Evaluation of Electrical Conductivity as a Quality Parameter of Lemongrass Leaves (Cymbopogon citratus Stapf) Submitted to Drying Process

This study aims to evaluate the quality of lemongrass plants after drying at different speeds (1.0, 1.5, 2.0 m s^?1), temperatures (40, 50, 60, and 70°C), and drying air control systems (manual and automatic) using electrical conductivity as a parameter for evaluation. Firstly, we evaluated the time necessary for imbibitions of material in deionized water after drying for different air speeds and control systems. Secondly, the effect of temperature in fresh and dry plants was evaluated, comparing them with contents of essential oils and the quantity of ions leached by the electrical conductivity test. According to the results, the value of liquid diffusion increased with the increase of drying air temperature, and the value of activation energy was 62.84 kJ mol^?1. The quality of lemongrass plants evaluated by the electrical conductivity test was inversely proportional to the increase in drying air temperature, and the levels of essential oils were higher in dry plants with lower drying air temperatures. The adaptation of the electrical conductivity methodology to lemongrass plants was effective. A period of 33 h of imbibitions of the material in deionized water was necessary to obtain consistent results from leaching of potassium ions. The electrical conductivity can be used as a quality parameter for drying of medicinal plants.     

荆芥不同干燥加工方法药材质量变化研究

比较不同干燥加工方法引起荆芥药材的质量变化。选用传统的阴干、晒干干燥和3种温度的恒温烘干干燥方法,以水分含量,挥发油含量与挥发油中两种主要成分的含量与相互比例为指标进行观察。结果:与传统干燥方法相比,恒温烘干干燥能较快地去除水分,控制温度在一定范围也有助于减少挥发油的损失。但加工后药材挥发油中两种主要成分薄荷酮与胡薄荷酮的含量与相互比例均有显著改变。将恒温干燥方法用于荆芥药材加工可能对其质量有较大影响。     

Peppermint Drying Performance of Contact Dryer in Terms of Product Quality,Energy Consumption,and Drying Duration

Drying is a commonly used postharvest operation for medicinal and aromatic plants. Their high initial moisture contents, requirement of moderate drying temperatures, and quick deterioration of their quality attributes make their drying processes energy intensive and time consuming. These properties may also cause the dried product to be of heterogeneous quality. A contact dryer that transferred energy to drying plants mainly by heat conduction was developed and tested by mixing or not mixing batches of 15 kg of chopped peppermint plants. The contact dryer had three main operational units: a drying table, a mobile mixing/aeration car, and a control panel. The contact dryer was operated with one of four drying programs. All programs affected the completion duration of drying, essential oil content, and dried product color differently. The shortest drying time (15 h) was obtained using the drying program of gradually increased water temperature from 55–60 to 75–80°C in 6 h and mixing/aeration. However, mixing and aeration changed the product color slightly more and partially increased essential oil loss. These drawbacks can be alleviated by selecting the appropriate duration of mixing and aeration. The menthol and menthone percentages of fresh peppermint essential oil ranged from 31.02 to 34.02% (average value: 32.52%) and 23.23 to 26.47% (average value: 24.85%), respectively. The menthol and menthone percentages of dried peppermint essential oil ranged from 22.74 to 42.07% and from 8.95 to 21.76%, respectively. The significant variations in the essential oil composition of dried peppermint leaves within replications were possibly caused by the variations associated with the age and cutting order of fresh peppermint plants at harvest.     

