基于变异系数法对气流膨化处理马铃薯方便粥品质的评价

为得到最优的马铃薯方便粥气流膨化处理条件,本实验采用理化分析技术结合色差仪、质构仪、气相色谱-质谱仪等研究不同气流膨化处理条件对马铃薯方便粥营养成分、色泽、质构特性、复水特性以及挥发性香气成分等的影响,并采用变异系数法进行综合评价。结果表明：适宜的气流膨化处理可降低马铃薯方便粥水分质量分数,较好地保持马铃薯方便粥的色泽、总膳食纤维以及可溶性膳食纤维含量,缩短复水时间,提高复水率并赋予马铃薯方便粥坚果似烤香、焦香及特有的薯类香气。基于变异系数法得出水分质量分数、挥发性香气成分（杂环化合物、醛类、烃类）质量浓度、咀嚼性、硬度、复水时间这7 个指标所占权重较大,综合评分结果表明130 ℃处理50 s得到的马铃薯方便粥品质最好。扫描电子显微镜观察发现经气流膨化处理后马铃薯方便粥出现多孔网状结构,内部变得膨胀疏松。傅里叶变换红外光谱分析表明气流膨化处理会影响马铃薯方便粥中蛋白质、淀粉等分子的构型。结论：适宜的气流膨化处理可以改善马铃薯方便粥品质,缩短复水时间。     

挤压变量对马铃薯方便粥品质特性的影响

以马铃薯全粉、大米粉为主要原料,采用双螺杆挤压微膨化工艺,联用常压连续气流膨化技术开发马铃薯方便粥.研究了马铃薯全粉含量、挤压温度、水分含量对马铃薯方便粥品质特性的影响,并采用因子分析法对马铃薯方便粥的品质特性指标进行综合评价.结果表明:随着马铃薯全粉含量、挤压温度的升高,马铃薯方便粥的颜色均逐渐加深,质构特性逐渐降低...     

基于SPME-GC-MS和PCA分析气流膨化处理对马铃薯方便粥香气成分的影响

采用固相微萃取结合气相色谱-质谱对气流膨化处理前后马铃薯方便粥的香气成分进行分离鉴定,并应用主成分分析(principal component analysis,PCA)气流膨化条件对马铃薯方便粥香气成分的影响。结果表明,未经气流膨化处理的马铃薯方便粥含有50种香气成分,其中8种特征性香气成分分别为正己醛、壬醛、反-2-壬烯醛、苯乙醛、甲硫基丙醛、3-辛烯-2-酮、呋喃酮和2,4-二叔丁基苯酚。气流膨化处理后马铃薯方便粥的香气组成从烃类物质为主转变为杂环化合物(吡嗪类)与醛类为主,赋予马铃薯方便粥坚果似烤香、焦香及特有的薯类香气。通过PCA得出,3个主成分的累计贡献率达到90.758%,可代表气流膨化处理马铃薯方便粥的香气变化趋势。PCA结果表明不同气流膨化处理的马铃薯方便粥可分为4类,其中未经气流膨化处理的为一类,110℃/30 s、130℃/30 s、130℃/40 s、130℃/50 s以及130℃/60 s处理的为一类,150℃/30 s处理的为一类,170℃/30 s处理的为一类。气流膨化处理对马铃薯方便粥整体香气具有一定影响,其中气流膨化温度对样品香气影响较大,处理温度过高,样品香气会呈现焦糊味且颜色变深。气流膨化处理马铃薯方便粥的工艺条件为150℃处理30 s。     

黄秋葵热风与远红外干燥特性、动力学及品质的比较

为获得黄秋葵干燥工艺条件,选取不同干燥方式、干燥温度对黄秋葵进行干燥,研究不同干燥工艺条件对干燥特性、动力学和品质的影响。结果表明：热风干燥速率受干基含水率的影响大,远红外干燥速率受干基含水率的影响小。Midilli 模型能准确描述黄秋葵热风和远红外干燥过程。在相同温度下,热风干燥的有效水分扩散系数比远红外干燥的大0.52～1.10 倍,热风干燥所需活化能比远红外干燥所需活化能低5 481.76 J/mol。干制品的VC 降解、复水比和硬度受温度和时间累积效应的影响。以干燥特性、动力学和干制品品质为指标,基于主成分分析获得黄秋葵干燥条件,热风温度70 ℃,干燥时间为300min,有效水分扩散系数为1.36×10-9m2/s,所得干制品VC 含量7.71mg/100g、复水比6.03、硬度3.25 N。     

辣椒渗透脱水处理及渗后热风干燥特性及品质分析

以脱水率、固形物获取率、脱水率与固形物获取率比值、有效水分扩散系数、活化能、VC保留率、辣度、复水比、复原率和感官评价为考察指标,通过渗透脱水实验、渗后热风干燥实验和复水实验,考察了辣椒的渗透脱水特性、渗后热风干燥特性、复水特性和品质。结果表明:随着渗透温度的升高或渗透液中食盐含量的增加,辣椒的脱水率和固形物获取率增大。对渗透后的辣椒样品进行热风干燥处理发现,热风温度是影响热风干燥的最主要因素,其次是风速。辣椒样品的有效水分扩散系数随着温度的升高而增大,在风速为1.8 m/s的条件下,直接热风干燥辣椒样品和渗后热风干燥辣椒样品的活化能分别为(53.25±1.08)k J/mol和(44.42±0.88)k J/mol。渗后热风干燥样品的有效水分扩散系数、VC保留率、辣度、复水比和复原率均高于直接热风干燥样品,渗后热风干燥样品的复水特性和品质更好。     

