Flour quality and dough elasticity: Dough sheetability

Current practices in testing flours call for measuring dough strength, not elasticity. Sheeting is a common method for processing developed doughs, the elasticity of which governs dough’s sheetability as dough springs back exiting rollers. To characterise dough sheetability, a study was conducted testing 18 different doughs made from six different flours. Each dough was sheeted using an instrumented sheeter and data for exit sheet thickness and roll forces were captured under a range of sheeting conditions. The true rheological properties of doughs were measured and used to calibrate the ABBM constitutive model for dough (1). Numerical simulations of sheeting operations were conducted; the R² coefficients between measured and predicted sheet thicknesses and roll forces (vertical and horizontal) were nearly all >0.9. Relaxation times were derived from dough model parameters and revealed that flour quality for dough elasticity should be assessed by examining moisture effects on dough relaxation time.     

稀土元素铈对霍山石斛类原球茎悬浮培养细胞生长和多糖合成的影响

研究外源稀土元素铈对霍山石斛类原球茎悬浮培养细胞生长、多糖合成、培养基中碳氮磷源消耗的动力学特性,以及对胞内糖、胞内氮、胞内磷转化的影响。结果表明：适量的铈能够改善霍山石斛类原球茎对碳氮源的利用,提高胞内糖、胞内氮、胞内磷的含量,从而促进细胞生长和多糖合成。以添加10μmol/L 的铈效果最好,细胞的生长速率从0.501g/(L·d)提高到0.649g/(L·d);培养至24d 时,每升培养液中类原球茎干质量为25.45g,比对照提高了20.2%,培养至18d 多糖总质量浓度达到峰值3.35g/L,是对照的1.53 倍。     

Z-15-二十四碳烯酸的制备

对蒜头果油皂化制备Z 15 二十四碳烯酸的实验室工艺进行改进 ,即直接酸化后利用丙酮分步结晶 ,工艺已实现了大规模生产 ,收率达 33%。     

基于连续备择集的模糊综合评判

基于离散备择集的常规模糊综合评判不能准确地描述整个备择区间上的各因素的隶属度,也难以最终得到最优方案,本文提出了基于连续备择集的模糊综合评判,主要利用连续的备择集和函数优化的思想,克服了上述缺陷,可以最终得到最优方案。     

高效液相色谱-光电二极管阵列检测器法测定野山楂中两组分的含量

【摘要】 建立高效液相色谱法测定了野山楂中乌索酸和齐墩果酸的含量,同时采用光电二极管阵列检测器检测两组分的紫外光谱。色谱柱为NucleosilC18柱(4.6mm×250mm,5μm),流动相为甲醇-水(87:13,V/V),流速0.8ml/min,检测波长210nm,柱温26℃。乌索酸在0.1244～2.488μg范围内线性关系良好(r=0.9996),平均回收率为98.1%。齐墩果酸在0.1192～2.384μg范围内线性关系良好(r=0.9999),平均回收率为101.2%。方法简便、准确、重现性好、线性范围宽,适用于测定野山楂中乌索酸和齐墩果酸的含量。     

石斛花金柚幼果功能性果酒酿造工艺研究

以金柚幼果以及新鲜铁皮石斛花为原料，经过打浆、酶解、过滤、添加石斛花浸提液、脱苦等步骤，探究最佳石斛花金柚幼果功能性果酒的酿造工艺。首先以出汁率、可溶性固形物和感官评分为评价指标，确定果胶酶添加量为0.2%，β-环糊精添加量为3.0%。通过单因素试验和响应面试验，选取酵母接种量、发酵温度、发酵时间、初始pH为主要因素，进一步优化果酒的发酵参数。结果表明，加入3.0%的β-环状糊精脱苦，在接种量0.09%、初始pH值3.8、发酵温度24 ℃的条件下发酵9 d，其产品外观澄清，品质优良稳定，风味独特；与市面普通柚子果酒相比，石斛花金柚幼果功能性果酒具有丰富的抗氧化活性物质——黄酮（总黄酮含量0.03 g/L），为石斛花金柚幼果功能性果酒的开发提供思路。