共查询到20条相似文献，搜索用时 15 毫秒
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Corn starch and starches separated from different potato cultivars were acetylated to evaluate the effect of plant source on the physicochemical, morphological, thermal, rheological, textural and retrogradation properties of the starches. Corn starch showed a lower degree of acetylation than potato starches under similar experimental conditions. The degree of acetylation for different potato starches also differed significantly. Morphological examination revealed that the granules of acetylated Kufri Chandermukhi and Kufri Sindhuri starches tended to appear as fused and less smooth than native starch granules. Acetylation of corn and potato starches decreased the transition temperatures and enthalpy of gelatinization and increased swelling power and light transmittance. However, the change in these was greater in the potato starches with higher percentage of small sized granules. Acetylated starches showed higher peak G', G'' and lower tan δ than their counterpart native starches during heating. Among the starches from different cultivars, the change in the rheological parameters after acetylation differed to a significant extent. The retrogradation was observed to be negligible in the acetylated cooked starch pastes. Results implied that the change in functional properties of starches with acetylation depends on source and granule morphology of native starch. 相似文献
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从河北省玉米主栽品种中选取15个玉米品种作为供试材料,对玉米粉的白度、色差、蛋白质含量、脂肪含量、淀粉含量及玉米淀粉透明度、持水率、溶解度与膨胀势、冻融稳定性、凝沉性、糊化特性、凝胶质构以及微观结构进行系统研究。结果表明,不同玉米品种理化性质及淀粉品质间差异显著,并对淀粉品质测定结果进行分析,将所选的15种玉米根据类别分为糯玉米和普通玉米两大类,然后对普通玉米品种进行聚类分析,在平方Euclidean距离为10处,可将14种普通玉米根据淀粉性质分为3类,因此可根据不同加工目的选择不同类型的玉米品种。 相似文献
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Zormy Correa Alejandro Zúiga Carolina Garfias Luis Arturo Bello‐Prez 《Starch - St?rke》2013,65(11-12):991-998
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Babak Ghanbarzadeh Hadi Almasi Ali A. Entezami 《Innovative Food Science and Emerging Technologies》2010,11(4):697-702
Novel modified starch/carboxy methyl cellulose (CMC) composite films were prepared by a casting method. The effects of CMC addition on the some physical properties of the resulted blend films were investigated. The blend film composed of 15% W/W CMC /starch, showed the lowest water vapor permeability (WVP) value (2.34 × 10−7 g/m.h.Pa).The moisture absorption and solubility in water properties of the blend films exhibited similar trends. The addition of CMC at the level of 20% W/W starch caused an increase in the ultimate tensile strength (UTS) by more than 59% in comparison to the pure starch film without any significant decrease in the strain to break (SB). The measurement of color values showed that by the increasing of the CMC content in polymer matrix, the b values (yellowness), YI and ∆E of the blend films decreased and the L values (Lightness) and WI index increased.
Industrial relevance
Ecological concerns have resulted in a renewed interest in natural and compostable materials, and therefore issues such as biodegradability and environmental safety are becoming important. Tailoring new products within a perspective of sustainable development or eco-design, is a philosophy that is applied to more and more materials. It is the reason why material components such as natural fibres, biodegradable polymers can be considered as interesting – environmentally safe – alternatives for the development of new biodegradable composites.Development of biodegradable materials based on starch has become a very attractive option and production of starch based plastic are gradually obtained considerable concern in the world.In this research, improvement of starch film properties is investigated. 相似文献7.
目的 确定玉米淀粉/卡拉胶/甘油复合膜的最佳成膜工艺.方法 以玉米淀粉为基材,与卡拉胶和甘油共混,通过流延法制备复合膜,以薄膜的机械性能为评价指标,通过单因素实验及正交实验来确定最佳成膜工艺.结果 正交实验结果表明当玉米淀粉添加量为3％、卡拉胶添加量为30％、甘油添加量为25％时,玉米淀粉薄膜的机械性能最佳.结论 本研... 相似文献
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Acetylated starches are a commercially important group of modified starch known for their reduced retrogradation tendency, high clarity, low viscosity, high swelling power, and lower gelatinization temperature and time. Due to these remarkable properties, acetylation is a commonly used chemical modification for preparing stabilized starches. This review summarizes the methods used for preparation of starch acetates and corresponding effects of acetylation on morphological, thermal, pasting, digestibility, textural, and other functional characteristics of starches isolated from various botanical sources. Starch acetates are also useful as packaging material, as wall material for encapsulating active ingredients, and to improve the storage stability of different products. 相似文献
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Physical aging of glassy corn starch and its effect on the physical properties of compressed starch bars were investigated by using differential scanning calorimetry (DSC), dynamic mechanical thermal analyzer (DMTA), and Instron texturometer. Amorphous corn starch samples were prepared by drying a starch paste, followed by compressing the dried powders to bar‐type specimens under heat (100°C, 1.38×107 Pa). These bars were then aged at 25°C for up to 22 days, after which thermal and mechanical characteristics were determined. There were progressive increases in glass transition temperature and relaxation enthalpy during the aging, which reached limiting values as structural equilibrium of the amorphous matrix was approached. The peak temperature of the relaxation endotherm (DSC thermogram) changed with time in a trend similar to the relaxation enthalpy. The storage modulus (DMTA) increased with aging time, but the peak intensity of tan δ decreased. The breaking strength (Instron texturometer) increased gradually with time of aging and reached a maximum. It has been demonstrated the relaxation kinetics for glassy amorphous corn starch can be characterized by both thermal and mechanical properties, such as relaxation enthalpy, storage modulus, and breaking strength. 相似文献
