Effects of formulation and extrusion cooking conditions on furfural and hydroxymethylfurfural content

The objective of this research was to investigate the effects of different ingredients (reducing sugars, leavening agents, citric acid), processing conditions (feed moisture content, exit die temperature), and extrusion cooking methods (with/without CO₂ injection) on furfural and 5-hydroxymethylfurfural (HMF) formation in corn-based extrudates. The decrease in furfural levels was 16% upon addition of sodium-bicarbonate, while the increase was 12% upon addition of ammonium-bicarbonate for extrudates produced at 150 °C and feed moisture content of 22%. The furfural concentration of extrudates produced at 150 °C and feed moisture content of 22% without leavening agents was 810 μg/100 g and increased to 11,901 μg/100 g upon citric acid addition (about a 15-fold increase). Furthermore, both low feed moisture and high exit die temperature had promoting effects on furfural and HMF contents. The CO₂ injection method did not have considerable effect on furfural and HMF levels of the extrudates; however, it positively affected the physical properties of extrudates.     

挤压膨化大米辅料麦汁和啤酒的糖类组分分析

用液相色谱技术对挤压膨化大米啤酒辅料对应的麦汁、啤酒的糖类组分进行了测定，表明：膨化大米辅料麦汁中麦芽糖含量明显高于未膨化大米辅料麦汁，未膨化大米辅料麦汁中葡萄糖、果糖、蔗糖和麦芽三糖的含量均略高于膨化大米辅料麦汁，膨化和未膨化大米辅料对应的啤酒中没有检测出果糖、葡萄糖、蔗糖、麦芽糖，只检测出微量的麦芽三糖。     

挤压加工对脱壳菜籽油脂品质的影响

研究了脱壳油菜籽挤压系统参数(套筒温度、螺杆转速、螺头至模板距离、模孔长度、模孔孔径)对从榨笼中挤压出的菜籽油的游离脂肪酸、碘值和油脂稳定性的影响规律。结果表明:挤压系统参数对脱壳菜籽油的游离脂肪酸及油脂稳定性的影响较大,对油脂碘值影响较小。比较了传统压榨菜籽油、挤压不脱壳菜籽油、挤压脱壳菜籽油的游离脂肪酸、碘值和油脂稳定性,结果显示:从榨笼挤出的脱壳菜籽油的游离脂肪酸及油脂稳定性都好于传统压榨油和不脱壳挤压油。     

挤压系统参数对脱壳菜籽残油率影响的试验研究

研究了用于浸油的脱壳菜籽挤压膨化预处理工艺(油菜籽清理—脱壳—膨化—浸油)的可行性,及菜籽挤压膨化系统参数(挤压机螺杆末端至模板内表面的距离δ、模孔直径Φ、套筒温度Τ、螺杆转速N、模孔长度L)对各考察指标(膨化物含油率Y1、榨笼出油率Y2和粕残油率Y3)的影响规律和挤压系统优化参数的范围,即δ=20~30mm、Φ=8~12mm、Τ=80~100℃、N=20~35r/min、L=10~30mm。指出:只要挤压系统参数选择合适,油菜籽清理、脱壳、挤压膨化、浸出的脱壳菜籽浸油预处理工艺是可行的,且粕残油率较低。为生产中应用上述脱壳菜籽挤压膨化浸油预处理工艺提供科学依据。     

Preparation, physicochemical and texture properties of texturized rice produce by Improved Extrusion Cooking Technology

Using broken rice and rice bran as raw material, texturized rice (TR) was prepared by Improved Extrusion Cooking Technology (IECT) in which gelatinization is formed by means of low temperature and high pressure. The expansion of extrudate was hardly changed so that TR showed similar texture properties and shape with polished rices. The effect of rice bran addition (0% and 4%) and IECT conditions, including feed moisture content (26.6-33.4%), screw speed (20.1-32.6 rpm) and shearing compression metering zone temperature (SCMT, 69.8-120.2 °C) on the physicochemical, texture and nutritional characteristics of TR, were investigated by response surface methodology using Central Composite Design. When the bran addition was 4%, feed moisture content was 30%, screw speed was 26.6 rpm, SCMT was 95 °C, prepared TR contained 16.61 ± 0.02% of total dietary fiber, 9.40 ± 0.04% of protein, 3.68 ± 0.03% of fat, 2.42 ± 0.02 μg/g of thiamin, 0.52 ± 0.01 μg/g of riboflavin and 16.07 ± 0.12 mg/100 g of γ-oryzanol (dry matter content). The content increase of TDF for TR was 15.81% and the content increases of nutrients for thiamin, riboflavin, and γ-oryzanol were 1.39 μg/g, 0.24 μg/g, and 8.99 mg/g dry matter content, respectively, compared with those of polished rice.     