三种芳香植物的抗氧化性研究

本研究为了验证罗勒 (OcimunbasilicumLine) ,鼠尾草 (SalviaofficinalisL .) ,百里香 (ThymusvulgarisLine)等草本芳香植物的叶中是否含有抗氧化物质 ,选用猪油作为氧化材料进行了抗氧化实验分析。同时为了进一步证明植物体中抗氧化物质的存在形式 ,分别采用植物的干燥叶片和从植物中提取的精油进行抗氧化处理。最后对三种植物抗氧化性的强弱作对比分析。其结果为 :三种植物都具有抗氧化性 ,其中干燥叶片的抗氧化性比精油更强 ,证明更多的抗氧化物质存在于除精油成分以外的非挥发性物质中。三种植物抗氧化性强弱顺序为 :百里香 ,鼠尾草 ,罗勒     

柠檬香茅精油的提取及抗氧化活性

采用水蒸气蒸馏法对海南产柠檬香茅进行精油提取,考察了提取时间、料液比、香茅粗细、香茅部位、提取液成分等因素对精油收率及主要成分的影响,精油提取率为0.09%～1.06%;50 g长2 cm的干柠檬香茅在1 400 mL含8 g NaCl的水溶液中,提取时间180 min时精油出油率最高,为1.06%。随提取条件不同,精油成分有差异,但主要成分无明显变化,主要为香叶醛、橙花醛、香叶醇、香叶酸和芳樟醇,该5种主要成分的质量约占精油总质量的86%～96%。电子自旋共振法测试结果表明,质量分数1%香茅精油乙醇溶液对羟基自由基具有一定清除活性,清除率约32%。     

柠檬香茅精油的提取及抗氧化活性研究

文中采用水蒸汽蒸馏法对海南产柠檬香茅进行精油提取,研究了提取时间、料液比、香茅粗细、香茅部位、提取液成分等因素对精油收率及主要成分存在影响,精油提取率为0.09-1.06%,50g 长2cm的干柠檬香茅在1400mL含8 g NaCl的水溶液,提取时间180min时精油出油率最高,为1.06%;随提取条件不同,精油成分有所变化,但主要成分无明显差异,主要为芳樟醇、橙花醛、香叶醛、香叶醇和香叶酸,此五种主要成分的含量约占精油总量的86-96%。电子自旋共振法（ESR）测试结果表明1%香茅精油乙醇溶液对羟基自由基具有一定清除活性,清除率32%。     

Enhanced extraction of essential oil from Cinnamomum cassia bark by ultrasound assisted hydrodistillation

Cinnamon essential oil with many bioactivities is an important raw material for the production of various chemicals,and the conventional hydrodistillation(HD) for cinnamon oil extraction always require a longer extraction time. In this work, ultrasound-assisted hydrodistillation extraction(UAHDE) technique was employed to enhance the extraction efficiency of essential oils from cinnamon barks. The parameters with significant effects on the essential oil extraction efficiency(ultrasound time, ultrasound power, extraction time, liquid–solid ratio) were optimized, and the proposed UAHDE was compared with the conventional HD extraction in terms of the extraction time, extraction yield, and physicochemical properties of extracted oils. Compared to the HD extraction, the UAHDE resulted in a shorter extraction time and a higher extraction yield. Using GC–MS analysis, the UAHDE provided more valuable essential oil with a high content of the vital trans-cinnamaldehyde compounds compared with the HD. Scanning electron micrograph(SEM) confirmed the efficiency of ultrasound irradiation for cinnamon oil extraction. In addition, the analysis of electric consumption and CO2 emission shows that the UAHDE process is a more economic and environment-friendly approach. Thus, UAHDE is an efficient and green technology for the cinnamon essential oil extraction, which could improve the quantity and quality of cinnamon oils.     

Extraction of Siphonochilus aethiopicus Essential Oil by Steam Distillation

Siphonochilus aethiopicus is an indigenous South African plant also known as African ginger. It has often been used for its medicinal properties to treat various ailments such as flu, colds, and so forth. The research aim of this study was to optimize the process parameters of steam distillation for the extraction of oil from African ginger rhizomes. This technology is the oldest and well known for extracting essential oils due to its economic viability and the higher final oil purity. The effects of operating parameters such as extraction duration, moisture content, particle size, and temperatures between 80°C and 100°C were studied for maximum oil recovery. The oil recovery of 0.61% (w/w) was achieved after 270?min of extraction time, using 6.37% (dry) moisture content of particle size 2.4?mm–4?mm at a maximum temperature of 100°C. Fick’s first law was used to mathematically model the experimental data of this study.     

