亚麻籽挤压膨化脱毒的工艺优化

采用SLG67-18.5双螺杆挤压机优化亚麻籽脱毒工艺。通过二次正交旋转组合设计试验,研究了温度、含水率、螺杆转速、喂料速度对亚麻籽中氰华氢(HCN)去除率的影响。单因素分析表明,亚麻籽中HCN去除率随温度升高、含水率增加、螺杆转速提高而升高;随喂料速度增加呈抛物线,中等喂料速度脱毒效果更好。利用频数分析法进行优化,得到亚麻籽中HCN去除率有95%的可能高于90%的参数范围,即膨化温度为147～153℃,亚麻籽含水率为13.8％～17.6%,螺杆转速为186～211 r/min,喂料速度为61.7～74.0 kg/h,从而为亚麻籽脱毒和开发利用及现有挤压膨化机的操作和调整提供了理论依据。     

单螺杆挤压机对农产品加工因素的优化

在农产品和食品挤压机加工过程中,由于各种因素的变化,对产品的膨化质量有很大影响。通过挤压机螺杆与螺套之间的间隙、螺杆转速和物料含水率的变化,对产品的膨化指数,挤压机的生产率和功耗进行测定,分析在不同工况下挤压的工作情况以及产品特性。试验结果表明,影响试验指标的主要因素是螺杆与螺套之间的间隙,试验因素主次排列为间隙,含水率和转速,其较优组合为螺杆螺套之间的间隙0.75mm,螺杆转速300r/min,物料含水率18％。     

香菇双螺杆挤压膨化机的设计与试验

针对现有双螺杆挤压膨化设备生产香菇膨化产品时存在物料堵塞、预熟度低、作业参数缺失等问题而导致生产的产品膨化率低、吸水性差、硬度高等缺陷,该研究设计了一种香菇双螺杆挤压膨化设备,并对设备中的关键部件喂料搅拌防堵装置、预熟调质装置与双螺杆结构参数进行了设计与确定。同时,为探究设备中的作业参数对产品膨化性能的影响,研究了设备的螺杆转速、膨化温度、物料含水率对产品的膨化率、硬度、脆度、吸水性的影响。结果表明:影响膨化率的显著性顺序依次为螺杆转速、物料含水率、膨化温度;影响硬度的显著性顺序依次为螺杆转速、膨化温度、物料含水率;影响脆度的显著性顺序依次为膨化温度、物料含水率、螺杆转速;影响吸水性的显著性顺序依次为膨化温度、物料含水率、螺杆转速。其次,结合各因素交互作用的影响规律与目标优化结果,得出设备的最佳作业参数为:螺杆转速167.23r/min,膨化温度151.68℃,物料含水率16.83%,此时,产品的膨化率、硬度、脆度、吸水性分别为4.04%、18.61N、-8.46mm/cm^2、313.86%。将优化后的参数值在设备中进行了生产性应用,得到生产值与优化值的误差均小于4%,最大生产率为165 kg/h。与扬州大学机械工程学院实验室内的现有设备相比,在提高物料送料的连续性与调质熟化度的基础上,膨化率提高了25.00%,硬度降低了48.21%、脆度提升了40.55%、吸水性提高了62.35%。因此,该机的设计可为香菇膨化产品的开发提供了一种较为成熟的技术装备。     

复合组织蛋白挤压加工工艺的初步研究

该文利用FTS-50型双螺杆食品挤压机，进行了复合组织蛋白挤压加工工艺的研究。试验研究了各个工艺参数对产品组织化的影响，得出了较佳的工艺条件。结果表明：适量的油脂(2%～10%)可以降低主机功耗，并稳定组织化结构；原料的pH为6.5～7.5时，产品的纤维强度较好；淀粉添加量在10%以内，产品的纤维化结构明显而且口感适中；含水率和螺杆转速对挤压产品组织化质量有着复杂的影响；挤压变性段温度提高，产品的组织化程度提高。     

