Comparison of xylo-oligosaccharides production by autohydrolysis of fibers separated from ground corn flour and DDGS

Xylo-oligosaccharides (XOS) are known to have beneficial health properties, and are considered to be functional food ingredients. The objective of this study is to compare corn fibers separated from ground corn flour and distillers dried grains with solubles (DDGS) for XOS yield and optimum autohydrolysis conditions. Based on the initial xylan content, the fiber separated from ground corn flour (FC) resulted in higher XOS yield (71.5%) than the fiber separated from DDGS (FD) (54.6%) at the maximum XOS production conditions. XOS produced were mainly xylobiose and xylotriose. Based on total initial material also, FC resulted in higher XOS yield (8.9%) than FD (8.0%), based on total original masses. Thus, fiber separated from ground corn flour would be a better feedstock for production of XOS than fiber separated from DDGS. The conditions for maximum XOS production from FD and FC were 180 °C with 20 min hold-time and 190 °C with 10 min hold-time, respectively.     

Synthesis of Cellulose-Based Macromolecular Coupling Agent and its Utilization in Poly (butylene succinate)/Wood Flour Composites

A long fatty side chain was introduced into the macromolecule of hydroxyethyl cellulose (HEC) via esterification reaction. The hydrophobicity of hydroxyethyl cellulose lauric acid ester (HECLAE) was enhanced in comparison with HEC. The obtained HECLAE was used as macromolecular coupling agent in poly (butylene succinate)/wood flour composites and exhibited a positive influence on improving the mechanical performance of composites. Besides, HECLAE plays a role as a hydrophobic agent in composites. A significant increase in storage modulus (E’) was observed upon the incorporation of treated wood flour. SEM images showed that the dispersion of treated wood flour in PBS matrix was improved.     

免化学试剂-离子色谱法测定小麦粉中溴酸钾的不确定度评定

利用离子色谱法测定了小麦粉中溴酸盐,对溴酸盐测量不确定度的来源进行了分析和量化评定.实验测得:当小麦粉中的溴酸盐含量为0.42mg·kg-1时,扩展不确定度为0.08mg·kg-1(k=2).     

Effect of precooking time and drying temperature on the physico-chemical characteristics and in-vitro carbohydrate digestibility of taro flour

Achu is a thick porridge obtained by cooking and pounding taro (Colocasia esculenta) corms and cormels in a mortar. This study was undertaken with the objective of producing precooked taro flour that can be used in the preparation of achu. Taro slices were precooked to times of 0, 20, 45 and 90 min and dried in an air convection oven at varying temperatures of 50, 60, 70 or 80 °C before milling into flour which was then analysed for its water absorption capacity (WAC), water solubility index, emulsion activity and stability, bulk density, foam capacity and least gelation concentration (LGC). Achu made from the flours were equally analysed for their relative penetrometric index, bulk density and colour. The results showed that precooking induced significant (P<0.05) decrease in foam capacity, penetrometric index, and increase in LGC, emulsion stability and WAC. The drying temperature also induces significant reduction in emulsion capacity and stability, penetrometric index, and increase in LGC, WAC. Long precooking time (>45 min) and drying temperature (>60 °C) induced significant reduction of the in-vitro carbohydrate digestibility of taro achu.     

Emulsifying Capacity and Emulsion Stability of Soy Proteins Compared with Corn Germ Protein Flour

Both emulsifying capacity (EC) and emulsion stability (ES) increased with increasing concentrations from 0.4% to 0.8% of soy flour (SF), soy concentrate (SC), soy isolate (SI) and corn germ protein flour (CGPF) when studied by response surface methodology. EC and ES increased as pH increased from 6 to 8 in all samples. Increasing incubation temperatures of protein solutions from 20–70°C or from 4–20°C did not affect EC or ES, respectively. SF had the highest EC, followd by SI, SC, and CGPF.     