马铃薯片热风干燥特性及收缩动力学模型

为提高马铃薯片的热风干燥效率及品质,控制其干燥过程中的收缩变形,本文研究了不同热风温度（45、55、65、75 ℃）和切片厚度（3、5、7、9 mm）对马铃薯片热风干燥特性曲线、有效水分扩散系数及活化能等指标的影响。结果表明,干燥室内热风温度越高、马铃薯切片厚度越小时,干燥速率越快。在研究范围内,马铃薯片的有效水分扩散系数在5.02×10?10~11.53×10?10 m2/s范围内,其值随热风温度升高或切片厚度减小而增大。此外,研究发现Weibull分布函数能够很好地描述马铃薯片的降速干燥过程和收缩动力学模型。通过Arrhenius方程计算得到马铃薯片的干燥活化能和收缩活化能分别为27.35和46.44 kJ/mol,马铃薯片干燥比收缩消耗活化能少。本研究为马铃薯片在热风干燥加工中水分迁移和体积收缩变化的预测提供了理论依据和技术支撑。     

黑毛豆仁气流膨化干燥工艺优化

为优化气流膨化干燥黑毛豆仁的工艺,采用三因子二次正交旋转组合设计,分析了预干燥后水分含量、膨化温度和抽空干燥时间对产品的水分含量、硬度、脆度和a*值的影响,并进行响应曲面分析结果表明:预干燥后水分含量、膨化温度、抽空干燥时间对膨化黑毛豆仁的各指标影响显著,黑毛豆仁气流膨化的最佳工艺为:预干燥后水分含量30.75％,膨化温度100℃,抽空干燥时间98min.     

人造米复水过程水分传递特性的研究

对人造米复水过程中水分传递特性进行了研究，结果表明：含水量和温度对扩散系数有显著影响；在复水过程中，扩散系数随含水量增加而增大；与温度呈指数上升趋势，一定温度下的活化能与含水量呈正相关。     

苹果片红外热风联合干燥特性研究

以苹果为原料,研究不同红外辐射距离和热风温度下苹果片的干燥特性,并对苹果脆片的干燥时间、色泽、硬度、脆度和复水性进行分析。结果表明,在苹果片红外-热风联合干燥过程中,热风温度对干燥时间和脆片品质影响显著;干燥过程为降速干燥,水分有效扩散系数范围在2.92×10~(-8)~8.85×10~(-8)m~2/s内,且随热风温度升高而增大;苹果片干燥活化能为75.67 k J/mol。苹果片在红外辐射距离50 mm,辐射功率1500 W,热风温度80℃,风速0.8 m/s的条件下,干燥时间仅162 min,并具有良好的色泽(L*值75.01,a*值8.92、b*值32.97)和质构(硬度1063.66 g,脆度0.531 s)。先红外后热风的联合干燥方式能有效抑制酶活和提高干燥速率,以及改善产品品质。     

苦荞麦高温短时气流膨化工艺初步研究

对高温短时气流膨化苦荞麦工艺进行初步探讨,主要研究进料量、膨化温度、膨化时间和水分含量对产品膨化率、复水率和色差值三种指标的影响,得出较佳膨化工艺条件为物料进料量100～150g、膨化温度260℃、膨化时间40s、物料水分含量10%。     

Hot Air Puffing Kinetics for Soy-fortified Wheat-based Ready-to-Eat (RTE) Snacks

The soy-fortified wheat-based flat cold extrudate, after requisite steaming, was puffed in hot air using the high-temperature short-time (HTST) whirling-bed puffing system. The hot-air puffing was conducted at five different hot air temperatures, 200 to 240 °C at constant fluidizing air velocity of 3.95 m s⁻¹ for 50 s of puffing time. The initial moisture of sample was 0.4617 kg kg⁻¹ dm. The already existing 15 different thin layer-drying models were applied to determine the hot air puffing kinetics, based on puffing temperatures. It was found that the Page model could represent hot air puffing kinetics of the steamed flat cold extrudate within 99.3% accuracy. The effective diffusivity was found to be between 1.15623 × 10⁻⁹ and 2.58631 × 10⁻⁹ m² s⁻¹ for steamed flat cold extrudate in the temperature range of 200 to 240 °C. The activation energy for diffusion was found to be 2,341.824 kJ kg⁻¹. The optimum puffing conditions with respect to expansion ratio (ER) and sensory color score were found at puffing temperature of 220 °C and puffing time of 30 s. The variation in ER for the product was found to follow a linear relationship with moisture content of steamed flat cold extrudate during puffing. The Dincer Number for steamed flat cold extrudate puffed in fluidizing air at temperature 220 °C and 3.95 m s⁻¹ velocity was determined to be 276,223.8. This Dincer Number was used to predict the puffing time required to achieve predetermined moisture content of product. The prediction was found to be effective within 10% deviation from the values of experimental puffing time except during the initiation of puffing.     

