响应面试验优化漂白紫胶流化床干燥工艺

采用流化床干燥漂白紫胶,以期对漂白紫胶在较低温度条件下进行快速干燥。通过单因素试验,考察进气温度及空气流量2个主要因素对漂白紫胶颜色指数及干燥时间的影响,用响应面法设计试验并建立了流化床干燥条件下的回归模型。结果表明:预测值和实测值的一致性较好,误差为1.12%,所建立的数学模型(颜色指数R2为0.949 1,干燥时间R2为0.937 7)可以用于描述和预测漂白紫胶流化床干燥。得到的较优操作条件为进气温度36℃、空气流量45 m3/h条件下干燥28 min,可以得到颜色指数为0.90的漂白紫胶,其指标符合国家精制漂白紫胶1级标准。     

营养冲调粥流化床干燥特性及动力学模型的建立

利用流化床干燥装置,对营养冲调粥（玉米、红豆、荞麦、燕麦和小米质量比为3.5∶3.0∶2.0∶0.7∶0.8,加水后经双螺杆挤压膨化制得）的流化床干燥特性进行实验研究,探讨干燥过程中不同风速、进风温度以及产品加工过程中的加水量对营养冲调粥干基水分质量分数和干燥速率的影响,得到了营养冲调粥流化床干燥的失水特性规律。根据实验数据建立营养冲调粥流化床干燥的动力学模型,并对模型进行统计检验。结果表明,经拟合得到营养冲调粥流化床干燥的最佳模型为Page模型,拟合方程为：ln（－ln MR）＝－4.064 63＋0.014 14T＋0.069 85v＋0.327 5H＋（0.570 96＋0.000 976 25T－0.009 68v－0.265 5H）ln t（T为进风温度/℃;v为干燥风速/（m/s）;H为原料加水量/%）,此方程能够较好地描述营养冲调粥的干燥过程,准确预测各阶段营养冲调粥的干基水分质量分数和干燥速率。     

Effect of Osmotic Dehydration and High Temperature Fluidized Bed Drying on Properties of Dehydrated Rabbiteye Blueberries

Rabbiteye blueberries were dried using an experimental high temperature fluidized bed (HTFB) dehydrator and the properties of the dried product were evaluated. 15 m/sec air velocity was required for fluidization and at 170°C the moisture content (MC in kg water/kg dry matter) of thawed blueberries was reduced from 5.8 to 0.7 after 8 min. After osmotic dehydration in sucrose, MC was 1.3, and 4 min in the HTFB drier at 150°C reduced MC to 0.28. Reduction of water activity to 0.5 after HTFB required cabinet drying at 60°C and 4 m/ set for 2.13 and 2.75 hr for the untreated and osmotically dehydrated berries, respectively. HTFB simultaneously dried and puffed the berries, resulting in reduced bulk density compared to berries produced using conventional drying. Osmotic dehydration prior to HTFB imparted a raisin-like texture to the product.     

盐的干燥及振动流化床气体分布板的研究

在振动流化床中进行了盐的干燥实验,确定了干燥操作的适宜的工艺参数:静床高H=100 mm,进风温度Tin=120℃,进风速度u=0.8~1.0 m/s,振幅A=3 mm,振频f=16Hz。实验结果可为工业化干燥器的设计提供依据。实验中还对流化床的均风结构进行了研究,研究发现,在气体分布板下布置一层编织网可在不增大床层压降的情况下取得很好的均风效果,并可有效地防止漏料。     

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。     

响应面试验优化甘薯渣流化床干燥工艺

甘薯渣在传统干燥时,易发生黏结、结块的现象,为了改善这种状态,本研究以甘薯渣为原料,采用Box-Behnken优化试验研究流化床甘薯渣单位面积加载量、床层温度、空气流量3个因素对甘薯渣干燥时间和甘薯渣粒度综合评分的影响,并对流化床干燥甘薯渣的工艺条件进行了优化。结果表明:对流化床干燥甘薯渣综合评分的影响大小顺序为单位面积加载量空气流量床层温度,从回归模型中得到最佳工艺参数为单位面积加载量5 264 g/m~2、空气流量52.73 m~3/h、床层温度51.33℃,此条件下综合评分预测值为0.790,验证实验结果预测精度为93.60%。与传统干燥方式相比,干燥时间缩短,流化床干燥制得的样品20目过筛率82.3%,堆积密度为0.446g/mL,密度明显提高25.8%;硬度485.382 g,且硬度明显减小;扫描电镜中颗粒内部空隙增大,样品松散,可减小粉碎成本。本研究结果为工业化干燥、延长保存时间及其深加工生产提供理论依据。     

