单螺杆挤压机加工工艺参数的优化

对豆粕挤压膨化系统诸参数(物料含水率、螺杆转速、机筒温度)对成本的影响规律和挤压膨化系统最佳参数进行了研究。结果表明,影响实验指标的主要因素是螺杆转速,实验因素主次排列为螺杆转速、机筒温度、物料含水率。其较优组合为:转速295 r/min、机筒温度130℃、物料含水率27%。      

单螺杆挤压机中长螺杆的改进

对现有国内普遍使用的单螺杆挤压机中的长螺杆进行改进研究,提出一种带有交变螺距的螺杆组件结构,改进后的单螺杆挤压机省去了原来利用电能加热的装置,达到节约能源、方便生产,用此机组生产出的挤压膨化食品膨化效果优于未改进前,每小时的班产量是未改进前的3倍。     

单螺杆挤压机比能耗的参数优化及影响因素分析

本文作为螺杆食品挤压机生产率计算模型的一个应用,以比能耗为目标函数,对螺杆转速,机筒温度,物料湿含量进行了优化研究,还就挤压机操作参数和几何参数对比能耗,生产率和物料温度的影响进行了分析。     

单螺杆挤压机比能耗的参数优化及影响因素分析

本文作为螺杆食品挤压机生产率计算模型的一个应用, 以比能耗为目标函数, 对螺杆转速、机筒温度、物料湿含量进行了优化研究; 还就挤压机操作参数和几何参数对比能耗、生产率和物料温度的影响进行了分析     

玉米蛋白粉挤压膨化工艺参数优化研究

以单螺杆挤压膨化机为试验设备对玉米蛋白粉进行膨化试验,运用二次通用旋转组合设计试验方法研究了玉米蛋白粉含水率、膨化机螺杆转速和机筒温度对加工后的玉米蛋白粉持水性的影响。结果表明:影响玉米蛋白粉持水性的主要因素是机筒温度,试验因素主次顺序依次为机筒温度、螺杆转速、物料含水率;较优组合为:物料含水率43%、螺杆转速334r/min、机筒温度157℃。     

挤压膨化工艺参数对产品质量影响概述

挤压膨化加工工艺参数指在挤压膨化加工过程中能够人为改变且影响产品质量的一系列参数，包括加工温度、物料含水量、喂料速度和螺杆转速等。膨化产品质量的评价指标包括膨化率、吸水性和质构等物性指标，以及产品的营养成分。大量研究表明，膨化加工工艺对产品质量有重要影响。本文根据国内外研究论文和报告，从膨化加工工艺对产品质量影响的角度，介绍了挤压膨化技术的研究现状和进展．     

加工参数对棉籽饼粕双螺杆挤压脱毒的影响

利用双螺杆食品挤压机对棉籽饼粕进行了挤压脱除棉酚的试验，考察了加工参数对脱毒效果的影响。结果表明：增大螺杆转速，脱毒效果变好；减小含水量，脱毒效果变好；增大螺杆转速，产量增大；增大含水量，产量增大；捏合盘的加入能有效改善脱毒效果，捏合盘长度和位置是影响脱毒效果的显著因素。试验结果还表明，双螺杆挤压机用于棉籽饼粕挤压脱毒，效果十分显著。     

挤压膨化制备甘薯熟粉加工工艺的研究

本实验以市场所购甘薯为原料，利用双螺杆挤压膨化机，采用挤压膨化工艺加工甘薯熟粉，同时研究膨化温度和物料含水量对于甘薯熟粉及膨化工艺参数的影响。结果表明：在实验设计范围内，膨化温度和物料含水量对甘薯熟粉特性(粘稠度)和膨化工艺参数(扭矩、压力)均有显著影响。物料水分含量18％，膨化温度为145℃时，膨化条的硬度、韧性、膨化率最大。随着膨化温度的升高，甘薯熟粉的粘性增加，在本实验设计的最大温度时，甘薯熟粉的粘性达到最大。挤压膨化温度和含水量对膨化工艺参数有显著影响：随着膨化温度升高，扭矩在总体上呈升高趋势，而压力随之减小；随着水分的减小扭矩显著增大。     

响应曲面法优化谷物复合挤压膨化最佳工艺参数的研究

以小米、大麦和豆粕为原料(8∶1∶1),以德国进口的DSE-25型双螺杆挤压膨化实验室工作站为膨化设备,利用响应曲面法优化原料水分含量、加工温度、螺杆转速和喂料速度4个工艺参数,最终确定产品挤压膨化的最佳工艺参数为物料含水量为18.13%、加工温度为163.85℃、螺杆转速为176 r/min、喂料速度为30 r/min。此时,产品的膨化度为3.33,糊化度为98.52,达到最佳膨化效果。     

