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。     

微波真空干燥技术现状

阐述了国内外微波真空于燥的研究现状，重点分析了脉冲微波真空干燥(间歇式微波干燥)的主要参数脉冲比、真空度、微波功率和能量效率。对微波真空于燥技术的发展提出了个人的看法。     

微波真空干燥技术的探讨

干燥是高能耗行业,我国干燥能耗约占全部工业能耗的12％。“节能减排”是保障我国能源安全、发展经济和保护环境的基本国策。根据不同的生产条件,科学选用烘干工艺和设备,对节约能源、减少原材料消耗、降低生产成本、提高经济效益、增强企业市场竞争力具有重要的意义。     

胡萝卜微波真空干燥试验研究

以胡萝卜为原料，采用均匀设计对微波真空干燥的微波功率、干燥温度及料层厚度进行试验研究，分析各试验条件下的水分含量及胡萝卜素含量，得到了干燥曲线和胡萝卜素保有量曲线，得出了胡萝卜失水量、胡萝卜素含量与各因素之间的回归方程，可用于描述胡萝卜的微波真空干燥特性。     

微波及辐射真空干燥过程中的干燥动力学及能量消耗

The general objective of this work is to analyze energy input in a vacuum process with the incorporation of microwave heating. Thus, necessary criteria for designing an efficient freeze-drying operation are considered through the analysis of strategies based on the combination of different intensities of raxiiant and microwave heating.The other aim of this research topic is to study the kinetics of drying in relation to mass transfer parameters.Five freeze-drying strategies using both heating systems were used. Consequently, energy input could be related to diffusivity coefficients, temperature and pressure profiles during dehydration of the product and analyzed in comparison to a conventional freeze-drying process.     

微波真空组合干燥果蔬的研究

本文论述了微波真空组合干燥的基本原理及干燥特点,剖析了国内外微波真空组合干燥果蔬的研究进展情况,探讨了影响微波真空干燥果蔬品质的主要因素及应用前景。     

微波真空组合干燥技术的研究

微波真空干燥是综合微波干燥和真空干燥各自优点的一项新技术,将微波干燥的快速高效性和真空干燥的低温高质相结合,在真空条件下利用微波对物料进行干燥处理,从而实现物料的快速低温干燥。着重阐述了微波真空组合干燥技术的机理、特点、干燥动力学以及影响微波真空干燥的重要因素,并对微波真空组合干燥的应用研究进行了介绍。     

黄精微波真空-热风联合干燥工艺研究

以黄精含水率为指标,采用单因素和均匀实验方法,对黄精微波真空干燥工艺进行优化,考察联用的热风干燥温度和时间对黄精多糖含量及其抗氧化活性的影响。结果表明,微波真空-热风联合干燥的最优工艺条件为:微波功率2 k W、间歇比1.67(75/45),真空度0.085 MPa,微波真空干燥37 min,再在55℃的热风下干燥约77 min。在该条件下,黄精干制品多糖含量达61.7 mg/g,对O^(2-)的抑制率达24.1%。微波真空-热风联合干燥技术可以应用于黄精的干燥。     

粒状产品的真空和微波干燥技术

介绍了适用于粒状产品,特别是药品的几种典型干燥技术,如真空干燥、气流辅助真空干燥、微波-真空干燥等的特点及其应用。     

微波真空干燥法生产无水氯化亚锡的研究

以微波真空干燥的方法来生产无水氯化亚锡,操作安全简单,无废料,经济效益明显。生产出的无水氯化亚锡含量高、浊度低、品质优良,主含量大于99.3%,铁含量低于70 mg/kg,浊度可控制在10 NTU以下。     

Dehydration of Concentrated Ganoderma lucidum Extraction by Combined Microwave-Vacuum and Conventional Vacuum Drying

Combination of microwave-vacuum drying and conventional vacuum drying was investigated as a potential method for drying concentrated Ganoderma lucidum extraction. The Ganoderma lucidum was extracted by hot water (60-65°C) and then concentrated to moisture of about 70% (wet basis) in a rising-film evaporator. The concentrated sample was dried by microwave-vacuum until the moisture content reached 10% (wet basis), and then by conventional vacuum drying at the temperature of 55-60°C to final moisture content about 6% (wet basis). The retention of polysaccharide and triterpenes of Ganoderma lucidum dried by this method were evaluated and compared with those dried by freeze drying and conventional vacuum drying alone. The comparison showed that the quality of extraction dried by the current method was close to that of freeze-dried extraction and much better than that of conventional vacuum-dried ones.     

Dehydration of Concentrated Ganoderma lucidum Extraction by Combined Microwave-Vacuum and Conventional Vacuum Drying

Combination of microwave-vacuum drying and conventional vacuum drying was investigated as a potential method for drying concentrated Ganoderma lucidum extraction. The Ganoderma lucidum was extracted by hot water (60–65°C) and then concentrated to moisture of about 70% (wet basis) in a rising-film evaporator. The concentrated sample was dried by microwave-vacuum until the moisture content reached 10% (wet basis), and then by conventional vacuum drying at the temperature of 55–60°C to final moisture content about 6% (wet basis). The retention of polysaccharide and triterpenes of Ganoderma lucidum dried by this method were evaluated and compared with those dried by freeze drying and conventional vacuum drying alone. The comparison showed that the quality of extraction dried by the current method was close to that of freeze-dried extraction and much better than that of conventional vacuum-dried ones.     