Effect of olive residue benzylation on the thermal and mechanical properties of poly(vinyl chloride)/olive residue composites

The changes in mechanical properties, the thermal stability, and the water absorption capacity of poly (vinyl chloride)/olive residue flour composites were studied as a function of various residue olive flour ratios, i.e., 0, 5, 15, and 25% by weight taking into account the effect of benzylation chemical treatment of the filler. The study showed that composite samples prepared with the untreated filler exhibited higher tensile modulus and hardness compared with the neat resin, whereas elongation and tensile strength were observed to decline. On the other hand, the PVC hardness was found to increase with addition of the untreated olive residue flour (ORF), however the composite samples prepared with the benzylated flour exhibited lower hardness than those prepared with untreated olive residue. Moreover, the amount of absorbed water depends on the amount of filler in the composite. The comparison of the results obtained from the samples of F5, F20, and F30 formulations between the untreated and treated ORF indicated a reduction in absorbed water for the composite samples containing treated ORF with benzyl chloride. As a result, the mechanical properties of the treated composites were improved. Furthermore, the thermal characterization of the different samples carried out by color change test and thermogravimetric analysis revealed an increase in the onset temperatures of decomposition for the treated composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

关于影响面条食用品质相关因素的探讨

从小麦生产概况、面条发展历史和工艺、国内外对面条食用品质的研究3个方面,分析了我国面条工业发展缓慢的原因,提出了小麦育种-面粉工业-制面工业,3个环节紧密配合,协调发展,才能形成良性循环的新思路。     

Biodegradability and mechanical properties of agro‐flour–filled polybutylene succinate biocomposites

The objective of this study was the production of rice husk flour (RHF) and wood flour (WF) filled polybutylene succinate (PBS) biocomposites as alternatives to cellulosic material filled conventional plastic (polyolefins) composites. PBS is one of the biodegradable polymers, made from the condensation reaction of 1,4‐butanediol and succinic acid that can be naturally degraded in the natural environment. We compared the mechanical properties between conventional plastics and agro‐flour–filled PBS biocomposites. We evaluated the biodegradability and mechanical properties of agro‐flour–filled PBS biocomposites according to the content and filler particle size of agro‐flour. As the agro‐flour loading was increased, the tensile and impact strength of the biocomposites decreased. As the filler particle size decreased, the tensile strength of the biocomposites increased but the impact strength decreased. The addition of agro‐flour to PBS produced a more rapid decrease in the tensile strength, notched Izod impact strength, and percentage weight loss of the biocomposites during the natural soil burial test. These results support the application of biocomposites as environmentally friendly materials. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1513–1521, 2005     

羟丙基糯米粉糊的特性及应用初探

研究了羟丙基糯米粉糊的性质，以及流变特性和温度影响流变特性的规律，并对其在蚝油食品中作为增稠稳定剂的应用做了初步研究。结果表明，糯米粉经羟丙基化后，凝沉性更弱，受热易于成糊和分散，糊的粘度提高，冻融稳定性极佳，透明度大为提高，但是抗剪切稳定性反而降低。在实验测定的温度下，羟丙基糯米粉糊呈现假塑性流体的特征且假塑性随醚化程度的提高而增强。应用试验表明其增稠效果好、稳定性高，可用做增稠稳定剂。     

PVC／OMMT／WF纳米复合材料性能研究

对蒙脱土进行有机改性制得有机蒙脱土（OMMT），并制备了聚氯乙烯侑机蒙脱土／木粉（PVC／OMMT／WF）纳米复合材料。采用硅烷偶联剂对木粉表面进行改性，有效提高了聚氯乙烯／木粉（PVC／WF）复合材料的力学性能，其中加入1．5％（质量含量，下同）硅烷偶联剂可使复合材料的冲击强度和拉伸强度分别提高14．8％和18．5％。研究了OMMT的加入对木粉改性前后的PVC／WF复合材料力学性能、耐热性能及阻燃性能的影响，结果表明，木粉未经改性时，OMMT加入无助于PVC／OMMT／WF复合材料力学性能的提高；木粉用硅烷偶联剂改性后，添加少量的OMMT，可使PVC／OMMT／WF复合材料的冲击强度和拉伸强度明显提高。研究表明，添加OMMT可显著延迟复合材料的点燃时间，燃烧残余率也明显增加，OMMT是PVC／WF复合材料的高效阻燃剂。