Optimization of citrus peels D-limonene extraction using solvent-free microwave green technology

Attention is presently drawn to the development of a new and green alternative technique for the extraction of essential oil from citrus plant materials. This study was aimed at the extracting essential oil from orange and lemon peels using solvent-free microwave method. This process uses microwave-assisted hydro-diffusion technique to extract essential oil from citrus peels. Response surface methodology was used to investigate the effect of microwave power (200–1,000?W) and extraction time (10–40?min) on the essential oil yield. The oil extracted was characterized using Fourier transform infrared radiation (FTIR) and Gas chromatography–mass spectrometry analysis to determine the functional groups and chemical components present, respectively. The optimum yield of extract from orange and lemon peels were 3.7 and 2.0%, respectively at corresponding power of 1,000?W and time of 10?min. The analysis of variance results showed that the resulting models for both orange and lemon peels were significant and microwave power had greater influence on the extraction processes at both linear and quadratic levels. The FTIR analysis revealed prominent functional groups of alkenes that majorly constitute limonene compound at 1,642 and 1,643?cm^?1 for orange and lemon peels, respectively. The present process permits fast and efficient extraction, avoids water and solvent consumption, and allows substantial energy savings.     

Unglazed Transpired Solar Dryers for Medicinal Plants

Three different solar drying methods were carried out on four different medicinal plants to investigate the benefits of using an unglazed transpired solar dryer (UTSD) over other traditional methods. Methods involved included drying in an unglazed transpired solar dryer (using suction air flow rate of 0.06 m³s^?1), drying in the open air under direct sun rays and a common traditional drying method in a shaded drying house. The three drying methods were used to dry the following medicinal plants: henna (Lawsonia inermis L.), rosemary (Rosmarinus officinalis L.), marjoram (Majorana hortensis L.), and moghat (Glossostemon bruguieri L.). Drying processes were carried out under the climatic weather conditions of Ismailia, Egypt. Drying rate, drying ratio, and the medicinal plants qualities in terms of oil quantity and sensation tests were considered. The results showed higher oil quantity obtained from rosemary and marjoram dried in the UTSD, compared with those dried in the shaded drying house and in the open air under direct sun.     

Oil quality from hydraulic pressed soybeans

Summary HYDRAULIC pressed soybean oil quality is affected a great deal by the moisture of the beans at the time of milling. At moistures above 12 to 13% the oil quality deteriorates sharply. A great improvement in the oil from wet or even moisture damaged soybeans can be made by drying the beans in below 12% before milling. Even badly deteriorated (sample grade) beans have been vastly improved. Blending of wet and dry soybeans to an average moisture below 12% does not seem to yield as good quality oil as drying wet beans to a corresponding moisture. Normal variations in other soybean characteristics determining bean grade have lesser effects on soybean oil quality. Some data on the effect of bean damage, splits, off-color varieties, and foreign material are included in this paper. Hydraulic oil mills operating on soybeans will be able to make large improvements in oil quality by drying whole wet beans at the mill and by removing foreign material from the beans.     

