Barrel-Valve Assembly Affects Twin-Screw Extrusion Cooking of Corn Meal

The effects of a barrel-valve assembly on extrusion system dynamics and product properties with various screw speeds and specific feeding loads (SFL) were studied using an APV Baker twin-screw extruder. Turning the barrel-valve from the open to closed position resulted in a convex response of die pressure due to the axial offset of paired orifice plugs, with concomitant changes in system responses and extrudate properties. Variations in SFL by changing feed rate or screw speed caused more pronounced effects on product properties compared with barrel-valve control.     

两种小麦各系统粉面包烘焙特性比较研究

选用两种不同品种的小麦,用同一粉路制粉。对其不同系统粉的面包烘焙品质进行比较研究,发现面包烘焙品质变化基本相同,即前路皮磨B2、B3的面包烘焙品质最好;再筛系统（DIVI1、DIVI2、DIVI3、DIVⅡ）和打麸粉、刷麸粉（DF1、DF2、DBr）次之,前中路心磨系统粉较差,后路心磨C8、C9粉的面包烘焙效果最差。     

双螺杆挤压对玉米重组米理化特性及品质特性的影响

为研究双螺杆挤压技术对玉米粉挤压前后理化特性及品质特性的影响,采用SLG-30双螺杆挤压机对吉林省17?个品种玉米进行挤压膨化,对双螺杆挤压处理前后重组米理化特性及品质特性进行分析。结果表明,挤压处理后不同品种玉米粉的蛋白质量分数平均降低11.32%,脂肪质量分数平均降低29.88%,直链淀粉质量分数平均降低5.11%,冻融稳定性平均提高58.90%,糊化度平均提高88.62%,吸水性平均提高77.03%,水溶性平均提高73.57%,膨润力平均提高87.51%。相关性分析表明,挤压处理后糊化度与脂肪、直链淀粉、蛋白质量分数均呈负相关,与吸水性和水溶性均呈极显著正相关（P＜0.01）;直链淀粉、脂肪质量分数与冻融稳定性、糊化度、吸水性和水溶性均呈极显著负相关（P＜0.01）。挤压处理对玉米的理化特性指标有负面影响,但能明显提高产品加工性能和食用特性。     

Extrusion Cooking in Enzymatic Liquefaction of Wheat Starch

Wheat starch was treated for gelatinization, partial liquefaction, and subsequent further hydrolysis by extrusion cooking together with a thermostable Bacillus licheniformis α-amylase followed by batch incubation of the extrudates at 80°C. The degree of hydrolysis depended on the extrusion feed moisture content, enzyme concentration, mass temperature during extrusion cooking, and the length of the counter screw elements. The degree of hydrolysis was followed both by dextrose equivalent and by molecular weight distribution pattern as determined by high performance gel permeation chromatography. A reaction velocity model was shown to fit well to the kinetic data obtained. The enzyme was only incompletely inactivated by mercuric chloride suggesting the presence of also other than sulfhydryl dependent amylase.     

苦荞麦粉的挤压膨化特性研究

本文研究了苦荞麦粉在QPS65X2型双螺杆挤压膨化机膨化时,螺杆转速,含水量,进料量对膨化度的影响,结果表明化度随含水量增加而下降,随杆转速,进料量的增加而上升,研究了苦荞麦粉与其它辅料（大豆,芝麻,南瓜粉）的配比,螺杆转速,进料量,含水量协同挤压膨化,结果表明：苦荞麦心粉与皮粉的比例为70：30,螺杆转速为350r/min,进料量为450g/min,水分含量为15％时膨化效果最好;苦荞麦粉与大豆的比例为95：5,螺杆转速为350r/min,进料量为350g/min,水分含量为10％时膨化效果最好;苦荞麦粉与芝麻的比例为98：2,螺杆转速为350r/min,进料量为450g/min,水分含量为15％时膨化效果最好;苦荞麦粉与南瓜的比例为95：5,螺杆转速为350r/min,进料量为550g/min,水分含量为10％时膨化效果最好。     

棉籽饼粕双螺杆挤压脱毒中的参数研究

考察了棉籽饼粕双螺杆挤压脱毒中不同加工参数对脱毒效果的影响。结果表明：增大螺杆转速、减低喂料速度，脱毒效果变好。但考虑到产量要求，喂料速度不宜过低，故实际中应做到均衡。含水率的影响较为复杂，因原料、操作条件不同而异，一定范围内含水率提高可配以较高螺杆转速、温度及较小口模直径，不同捏合盘长度和位置其效果也不一样，因而一定操作条件下各加工参数间应适宜匹配。此外，实验结果还表明棉籽饼粕双螺杆挤压脱毒是成功的，效果显著。     

Component Interactions in the Extrusion Cooking Process: Influence of Process Conditions on the Functional Viscosity of the Wheat Flour System

Wheat starch, vital gluten and wheat flour solubles were processed in combination, in a single screw extruder. The paste viscosity profile and degree of cook of the starch component were used to assess interactive effects. The composite of all 3 components, simulating a wheat flour, was more cooked and gave thicker pastes than wheat flour itself when processed under the same extrusion conditions. The data suggest that the integral structure of wheat flour particles imparts a greater resistance to water penetration and cooking than when the individual components exist at random in a composite formulation.     

