Properties of pregelatinized rice flour made by hot air or gum puffing

Three varieties of rice, TCW 70, TN 67 and TCN 1, with an amylose content of 1.0, 20.3 and 32.0%, were used to produce pregelatinized rice flour by using hot air fluidized‐bed puffing or gun‐puffing methods. Serious molecular degradation was introduced by the gun‐puffing process. However, there were no significant differences in the molecular weights of rice flour before or after the hot air fluidized‐bed puffing process. Pasting properties of pregelatinized rice flours were dependent on the rice variety and the types of pretreatment, and were significantly affected by the puffing method. Hydrothermal pretreatment had different effects on the pasting and hydration properties of pregelatinized rice flour, depending on whether it was made from waxy or non‐waxy rice. Various properties of pregelatinized rice flour could be attributed to the combined effects of gelatinization, retrogradation and degradation of starch molecules during processing.     

魔芋胶膨化食品制备工艺研究

以魔芋精粉为主要原料,以糯米粉、预糊化淀粉和超微粉碎玉米粉为辅料,对魔芋胶膨化脆片的制作工艺进行了研究。通过实验确定了产品的制作工艺、主要工艺条件及配方。结果表明：魔芋精粉和水的比例为1：15的魔芋胶,糯米粉添加量为魔芋胶量40％,超微玉米粉添加量2％,预糊化淀粉添加量20％,经蒸煮、定型、干燥后的坯料水分含量在20％,使用微波功率700W、时间15s加热处理下膨化,所得产品膨化效果好,感官质量佳,产品抗消化性淀粉含量为17．5g／100g。     

Effect of process parameters and soy flour concentration on quality attributes and microstructural changes in ready-to-eat potato-soy snack using high-temperature short time air puffing

High-temperature short time (HTST) air puffing has been found to be very useful process for production of potato-soy ready-to-eat snack food as it ideally produced highly porous and light texture. The process parameters considered viz. puffing temperature (185-255 °C) and puffing time (20-60 s) with constant initial moisture content of 36.74% and air velocity of 3.99 m/s for potato-soy blend with varying soy flour content from 5% to 25% were investigated using response surface methodology with central composite rotatable design (CCRD). The optimum product in terms of maximum expansion ratio (3.69), minimum hardness (2754.3 g) and maximum overall acceptability (7.3) were obtained with 10.31% soy flour blend in potato flour at the process conditions of puffing temperature (230.06 °C) and puffing time (25.46 s). Microstructural changes were evaluated at different stages (with an interval of 5 s) of HTST puffing for product obtained with the optimum processing conditions. The maximum expanded porous structures with larger cracks and smaller pits were recorded in the SEM micrographs at 20 s of HTST air puffing.     

苦荞脆片加工工艺优化及其挥发性成分分析

为了提高苦荞资源的多元化利用,开发苦荞脆片类休闲食品。选取苦荞粉添加量、膨化温度和膨化时间进行单因素实验,以综合评分为响应值,利用响应面Box-Behnken试验优化苦荞脆片生产工艺,并利用气相离子迁移谱技术（GC-IMS）对其挥发性成分进行对比分析。试验结果表明,苦荞脆片的最佳工艺条件为:苦荞粉占面粉质量比10%,膨化温度180 ℃,膨化时间10 min。在该优化条件下,苦荞脆片的综合评分为80.73分,与模型预测值综合评分83.19分基本一致。通过GC-IMS检测苦荞脆片中富含醛类、醇类、酮类等43种挥发性有机物,与空白脆片相比,其相对主要风味成分为E-2-辛烯醛、反式-2-戊烯醛、2-甲基丁醛、糠醛、 γ -丁内酯、2-乙酰基呋喃、1-辛醇、丙酸等物质。本研究结果为制备具有独特风味的苦荞脆片休闲食品及其风味评价提供一定理论依据。     