Effect of method of stabilization on aqueous extraction of rice bran oil

Rice bran oil is widely used in pharmaceutical, food and chemical industries due to its unique properties and high medicinal value. In this study aqueous extraction of rice bran oil from rice bran available in Sri Lanka, was studied. Key factors controlling the extraction and optimal operating conditions were identified. Several methods of bran stabilization were tested and the results were analyzed. The yield and quality of aqueous extracted oil was compared with hexane extracted oil.Aqueous extraction experiments were conducted in laboratory scale mixer–settler unit. Steaming, hot air drying, chemical stabilization and refrigeration better controls the lipase activity compared to solar drying. Steaming is the most effective stabilization technique. The extraction capacity was highest at solution pH range 10–12. Higher oil yield was observed at higher operating temperatures (60–80 °C). Kinetic studies revealed that extraction was fast with 95% or more of the extraction occurring within first 10–15 min of contact time. Parboiling of paddy increases the oil yield. Highest oil yield of 161 and 131 mg/g were observed for aqueous extraction of parboiled bran and raw rice bran respectively. The aqueous extracted oil was low in free fatty acid content and color compared to hexane extracted rice bran oil and other commonly used oils. Major lipid species in rice bran oil were oleic, linoleic and palmitic.     

芳烃抽余油磺化工艺的研究

以气相三氧化硫为磺化剂,芳烃抽余油为原料,通过气体SO3和芳烃抽余油液膜进行连续的管式气-液反应,考察了SO3气体流量、夹套的水温、进料温度和流量对抽余油磺化收率的影响.实验结果表明,SO3气相膜式磺化反应的条件为：抽余油的进料流量为77 g/min,进料温度为30℃、SO3气体流量为2.5 L/min、干燥空气流量为l00 L/min、改变夹套水温35℃时,抽余油磺化产率最高,最高产率为52.7％.     

新疆混合原油减三线馏分生产橡胶油工艺研究

利用糠醛、N-甲基吡咯烷酮(NMP)、二甲基亚砜(DMSO)等极性溶剂,正戊烷、正庚烷、石油醚等非极性溶剂对新疆混合原油减三线馏分进行萃取、反萃取,结合Al2O3色谱柱吸附、洗柱等方法,从副产物中生产出主要质量指标合格的高芳烃橡胶油和环保型橡胶油。高芳烃橡胶油芳烃质量分数达80%以上,环保型橡胶油多环芳烃(PCA)质量分数在3%以下。剩余原料的杂质含量降低、碳型分布合理、黏度指数提高,比较适合做润滑油原料。做为催化裂化原料时轻质油收率提高2.9%、焦炭产率下降1.3%。     

Cooking and Sun Drying Effects on Properties of Allanblackia stanerana Kernels’ Oil

Previous studies have evaluated the nutritive potential of Allanblackia oils. Oil extraction from Allanblackia is done after a pretreatment of the kernels which has an influence on oil quality. In Cameroon, the pretreatment consists of cooking, followed by drying of the almonds in the sun. The oil is either edible or used as a body cream. Because of these important applications, it is necessary to determine treatment conditions that maximize extraction yields and preserve its quality. This study was aimed at finding the mathematical models that simulate the best pre-treatment conditions. The use of multiple linear regression analysis allowed developing satisfactory models and surface response plots that predict the evolution of the extraction rate as well as the quality of the extracted oil, depending on cooking and sun drying times. The coefficients of correlation obtained were 72.03 % for water content; 53.06 % for extraction yield; 71.06 % for acid; 76.48 and 83.29 % for iodine and refractive values respectively, indicating a suitable model of the experiment according to the studied variables. The response surface curves were superimposed to obtain a single optimal range that satisfies all response factors. The average cooking time of 12.5 min and the mean residence time of 8.5 days drying gave the following optimal values for the different response factors studied: moisture content 21.60 %; oil yield 70.69 %; refractive index 1.4546; iodine value 34.72; and acid value 0.38 mg KOH/g oil. The conditions to obtain a maximum extraction yield and low acidity were those that gave a residual water content of about 10–15 %. The quality indicators measured in this work generally remained within the threshold.     

