树莓果片微波膨化机理

为了揭示微波加热树莓果片的体积膨胀机理,对树莓果片微波膨化特性进行研究,根据电磁场、传热场、结构力学及稀物质传递理论,建立了树莓果片微波膨化四场耦合模型,选取微波强度和初始水分质量分数作为影响参数,得到了膨化过程中树莓果片的温度分布、水分质量分数及膨胀变形的变化规律,并与实验结果进行对比分析。结果表明：微波加热条件下,果片内部的水分蒸发使得果片内产生较高的压力,推动果片膨胀,果片表面水分的蒸发使得果片发生收缩行为,膨胀和收缩这两种相反的趋势最终决定树莓果片的体积变化。果片的温度分布主要由微波穿入果片的渗透深度决定,随着微波加热时间的延长,果片的水分质量分数逐渐降低。温度的升高和水分质量分数的降低导致树莓果片弹性模量的增大,弹性模量的变化影响着果片体积的膨胀。当微波强度为20～40 W/g、果片初始水分质量分数为26%时,膨化后树莓果片的品质较好,且膨化率也比较高,最大膨化率可达到3.91。     

Optimising pulsed microwave‐vacuum puffing for Shiitake mushroom (Lentinula edodes) caps and comparison of characteristics obtained using three puffing methods

Shiitake mushroom (Lentinula edodes) caps were puffed using pulsed microwave‐vacuum puffing (PMVP), microwave‐vacuum puffing (MVP) and microwave puffing (MP). The response surface method was used to optimise the process parameters for using PMVP to puff mushroom caps. The experiments were conducted using a central composite design to determine the visual appearance and initial moisture content (30–50%) of the mushroom caps. The initial moisture content and microwave power intensity showed highly significant linear relations with the expansion ratio and sensory evaluation. The optimal conditions for puffing mushroom caps were initial moisture content, microwave intensity, vacuum pressure and pulse ratio of 35%, 40 W g^?1, 77.5 ± 1.5 kPa and 1.35, which resulted in an optimal expansion ratio and sensory score of 163.2% and 6.83, respectively. The caps puffed using PMVP showed better textures, sensory scores and microstructures than those puffed using either MP or MVP.     

双孢菇微波膨化工艺的优化

为了确定适宜的双孢菇膨化干燥工艺,在单因素的基础上,采用Box-Behnken中心组合响应面设计,对双孢菇膨化工艺进行了优化,分析了初始含水量(X1),切片厚度(X2),微波功率(X3)3因素作为输入变量,对膨化度(Y1)、感官得分(Y2)指标的影响。根据试验数据推论出描述这2个指标的二次回归模型,并进行了响应面分析,得出了双孢菇优化膨化工艺。结果表明:在微波功率为540 W、双孢菇片厚度为8 mm、双孢菇初始含水率为38%的条件下,膨化率达到195%,感官指标为9.5。     

微波膨化猕猴桃脆片工艺的优化

以猕猴桃为原料,研究了微波膨化猕猴桃脆片的最佳工艺。通过单因素实验分别考察了水分含量、切片厚度以及微波时间等因素对膨化率的影响。在此基础上,以膨化率为指标,设计了响应面分析方案,通过数学推导及实验分析,得出微波膨化猕猴桃脆片的数学模型及相关参数。结果表明,微波膨化猕猴桃脆片的最佳工艺参数为:猕猴桃片的水分含量为20%、切片厚度4mm、微波时间62s,在此优化条件下得到的猕猴桃脆片膨化率为73.8%,与回归方程的预测值(73.1%)基本一致。膨化后猕猴桃脆片的水分含量为5.4%,因此会有较酥脆的口感和贮藏稳定性。VC含量在猕猴桃片干燥的过程中和膨化后都显著的减少了。      

响应面法优化微波膨化紫心甘薯片的工艺

将水分含量为20%的紫心甘薯片微波膨化,可得色泽、口味、膨化酥脆度适中的脆片。在单因素试验基础上,采用Plackett Burman试验,筛选出具有显著性影响因素,通过响应曲面法进一步分析这些因素的交互作用对微波膨化紫心甘薯脆片的影响,得到最佳膨化工艺参数,薯片厚度为1 mm,水分含量20%,均湿时间2 d,微波功率430 W,膨化时间40 s。     

微波膨化果蔬小食品的研究

探讨了微波膨化技术在山药和胡萝卜脆片加工中的应用。以膨化率为指标,结合感官评价,实验了添加不同比例的淀粉原料对山药及胡萝卜脆片膨化效果的影响,并讨论了样品初始水分含量、样品的厚度以及微波功率和时间对膨化率的影响,且通过正交实验确定了最佳膨化工艺条件。     