响应曲面法对双螺杆挤压蒸煮玉米粉条件的优化

以普通玉米粉为原料,通过双螺杆挤出对玉米粉进行改性,探讨高水分条件下物料含水量、挤出温度、螺杆转速对挤出物糊化度的影响,并建立物料含水量(X1)、挤出温度(X2)、螺杆转速(X3)之间的数学模型,即Y＝96.97－1.49X1－1.21X2－1.85X3－0.37X1X2－1.15X1X3－2.35X2X3－2.20X12－2.50X22－3.77X32,确定了最佳蒸煮条件为含水量34%、挤出温度139℃、螺杆转速223r/min。在此条件下,玉米粉的糊化度为97.5%,与理论预测值基本相符。     

Extrusion of Soybean and Wheat Flour as Affected by Moisture Content

The effect of moisture content (MC) on texture and properties of extrudates with varied ratios of soybean flour (SF) and wheat flour (WF) was studied. A single-screw extruder was used at screw speed 200 rpm. MCs of blends were 16, 17 or 18%, w.b. The properties of extrudates depended on flow rate of the material during extrusion. The flow rate revealed a nonlinear dependence on the blend composition and the MC at the same volume of filling of the screw feeding section. The expansion ratio of WF or SF extrudates increased with lowering of the MC. Unexpectedly, the expansion ratio decreased with lower MC for the composite extrudates. Optimal extrudate properties at 16% (w.b.) MC corresponded to 80, 90 or 100% (d.b.) WF and 20, 10% or no SF, respectively. At 17 and 18% MC, optimal properties were found for products containing 80 or 90% WF and 20 or 10% SF, respectively.     

挤压膨化压力对小麦麸皮粉特性的影响

以小麦麸皮为原料,分别在1.3 MPa～1.6 MPa模头压力下进行膨化处理,研究不同的膨化压力对小麦麸皮粉理化特性、微观结构和加工特性的影响。结果发现,随着处理强度的提高,小麦麸皮的可溶性膳食纤维含量提高、植酸含量降低,褐色反应逐渐明显;微观结构观察表明,挤压膨化会导致小麦麸皮粉颗粒破碎,粒径降低;加工特性研究发现,随着挤压强度的增大,小麦麸皮粉的堆积密度、振实密度和相对增重有所提高,流动性、水合特性、热稳定性和抗氧化性显著增强（P＜0.05）。由试验结果可知,小麦麸皮粉经挤压膨化处理后可作为一种高膳食纤维类食品配料,数据可为挤压膨化自动化参数设置提供参考。     

小麦制粉过程中的吸风粉淀粉与小麦粉淀粉的理化性质对比研究

通过3条小麦制粉生产线6组淀粉样品的对比分析,探讨了吸风粉淀粉与相应小麦粉淀粉的颗粒特性及糊化特性。结果表明:吸风粉淀粉与小麦粉淀粉的颗粒特性差异较大,吸风粉中小颗粒淀粉居多,大颗粒淀粉较少,损伤淀粉含量较高。吸风粉淀粉的糊化峰值黏度、低谷黏度、最终黏度及衰减值较低;吸风粉淀粉的沉降体积较高,溶解度稍低,凝沉性与冻融稳定性稍差。     

Reverse Screw Element(s) and Feed Composition Effects during Twin-Screw Extrusion of Rice Flour and Fish Muscle Blends

The influence of location and spacing of reverse screw element(s) on specific mechanical energy input and product attributes during twin-screw extrusion of rice flour and pink salmon blends was investigated. Incorporation of reverse screw element(s) increased specific mechanical energy, expansion ratio and water solubility index; but decreased bulk density and Warner-Bratzler shear stress. Opposite trend was observed with increasing fish content except for shear stress, which was little affected either for rice flour or its blends with 30% fish solids in the expansion ratio range 5 to 10. Linear relationships were found between shear stress and bulk density and between solubility index and specific mechanical energy.     

大豆粉对面粉及面制品品质影响

使用添加剂对面粉品质进行改良是面粉行业发展的必然趋势.大豆粉作为一种新型的天然添加剂已经引起广泛关注.大豆粉对面粉色泽和筋力、对面团的流变特性,对面制品的营养品质、食用品质都有很大的影响.但要合理添加.     