Dehydration of Garlic Slices by Combined Microwave-Vacuum and Air Drying

Combination of microwave-vacuum drying and air drying was investigated as a potential mean for drying garlic slices. The sample was dried by microwave-vacuum until the moisture content reached 10% (wet basis), and then by conventional hot-air drying at the temperature of 45°C to final moisture content less than 5% (wet basis). Pungency, color, texture, and rehydration ratio of garlic slices dried by this method were evaluated and compared with those dried by freeze drying and conventional hot-air drying. The comparison showed that the quality of garlic slices dried by the current method was close to that of freeze dried garlic slices and much better than that of conventional hot-air dried ones. The lab microwave-vacuum dryer which the materials to be dried could be rotated in the cavity was developed by the authors.     

Dehydration of Garlic Slices by Combined Microwave-Vacuum and Air Drying

Abstract

Combination of microwave-vacuum drying and air drying was investigated as a potential mean for drying garlic slices. The sample was dried by microwave-vacuum until the moisture content reached 10% (wet basis), and then by conventional hot-air drying at the temperature of 45°C to final moisture content less than 5% (wet basis). Pungency, color, texture, and rehydration ratio of garlic slices dried by this method were evaluated and compared with those dried by freeze drying and conventional hot-air drying. The comparison showed that the quality of garlic slices dried by the current method was close to that of freeze dried garlic slices and much better than that of conventional hot-air dried ones. The lab microwave-vacuum dryer which the materials to be dried could be rotated in the cavity was developed by the authors.     

Effects of pretreatments on properties of microwave-vacuum drying of sweet potato slices

Abstract

Pretreatments of blanching (BL); osmotic dehydration at 35°Brix of sucrose (OD); ultrasound in distilled water (UD), and ultrasound-assisted osmotic dehydration (UO) were carried out for microwave-vacuum drying (MVD) orange- and purple-flesh sweet potato slices, and effects on their properties were investigated in this study. UO had improvements effects on water loss, solid gain, and relaxation time of the samples compared to other pretreatments. Low-field nuclear magnetic resonance results offered a view of water state concerning the effects of different pretreatments on sweet potato. UD treatment following by BL showed a long relaxation time corresponding to the weaker degree of bound hydrogen proton or the greater freedom degree of hydrogen comparing to other pretreated samples. Differential scanning calorimetry parameters appeared to be sensitive to pretreatments by increased Tg value compared to blanched sample. The value of Tg shows that it does not depend only of the water content but also on the experimental conditions (pretreatments). The dried sweet potato exhibited amorphous structures as evidenced by the X-ray diffractograms due to the BL treatment and MVD. Concentration of total phenolics and anthocyanins were high in purple sweet potatoes, whereas content of vitamin C and total carotenoid were high in orange ones. Application of UO is suitable for retention of bioactive compound and stability of MVD sweet potato slices.     

灵芝提取灵芝多糖的中间试验研究

灵芝,作为药物有2000多年的历史,临床和药理研究表明,灵芝具有多种生理活性与药理作用;而灵芝多糖(Ganoderma Lucidum Polysaccharide)是其主要活性成分,具有免疫调节功能和明显抗癌和抗衰老功能。本文就灵芝多糖的超声波工业化生产的工艺进行了中间试验研究。试验结果表明:超声波提取灵芝多糖工艺条件:料液比为:1:18,提取时间1h,提取3次,为工业化生产提供了试验基础。     

Dehydration of asparagus cookies by combined vacuum infrared radiation and pulse-spouted microwave vacuum drying

ABSTRACT

The restructured cookies were made from old stalks of asparagus (Asparagus officinalis). Combination of vacuum infrared radiation drying and pulse-spouted microwave vacuum drying (VIRD–PSMVD) was studied as a potential mean for dehydration of restructured cookies. The samples were first dried by VIRD and then by PSMVD to final moisture content less than 6%. Expansion ratio, texture, color, flavor, and other attributes of samples dried by this method were evaluated and compared with those dried by PSMVD and VIRD. Results showed that the samples dried by VIRD–PSMVD showed higher overall acceptability, crisper texture, and higher expansion ratio.     

Maximizing the Retention of Ganoderic Acids and Water-Soluble Polysaccharides Content of Ganoderma lucidum Using Two-Stage Dehydration Method

Ganoderic acids and water-soluble polysaccharides are the main bioactive ingredients of Ganoderma lucidum and are heat sensitive. Hence, it is crucial to apply a suitable drying method for the drying of G. lucidum to minimize the loss of these bioactive ingredients. In this study, a two-stage drying method was applied to enhance the drying kinetics, as well as the retention of both ganoderic acids and water-soluble polysaccharides in dried G. lucidum fruiting bodies and slices compared to other single-stage-dried products. The results showed that two-stage drying enhanced the overall drying rate, which consequently shortened the total drying time up to 61 and 330% for fruiting bodies and slices, respectively, compared to single-stage drying methods. Furthermore, two-stage drying of Ganoderma fruiting bodies, which involves 18-h vacuum drying followed by 5-h heat pump drying, maximized the retention of ganoderic acids and water-soluble polysaccharides, with the retention of 97.90% of water-soluble polysaccharides and 4.2% more ganoderic acids than freeze-dried products. On the other hand, drying of Ganoderma slices within the shortest total drying time, which is 10-min heat pump drying followed by 50-min oven drying, also retained most of the ganoderic acids and water-soluble polysaccharides in the dried products; that is, about 80% of water-soluble polysaccharides and 11% more ganoderic acids than freeze-dried slices.     

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.