微波膨化银杏脆片的工艺研究

探讨了微波膨化技术在银杏脆片加工中的应用。以膨化率为指标结合感官评价,试验了添加不同比例的淀粉原料对银杏脆片膨化效果的影响,并讨论了样品初始水分含量、样品的厚度以及微波功率和时间对膨化率的影响,且通过正交试验确定了最佳膨化工艺条件。     

Physical,chemical and nutritional characteristics of puffed quinoa

Puffed quinoa can be used as ready-to-eat breakfast food or as an ingredient in snack formulations. In this study, puffed quinoa products with and without starch–chitosan coating were developed by gun, extrusion and microwave puffing at different process conditions (pressure, power, moisture content and energy consumption). Size, bulk density, colour, expansion index, water absorption and solubility, microstructure, mechanical and thermal properties, chemical composition and in vitro digestibility of organic matter and proteins of popped quinoa were assessed. Optimal process conditions for gun puffing were maximum 1.31 MPa after 780 s, 500 r.p.m. and 180 s for extrusion puffing and 1200 W for 60 s applying microwave puffing at 18–20% moisture contents. Gun and extrusion puffing yielded high-quality popped quinoa with a biological availability of organic matter between 84–88% and 79–90% for proteins. Extrusion and gun puffing are the most promising processes to prepare quinoa snacks.     

Influence of energy input and initial moisture on physical properties of microwave-vacuum dried strawberries

In microwave-vacuum drying, thermal energy is replaced by electric energy for heating the material. The additional application of a sufficient vacuum results in a gentle treatment, and specific product features such as aroma and flavor components, and color can be conserved. A crisp texture results from puffing due to expansion when moisture evaporates within the product, and is related to porosity. Using strawberries, a statistical central composite design was applied to relate specific drying energy and evaporation rate as well as raw and bulk density, and particle size distribution to absorbed microwave power input ranging from 2.4 kW kg⁻¹ to 10.5 kW kg⁻¹ dry matter, and to an initial moisture content of 0.17 kg kg⁻¹ to 0.73 kg kg⁻¹ on dry basis, achieved by convective predrying. A low initial moisture content and high microwave power lead to products with low density, porous structure and optimum puffing effects, but shows disadvantages with respect to moisture evaporation rate and energy utilization. On the other hand, optimum efficiency results from the use of raw materials with a high initial moisture content and from applying a high microwave power input.

Microwave puffing: Determination of optimal conditions using a coupled multiphase porous media - Large deformation model

Increased interest in microwave puffing is due to its ability to obtain low-fat and ready-to-eat healthy products. Determination of optimal conditions for this complex process has been difficult and although several patents exist on the concept, we are yet to see any large scale commercial use. A fundamental physics based modeling approach integrated with relevant experimentation, developed in this work, is an ideal framework to understand and optimize microwave puffing. The results showed that puffing may not be successful unless carried out using an intensive heating source such as microwaves. Addition of infrared and hot air leads to better quality product whereas using forced air convection is not desirable. There is an optimum initial moisture content depending on the puffing conditions. The study provides critical guidelines to food product/process developers for successful development, control and automation of microwave puffing, thereby leading to value-added nutritious products.     

响应面法优化苦荞麦微波膨化工艺

采用苦荞麦为原料,以膨化率、复水率为评价指标,色差值为参考指标,通过响应面优化试验研究苦荞麦微波膨化工艺条件。结果表明,苦荞麦微波膨化的最佳工艺条件为:膨化时间110 s,原料水分含量6%,微波功率480 W。在此条件下的验证实验结果为:膨化率2.16,复水率1.25。     

微波真空膨化山楂片工艺参数优化研究

为确定膨化山楂片的最佳工艺,在单因素实验的基础上,采用响应面法（RSM）优化膨化山楂片的工艺。分析了初始含水量、真空压力、微波强度三个因素对膨化山楂片的膨化度、感官评分两个指标的影响;测定膨化过程中山楂片的营养成分变化和物理特性变化,得出微波膨化山楂片最佳工艺。结果表明,在初始含水量35%±0.5%、真空压力-74 k Pa、微波强度31 W/g时,膨化度为1.663±0.235,感官评分为6.382±0.521;研究发现,膨化过程中山楂片的活性成分VC、黄酮、花色苷均有不同程度的降低,硬度和咀嚼性增加,弹性和粘附性降低;扫描电镜图片显示膨化过程中山楂组织结构由致密变为疏松。      

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.     