蒸煮挤压过程中淀粉的变化

研究了挤压过程中，挤压温度、螺杆转速、进料速度、原料水分含量对淀粉的糊化、降解及对挤出物的溶解指数和膨化度的影响。     

不同粒度小麦粉的理化特性研究

通过对不同研磨系统,相同研磨强度下不同粒度小麦粉的水分、灰分、白度、面筋、破损淀粉含量、粉质、拉伸特性,研究面粉粒度对面粉理化特性及流变学特性的影响。面粉在相同的研磨条件下,随着粒度的减小,其白度会增加,破损淀粉含量明显增加,吸水率随之提高,面团的流变学特性也会发生变化。而同一粒度下不同的研磨方式中,石磨的研磨强度较大,所以各方面指标也较特殊。     

Changes in Moisture, Protein, and Fat Content of Fish and Rice Flour Coextrudates during Single-Screw Extrusion Cooking

Changes in proximate composition of fish and rice flour coextrudates like moisture, protein, and fat content were studied with respect to extrusion process variables like barrel temperature, x ₁ (100–200 °C); screw speed, x ₂ (70–110 rpm); fish content of the feed, x ₃ (5–45%); and feed moisture content, x ₄ (20–60%). Experiments were conducted at five levels of the process variables based on rotatable experimental design. Response surface models (RSM) were developed that adequately described the changes in moisture, protein, and fat content of the extrudates based on the coefficient of determination (R ²) values of 0.95, 0.99, and 0.94. ANOVA analysis indicated that extrudate moisture content was influenced by x ₄, protein content by x ₁ and x ₃, and fat content by x ₃ and x ₄ at P?<?0.001. Trends based on response surface plots indicated that the x ₁ of about 200 °C, x ₂ of about 90 rpm, x ₃ of about 25%, and x ₄ of about 20% minimized the moisture in the extrudates. Protein content was maximized at x ₁ of 100 °C, x ₂?>?80 rpm, x ₃ of about 45%, and x ₄?>?50%, and fat content was minimized at x ₁ of about 200 °C, x ₂ of about 85–95 rpm, x ₃?<?15%, and x ₄ of about >50%. Optimized process variables based on a genetic algorithm (GA) for minimum moisture and fat content and maximum protein content were x ₁?=?199.86, x ₂?=?109.86, x ₃?=?32.45, x ₄?=?20.03; x ₁?=?199.71, x ₂?=?90.09, x ₃?=?15.27, x ₄?=?58.47; and x ₁?=?102.97, x ₂?=?107.67, x ₃?=?44.56, x ₄?=?59.54. The predicted values were 17.52%, 0.57%, and 46.65%. Based on the RSM and GA analysis, extrudate moisture and protein content was influenced by x ₁, x ₃, and x ₄ and fat content by x ₂, x ₃, and x ₄.     

小麦粉路系统面粉冻融稳定性研究

对国内典型中长粉路小麦制粉系统进行抽样,分析了各粉路系统面粉样品的部分理化性质和冻融稳定性。结果认为:冻融稳定性较好的面粉集中于前路心磨系统,皮磨、渣磨、尾磨面粉和吸风粉、打麸粉的冻融稳定性较差。找出了冻融稳定性较好的11个特定取粉点,可作为生产速冻食品专用粉的基础原料,总取粉率占出粉率25%~30%,并具有蛋白质和湿面筋含量适中,灰分较低,白度好,a*值偏绿且绝对值较高的品质特点。     

The Effects of Extrusion Conditions on the Physical Properties of Wheat Flour Extrudates

The effects of extrusion conditions (feed moisture content and rate, process temperature, screw speed and geometry, and die diameter) on expansion ratio, bulk density, and breaking strength of wheat flour extrudates were investigated. Extrudate samples were prepared by using a Brabender single-screw extruder. Higher feed moisture content and process temperature were required for proper expansion. At 3.18mm die opening, the relationship between expansion and bulk density was positive. Feed rate was the most effective factor for increasing bulk density. Breaking strength was significantly decreased with increasing process temperature. Under extrusion conditions of 22% feed moisture, 110g/min feed rate, 160°C process temperature, and 130rpm screw speed with 5:1 CR, wheat flour was puffed with low bulk density and breaking strength.     

Analysis of Shear and Thermal History During Co-Rotating Twin-Screw Extrusion

A computation procedure was developed for calculating contributions of frictional and viscous heat generation during co-rotating twin-screw extrusion. Application of energy balance to experimental data (mechanical energy input, feed rate, feed moisture, screw speed, die pressure, barrel wall and dough temperature profiles) indicated how conditions affected fill, filled length, shear and thermal energy inputs to the foods. Kneading blocks increased degree of fill in partially filled sections, and dissipated 4–6 times more viscous heat than conveying elements in completely filled sections. Energy input profiles along extruder screw axis clearly demonstrated how heat generation from shear and heat transfer between extruder and foods influenced total energy input.     

不同品种甘薯与小麦配粉对粉质及馒头品质的影响

研究5个高胡萝卜素甘薯品种(秦薯8、普薯32、南薯010、徐渝薯34、泰中14)的甘薯全粉不同添加量对配粉面团特性及配粉馒头品质的影响。结果表明,随着甘薯全粉质量分数的增加,5种甘薯配粉面团的形成时间、稳定时间及粉质指数均逐渐下降,弱化度均升高。添加甘薯全粉后,5种甘薯全粉制作的馒头亮度均降低、色泽均变暗,馒头感官评价得分随甘薯全粉质量分数的增加逐渐降低。同一质量分数下,5种甘薯配粉的面团特性及配粉馒头品质存在品种差异,南薯010配粉馒头感官评价得分最高。制作配粉馒头时,南薯010、普薯32、秦薯8号甘薯粉的添加量可以添加到15%,徐渝薯34和泰中14甘薯粉的添加量不能高于10%。