新型改性玉米淀粉粘合剂的研制

介绍一种以玉米淀粉为主要原料,经过改性制备瓦楞纸粘合剂的方法.该法制得的粘合剂性能好,成本低,使用操作方便,尤其适用小规模、单机生产.     

KPS引发淀粉接枝甲基丙烯酸二甲氨基乙酯的合成

以玉米淀粉为母体,过硫酸钾为引发剂,接枝共聚甲基丙烯酸二甲氨基乙酯,研究了不同条件对淀粉接枝甲基丙烯酸二甲氨基乙酯反应的影响,认为该反应体系的最佳反应条件为:DM浓度为0.35mol/L,引发剂浓度为6.5mmol/L,淀粉糊化温度为85℃,反应温度为65℃,pH为8左右,反应时间为3h。     

Effect of Turbulence on Flame Propagation in Comstarch Dust-Air Mixtures

Following the quantitative determination of dust cloud parameters, this study investigated the flame propagation through cornstarch dust clouds in a vertical duct of 780 mm height and 160×160 mm square cross section, and gave particular attention to the effect of turbulence on flame characteristics. The turbulence induced by dust dispersion process was measured using a particle image velocimetry (PIV) system. Upward propagating dust flames were visualized with direct light and shadow photography. The results show that a critical value of the turbulence intensity can be specified below which laminar flame propagation would be established. This transition condition is about 10 cm/s. The measured propagation speed of laminar flames appears to be in the range of 0.45-0.56 m/s, consistent with the measurements reported in the literature. For the present experimental conditions, the flame speed is little sensitive to the variations in dust concentration. Some information on the flame structure was revealed from the shadow records, showing the typical heterogeneous feature of dust combustion process.     

高流动性、强疏水性淀粉的制备及性能

采用干法改性处理技术对玉米淀粉进行改性处理,制备得到具有高流动性及强疏水性的玉米淀粉。通过活化指数、接触角、流动时间及休止角等指标,对改性前后玉米淀粉的流动性及疏水性进行评价。结果表明,经过改性处理,玉米淀粉由亲水性表面转变为强疏水性表面,并且改性后的玉米淀粉具有了良好的流动性。X射线衍射(XRD)测试结果表明,改性处理并没有改变玉米淀粉的结晶结构,只是改变玉米淀粉的表面性质。     

废纸浆增强玉米淀粉基复合材料的制备及其力学性能研究

以甘油和尿素作为混合塑化剂、废纸浆为增强体,玉米淀粉、聚乙烯醇为基体,利用熔融共混法制备了废纸浆增强玉米淀粉复合材料。研究了混合增塑剂、废纸浆、水含量、氢氧化钠浓度对复合材料力学性能的影响。力学性能测试结果表明,甘油和尿素混合塑化剂对复合材料有反增塑作用,当甘油/尿素含量分别为10/20份时,拉伸强度最佳为10.26MPa;氢氧化钠浓度为4%时,复合材料综合力学性能最好;废纸浆对复合材料有增强作用,当含量为35份时,拉伸强度最佳为11.35MPa;随着含水率的增加,材料的拉伸强度降低,断裂伸长率先增加后降低;扫描电镜观察发现,甘油和尿素混合塑化剂能够增塑淀粉,很好的改善废纸浆和玉米淀粉之间的相容性。     

萌发玉米淀粉的糊化特性及其对面包品质的影响

研究了萌发玉米淀粉的糊化特性及对面包品质的影响。结果表明,与原淀粉相比,萌发玉米淀粉的糊化温度有所降低,糊化时间有所缩短。5种面包样品的仪器测定和消费者实验表明,添加适量的萌发玉米淀粉能够有效提高面包质地特性和总体接受程度、口感、外观、气味等特征。     

Optimization of Gluten-Free Bread Prepared from Cornstarch, Rice Flour, and Cassava Starch

ABSTRACT: The proportions of cornstarch, cassava starch, and rice flour were optimized for production of gluten-free bread (with 0% and 0.5% soy flour) to maximize specific volume (Y₁,Y₁'), crumb-grain score (Y₂,Y₂'), and bread score (Y₃,Y₃'). A central composite design involving cornstarch/cassava starch ratio (X₁) and rice flour/cassava starch ratio (X₂) was used, and 2nd-order models for Y₁ and Y₁' were employed to generate response surfaces. The maxima of response surfaces for crumb-grain score and bread score indicate that optimal gluten-free bread can be prepared from 74.2% cornstarch, 17.2% rice flour, and 8.6% cassava starch. Addition of soy flour at the 0.5% level also improved bread texture.     

Physicochemical properties and application of micronized cornstarch in low fat cream

With normal cornstarch (CS) as material, micronized starch was prepared first by acid hydrolyzed pretreatment and then ball-milling (HMS). A control sample (MS) was prepared by ball-milling without pretreatment. Particle size and shape of micronized starch were investigated, and its application in low fat cream was studied. The Maltase cross of HMS granules almost disappeared and the particle size clearly decreased. It was evident that acid-lintnerised starch granules were more susceptible to break down upon milling. However, the granules would aggregate with an increase in milling time. Compared with full-fat cream, the apparent viscosity of low-fat cream increased, while fat globules partial coalescence rate, overrun and textural properties decreased with the increasing of the fat replacement rate. The average particle size of whipped cream increased with the increase of whipping time. Results indicate that a 15% fat replacement rate would produce cream with good foaming and storage stability.     

甘油对高直链玉米淀粉成膜性能的影响

研究甘油添加量为0～40% 的高直链玉米淀粉糊的流变性能。采用流延法将添加了甘油量为0～40% 的高直链玉米淀粉糊成膜,并对其结晶结构和耐酸性能进行研究。制备以VB1 为功能因子的淀粉薄膜包衣微丸,系统考察不同甘油添加量的高直链玉米淀粉包衣微丸在模拟人体消化道环境中的控缓释性能。结果表明：随着甘油添加量的增加,高直链玉米淀粉糊的黏度下降,膜的结晶性能和耐酸性能下降。通过调节甘油添加量和包衣厚度,使得高直链玉米淀粉能够抵御胃酸的作用而到达小肠,包衣后的微丸具有一定的控缓释功能。     

一种利用玉米淀粉制备胶粘剂的新方法

分析了淀粉胶难以取代泡花碱胶粘剂的原因,选用新型的催化剂,探讨了各种因素对淀粉氧化和糊化的影响及简要机理,得出了制备淀粉胶的最佳条件为：于40％的淀粉乳中加入5％的氧化剂,在催化剂存在时于58℃下氧化30min,加入10％的NaOH糊化,加填料、加水调节固含量至12％(均以淀粉质量为基准),合成的玉米淀粉胶粘剂成本低、干燥快,有望彻底取代泡花碱。将这种胶粘剂进行了工业化试生产,并对应用情况作了简略介绍。