An innovative approach for significantly increasing enzyme resistant starch type 3 content in high amylose starches by using extrusion cooking

In this study effects of extrusion cooking on enzyme resistant starch (RS) formation in high amylose corn starches (Hylon V and VII) and the functional properties of RS preparations were investigated. Native starches were extruded at 50, 60, 70% feed moisture contents, at constant screw speed (100 rpm) and barrel temperature (140 °C). Among these samples, the highest RS contents were observed at 60% feed moisture. Therefore, feed moisture in the second and third extrusion cycles was set at 60%. There were significant increases in RS contents of both Hylon V and Hylon VII after the second extrusion cycle (p < 0.05). After the third extrusion, the RS levels reached to 40.0 and 45.1% for Hylon V and Hylon VII, respectively. Substantial loss of birefringence in these samples indicated that the increases in RS were mainly due to RS3 formation. The RS samples produced by extrusion did not have high emulsion capacity, but the ones produced from Hylon VII had high emulsion stability. Although, decreases in L* and increases in b* values of extruded samples were significant as compared to respective native starches, the changes were not substantial. Therefore, their incorporation is not expected to cause major changes in the colour of end-products.     

鱼肉脱脂对双轴挤压组织化的影响

鲱经采肉,脱脂等处理后,与大豆分离蛋白混合经双轴挤出机共同挤出,套筒温度为１６０℃,送料速度３３ｋｇ／ｈ,螺轴转速１２０ｒ／ｍｉｎ,实验结果表明,脂肪含量为２．８％,１．６％（干基）的两种脱脂鱼肉,呈现出优越的组织化性能,挤出物呈多孔膨松结构,并且具有类似畜肉的韧性和咀嚼感,电子显微镜扫描结果显示,该组织化产量具有良好纤维结构并没有挤出方向定向。     

维生素B1、维生素B2营养米的挤压强化法制备与品质分析

利用挤压强化技术制备维生素B1、维生素B2营养米,高效液相色谱结果表明维生素B1、维生素B2的保留率分别为62.8%、81.0%。挤压制备的营养米理化特性与原料相比发生较大变化,其中糊化度、水溶性碳水化合物质量分数分别由8.86%、0.58%增加至86.21%、2.98%,而表观密度则由0.91 g/cm3下降至0.80 g/cm3;扫描电镜结果显示强化营养米的表面呈微孔状,但较光滑平整。利用TA-XT2i型物性测定仪分析强化营养米、杂交籼米(原料)和优质粳米,发现营养米的食用品质接近优质粳米。     

淀粉糖浆的挤压酶解技术

采用二次正交旋转组合试验,研究了挤压酶解法生产淀粉糖浆时挤压机参数对淀粉糖浆DE的影响规律,并采用正交试验设计对酶解挤压玉米粉的液化、糖化技术条件进行了研究。结果表明,在挤压机模孔孔径12．2～13．0mm、套筒温度64．2～70．9℃、进料含水率18．43％～19．66％和螺杆转速193～202r／min条件下对获取的挤压玉米粉进行酶解生产淀粉糖浆的酶解条件为水料比3．0mL／g、液化20min、糖化40min。在该挤压条件和酶解条件下,获取的淀粉糖浆的平均DE值为40．80％,糖液出品率及过滤性能等指标均优于对照工艺。     

膨化处理对全脂大豆抗营养因子及营养价值的影响

用螺杆转速为300r/min，模口直径为4Φ8的干法膨化机，在膨化腔指示温度为90度，110度，120度，130度和140度时膨化大豆，研究膨化处理对全脂大豆中抗营养因子及营养价值的影响，结果表明：（1）膨化大豆产品中水分随膨化温度的升高而降低，140度膨化处理大豆中粗脂肪和赖氨酸含量下降。（2）胰蛋白酶抑制因子和脲酶活性随膨化温度的升高呈对数下降，且存在显著的相关性，但二者对热的敏感性不同，凝集素对热的敏感性高于胰蛋白酶抑制因子和脲酶活性，蛋白质溶解度在膨化温度超过130度时下降迅速。（3）110－130度膨化处理大豆中脲酶活性为0．38－0．06ΔpH，胰蛋白酶抑制因子含量为 14．85－5.59mg/g，失活69％－88％，凝集素为0．72－0．00mg/g， 蛋白质溶解度为82．50％－71．58％，时，肉仔鸡生长性能和氮代谢率与豆饼对照组未表现出明显的差异（P＞0．05），膨化温度升高或降低对肉仔鸡生长性能和氮代谢率均有不利影响。