爆裂玉米的化学成分对微波膨化率的影响

通过测定黄玫瑰型３种不同产地的爆裂玉米的水分，淀粉，蛋白质含量，研究其对微波膨化效果的影响，同时对乙醇处理后的爆裂玉米的微波膨化效果，进行了初步探讨，结果表明，爆裂玉米的微波膨化率随淀粉含量的增加而提高，尤其是支链淀粉的含量；蛋白质和水分通过与淀粉之间的相互作用，影响爆裂玉米的微波膨化效果，微波膨化后，爆裂玉米的淀粉含量减少，低聚糖含量增加，蛋白质含量不变，乙醇浸渍后，可提高爆裂玉米的微波膨化率。     

鱼糜微波膨化工艺优化及水分状态研究

以冷冻淡水鱼糜(鲢鱼)为研究对象,优化鱼糜微波凝胶化和膨化的最佳工艺条件,研究微波凝胶化和膨化过程鱼糜中水分迁移特性。采用二因素二次回归正交旋转组合设计试验,优化微波功率和微波作用时间两个因素在鱼糜微波凝胶化和膨化过程中的工艺条件,利用低场核磁等技术研究水分状态的变化。结果表明,鱼糜微波凝胶化最佳条件为:微波功率124 W,微波作用时间为11.0 min;鱼糜微波膨化最佳条件为:微波功率273 W,微波时间为10.0 min。在此条件下,可得到金黄色带有鱼香味的脆性膨化鱼糜制品,微波膨化鱼糜制品膨胀率为258%±23.9%,硬度为(26.98±1.85) N,脆性为(13.95±1.23) N。鱼糜微波凝胶过程中,水分存在状态由单一的不易流动水(T₂₂)转变为自由水(T₂₃)和不易流动水(T₂₂)两种状态,其中T₂₂部分转为成T₂₃,T₂₃被锁闭于鱼糜凝胶网状架构中,水分状态的稳定性增强,表现为驰豫时间减小。鱼糜微波膨化过程中,各水分存在状态的比例由结合水(1.62%)、不易流动水(95.75%)、自由水(2.58%)转变为结合水(88.95%)、不易流动水(11.05%)。     

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。     

微波膨化白茅根工艺的优化

在单因素实验的基础上,以长度、含水量、微波功率和微波时间为考察因子,以综合得分为评价指标进行实验设计,利用响应曲面分析法对微波膨化白茅根的工艺参数进行优化。结合实际条件,得到最优工艺参数为:长度3.3cm、水分含量16.0%、微波功率690 W和膨化时间21 s。在此条件下得到的白茅根综合得分为8.15,多糖含量增加了15%。      

挤压膨化工艺参数对夏秋绿茶多酚含量及膨化度的影响

利用双螺杆挤压膨化机对夏秋绿茶进行挤压膨化,研究物料含水量、套筒温度以及螺杆转速对膨化绿茶粉中茶多酚含量以及膨化度的影响,并分析夏秋绿茶膨化前后浸出功能成分及微观结构的变化。结果表明:随物料含水量增加,茶多酚含量先减少后增加;增加套筒温度会增大茶多酚的浸出,当温度过高时会导致茶多酚的损失;随螺杆转速增大,茶粉破损程度加大,促进茶多酚的浸出。套筒温度、螺杆转速对挤出物膨化度的影响较小,物料含水量的影响相对较大。与未加工夏秋绿茶粉相比,加工后的夏秋绿茶粉中茶多酚、粗纤维、可溶性总糖含量降低,茶氨酸含量增高。夏秋绿茶膨化后,其表面结构变得平整光滑,且机械力作用使物料自身化学键断裂。     

板栗糯米饼的微波膨化工艺和酥脆度改善方法的研究

本实验以面粉、糯米粉及板栗粉为主要原料,将糯米粉、面粉、板栗粉、土豆淀粉混合后使用微波膨化技术制作成膨化板栗饼。首先通过单因素实验了解不同因素对产品感官品质的影响,然后采用正交实验进一步对关键因素进行优化,确定了膨化板栗饼制作的最佳工艺条件为:原料(面粉、板栗粉、糯米粉)配比为4∶6∶8,原料初始含水量为20%,土豆淀粉的添加量为7%,微波炉膨化时间为100s,功率为520W,设定温度为150℃。在此工艺条件下所得产品膨化度为2.9,制得口感较佳的膨化板栗饼。      

Quality Attributes of High Temperature Short Time Air Puffed Ready-to-eat Potato Snacks

The effects of process parameters for high temperature short time (HTST) air puffing viz. puffing temperature (175–275°C), puffing time (15–75s), moisture content (30–40%), and air velocity (2.4–4.8m/s) on quality attributes such as expansion ratio (ER), bulk density (BD), colour (L-value), and texture (hardness) of ready-to-eat (RTE) potato snacks were investigated, based on central composite design. Increasing puffing temperature resulted in potato snack with a higher ER, lower hardness, lower BD, and lower L-value. Increasing puffing time produced lower hardness and lower L-value but no significant effect on the ER and BD. Higher moisture content increased ER and L-value but reduced hardness and no significant effect on the BD. Increasing air velocity resulted in potato snack with a higher ER, higher L-value, lower BD and lower hardness.