速食黑糯玉米粉的研制

采用远红外干燥、微波干燥、电热鼓风干燥对煮熟的黑糯玉米进行干燥制粉，另采用膨化干燥黑糯玉米制粉。然后对四种粉进行感官评价，对粉及糊进行性质测定。对评价结果最好的膨化干燥方法制作的黑糯玉米粉采用多因素正交设计和模糊评价产品质量的方法，对黑糯玉米粉中添加脱脂大豆粉、奶粉、低聚果糖的配方进行优化选择。实验结果提出最优配方：脱脂大豆粉10％，低聚果糖0.5％，奶粉10％。     

苦荞羹的研制

以苦荞麦粉为主要原料,经挤压膨化、调配、粉碎等加工成苦荞羹,成品色泽淡黄、清香爽口、即食性好、营养丰富。     

Effect of processing on starch fractions in different varieties of finger millet

The effect of processing on starch fractions in finger millet (ragi) was studied in a standardized system and convenience mixes. In raw varieties, rapidly available starch (RDS) was 8.3% to 11.1% with slowly digestible starch (SDS) of 26.4% to 35.3%, and total available starch (TAS) 39–53%. The changes in the SDS and TAS were statistically significant. Puffing resulted in an increased RDS and decreased SDS. The changes were more prominent in hill grown varieties as compared to base varieties. Resistant starch (RS) ranged from 0.9% to 1.0% among raw varieties and decreased during puffing. The effect of puffing on gelatinisation of ragi flour was investigated, MR-1 variety showed a single phase transition with gelatinisation temperature of 64 °C, the same was found to be absent in puffed flour reflecting the gelatinisation during puffing. RS formation was influenced by the processing methods, increased during pressure cooking and roasting while dietary fiber increased during cooking and both decreased in all other processing methods. However, its implication in the convenience mix has shown that other ingredients also play a role in the RS content.     

螺杆挤压法制备即食葛米粥

将葛粉与籼米粉等主要原料按不同配比经螺杆挤压制备即食葛米粥。对产品的营养组成、质构特点和感官性质进行分析,结果表明:即食葛米粥的主要成分是淀粉、几乎不含黄酮;无论是非膨化的米粒状还是膨化的片状米粥产品,其体外消化率均比原料大幅提高;在能够成型的范围内,添加20%葛粉的米粥产品具有较高的粘性、咀嚼性、硬度和弹性;感官分析表明,20%葛粉的米粥产品容重较高、组织结构较为致密均匀,因而获得了相对较高的感官评分。     

金虫草冲调米粉的挤压膨化制备工艺优化

对培养完金虫草的大米培养基进行挤压膨化试验。通过单因素试验研究不同的物料含水率、挤压温度和螺杆转速及对米粉的碘蓝值的影响,并通过正交试验设计优化挤压膨化工艺。结果表明:物料含水量对米粉的碘蓝值影响显著,即对米粉糊化度的影响最大。当物料含水量为19%,螺杆转速为147.0 r/min,挤压温度为160℃时,碘蓝值可达到1.316,说明米粉的糊化度最好。证明挤压膨化法制备功能性米粉的优势。研究成果可应用于未来蛹虫草功能性米粉的开发与研究。     

变温压差膨化干燥对芒果品质的影响

以凯特芒果为原料,采用变温压差膨化干燥技术,探讨了切条厚度、预干燥后水分含量、膨化温度、膨化压力差、抽空温度、抽空时间和停滞时间对芒果膨化产品的硬度、脆度、色泽、膨化度和含水率的影响.结果表明:芒果膨化的最佳厚度为6 mm;预干燥后水分含量、膨化温度和抽空时间是影响芒果膨化产品品质的关键因素;预干燥后,含水量在61.7...     

