渗透脱水蓝莓流化床干燥工艺的研究

经渗透脱水处理的蓝莓在流化床中用5种不同的干燥温度(50、60、70、80、90℃)进行干燥,结果显示, 干燥温度影响物料的水分散失,水分散失率随温度的提高而增加。随着干燥处理的进行水分含量和水分活度都呈下降趋势,且温度越高,两者下降越多。根据费克第二不稳定扩散法则,计算出不同温度下的有效水分扩散率 (D_(eff))分别为(0．753 2～3．673 7)×10~(-10)m~2/s。在干燥脱水处理过程中 D_(eff)随处理温度升高而增加。     

真空、脉冲真空和常压下蓝莓渗透脱水的研究

研究了真空渗透脱水、脉冲真空渗透脱水和常压渗透脱水下蓝莓水分含量和水分活度的变化规律，结果表明：真空渗透脱水时，蓝莓的水分含量和水分活度降低得最快。真空渗透脱水、脉冲真空渗透脱水、常压下渗透脱水蓝莓的有效水分扩散率分别为1.6777×10^-9、1.3629×10^-9、0.5679×10^-9m^2/s。真空渗透脱水、脉冲真空渗透脱水、常压下渗透脱水的有效固性物扩散率分别为9.1705×10^-10、6.3919×10^-10、5.1007×10^-10m^2/s。     

蓝莓渗透脱水和流化床干燥过程中理化变化的研究

蓝莓在高果糖浆(70±1°Brix)和不同渗透温度(45、55、65℃)条件下,不同的渗透液温度处理对蓝莓VC的损失有不同影响,其中以渗透液温度65℃处理对VC的含量影响最大,45℃下渗透脱水VC的损失最少。在5±1℃贮藏时蓝莓干中的花色苷比在22±1℃贮藏时稳定性好。光照使蓝莓干在贮藏过程中总花色苷残留率迅速下降,而暗箱贮藏使蓝莓干在贮藏过程中总花色苷残留率下降缓慢。     

渗透预处理对蓝莓冻结特性的影响

为了研究渗透预处理对蓝莓冻结特性的影响,以冻结曲线、滴水损失率、色差、可溶性固形物质量分数、质构、花色苷含量、水分迁移为指标,探究蒸馏水、海藻糖、海藻糖-氯化钙渗透预处理对冻结蓝莓品质特性的影响。结果表明：海藻糖-氯化钙处理组蓝莓花色苷含量、可溶性固形物质量分数、硬度均显著高于另外两个处理组的样品（P＜0.05）,冻结曲线显示,海藻糖-氯化钙处理组通过最大冰晶区的时间为886.67 s,显著低于其他处理组,降低了冻结对蓝莓组织细胞的损坏,海藻糖处理组的T23值显著低于另外两个处理组（P＜0.05）,且海藻糖的加入对蓝莓的色泽和细胞持水性有一定保护作用。     

南瓜馅料渗透脱水工艺研究

为探索不同参数对南瓜渗透脱水的影响规律,寻找较好南瓜馅料加工方法,选当季新鲜南瓜为试验材料,用不同浓度的麦芽糖浆为渗透液,通过恒温水浴锅创造稳定的温度,对南瓜进行脱水处理。以脱水率和脱水后炒制成的南瓜馅料感官性状为标准,分析渗透脱水过程,比较出渗透液种类、渗透液浓度、处理温度、南瓜条大小等因素对南瓜渗透脱水的影响。脱水后的南瓜馅料进行炒制得到较好的脱水方案:渗透液为30%麦芽糖溶液+10%NaCl,渗透温度为45℃,渗透时间为6 h,南瓜条宽2 mm~3 mm,厚1 mm~2 mm。馅料炒制后水分活度为0.73,有利于馅料的保存。南瓜馅料渗透脱水工艺简洁,易于操作。制品色泽金黄、香味浓郁、半固体状态、口感细腻润滑。     

蘑菇渗透脱水规律的研究

通过多因素正交试验，得出影响蘑菇渗透脱水因素的主次顺序及因素间交互作用的关系；应用均匀试验，建立了蘑菇渗透脱水的回归数学模型，其理论值与实测值具有很好的一致性；利用回归模型，建立了不同条件下的渗透脱水规律预测表。     

莴笋渗透脱水有效扩散系数研究

以葡萄糖溶液浓度(10%～40%)和温度(35～65℃)为影响因素,研究了莴笋渗透脱水的动力学过程。分别使用Azuara模型和Fick第二扩散定律计算出了平衡时刻的失水率、固形物增加率以及相应的水分和固形物有效扩散系数。设计了均匀实验,通过曲面拟合的方法得到了水分、固形物有效扩散系数与因素的回归方程。结果表明:失水率随着葡萄糖溶液浓度增加而增大,但随着温度的升高而降低;固形物增加率随着溶液浓度和温度的增加而增加。Azuara模型可用来预测失水率和固形物增加率,通过曲面拟合得到的有效扩散系数回归方程拟合性较高。有效扩散系数反映了失水率和固形物增加率达到平衡时刻的快慢程度。     

