不同脱盐方式对海芦笋干制品品质的影响

分别对清水浸泡、真空渗透、超声波处理等不同脱盐方式对海芦笋干制品合盐量的影响进行了讨论，以合盐量、Vc、叶绿素、干制品复水前后的感官评定等为质量参数，分别进行比较。实验结果表明，采用真空渗透处理既能达到脱盐的目的，又能最大限度地保持产品品质。     

黑加仑真空冷冻与微波真空联合干燥工艺研究

以黑加仑为原料,对其进行了真空冷冻与微波真空联合干燥工艺的研究。结果表明：先真空冷冻后微波真空干燥（FDMV）的组合方式是可行的;联合干燥合理工艺参数为：微波功率1．34kW。绝对压力11kPa,转换含水率为20％（wb）;通过试验验证,联合干燥生产的脱水黑加仑的感官品质和营养成分接近真空冷冻干燥,联合干燥方式对节省干燥时间和降低能耗是有效的。     

香精香料信息15则

1．对伊朗两种栽培品种的罗勒油的分析;2．小豆蔻用不含溶剂的微波法提取：对这种提取精油新技术的多重研究3、比较用三种不同方法脱水的香蕉粉的挥发物;真空干燥带式干燥．冷冻干燥和空气干燥法。     

干燥前预处理对豌豆脱水后的品质影响

对烫漂，冻结，糖液浸渍等预处理后的豌豆进行干燥实验，分析研究预处理对干燥过程中干燥速率，产品复水率及其品质的影响。结论：干燥前对豌豆进行烫漂预处理效果最佳。     

热风与真空冷冻联合干燥毛竹笋的试验研究

对毛竹笋进行了热风与真空冷冻联合干燥(AFD)的研究，应用热风与真空冷冻(AD FD)和真空冷冻与热风(FD AD)两种方式做不同转换点试验，将得到的产品分别与完全的热风干燥和冷冻干燥的产品比较其能量消耗和物化特性，并对它们的产品进行理化分析，确定了AFD联合干燥的方式和最佳转换点，得出了真空冷冻与热风(FD AD)联合干燥的产品接近完全真空冷冻干燥(FD)产品的结论，AFD联合干燥对于提高脱水笋干的质量、节省能量消耗是有效的。     

流化床热风干燥洋葱及护色工艺研究

采用间歇流化床干燥洋葱片,考察了风温、风速、漂烫时间和漂烫温度等对洋葱含水率的影响。结果表明,洋葱切片在95℃热水中漂烫3 min,干燥风温为60℃,风速为1.06 m/s(30 Nm3/h),干燥60 min,含水率可达5%。此法在较短时间内有效降低了洋葱含水率,比相关文献干燥时间缩短3 h,含水率降低3%。     

干式稀油密封煤气柜密封油聚结-真空联合脱水工艺探讨

对煤气柜密封油进行聚结分离脱水、真空分离脱水、聚结-真空串联和聚结-真空并联的联合脱水。结果表明,相较于单纯的聚结分离脱水和真空分离脱水,密封油聚结-真空联合脱水具有较为明显的优势;相较于聚结-真空串联工艺,聚结-真空并联工艺可根据密封油工况调节聚结分离和真空分离的联合方式,在脱水效率、能耗方面的优势较为明显。     

干式稀油密封煤气柜密封油聚结-真空联合脱水工艺探讨

对煤气柜密封油进行聚结分离脱水、真空分离脱水、聚结-真空串联和聚结-真空并联的联合脱水。结果表明,相较于单纯的聚结分离脱水和真空分离脱水,密封油聚结-真空联合脱水具有较为明显的优势;相较于聚结-真空串联工艺,聚结-真空并联工艺可根据密封油工况调节聚结分离和真空分离的联合方式,在脱水效率、能耗方面的优势较为明显。     

框架真空预压法对水力冲挖淤泥脱水效果的试验研究

水力冲挖淤泥的快速脱水是现阶段城区水系疏浚的突出问题,真空预压法作为一种地基处理方法已经非常成熟,将真空预压法应用于含水率极高的水力冲挖淤泥的脱水具有可行性。本文通过自行设计的框架真空预压法进行水力冲挖淤泥的脱水试验研究,对比传统的自然晾晒方式,淤泥的脱水效果明显,同时框架真空预压法的脱水效果最优。     

真空系统在气化渣脱水中的应用探讨

介绍某煤气化装置渣脱水技术选择、真空脱水实验、渣脱水装置建设投用等方面的情况，总结真空系统在气化渣脱水中的应用，以便为气化渣脱水找到一种简单适用、易于维护的方式。     

APPLICATION OF VARIOUS DRYING METHODS IN SELENIUM-ENRJCHED VEGETABLE DEHYDRATION

ABSTRACT

Some Chinese popular vegetables are very low in the selenium(Se). The Se enrichment on these vegetables is very beneficial to the health of the local people. Drying and preservin¨g Se-enriched vegetables can provide a valuable food source. Preservation tests on sweet pepper, eggplant and cucumber enriched with Se by different drying methods of microwave, low-vacuum, heated airflow, and high-vacuum after freezing were conducted. Affecting curves have been developed for different drying temperatures. Effects of drying methods, initial selenium contents, sample moisture contents and blanching on keeping quality of Se-enriched sweet pepper bars are discussed.     