水产沉性颗粒饲料挤压蒸煮工艺对其理化特性的影响

为了规模化生产出低污染、高转化率的环保型水产沉性颗粒饲料,选用双螺杆挤压机对水产全价配合原料进行挤压熟化研究。以沉性水产硬颗粒饲料理化特性(膨化度、近似密度、糊化度、耐久性和水中稳定性)为重要指标,采用表面响应分析法研究了物料含水率（22%～38%）、套筒温度（70～170℃）和螺杆转速（73～107?r/min）对其挤压工艺和饲料理化特性的影响规律,SEM分析其微观结构。结果表明：物料含水率、套筒温度和螺杆转速均显著影响饲料的理化特性。中高物料含水率和套筒温度及低螺杆转速时,才能获得理想的沉性高熟化水产颗粒饲料,其理化特性具有低膨化度（1.14）,高近似密度（757.6?g/L）、糊化度（879.5?g/kg）、耐久性（96.6%）和水中稳定性（88.7%）。SEM分析显示优化条件（物料含水率31%,套筒温度126℃,螺杆转速78?r/min）下生产的颗粒饲料结构光滑质密。该研究可为发展高效、低耗、低碳高品质沉性水产饲料研究和生产提供参考。     

挤压加工参数对重组米生产过程及产品膨胀度的影响

为了考察重组米生产过程中挤压加工变量对几种系统参数与产品膨胀度的影响,试验以杂交籼米（9?718品种）为原料,利用响应面模型,以螺杆转速、进料速度、进料含水率以及末端机筒温度为输入变量,以挤压系统参数（物料温度、模头压强、扭矩、比机械能和产品含水率）和重组米膨胀度为响应变量,探索在重组米生产过程中加工变量与系统参数及产品膨胀度的关系。结果表明,压强、比机械能和产品膨胀度都受到4个挤压变量的显著影响,但是物料温度受进料速度影响不显著,马达扭矩受末端机筒温度影响不显著,产品含水率仅受进料含水率的显著影响。比机械能与螺杆转速正相关,与进料速度、进料含水率和末端机筒温度负相关。所得二次回归模型均拟合良好,建立的挤压数学模型可应用于重组米生产,为重组米工业化生产的过程预测和产品性质预测提供参考。     

双螺杆食品挤压机计算机控制系统研究

为了提高双螺杆食品挤压机挤出食品的质量，在对挤压过程进行了分析和研究的基础上，研制了一套计算机控制系统。该系统能够自动控制双螺杆食品挤压机的各区温度和机头压力，能够在计算机屏幕上实时模拟挤压机的工作状态。经现场使用表明，该控制系统工作稳定、可靠，操作方便，省时、省工，确保了双螺杆食品挤压机挤出食品的质量的提高。     

双螺杆食品挤压机计算机控制系统研究

为了提高双螺杆食品挤压机挤出食品的质量，在对挤压过程进行了分析和研究的基础上，研制了一套计算机控制系统。该系统能够自动控制双螺杆食品挤压机的各区温度和机头压力，能够在计算机屏幕上实时模拟挤压机的工作状态。经现场使用表明，该控制系统工作稳定、可靠，操作方便，省时、省工，确保了双螺杆食品挤压机挤出食品的质量的提高。     

菜籽挤压膨化系统参数对出油率影响的试验研究

该文研究了用于浸油的一种菜籽挤压膨化预处理工艺(油菜籽清理—带壳粉碎—膨化—浸油)的可行性，油菜籽挤压膨化系统参数(模孔孔径、套筒温度、物料含水率、螺杆转速)对各考察指标(粕的残油率、膨化物含油率及榨笼出油率)的影响规律，挤压膨化系统优化参数的范围为模孔孔径8～12 mm、套筒温度105～125℃、物料含水率6.6%、螺杆转速35～55 r/min。研究表明：只要参数选择合适，带壳油菜籽清理、粉碎、挤压膨化、浸出的菜籽浸油预处理工艺是可行的，且残油率较低。该菜籽挤压膨化浸油预处理工艺可供生产参考。     