自熟多功能单螺杆挤压重组牛肉的加工工艺研究

本论文利用自熟多功能单螺杆食品膨化机,通过挤压膨化牛肉制品的开发与研究,增加维持生命最重要的营养素赖氨酸,使之营养平衡。应用响应面法研究了恒定螺杆转速下,牛肉的添加量、进料湿度及进料粒度三个操作参数对牛肉蛋白挤出物的膨化度、脂肪酸、氨基酸成分变化程度的影响。确定了最适工艺条件:螺杆恒定转速为370 r/min,牛肉的添加量是37.00%,进料湿度是24.08%,进料粒度是16目。通过对挤压前后牛肉脂肪和氨基酸的变化研究,表明在挤压膨化过程中,脂肪酸的损失率较高,特别是γ亚麻酸。挤压膨化牛肉中7种人体必须氨基酸的含量相对是减少的,赖氨酸和丝氨酸减少的比例最大,分别是16.82%和16.20%,酪氨酸和组氨酸减少的比例最小,分别是13.3%和13.8%。     

单螺杆挤压机生产微量营养素强化大米成形工艺研究

本研究以产品成品率和维生素A保留率为指标,考察了套筒温度、螺杆转速、物料水分含量和乳化剂(单甘酯)用量对微量营养素强化大米单螺杆挤压生产成形品质的影响。试验结果表明:产品成品率与淀粉糊化度密切相关,淀粉糊化度过高或者过低均不利于挤压成形;随着淀粉糊化度的增大,强化大米产品的维生素A保留率总体呈现降低趋势;通过正交试验,确定了微量营养素强化大米单螺杆挤压生产的最佳工艺条件为:套筒温度20℃、物料水分质量分数36%、螺杆转速100 r/min、单甘酯用量0.6%(w/w);在此条件下,产品成品率和维生素A保留率分别为93.5%和88.0%。本研究为碎米的综合利用以及主食营养强化提供了一条合理简便的途径。     

The effect of die shape on velocity profile of extrudate using a single-screw extruder

A uniform velocity profile of extrudates can be helpful for quality assurance of sheet-type extruded products. In this study, four different shapes of die and various operating conditions (including temperature and water content) were studied to investigate a die design method which yielded a uniform velocity profile of extrudates. The operating conditions affected the velocity profile. The velocity deviations between the center and edge of extrudates were more than 10% at the conditions tested. The die shape was a key factor in achieving uniformity in velocity profile and thickness of extrudates. When a concavo-concave die with proper curvature was used, uniform velocity and thickness of extrudates were obtained, with less than 5% velocity deviations, and thickness deviations between center and edge of extrudates of mostly less than 10%. There were five runs yielding zero thickness deviation among 15 different conditions tested.     

Numerical simulation of the extrusion process for food materials in a single-screw extruder

A numerical study of extrusion cooking of starch based materials in a single-screw extruder is carried out. The low moisture levels and high temperatures typically encountered in practical circumstances are considered. The starch conversion process is studied in the rheological region of the extruder which is often the last few turns of the screw, where the material is treated as a non-Newtonian fluid. A numerical method based on finite-difference approximation is employed to solve the governing non-linear equations for momentum, energy and mass conservation for a non-Newtonian fluid undergoing physicochemical changes. The initial conditions for the problem are taken from experimental observations. The screw configuration and the operating parameters, such as barrel temperature, screw speed and throughput, are varied to study their influence on the conversion of starch. It is found that 28% conversion is obtained due to viscous dissipation alone, whereas 61% conversion occurs by raising the barrel temperature by about 25 °C above the inlet. It is also observed that, at any screw speed, a smaller flow rate caused by a smaller die diameter leads to a higher degree of conversion. Furthermore, it is found that the compression ratio of the screw has a significant influence on pressure rise, bulk temperature and average residence time. As the compression ratio increases the temperature increases but the residence time decreases. The former effect increases the degree of conversion where as the latter decreases the degree of conversion. Therefore there exists a compression ratio at which a minimum degree of conversion at the die is obtained.     

Distribution of the residence time in a single-screw extruder with differing numbers of mixing elements

Starch was extruded with sodium trimetaphosphate and sodium hydroxide in a single‐screw extruder at 40% moisture content and screw speeds of 90 and 140 r.p.m. The effect of screw configurations, which included one and two mixing elements, on mean residence time, spread of residence time distribution (RTD), and flow pattern were determined. Increasing the screw speed and reducing the number of mixing elements reduced mean residence time. Higher RTD spread values were obtained at a screw speed of 90 r.p.m. when compared with 140 r.p.m. and increasing the number of mixing elements in the screw increased the RTD spread. The flow pattern was between plug and mixed flow, and increasing the number of a mixing element in the screw did not significantly affect the flow pattern in the single‐screw extruder.     