莴笋渗透脱水有效扩散系数研究

以葡萄糖溶液浓度(10%～40%)和温度(35～65℃)为影响因素,研究了莴笋渗透脱水的动力学过程。分别使用Azuara模型和Fick第二扩散定律计算出了平衡时刻的失水率、固形物增加率以及相应的水分和固形物有效扩散系数。设计了均匀实验,通过曲面拟合的方法得到了水分、固形物有效扩散系数与因素的回归方程。结果表明:失水率随着葡萄糖溶液浓度增加而增大,但随着温度的升高而降低;固形物增加率随着溶液浓度和温度的增加而增加。Azuara模型可用来预测失水率和固形物增加率,通过曲面拟合得到的有效扩散系数回归方程拟合性较高。有效扩散系数反映了失水率和固形物增加率达到平衡时刻的快慢程度。      

海鳗盐渍过程中的渗透脱水规律研究

研究了海鳗在盐渍过程中的渗透脱水规律。海鳗经盐渍发生了物理、化学和组织的变化。温度对鱼体盐渍的重量变化影响不是决定性的，食盐浓度是影响鱼体重量变化的关键因素；温度和浓度对于食盐渗透速度的影响是显著的，并且为正相关。电镜显示经过盐渍后的肌肉组织结构变硬和嚼密。在盐卤中氨基酸随着盐渍温度的提高溶出的数量增加。随着盐渍浓度的提高，盐卤中的氨基酸溶出的数量减少。而鱼体肌肉蛋白质的分解，盐渍浓度对其有较大影响。这些研究对于海鳗的腌制生产具有实际指导意义。     

辣椒果肉的渗透脱水效果研究

研究了不同渗透溶液对辣椒果肉的脱水效果,从失水率、固形物增加率、含盐量和色泽变化等方面综合分析了不同浓度的纯糖溶液(50%和65%)、纯盐溶液(10%和20%)和糖盐混合溶液(10%盐,50%糖)的作用效果。结果表明,蔗糖和盐混合溶液的脱水效果最好,8h的失水率可以达到54.20%,可溶性固形物增加率仅有7.53%,且含盐量更是低于纯盐溶液的含盐量变化,只增加了2.62g/100g干基。在渗透后的颜色方面,混合溶液渗透后的变化差异没有纯溶液渗透后的明显。     

Enhanced Mass Transfer During Osmotic Dehydration of High Pressure Treated Pineapple

High pressure pretreatment (100–700 MPa) was applied to enhance mass transfer rates during osmotic dehydration of pineapples and accelerate the process. Experimentally determined diffusivity values, based on a Fickian model, increased fourfold for water and twofold for sugar. Diffusivity values were correlated with pretreatment pressure by an equation of the form D=A exp(–B/P), which suggests that diffusivity would level after an initial increase in pressure. The increase was attributed to breaking-up of cells walls which facilitated the transport of water. Evidence for the extent of cell wall break-up with applied pressure was based on differential interference contrast microscopic examination of tissue. Preliminary experiments on rehydration characteristics showed high pressure pretreated samples did not absorb as much water as controls.     

Kinetic Analysis of Osmotic Dehydration Carried Out with Reused Sucrose Syrup

ABSTRACT Processing times required to achieve a target level of soluble solids were determined in apple pieces during sequential osmotic dehydrations carried out with reused sucrose syrup, in which new loads of fruits were charged in each turn. Effective diffusivities for water and sucrose in apple pieces were experimentally determined as a function of syrup soluble solids. A computer program was written to predict soluble solids change both in apple pieces and in syrup during the sequential osmotic dehydration process. Experimental data on the change of soluble solids for apples and syrup for 10 batches arranged in 2 sets of 5 were obtained. A good agreement between observed and predicted values of soluble solids in both fruit and the syrup was obtained, with root mean square values ranging from 1.3% to 4.6%.     