Effect of Drying Process Parameters on Dehydrated Cabbage Enriched with Selenium

Cabbage (Brassica oleracea var. capitata L.) enriched with selenium through foliar spraying was used to study the effect of drying process on its selenium retention and other quality criteria. Parameters such as blanching, seasoning, temperature, pH, and time of treatment were studied and evaluated to obtain an optimal processing condition for dehydrated selenium-enriched cabbage. After blanching, the barrier for mass and heat transfer of cabbage cellular materials became lower so that the heat damage was high. Blanching parameters set at 95°C and 60 s retained selenium and vitamin C in cabbage best as well as inactivated enzymes present in cabbage. Seasoning reduced the water activity of cabbage and subsequently reduced the loss of selenium. Blanching and seasoning could prevent browning deterioration of cabbage and reasonably kept the fresh color. The selenium loss kinetics during drying obeyed the first-order reaction and its activation energy was 44.0 kJ mol^-1.     

Effect of Drying Process Parameters on Dehydrated Cabbage Enriched with Selenium

Cabbage (Brassica oleracea var. capitata L.) enriched with selenium through foliar spraying was used to study the effect of drying process on its selenium retention and other quality criteria. Parameters such as blanching, seasoning, temperature, pH, and time of treatment were studied and evaluated to obtain an optimal processing condition for dehydrated selenium-enriched cabbage. After blanching, the barrier for mass and heat transfer of cabbage cellular materials became lower so that the heat damage was high. Blanching parameters set at 95°C and 60 s retained selenium and vitamin C in cabbage best as well as inactivated enzymes present in cabbage. Seasoning reduced the water activity of cabbage and subsequently reduced the loss of selenium. Blanching and seasoning could prevent browning deterioration of cabbage and reasonably kept the fresh color. The selenium loss kinetics during drying obeyed the first-order reaction and its activation energy was 44.0 kJ mol^?1.     

Comparison of four pretreatments on the drying behavior and quality of taro (Colocasia esculenta L. Schott) slices during intermittent microwave vacuum-assisted drying

ABSTRACT

Effect of different pretreatments on drying behavior and quality of taro slices during intermittent microwave vacuum-assisted drying were investigated. Taro slices were subjected to the following pretreatments: blanching (B), blanching and freezing (B?+?F), blanching and immersion in maltodextrin solution (B?+?M), and blanching and immersion in maltodextrin solution and freezing (B?+?M?+?F). The reduction in amylose content, the increase in amylose to amylopectin ratio, the change of mechanical properties, the increase in sample bulk density and reduction in sample porosity and structure collapse during pretreatment processes facilitated heat and moisture transfer and quality changes during drying of taro slices. During drying process, all the pretreatment reduced the drying time of samples. The drying rate included a warming-up period and a falling rate period. The values of effective moisture diffusivity increased gradually as the moisture content decreased. The B?+?M?+?F pretreatment had the shortest drying time, the highest drying rate and the biggest effective moisture diffusivity. Moreover, for B?+?M?+?F pretreatment, the parameters including hardness, crispness, color, and microstructure had remarkable changes as compared with the other pretreatments.     

Production of dried ivy gourd sheet as a health snack

Ivy gourd (Coccinia grandis) has recently been recognized as a rich source of β-carotene. To add value to the fresh leaves a process to produce dried ivy gourd sheet as a health snack was the aim of this study. The effects of pretreatment, i.e., blanching in NaCl solution (0-3% w/v), and drying methods, i.e., hot air drying and vacuum drying at 60-80 °C, on the drying characteristics and quality, viz. colour, texture and β-carotene content of dried ivy gourd sheet were investigated. The results showed that dried sheet pretreated by brine blanching and vacuum drying resulted in better retention of colour and β-carotene as well as texture of the dried sheet as compared to the dried untreated and dried water blanched samples. Higher drying temperature also resulted in higher β-carotene retention due to shorter drying time.     

The Effects of Predrying Treatments and Different Drying Methods on Phytochemical Compound Retention and Drying Characteristics of Moringa Leaves (Moringa oleifera Lam.)