Explosion puffing of bananas

Banana slices were satisfactorily dehydrated by incorporating explosion puffing into the drying process. Water contents in the range 27–38%, steam temperatures of 152–160°C, internal pressures of 0.8–1.0 Kg cm^-2 and residence times of approximately 1 min were typical explosion puffing conditions. Initial and final drying were performed with hot air at a temperature of 70°C, velocity 3.6 m s^-1, and relative humidity 35%. The increase in porosity obtained by puffing clearly reduced the total drying time compared with conventional air dried (CAD) samples. A simple diffusional model was applied to calculate the effective diffusivities of water vapour during drying of samples with and without puffing treatment. Analytical tests for colour differences, bulk density, porosity, rehydration parameters, and scanning electron microscopy in both puffed and CAD banana samples were also performed.     

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.     

糙米复配粉中淀粉直/支比对挤压速食粥品质与结构的影响

糙米是一种营养丰富的全谷物食品,但较差的适口性、蒸煮性和消化性制约着其成为主流餐桌食品。为改善其食用品质,本文通过分析不同淀粉直/支比(0.176、0.196、0.216、0.236、0.256、0.276)糙米复配粉的原料特性以及其对挤压速食粥糊化特性、复水品质、质构特性与结构的影响,探究制作糙米挤压速食粥原料复配粉最优的淀粉直/支比。结果表明:随着淀粉直/支比的增加,糙米复配粉的糊化温度和峰值温度增加,挤压速食粥米粒横截面的光滑度及紧密度增加。当淀粉直/支比为0.256时,挤压速食粥米粒横截面的结构最均一、最紧密,复水时间达到12.6 min,米汤固形物损失率和径向膨胀率最小(0.153 g和2.282%),此时的硬度、胶着度和耐咀性明显高于淀粉直/支比0.276,达到3323.85 g、1242.76 g·s和744.73 g。可见,糙米复配粉中淀粉直/支比0.256为制作挤压速食粥的较佳比例。     

百合热风薄层干燥特性及干燥品质

为提高规模化生产的百合品质,缩短干燥周期,以兰州百合为试样,运用JK-LB1700型薄层干燥试验台制干。系统研究了不同热风温度(60,70,80,90℃),热风速度(0.5,1.0,1.5,2.0m/s)和湿度(20%,30%,40%)对百合热风薄层干燥速率、色泽ΔE*值、VC含量、复水比的影响及各指标的变化规律;通过Weibull分布函数模拟了百合干燥过程及水分扩散规律。结果表明:随热风温度、热风速度增大百合热风薄层干燥时间显著缩短(P<0.01),不同相对湿度下无差异,但在干燥前期湿度大小与物料干燥速率呈正相关,后期呈负相关。采用Weibull分布函数能够准确(R2>0.99)描述百合热风薄层干燥过程,基于Weibull分布函数可准确获得百合薄层干燥水分有效扩散系数(1.213×10-6~3.992×10-6 m2/s),Deff值不仅受干燥参数影响,也受干燥设备和试样贮存时间的影响。试验干燥参数对百合品质指标色泽ΔE*值、VC含量和复水比的综合影响大小依次为干燥温度>热风速度>相对湿度,品质指标色泽ΔE*值和VC含量受干燥参数影响较大,复水比较小。     

响应面法优化番木瓜变温压差膨化干燥工艺

优化对番木瓜变温压差膨化干燥工艺,基于响应面的中心组合设计方法,分析预干燥时间、膨化温度、抽
空时间3 个因素对番木瓜膨化产品含水率、硬度、脆度、色泽和复水比5 个指标的影响。采用因子分析法确定5 个
指标的权重,通过综合评分得到番木瓜变温压差膨化干燥的最佳工艺参数范围。结果表明：预干燥时间、膨化温
度、抽空时间三因素对产品的含水率、硬度、脆度、色泽和复水比均有显著影响（P＜0.05）,且三因素交互作用
对产品品质影响显著;番木瓜变温压差膨化最优干燥参数为：预干燥时间4.96～6.00 h、膨化温度80.00～97.23 ℃、
抽空时间2.02～3.00 h。     

Effect of puffing conditions on physical properties and rehydration characteristic of instant rice product

The aim of this work was to study the effects of puffing conditions on the properties of instant rice and to obtain optimal processing condition for product with rehydration time within 5 min. Thai jasmine rice was soaked, cooked and dried at 80 °C in a tray dryer before being puffed at different moisture contents (15–20% wb), temperatures (200–220 °C) and time intervals (20–30 s). The rice puffed at higher moisture contents and puffing temperatures for longer time exhibited higher volume expansion ratios and shorter rehydration times. Presumably, case hardening of the grain surface occurred. Instant rice that can be rehydrated in 5 min with more acceptable hardness than the commercial instant rice was obtained. Regression models to predict the quality of instant rice were developed using response surface methodology.