Effect of a Starch-Lipid Fat Replacer on the Rheology of Soft-Serve Ice Cream

ABSTRACT: The rheology of soft-serve ice creams prepared with Fantesk™, a starch-lipid composite, was compared to a commercial product. Fantesk™ describes a class of stable starch-lipid composites formed by steam-jet cooking, and is used in this case as a fat replacer. Waxy maize starch and butter were used, and the butter content was selected to give 0.5 to 1.1 wt% butter in the ice cream mix. Despite the lower level of fat, the overrun and rheological properties of the Fantesk™-based ice creams were similar to the commercial product when differences in the freezing behavior of the different formulations were accounted for.     

振动流化床干燥机在盐行业的应用与改进

80年代以前,国内精制盐行业大多采用70年代初设计的固定沸腾床干燥器,这种干燥器存在着能耗高、成品物料水分不均匀,易产生死床等问题.进入90年代,振动流化床干燥机进入了制盐行业,并较好地解决了以上的问题.     

氯化钾内加热流化床干燥机理与工艺计算

文章介绍了我国氯化钾干燥技术现状,分析了"内加热流化床干燥机"的工作原理,给出了氯化钾内加热流化床干燥工艺计算方法,该工艺已越来越多的被氯化钾生产企业所采用。     

Process of Producing Parboiled Rice with Different Colors by Fluidized Bed Drying Technique Including Tempering

Steamer is utilized to gelatinize rice starch. High pressure or long steaming time is conventionally applied to obtain the dark brown color of the product. A new alternative method to produce dark brown parboiled rice was proposed in this work. High temperature fluidized bed drying technique including tempering was therefore explored to determine the operating condition to meet the requirement of light and dark brown parboiled rice along with high head rice yield. In addition, the couple of heat and mass transfer model was developed to determine the effective moisture diffusion coefficient, the temperature and moisture distributions within a grain kernel during drying. The effective diffusion coefficient was well correlated with grain temperature by Arrhenius equation. The drying temperature and moisture content after drying caused the drop of head rice yield. When the parboiled paddy at the intermediate moisture contents of 22 and 27% d.b. was tempered, the head rice quality was improved while the parboiled rice color was browner. To obtain high drying capacity, high head rice yield, and light brown color, the parboiled paddy should be dried at a maximum allowable temperature of 150 °C and tempered for 30 min. The tempering time should be extended to 60 min for the dark brown parboiled rice.     

复合脂肪替代物在牛肉制品中的应用

利用L9(34)正交试验最终确定复合脂肪替代物主要添加剂配比:单硬脂酸甘油酯1.9％、变性淀粉2.6％、谷氨酰胺转酶0.3％、精炼牛脂肪31％.感官评价及计算机视觉成像系统综合评价判定复合脂肪替代物在牛肉制品中的应用效果,牛肉大理石花纹等级平均为2级以上.     

循环流化床锅炉旋风分离器改造及应用效果

通过两台65t/h循环流化床锅炉旋风分离器磨损原因的分析,对设备进行了改造,在实际生产中取得了良好的效果。     

籼米基脂肪替代品对速溶咖啡口感的影响

研究了籼米为基质的脂肪替代品的制备工艺。通过单因素试验研究了耐高温α-淀粉酶添加量、籼米粉目数和水解时间对产品DE值的影响,并通过正交试验确定了制备籼米为基质的脂肪替代品的最佳工艺条件:酶添加量4.0 U/g米粉,水解时间30 min,籼米粉目数100目。制备的产品DE值3.0左右,干燥后产品为白色粉状物。利用提取脂肪替代品后的沉淀继续制备DE值13~17的麦芽糊精,工艺条件为:酶添加量40.0 U/g米粉,水解时间40 min。最后,添加质量分数6%的脂肪替代品和9%的麦芽糊精复配出的速溶咖啡口感最佳。     

核磁共振技术对食品玻璃化及玻璃化转变温度的研究

本文综述了核磁共振技术(NMR)测定玻璃化转变温度的原理和一些实际应用的例子,以及NMR状态图的概念及其在食品玻璃化转变和转变前后食品理化性质变化的研究中的应用.