Novel pearl millet couscous process for West African markets using a low-cost single-screw extruder

Traditional West African pearl millet couscous products are popular; however, their preparation is laborious, time-consuming and energy-demanding, involving agglomeration, steaming, drying and sieving steps. In this study, a process was developed to produce millet couscous using a high pressure, high temperature and low-cost single-screw extruder. The innovation was to directly process the cooked low-moisture extrudate to a couscous product by drying and milling to the appropriate particle size (ranging between 1 and 2 mm). Throughput for the traditional process as prepared for commercial sale is 50 kg per day, but with the same amount of labour, the extrusion process yields ~350 kg per day. A consumer sensory study held in Niamey (Niger) showed that the extruded millet couscous was comparable to traditional couscous, though this was dependent on selection of the proper millet variety. This novel extrusion process could stimulate small- to medium-scale manufacturing of couscous and couscous-type products in West Africa.     

果胶酶提高苹果出汁率工艺条件的优化

以陕西产红富士苹果为原料,利用活力单位为2万U/g的粉状果胶酶对苹果浆进行处理,以提高苹果出汁率,通过单因子试验和正交试验得到最佳的工艺参数为pH4.0、温度40℃、果胶酶的用量为0.3g/L、处理时间90min。     

气膨化法涨发鱼肚的工艺参数优化

目的 优化气膨化涨发鱼肚的工艺参数。方法 以干制鱼肚为原料,通过单因素试验和正交试验对鱼肚气膨化涨发进行研究,并对其主要营养成分、复水性和理化指标进行测定。结果 得出使鱼肚气膨化效果最佳的工艺条件为：上火90 ℃、下火100 ℃初烤30 min后,再上火225 ℃、下火230 ℃烤2 min。各因素对鱼肚气膨化涨发效果的影响程度依次为：第2阶段的烤制温度、第1阶段烤制温度、第1阶段烤制时间、第2阶段烤制时间。气膨化鱼肚最佳的复水条件为：15 ℃的水温复水35 min。复水后的鱼肚外形均匀完整,香味浓厚,无白点,弹性好。测定鱼肚经不同膨化方法处理后的主要营养成分含量,得到气膨化鱼肚的粗蛋白含量为75.94%,粗脂肪含量为0.53%,灰分含量为0.23%。结论 试验研究表明,气膨化法操作简单便捷,且效果比传统涨发方式更有优势,鱼肚的感官品质更优,营养价值更高。     

基于MATLAB的膨化机结构工艺参数的最优化设计

分析了单螺杆挤压膨化机结构和工艺参数对其性能的影响，在此基础上建立了膨化机结构、工艺参数优化设计的数学模型。利用MATLAB提供的最优化函数，获得了一定条件下机器的最佳结构和工艺参数。     

菠萝叶纤维脱胶工艺探讨

研究了不同脱胶工艺参数对菠萝叶纤维物理性能的影响,通过正交试验,选择了不同的工艺参数:煮练NaOH浓度、煮练时间、精练NaOH浓度、精练时间和酸洗H2SO4浓度,对菠萝叶纤维进行脱胶试验,分析不同参数对菠萝叶纤维脱胶效果的影响,包括脱胶纤维的残胶率、线密度、平均断裂强度等.结果表明,在多因素下,煮练时间对菠萝叶脱胶纤维残胶率的影响最为显著;精练NaOH浓度对线密度的影响最为显著;酸洗H2SO4浓度对平均断裂强度的影响最为显著,并得到了最佳的脱胶工艺参数组合.     

SC-Ⅱ澄清剂对红树莓原汁澄清及红树莓饮料的研究

文中对红树莓原汁澄清技术及其饮料口味进行研究。以透光率和浊度为指标,在单因素试验基础上,利用SC-Ⅱ澄清剂对红树莓原汁进行澄清,采用响应面分析建立红树莓原汁澄清工艺模型,通过Box-Behnken设计方法优化得出SC-Ⅱ澄清剂在42℃、添加量0.04%、反应1 h条件下,澄清度和浊度分别为73.6%和3.16 NTU,澄清效果理想;正交试验得出25%红树莓汁、10%白砂糖和0.05%柠檬酸的红树莓果汁饮料基础配方,且口感良好。