鱼糜-淀粉脆片压差膨化加工工艺研究

以糯米淀粉和鱼糜为主要原料,采用压差膨化技术制备鱼糜-淀粉脆片。以硬度、脆性、膨化率、色度和感官评分为评价指标,探讨鱼糜添加量、油脂添加量、盐添加量、糖添加量以及干燥时间对鱼糜-淀粉脆片品质的影响。结果表明,随着鱼糜含量的增加,脆片的膨化率下降而硬度上升;随着油脂含量的增加,脆片的膨化率和白度增大;随着糖含量的增加,脆片白度下降;随着盐含量的增加,脆片膨化率下降;在不同的干燥时间下,脆片的膨化率、质构、色泽与感官都发生明显变化。最后得到鱼糜-淀粉脆片的工艺参数为鱼糜添加量25%,油脂添加量5%,盐添加量1.2%,糖添加量1.2%,干燥3.5 h。     

微波膨化重组型紫薯白灵菇脆片的工艺优化

根据Box-Behnken的中心组合试验设计原理,在单因素试验的基础上,采用三因素三水平的响应曲面分析法,建立重组型紫薯白灵菇脆片加工的二次多项数学模型,以感官得分为响应值作响应面和等高线,分析膨化时间、紫薯白灵菇(质量比为1:1)添加量和水分平衡时间对重组型紫薯白灵菇脆片的影响。研究结果表明,重组型紫薯白灵菇脆片加工的最佳工艺参数为厚度0.6 mm、微波功率700 W、膨化时间121 s、紫薯白灵菇添加量16.9 g、特精粉50 g、水分平衡时间1.3 h,此时其感官得分为91.8。产品外观平整、颜色均匀,微孔大小适度、一致,香味浓郁且口感酥脆。     

微波膨化甘薯鱼糜脆片的加工工艺优化

以甘薯泥和三文鱼加工副产物制作而成的鱼糜为主要加工原料,采用微波膨化技术制作甘薯鱼糜脆片,以产品的感官品质和质构特性为评价指标,通过单因素实验,研究微波膨化条件、植物油添加量、糯米粉添加量、小苏打与碳酸氢铵添加量及其添加比例对甘薯鱼糜脆片的品质影响,并通过正交试验确定最佳工艺。结果表明:以鱼糜与甘薯泥总质量为基准,添加植物油4%,糯米粉30%,小苏打和碳酸氢铵以2:1比例添加1.0%,在500 W功率下微波膨化120 s,制得的甘薯鱼糜脆片感官得分为(86.5±1.01)分,硬度值与脆度值分别为(7654.125±123.521) g、(8165.365±105.347) g,外观完整,色泽均匀,口感酥脆。     

哈密瓜变温压差膨化干燥工艺研究

采用变温压差膨化干燥技术,探讨预干燥后水分含量、膨化温度、抽空温度、抽空时间、停滞时间和压力差等因素对哈密瓜脆片产品的水分含量、脆度、膨化度和色泽的影响。研究结果表明,预干燥后原料含水量、膨化温度、抽空时间对哈密瓜膨化产品质量影响较大;哈密瓜膨化的合适含水量在30.14%左右;较适的膨化温度为90℃、抽空温度为80℃;抽空时间为120min较为合适;停滞时间、压力差处理在一定范围内差异不显著,实验确定停滞时间和压力差分别为5min、0.2MPa。     

Rheological Behavior of Hot-Air-Puffed Amaranth Seeds

Force-deformation and force-relaxation experiments were performed on amaranth seeds puffed at 290, 330 and 370°C. Less force and energy was required to cause a given deformation in seeds processed at 290°C than in those puffed at 330 and 370°C. It was also observed that the forces and energies required to produce a given deformation did not differ significantly (p ≤ 0.05) for seeds puffed at 330 and 370°C. The three-element generalized Maxwell model and Peleg model were applied for modeling force relaxation of puffed amaranth seeds. It was found that the generalized Maxwell model predicted the experimental data better than the Peleg model. The elastic parameters and asymptotic residual force of the generalized Maxwell model were significantly affected by puffing temperature, showing an increase with its rise. Relaxation times were not significantly affected by the puffing temperature. It was concluded that a higher puffing temperature resulted in a more rigid material and less viscous behavior.     

