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1.
高压脉冲电场辅助提取番茄皮渣的番茄红素   总被引:2,自引:0,他引:2  
采用高压脉冲电场技术辅助提取番茄皮渣中的番茄红素。通过单因素试验和正交分析试验确定提取的最佳工艺参数,并与常规有机溶剂提取法、超声波辅助提取法、微波辅助提取法进行了对比试验。结果表明:当以乙酸乙酯为提取溶剂、电场强度为30 kV/cm、液料比为9 mL/g、脉冲数为8、温度为30℃、单次提取时,番茄红素提取率能达到96.7%,是常规有机溶剂法的2.4倍、是微波辅助法的1.23倍、是超声波辅助法的1.04倍,且处理时间短(16 μs)。因此,高压脉冲电场辅助提取法是一种新型快速的番茄红素提取方法。  相似文献   

2.
为提高淘汰蛋鸡副产物——卵泡的利用率,本研究以鸡卵泡为试验原料,经提取卵磷脂、脱去胆固醇后,将其卵泡残渣以溶剂萃取法提取出蛋黄油,通过单因素试验和正交试验研究了提取温度、提取时间、料液比和乙醇浓度对蛋黄油提取的影响。之后将提取的蛋黄油进行氧化调控,采用气相离子迁移色谱(GC-IMS)进行测定与分析。正交试验结果表明,鸡卵泡中蛋黄油提取的最佳工艺条件:提取温度80℃,提取时间55 min,料液比1∶10,乙醇浓度95%。氧化蛋黄油中含有多种挥发性物质,包括4种醇类、3种醛类、2种酯类、2种酮类、1种呋喃,其中3-甲基丁醛是氧化蛋黄油的特征风味物质。本研究结果为开发利用蛋鸡副产物,提高产品附加值提供了新思路。  相似文献   

3.
高压脉冲电场辅助提取鱼骨钙工艺优化   总被引:2,自引:1,他引:1  
为了提高鱼骨钙的提取效果,利用高压脉冲电场从淡水鱼骨中辅助提取鱼骨钙制备高钙鱼骨水解液。单因素试验和二次通用旋转组合设计试验表明,脉冲数、电场强度、柠檬酸与苹果酸比对鱼骨钙的提取率影响显著;建立鱼骨钙提取率与各影响因子间关系的回归数学模型;确定了高压脉冲电场辅助提取鱼骨钙的最佳工艺参数为电场强度为25kV/cm、脉冲数为8个、柠檬酸与苹果酸的质量比为1:1g/g、酸料比为1:1g/g、水料比为12:1mL/g,此时处理4g鱼骨粉所得的鱼骨水解液中钙提取率达84.2%。与超声波辅助提取鱼骨钙对比试验表明,高压脉冲电场辅助提取鱼骨钙的得率较超声波辅助提取提高了17%,且其耗时短。该研究可为高压脉冲电场辅助提取鱼骨钙深入研究及其高钙鱼骨口服液的研制提供借鉴参考。  相似文献   

4.
酶为介质有机溶剂提取万寿菊花中叶黄素的工艺研究   总被引:1,自引:1,他引:1  
以万寿菊(Tagetes erecta)花粉末为原料,采用液态纤维素酶处理和有机溶剂萃取同时进行的方法提取叶黄素,研究并优化此过程的工艺条件。试验结果表明:酶为介质有机溶剂提取万寿菊花中叶黄素工艺条件受多种因素影响,其中提取时间、萃取前保温时间、酶浓度、搅拌速度对提取过程影响较大。确定酶法提取较适宜的工艺条件为:2.000 g粒度60目的万寿菊花粉末、液态纤维素酶浓度为7%(m/m)、液料比为20∶1、萃取前保温时间为1.5 h、搅拌速度为700 r/min、提取时间为3 h,对此工艺条件进行验证叶黄素提取率可达92.37%。而单纯的有机溶剂法叶黄素提取率仅为77.53%,此方法明显优于单纯的有机溶剂法。  相似文献   

5.
硫酸软骨素(chondroitin sulfate,CS)是重要的功能性骨多糖,广泛分布于动物的软骨组织。为了提高动物软骨中CS提取率,该研究制备了12种天然低共熔溶剂(natural deep eutectic solvents,NADESs),基于CS提取率筛选了较佳NADESs组成、确定了CS较佳提取工艺条件,并考察了NADES的循环重用性。结果表明,NADES-3(甜菜碱/尿素,摩尔比1:2)的CS提取率较高,为16.49%。且在较佳提取条件(含水率40%、液料比30:1 mL/g、反应温度110℃、时间120 min)下,CS提取率可达17.33%,是传统水提法的2.88倍。NADESs的理化特性与CS提取率的相关性试验表明,提取率与黏度呈负相关,与pH值、极性呈正相关,与密度相关性不大,确定了含水率40%的NADES-3为该试验最佳提取CS的溶剂。回收试验表明,NADES-3重复使用5次后,CS提取率仍有15.89%,说明NADESs提取法能高效地从喉软骨中回收CS。研究结果为畜禽骨营养组分的高效利用提供新思路,也为后续运动健康类功能性骨源食品的开发提供参考。  相似文献   