减少玉米粗淀粉挤出物中抗性淀粉的工艺参数优化

为减少玉米粗淀粉经过挤压蒸煮后,在室温下冷却而产生的抗性淀粉Ⅲ,以降低其对挤出物制备糖化液葡萄糖当量值的影响,需要对挤压参数进行优化选择。该文以玉米粗淀粉为原料,采用五因素五水平二次正交旋转组合试验设计,研究挤压参数对挤出物中抗性淀粉Ⅲ质量分数的影响,得出产生抗性淀粉Ⅲ质量分数最小的挤压条件为：套筒温度60.0℃,原料含水率27.0%,模孔直径11.0 mm,螺杆转速200.0 r/min,轴头间隙10.0 mm,抗性淀粉Ⅲ质量分数可降低到1.48%。     

Extrusion Processing of Rice‐Based Breakfast Cereals Enhanced with Tocopherol from a Chinese Medical Plant

Brown rice flour was mixed with a Chinese medical plant (Euryale ferox Salisb.) and processed to make ready‐to‐eat breakfast cereals using twin‐screw extrusion. Levels of 15 and 20% feed moisture in flour, and 200 and 250 rpm screw speed were set, and the physicochemical properties and content of α‐, β‐, γ‐, and δ‐tocopherols were determined. The data showed that 15% feed moisture gave a low bulk density and water absorption index but a high expansion ratio and water solubility index. High screw speed (250 rpm) produced a result similar to that of 15% feed moisture. A sample with 85% brown rice flour with 15% E. ferox Salisb. retained the highest content of α‐, β‐, γ‐, and δ‐tocopherols (125, 6, 78, and 9 μg/g), respectively. The optimum extrusion conditions determined were 15% E. ferox Salisb. mixed with brown rice at 15% feed moisture and at 250 rpm screw speed.     

热压凝胶法制备营养质构米及其营养性质研究

为弥补食用精白米导致营养不良的状况,以大米加工过程中产生的碎米作为原料和载体,产生的米糠作为天然营养强化剂,采取热压凝胶法制备营养质构米。在预试验的基础上,采用响应面法考察热压凝胶过程条件包括喂料含水率,螺杆转速,5个加热区机筒温度对营养质构米的质构和营养特性的影响,得出制备最佳工艺条件:当喂料转速为30r/min,米糠添加量为4%,物料含水率为30%,螺杆转速为17.7r/min,5个区机筒温度分别为50,65,85,100,95～97℃。在此条件下制备的营养质构米含有质量分数总膳食纤维11.44%,蛋白质11.62%,脂肪6.49%,而维生素为B12.07μg/g,维生素B20.31μg/g和γ-谷维素12.04mg/100g。相比于天然精白米,质构特性相近,但维生素B1,维生素B2,γ-谷维素分别增加了1.17,0.06,5.83μg/g,为营养质构米工业化生产提供参考。     

Influence of Particle Size on the Twin-Screw Extrusion of Corn Meal

Effects of particle size (50–1,622 μm), screw speed (200–400 rpm), and feed moisture content (19–22%) on twin-screw extrusion of corn meal were investigated using a full-factorial design. Torque, specific mechanical energy, and product temperature generally showed no change within the commonly used particle-size range (100–1,000 μm), but each value dropped significantly as the particle size increased >1,000 μm. Die pressure was influenced by the three-way interaction of particle size, screw speed, and feed moisture content. The highest moisture level (22%), largest particle size (1,622 μm), and two lowest screw speeds (200 and 300 rpm) were the only conditions where the starch was <97.5% of transformation (gelatinization). Consequently, these two conditions also showed the least expansion and hardest product.     