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Fernanda H. Weber Maria Teresa P. S. Clerici Fernanda P. Collares‐Queiroz Yoon K. Chang 《Starch - St?rke》2009,61(1):28-34
The objectives of the present study were to analyze the chemical interactions between guar and xanthan gums and starches. Gels were obtained from normal (NCS), waxy (WCS) and high‐amylose (HACS) corn starches containing gums. The gels were evaluated according to their pasting properties and infra‐red absorption. The guar (GG) and xanthan (XG) gums affected the properties of the NCS paste more significantly than those of the WCS paste. In the infra‐red absorption spectra, no covalent bonds between the starches and gums were observed under the conditions studied, so probably the only interactions occurring between them were hydrogen bonds. 相似文献
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Biodegradable flexible films were developed from corn starch (CS) and chitosan (CH); their microstructure, mechanical and barrier properties were evaluated. Chitosan and starch blend filmogenic suspensions showed a pseudoplastic behavior, similar to that of chitosan solutions. Smooth surfaces, homogeneous and compact film structures were observed from microstructure studies using scanning electron microscopy (SEM). The addition of glycerol reduced film opacity and increased film solubility of both CS and composite CS‐CH films. Water vapor permeability values of composite CS‐CH films plasticized with glycerol ranged between 3.76 and 4.54× 10−11 g s−1 m−1 Pa−1, lower than those of the single component films. CS‐CH films were resistant and their flexibility increased with glycerol addition. Tensile strength values of CS‐CH films were comparable to those of low‐density and high‐density polyethylenes but lower than that obtained for cellophane, however, composite biodegradable films showed lower elongation at break values than the synthetic commercial ones. In conclusion, CS‐CH films can be described as biofilms with a homogeneous matrix, stable structure and interesting water barrier and mechanical properties, with great possibilities of utilization, and with the advantage of biodegradability. 相似文献
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Mahsa Majzoobi Zahra Kaveh Asgar Farahnaky Christopher L. Blanchard 《Starch - St?rke》2015,67(3-4):303-310
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Corn starch with 15–40% moisture was irradiated at 0.17 or 0.5 W/g for 1 h using the sophisticated Ethos 1600 microwave apparatus that accurately controls temperature and wattage. Temperature of irradiated starch was measured during microwaving. Thermal and pasting properties were studied on dehydrated starch after microwave irradiation. Temperature increases were greatest during the first 10 min for starch at all moisture contents at both microwave power levels. Starch irradiated at 0.17 W/g had a temperature below onset gelatinization temperature (To) after 1 h. Higher temperatures were observed for starch with higher moisture content and microwaved at 0.5 W/g. Compared to native starch, starch with 15–40% moisture had higher To (measured using differential scanning calorimetry) and with 35–40% moisture had higher peak gelatinization temperature and lower enthalpy change of gelatinization. All paste viscosity parameters measured by the Rapid Visco Analyser were reduced and pasting temperature was elevated for starch irradiated at 0.5 W/g compared to native starch. 相似文献
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乙酰化香蕉淀粉的特性 总被引：1，自引：1，他引：1
通过与玉米淀粉比较,乙酰化香蕉淀粉的灰分、蛋白质、脂肪含量均比乙酰化玉米淀粉高.乙酰化香蕉淀粉糊的透明率在低温下出现较小的退化趋势,但常温下淀粉糊的透明率较高且有较好的稳定性.在较高温度下,乙酰化香蕉淀粉的持水能力比原淀粉高.乙酰化作用增加淀粉的溶解度和膨胀率.乙酰化作用也增加了香蕉淀粉糊的粘度值. 相似文献
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Determination of some chemical and physical properties of Sakız faba bean (Vicia faba L. Var. major)
《Journal of food engineering》2003,60(4):475-479
In this study, some chemical and physical properties of faba bean (Vicia faba L. Var. major) grown up in Antalya region have been determined. Chemical properties such as dry matter, total energy, crude protein, crude cellulose, crude oil, mineral elements––Ca, P, K, Na, S, Al, Ba––and physical properties such as dimensions, weight, thickness, geometric mean diameter, sphericity, bulk density, volume, porosity, projected area, 1000 grain mass, terminal velocity and the rupture strength of grains involved in the study.
The total energy, crude protein, crude cellulose and crude oil contents (as percentage in dry matter) of faba bean are found as 18.87 MJ/kg, 29.63%, 6.39% and 1.06% respectively, and all elements determined in the research are listed in the text. The values of length, width, thickness, weight, geometric mean diameter and sphericity of faba bean are determined as 20.39, 14.54, 7.86 mm, 1.31 g, 13.25 mm and 0.651 for 10.90% moisture content, respectively. In the some moisture content, projected area, volume, 1000 grain mass, bulk density, kernel density, porosity and terminal velocity were measured as 2.79 cm2, 1210 mm3, 1349.34 g, 608.17 kg/m3, 1248 kg/m3, 51.48%, 4.94 m/s respectively. In addition, the rupture strength values of faba bean grains were varied between 310.83 and 542.38 N. 相似文献
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Refined field pea (Pisum sativum L.) starches were prepared from air‐classified pea starch by washing or from whole pea by wet milling, and analyzed for their physicochemical and pasting characteristics in the presence of alkali and borax. Commercial corn and high amylose corn starches were included in the study for comparative purposes. The two pea starches exhibited similar physicochemical characteristics. Amylose content markedly influenced pasting and other characteristics of the corn starches. Pea starch and high amylose corn starch exhibited little viscosity development during pasting in deionized water. The presence of alkali or borax significantly altered the peak viscosities and cold paste stabilities of all four starches in a concentration dependent manner. Alkali and borax increased peak and cold paste viscosity and reduced syneresis in all cases. 相似文献