6.
水酶法提取大豆油脂的中试研究   总被引:1,自引:2,他引:1  
为了提高水酶法油脂提取率,该文进行水酶法提取大豆油脂的中试和循环酶解试验,验证小试和扩大试验的酶解和破乳参数对中试油脂提取率的影响,并研究循环酶解过程中循环次数及酶添加量对油脂提取率影响和中试工艺中大豆油脂的品质。以大豆为原料,由水酶法提取大豆油的中试得出:脱皮大豆比未脱皮大豆有助于提高油脂提取率和破乳率(P0.05,油脂提取率:脱皮61.85%,未脱皮56.91%;破乳率:脱皮92.01%,未脱皮90.42%)。通过主成分分析可知:大豆油脂的质量分数、离心后游离油和乳状液的质量分数、蛋白质的质量分数和乳状液中水分都是影响油脂提取率的关键因素。采用中试工艺1(1次提取,2次离心,1次破乳)进行循环酶解,随着循环试验次数增加,油脂提取率逐渐增大,在第4次时达到最大值66.46%±0.28%。通过检测大豆油脂的特征值可知:水酶法提取的大豆油脂的酸值、过氧化值、磷含量显著低于溶剂浸提法(P0.05),说明水酶法提取的大豆油品质高于溶剂浸提法,并且除水分和挥发物质量分数外,其他指标均符合国家三级大豆油标准。研究结果为产业化推广提供了理论参考。  相似文献   

7.
超声辅助提取冻干番茄粉番茄红素的工艺优化   总被引:1,自引:1,他引:0  
为了提高番茄原料中番茄红素的提取率,增加番茄深加工的利用价值,该文研究了冻干番茄粉粒度范围、液料比、超声温度、超声比功率和超声处理时间5个因素对番茄红素提取率的影响,通过响应面分析优化出超声辅助提取(ultrasound assisted extraction, UAE)冻干番茄粉(<74 μm)中番茄红素的最佳工艺,并与常规溶剂提取(conventional solvent extraction, CSE)进行了比较。确定的最优工艺条件为:液料比41:1 mL/g、超声温度55℃、超声比功率18 W/g,超声处理时间15 min。响应面验证试验番茄红素提取率为1.82±0.05 mg/g(超声时间10 min),与优化模型预测值1.83 mg/g基本一致,验证了模型的可靠性。UAE的番茄红素提取率较CSE增加了6.04%,提取时间节省了92.47%。该文为番茄红素的高效提取及番茄的综合利用提供了参考。  相似文献   

8.
乙醇溶剂与超临界CO_2相结合提取高纯度卵黄磷脂的研究   总被引:5,自引:0,他引:5  
采用乙醇溶剂首先提取蛋黄粉中的卵黄油 ,然后用超临界 CO2 萃取方法脱除卵黄油中的中性脂肪 ,获得高纯度的卵黄磷脂。考察了工艺参数对提取效果的影响。试验表明 :在乙醇溶剂提取卵黄油阶段 ,乙醇浓度是影响卵黄油提取率的最主要因素 ,温度是影响卵黄磷脂提取率的最主要因素 ;在超临界 CO2 萃取阶段 ,磷脂的溶解度随萃取温度的升高而降低 ,中性脂质在 5 5℃时溶解度最大。采用此工艺 ,卵黄磷脂得率为 17.6 6 % ,纯度 94.41% ,且不含胆固醇。  相似文献   

9.
超声波辅助提取紫丁香叶叶绿素的工艺   总被引:1,自引:0,他引:1  
以深秋的紫丁香树叶为原料,利用超声波辅助提取其中的叶绿素。首先研究了4种不同溶剂对提取的影响,然后在单因子试验基础上,探讨了料液比、超声波功率、超声波处理时间和超声提取次数4个因素对叶绿素提取的影响,用正交试验法优化了超声波辅助提取叶绿素的条件。最后将超声波法与传统提取法进行了对比。结果表明,紫丁香树叶中叶绿素a和叶绿素b的含量分别为0.37%和0.15%,叶绿素的总含量为0.52%;以乙醇∶丙酮为1∶2之混合溶剂的提取效果最好;优化的叶绿素超声波辅助提取条件为:料液比1∶7.5,超声波功率400W,提取3次,每次处理时间20min,提取率能达到(91.85±0.8)%。室温条件下,超声波辅助提取的提取率高于传统提取法17.13个百分点。  相似文献   