挤压膨化大米做啤酒辅料的试验研究

该文通过实验室试验,研究了做啤酒辅料的大米挤压膨化系统诸参数(模孔孔径、套筒温度、物料含水率、螺杆转速),对醪液的主要考察指标(麦汁醪液的总还原糖、过滤速度)的影响规律,指出挤压膨化大米做啤酒辅料的可行性。     

Effects of Extrusion Variables and Chemicals on the Properties of Starch-Based Binders and Processing Conditions

The effects of extrusion variables (moisture, screw speed, and temperature) and chemicals (urea and sodium bicarbonate) on the properties of starch-based binders (water absorption, bulk density, binder yield, expansion ratio, solubility, pH) and processing conditions (die temperature and pressure, feed rate, and specific mechanical energy) were studied using a central composite design. All quadratic regression models, except the models for bulk density and pH, were significant at the P ≤ 0.06 level. These models can predict the binder properties and processing conditions when extrusion variables and the chemical concentrations are known. Optimum combinations of the chemical concentrations (g/100 g of starch) and extrusion variables to achieve high water absorption in the binders were 15–20 g of urea /100 g of starch, 0–4 g of sodium bicarbonate/100 g of starch, 35–40 g of moisture/100 g of starch, 100–120 rpm screw speed, and 185–215°C barrel temperature. The molecular degradation of the starch occurred during extrusion, especially when the moisture content of starch was <30 g/100 g of starch.     

Effects of Feed Rate and Screw Speed on Operating Characteristics and Extrudate Properties During Single-Screw Extrusion Cooking of Rice Flour

Rice flour (37% moisture content) was used to examine the effects of feed rate and screw speed on the specific energy input during single-screw extrusion cooking. Torque, raised by decreasing screw speed or increasing feed rate, was found to be a power law function of the ratio of feed rate to screw speed (F_r/S_s) with r² > 0.94. Specific mechanical energy (SME) calculated from torque also was a power law function of F_r/S_s with r² >0.84 and negative power law indices. The SME obtained was in the 225–481 kJ/kg range. Thus the extruder can be considered low shear. Increasing SME raised the die temperature and decreased both intrinsic viscosity and water absorption index (WAI). The degree of gelatinization and intrinsic viscosity of extrudates also were power law functions of F_r/S_s. The intrinsic viscosity correlated well with the degree of gelatinization, WAI, and cooking loss, and appeared to be a good index of the extrudate properties. Different screw profiles also affect torque measurement.     

Empirical Modeling of Mean Residence Time in a Co‐Rotating Twin‐Screw Extruder with Rice Flour

Mean residence time of rice flour in a twin‐screw extruder was determined using a blue tracer. Variables studied included moisture content, screw speed, barrel temperature, and screw configuration. Mean residence time increased with the increase of the barrel temperature and with the addition of reverse and kneading elements. Mean residence time was significantly related to screw speed, moisture content, die pressure, and screw configuration (P < 0.05). An empirical model was developed to predict mean residence time with the ability to reflect the changes of the barrel temperature and screw configuration. The effects of different extrusion operating conditions including screw speed, moisture content, barrel temperature, and screw geometry on the mean residence time were considered in the model. The validity of the developed model was extensively evaluated and verified using different screw geometries and other processing variables. The mean residence times predicted by the developed model are in good agreement with the experimental data.     

Effect of Extrusion Conditions on Pasting Behavior and Microstructure of Refabricated Rice: A Response Surface Analysis

The effects of moisture, screw speed, and barrel temperature on pasting behavior of refabricated rice grains were investigated in a corotating twin‐screw extruder with response surface methodology. The rice flour obtained from broken rice (≤1/8 of actual kernel size) of PR‐116 variety was used in the study. The screw speed was set at five levels between 49 and 150 rpm, barrel temperature between 59 and 110°C, and feed moisture between 31 and 45%. All pasting properties of refabricated grains evaluated—peak viscosity, hold viscosity, breakdown viscosity, final viscosity, and setback viscosity—were significantly (P < 0.01) affected by the three process variables. Barrel temperature was the most significant variable, with quadratic effect on all viscosity parameters. Response surface regression models were established to correlate the viscosity profile of refabricated rice grains to the process variables. The optimum moisture content, screw speed, and barrel temperature estimated by a response surface of desirability function for the production of refabricated rice were 36%, 130 rpm, and 89.5°C, respectively. Scanning electron microscopy also revealed that intermediate moisture and temperature along with high screw speed during extrusion could create a more realistic appearance of refabricated rice with less rupture of starch granules.