超声辅助低温固态渗透脱水制备茉莉花风味糖浆工艺优化及品质分析

随着中国风味食品和功能饮料市场的不断发展,具有特定营养和健康功效的风味糖浆被用来满足人们对风味饮料的需求。然而目前我国风味糖浆主要采用热浓缩技术进行生产,易导致热敏性芳香物质损失。鉴于此,该研究以茉莉花和黄冰糖为原料,采用超声辅助低温固态渗透脱水方法（Ultrasonic-Assisted Solid Osmotic Dehydration,USOD）制备茉莉花风味糖浆,通过单因素试验确定最佳工艺条件为：黄冰糖用量为茉莉花质量的120%（m/m）、颗粒度为6~20目、渗透时间为168 h及超声时间120 min。在此条件下风味糖浆得率为41.40%;总酚含量、总黄酮含量和DPPH自由基清除能力分别为175.18 mg GAE/kg dw、187.92 mg RE/kg dw和 313.55 mg Trolox/kg dw;茉莉花中绝大部分风味化合物都能被有效地提取出来,尤其是醇类化合物,芳樟醇37.94%~46.06%,其次是苯甲醇20.80%~23.90%,说明SOD工艺条件对风味物质提取影响显著。因此,该研究能有效提高风味糖浆得率且保留了茉莉花本身的风味成分和营养物质,为风味糖浆的开发利用奠定了一定的理论基础。     

蘑菇渗透脱水规律的研究

对蘑菇片在糖溶液中的脱水规律进行初步的试验研究。通过多因素正交试验，得出影响蘑菇渗透脱水因素的主次顺序及因素间交互作用的关系；通过应用均匀试验，建立了蘑菇渗透脱水的回归数学模型，其理论值与实测值具有很好的一致性；利用回归模型，建立了不同条件下的渗透脱水规律预测表。     

Osmotic Dehydration of Tomato in Sucrose Solutions: Fick's Law Classical Modeling

ABSTRACT:  Osmotic dehydration of tomato was modeled by the classical Fick's law including shrinkage, convective resistance at the interface and the presence of water bulk flow. Tomato slices having 8 mm thickness were osmotically dehydrated in sucrose solutions at 50, 60, and 70 °Brix and at 35, 45, and 55 °C. Other experiments were done in a 70 °Brix sucrose solution at 35 °C with tomato slices of 4, 6, and 8 mm thickness and at different motion levels (velocities 0, 0.053, and 0.107 m/s). Tomato weight, water content, and °Brix of the products were measured as a function of processing time (20, 40, 80, 160, and 320 min). Results showed that temperature, concentration, thickness, and solution movement significantly influenced water loss and sucrose gain during the osmotic dehydration of tomato. The model predicted the modifications of soluble solid content and water content as a function of time in close agreement with the experimental data. Experimental Sherwood number correlations for sucrose and water were determined as Sh _s = 1.3 Re ^0.5 Sc _s^0.15 and Sh _w = 0.11 Re ^0.5 Sc _w^0.5, respectively. The effective diffusion coefficients of water (4.97 10⁻¹¹– 2.10 10⁻¹⁰ m²/s) and sucrose (3.18 10⁻¹¹– 1.69 10⁻¹⁰ m²/s) depended only on temperature through an Arrhenius-type relationship.     

Osmotic Dehydration Behavior of Red Paprika (Capsicum Annuum L.)

ABSTRACT: Osmotic dehydration of red paprika was studied using a combined sucrose (5 to 45 g/100 g) and sodium chloride (0 to 15 g/100g) solution. The effective diffusion coefficients for water and solute were determined using the slope method based on the Fickian diffusion model. The effects of concentration of sucrose, sodium chloride and their complex interaction on water and solute diffusion coefficients as well as on equilibrium moisture and solid contents were studied using central composite rotatable design of experiments. The graphical optimization showed that at optimum conditions (sucrose concentration and sodium chloride concentration were 21.86 g/100 g and 2.02 g/100 g, respectively), the following criteria were achieved: water diffusion coefficient (D_ew) 0.80 × 10⁻⁹ m²/s, solid diffusion coefficient (D_es 0.82 × 10⁻⁹ m²/s, equilibrium moisture content (m∞) 6.85 kg/kg, and equilibrium solid content (s∞) 2.00 kg/kg.     

Osmotic dehydration kinetics of carrot cubes in sodium chloride solution

Osmotic dehydration kinetics of carrot cubes in sodium chloride solution having concentrations 5%, 10% and 15% (w/v), solution temperature 35, 45 and 55 °C, sample to solution ratio (STSR) 1:4, 1:5 and 1:6 were studied up to 240 min duration. During the experimentation, effect of solution temperature and process duration was significant and that of solution concentration and STSR were non-significant on water loss. Among the different models applied (Penetration model, Magee Model, and Azuara model), Azuara model best fitted to the experimental data for water loss and solute gain during osmotic dehydration. Effective diffusivities of water and solute were calculated by using the analytical solution of Fick's unsteady state law of diffusion by iterative technique with a computer program. For the above conditions, the effective diffusivity of water was found to be in the range between 2.6323 × 10⁻⁹ and 6.2397 × 10⁻⁹ m²/s and that of solute between 3.1522 × 10⁻⁹ and 4.6400 × 10⁻⁹ m²/s.