Foam Separation of Oil from Enzymatically Treated Wet-Milled Corn Germ Dispersions

More than 9 billion gallons of ethanol were produced in 2008, mostly from dry grind corn fermentation plants. These plants are a potential source of substantial amounts of corn oil, if an economical method of separating it can be developed. In this work, oil was separated from corn germ by aqueous enzymatic extraction (AEE). Batches of wet-milled corn germ in water were preheated in a pressure cooker, ground in a colloid mill, and churned in a vertical column/mixing vessel system, after the addition of enzyme. Nitrogen gas was then bubbled through the column removing an overflowing foam fraction which was subsequently centrifuged to separate free oil. Using a newly commercialized enzyme complex it was found that 80% of the oil could be recovered using a w/w ratio of enzyme solution to germ of 1:80. The low dose and low price of the enzyme complex leads to a cost estimate of AEE of corn oil from germ, similar to the wet-milled germ extracted, cost competitive with expelled oil (with the separation and drying of the foam protein), and feasible for commercialization in a dry grind plant retrofitted to separate germ.     

新品种丰花玫瑰鲜花细胞液提取率及化学成分分析初报

玫瑰是一种药食两用的芳香植物,丰花玫瑰是生产型玫瑰新品种,一年能多次开花,用其鲜花提取的细胞液,含有0.2%的玫瑰精油,具有天然的玫瑰花香,应用于化妆品和食品中,具有美容和保健作用。所用原料不同,细胞液的提取率不同;同一年不同花期的鲜花不仅细胞液提取率不同,其所含的化学成分亦不同。     

N-甲酰吗啉芳烃抽提塔试验研究

用小型碳钢筛板萃取塔进行了宽馏分重整脱庚烷油的N 甲酰吗啉抽提试验 ,考察了抽提温度、溶剂比、溶剂含水率对总芳烃收率及选择性的影响。结果表明 ,在抽提温度为 60℃、溶剂含水为 3 % (m )和溶剂比S/F =4(V)的抽提操作条件下 ,溶剂选择性较高 ,并可获得高的芳烃回收率     

Effects of different drying methods on the extraction rate and qualities of oils from demucilaged flaxseed

Effects of different drying methods, i.e., oven drying, freeze drying, vacuum drying, and microwave drying, on the extraction rate and qualities of oil extracted from demucilaged flaxseed were investigated. The results show that microwave drying and freeze drying have higher extraction rate and yield (46.36 and 46.16% vs. 33.90%) of oil compared with native flaxseed. The oil extracted from dried flaxseed, especially the one freeze dried, had higher peroxide value (21.63 vs. 6.15?meq/kg) and specific ultraviolet extinction at 232?nm (4.56 vs. 3.67) and 268?nm (1.23 vs. 1.12), as well as a shorter induction time (1.8 vs. 3.3?h) than the one from native sample. Demucilaging and drying have no significant effect on fatty acid composition of flaxseed oil. However, these processes increased the content of total phenols and total sterols while reduced the content of chlorophyll and carotenoid pigment. In addition, the oil extracted from vacuum dried flaxseed contained more tocols when compared with native sample (447.29 vs. 370.99?mg/kg).     

Extraktionsversuche mit Krillfarcen und Krillkoagulat

Extraction Studies with Krill Force-Meat and Krill Coagulate The advantages of dry products over water-containing frozen goods are due to low cost of transportation and storage as well as ease of handling. Since in dry products, fats tend to undergo rapid oxidative deterioration, their removal is important for a sufficient shelf life of the dry products. In krill (Euphausia superba Dana) the tendency towards autoxidation is high due to the high level of unsaturated fatty acids. Extraction studies on various dry krill products, obtained by drum drying, shovel drying, and fluidized bed drying, were carried out in a Soxhlet laboratory apparatus and in a larger pilot plant of a manufacturer of percolator extractors using isopropanol as solvent. Even after 10 extraction in the Soxhlet, the lipid content could not be reduced much below 1%. The sensory quality of the extracted powder, mixed with corn starch as a paste, was found to be of ?edible quality”? after 6 weeks of storage; in comparison, the corresponding unextracted product was found to be ?unedible”?. Dusty powders having a particle size from 5 to 15 μm were found to be unsuitable for percolation.