The most appropriate maturity stage of Moringa oleifera leaves was selected for drying based on phytochemical content, including quercetin and kaempferol. Desorption isotherms were developed and were best fit by the modified Henderson model. Prior to drying, samples were left untreated, blanched in boiling water, and blanched in NaHCO₃/MgO. The leaves were dried by hot air tray drying (TD) and heat pump–dehumidified drying air (HPD) at air temperatures of 40, 50, and 60°C. Alternatively, leaves were subject to microwave drying (MWD) at 150, 450, and 900 W and to freeze drying (FD). The moisture versus time data were fitted to five drying models. In general, a three-parameter model gave the best fit. The drying constant was related to the drying temperature or microwave power using an Arrhenius model. Effective moisture diffusivity (D _eff) increased with higher drying temperature, higher microwave power, or blanching treatments. Structural changes in the leaves after drying and upon rehydration were observed by scanning electron microscopy (SEM). Leaves blanched and dried using HPD at 50°C and fresh and dried using FD showed a partial breakdown of the tissue structure upon rehydration. HPD and blanching reduced the drying time by 8.3% and increased quercetin and kaempferol levels by 42.1 and 51.4%, respectively, compared to TD at 50°C. MWD provided the quickest drying followed by HPD and TD, respectively. HPD drying of M. oleifera after blanching resulted in relatively greater quality compared to TD and MWD.     

On the Development of Osmotically Dehydrated Seabuckthorn Fruits: Pretreatments,Osmotic Dehydration,Postdrying Techniques,and Nutritional Quality

Osmotic dehydration of whole seabuckthorn berries, followed by convective or vacuum drying, was investigated. First, different pretreatments were applied to the fruits in order to accelerate the rate of osmotic dehydration: immersion in liquid nitrogen, steam blanching, or freeze cycles. Immersion in liquid nitrogen was found to be the best pretreatment to maximize dehydration rate and to increase sugar gain during osmotic dehydration. An evaluation of moisture loss and sugar gain kinetics during osmotic dehydration of seabuckthorn fruits pretreated with liquid nitrogen, followed by vacuum or hot-air drying, was then performed. Loss of nutritional compounds due to processing was also measured. Sugar intake and partial dehydration of seabuckthorn samples increased with osmosis time and reached an equilibrium value after 4 h treatment. The finish drying methods (vacuum or convective) applied after OD showed a marked impact on the remaining moisture content of seabuckthorn samples. Concentration of some nutritional compounds was, however, dramatically reduced after the combined osmotic dehydration/drying processes.     

Quality evaluation of Panax notoginseng extract dried by different drying methods

Quality control still remains a big issue, affecting herbs, formulations, and even the practice of Traditional Chinese Medicine. A promising solution to the problem is to take advantage of innovative process techniques including alternative drying methods within the pharmaceutical processing. Nowadays, vacuum belt drying (VBD) has gained more and more importance in food and pharmaceutical processing. In this work, Panax notoginseng extract was made into powder by the gentle VBD as well as by classical spray drying (SD), freeze drying (FD), and vacuum drying (VD). Certain chemical and physical properties of the dried powders such as moisture content, drying time, porosity, density, saponins content, pH value and hydroxyl radicals scavenging activity were evaluated. The results showed the qualities of dried products were influenced to different extent by drying methods certainly. Vacuum belt drying was suggested to dry P. notoginseng extract for its high quality assurance of hygroscopic products and suitable for sticky or high viscous products.     

Dehydration of Low-Grade Asparagus

Dehydration by a forced convection process is one potential method to add value to low-grade asparagus for marketing purposes. The objectives of this study were to determine the optimum drying temperature, air velocity, and predrying blanching treatment and study the effects of those parameters on the drying curves for low-grade asparagus and the efficiency of the drying process. The ranges of investigation were 60 to 93^°C and 0.14 to 0.44 m/s for drying temperature and air velocity, respectively. Drying at 51 ^°C and 0.30 m/s yielded product with an optimum quality, and drying at 79^° C and 0.18 m/s yielded the optimum process efficiency of 17.9%. Drying temperature, air velocity, and predrying blanching treatment all affected the rate of drying in the constant-rate drying period and the length of the constant-rate drying period. In the falling-rate period, all of the process parameters studied had some effect on the shape of the drying curve.     

Pulsed vacuum drying (PVD) technology improves drying efficiency and quality of Poria cubes

The objective of this research was to examine the drying characteristics of pulsed vacuum drying (PVD) system as an alternative drying technology for a functional food—Poria cocos. Poria cubes in thin layer were dried at different temperatures (55, 65, and 75°C), vacuum duration (5, 15, and 25?min), and atmospheric pressure duration (4, 8, and 12?min) to evaluate the operating conditions on the drying kinetics and quality attributes of P. cocos. The quality attributes included volume shrinkage ratio, firmness, water-soluble polysaccharide content. Volume shrinkage ratio was determined by image processing technology and analyzed by Bigot’s curves. The material internal temperature was also recorded during the whole drying process. Considering the drying rate and quality attributes, drying temperature of 65°C, vacuum pressure duration of 15?min, and atmospheric pressure duration of 4?min were proposed as the most favorable drying conditions for drying Poria cubes. The current work indicates PVD is a promising technology for P. cocos drying as it not only enhances the drying process but also improves the quality attributes of it.