气流膨化过程中马铃薯方便粥水分变化动力学模型及品质变化分析

以双螺杆挤压微膨化工艺开发的马铃薯方便粥为原料,采用气流膨化技术处理马铃薯方便粥,通过测定干基水分含量、水分有效扩散系数、活化能以及色泽、膨化度、孔隙率和复水时间等研究膨化温度和气流速率对马铃薯方便粥水分及品质特性的影响,并建立气流膨化过程中马铃薯方便粥水分变化的动力学模型。结果表明：膨化温度和气流速率对马铃薯方便粥的水分变化均有明显影响。Page模型水分比预测值与实测值的拟合度较高,可以较好地预测马铃薯方便粥气流膨化过程中不同膨化温度、气流速率条件下的水分变化。水分有效扩散系数随着膨化温度、气流速率的升高均增大,气流膨化过程中马铃薯方便粥的活化能为18.96 kJ/mol。膨化时间、膨化温度和气流速率对马铃薯方便粥的亮度L*值、黄蓝度b*值、膨化度、孔隙率和复水时间均有明显影响。由相关性分析可知,气流膨化过程中马铃薯方便粥各品质特性指标间存在极显著相关性（P＜0.01）。本研究可为气流膨化过程中马铃薯方便粥水分实时监测及实现高品质气流膨化提供理论依据。     

冬枣变温压差膨化干燥工艺研究

以冬枣为原料,采用变温压差膨化干燥技术,探讨了预干燥时间、抽空时间、膨化温度、抽空温度、停滞时间和膨化压力对冬枣膨化产品硬度、脆度、色泽和水分含量的影响。结果表明:膨化温度、抽空温度和抽空时间是影响产品膨化质量的关键因素;冬枣预干燥6h后,膨化温度85℃,抽空温度60℃,抽空时间2h为较适合工艺参数;停滞时间和膨化压力差在一定范围内对膨化产品的质量影响不大,实验确定停滞时间15min,膨化压力差0.2MPa为较适合工艺参数。     

Characteristics of Tortillas Prepared from Dry Extruded Masa Flour Added with Maize Pericarp

Corn flour produced by extrusion was used to evaluate the effect of added maize pericarp (0 to 6%, w/w) on the following parameters: water absorption capacity of dry extruded masa flour (DEMF); weight loss during cooking and dehydration rate (DR) in fresh masa (FM), as well as rollability (R), puffing degree (PD), and cutting force (CF) of tortillas. CF was evaluated after 1 and 24 h of preparation. The viscoamylogram profiles, x‐ray diffraction, and crystallinity of DEMF and powdered tortillas were also obtained. The DEMF with 3% (w/w) of pericarp produced the highest tortilla yield, improved the PD, DR, R, and CF characteristics of FM and tortillas, and developed the highest viscosity and a structure with adequate crystallinity to make tortillas with commercial quality.     

SPECIFIC HEAT of INDIAN UNLEAVENED FLAT BREAD (CHAPATI) AT VARIOUS STAGES of COOKING

A simple inexpensive calorimeter was built to measure specific heat of foods at various process temperatures. By using vegetable/mineral oil as the heating medium in place of water, specific heat at temperatures beyond 100°C can also be evaluated. Specific heat of whole wheat dough and Chapati (round disc prepared mostly from whole wheat flour dough) at various stages of cooking and puffing were determined. Based on the experimental data a linear equation (C = 2476.56 + 23.56M ? 3.79T_e) is proposed from the experimental data for specific heat of wheat flour, dough, cooked and puffed Chapati and for other food materials at moisture levels ranging from 0.1% to 80% and temperature ranges from 303° to 336° K.     

Milling and Processing Parameters for Corn Tortillas from Extruded Instant Dry Masa Flour

A continuous extrusion process to provide instant corn flour for tortillas was evaluated. Variables investigated included two types of mill (knives and hammer) with screens with two diameters (0.5 and 0.8 mm), two types of corn (hard endosperm or normal and soft endosperm or cacahuazintle), lime concentration (0.15 and 0.25% w/w), processing moisture (45 and 48% w/w) and temperature (70,80 and 90°C). The water absorption capacity, water solubility index, color of instant corn flour, adhesiveness of masa, tensile strength, cutting force, rollability and puffing of tortillas, were compared. Based on textural data the hammer mill with 0.8 mm sieve, normal corn type, 0.15% lime, 48% moisture and 90°C processing temperature, produced the highest quality tortillas.