determined during cooling from 90 to 10°C or storage for 8 h, decreased in irradiated waxy and normal starches by pre‐conditioning at pH 8 and in irradiated waxy starches by pre‐conditioning at 5% NaCl. With 5% NaCl, G′ of irradiated normal maize starch during cooling increased up to the irradiation level of 10 kGy, and increased during storage for 8 h at all levels of irradiation. Incorporated salt prior to irradiation appears to induce incremental modifications in the molecular structure, rheological and retrogradation properties of starch by boosting the degradation of molecules.     

Development and Physicochemical Characterization of New Resistant Citrate Starch from Different Corn Starches

Resistant starch has drawn broad interest for both potential health benefits and functional properties. In this study, a technology was developed to increase resistant starch content of corn starch using esterification with citric acid at elevated temperature. Waxy corn, normal corn and high‐amylose corn starches were used as model starches. Citric acid (40% of starch dry weight) was reacted with corn starch at different temperatures (120–150°C) for different reaction times (3–9 h). The effect of reaction conditions on resistant starch content in the citrate corn starch was investigated. When conducting the reaction at 140°C for 7 h, the highest resistant starch content was found in waxy corn citrate starch (87.5%) with the highest degree of substitution (DS, 0.16) of all starches. High‐amylose corn starch had 86.4% resistant starch content and 0.14 DS, and normal corn starch had 78.8% resistant starch and 0.12 DS. The physicochemical properties of these citrate starches were characterized using various analytical techniques. In the presence of excess water upon heating, citrate starch made from waxy corn starch had no peak in the DSC thermogram, and small peaks were found for normal corn starch (0.4 J/g) and Hylon VII starch (3.0 J/g) in the thermograms. This indicates that citrate substitution changes granule properties. There are no retrogradation peaks in the thermograms when starch was reheated after 2 weeks storage at 5°C. All the citrate starches showed no peaks in RVA pasting curves, indicating citrate substitution changes the pasting properties of corn starch as well. Moreover, citrate starch from waxy corn is more thermally stable than the other citrate starches.