10.
为了探讨脉冲电场对黑曲霉生长和糖化酶活性的影响,研究采用响应面法设计脉冲电场工作参数(脉冲强度5~15 kV/cm、脉冲持续时间10~100μs和脉冲数50~99)并对黑曲霉孢子悬液进行处理和培养。结果表明:脉冲强度显著(P0.05)影响菌丝干质量和产糖化酶能力,当脉冲强度为12.975 kV/cm、脉冲宽度为54μs和脉冲数为66,黑曲霉的菌丝干质量和糖化酶活性分别为28.05 mg和18.01 U/mL,比对照(未采用脉冲处理)提高了68.27%和14.71%;酯酶同工酶分析未显示出PEF对黑曲霉有诱变作用,但PEF处理明显刺激了黑曲霉孢子萌发,使孢子萌发率增加了77.8%~231%。该研究为黑曲霉菌等霉菌生物学性能的提高及其在实际生产中的应用提供理论依据。  相似文献   

11.
【目的】以富士(Fuji)、 秦冠(Qinguan)嫁接在平邑甜茶(Malus hupehensis Rehd.)上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水(ZZ)、 低氮正常水(DZ)、 正常氮干旱(ZG)、 低氮干旱(DG)。氮素和水分均设置两个水平,分别为正常氮(6 mmol/L NO-3-N)、 低氮(0.3 mmol/LNO-3-N)、 正常供水(保持盆中砂子相对含水量为饱和含水量的80%~85%)、 干旱处理(保持盆中砂子相对含水量为饱和含水量的60%~65%)。【结果】富士和秦冠的生物量(茎和叶)、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水(ZZ)>低氮正常水(DZ)>正常氮干旱(ZG)>低氮干旱(DG),并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水(ZZ)>低氮正常水(DZ)>正常氮干旱(ZG)>低氮干旱(DG); 氮、 钾元素含量在植株各部位的分布顺序依次是叶>根>茎,磷元素则是根>叶>茎;光合氮素利用效率(PNUE)和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水(DZ)处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱(DG)处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。  相似文献   

12.
Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.  相似文献   

13.
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,  相似文献   

14.
The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.  相似文献   

15.
Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.  相似文献   

16.
Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L?1 nitric acid (HNO3) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L?1 ammonium acetate (NH4OAc) and 1.0 mol L?1 HNO3 extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils.  相似文献   

17.
Biologically enhanced dissolution offers a method to speed removal of chlorinated solvent dense non-aqueous-phase liquid (DNAPL) sources such as tetrachloroethene (PCE) and trichoroethene (TCE) from aquifers. Bioremediation is accomplished by adding an electron donor to the source zone where fermentation to intermediates leading to acetic acid and hydrogen results. The hydrogen and possibly acetic acid are used by dehalogenating bacteria to convert PCE and TCE to ethene and hydrochloric acid. Reductive dehalogenation is thus an acid forming process, and sufficient alkalinity must be present to maintain a near neutral pH. The bicarbonate alkalinity required to maintain pH above 6.5 is a function of the electron donor: 800 mg/L of bicarbonate alkalinity is sufficient to achieve about 1.2 mM TCE dechlorination with glucose, 1.7 mM with lactate, and a much higher 3.3 mM with formate. Laboratory studies indicate that in mixed culture, formate can be used as an electron donor for complete conversion to ethene, contrary to pure cultures studies indicating it cannot. Various strategies can be used to add electron donor to an aquifer for DNAPL dehalogenation while minimizing pH problems and excessive electron donor usage, including use of injection-extraction wells, dual recirculation wells, and nested injection-extraction wells.  相似文献   

18.
Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.  相似文献   

19.
Three slow-growing legume trees used for desert reforestation and urban gardening in the Sonoran Desert of Northwestern Mexico and the Southwestern USA were evaluated whether their growth can be promoted by inoculation with plant growth-promoting bacteria (Azospirillum brasilense and Bacillus pumilus), unidentified arbuscular mycorrhizal (AM) fungi (mainly Glomus sp.), and supplementation with common compost under regular screenhouse cultivation common to these trees in nurseries. Mesquite amargo (Prosopis articulata) and yellow palo verde (Parkinsonia microphylla) had different positive responses to several of the parameters tested while blue palo verde (Parkinsonia florida) did not respond. Survival of all tree species was over 80% and survival of mesquite was almost 100% after 10 months of cultivation. Inoculation with growth-promoting microorganisms induced significant effects on the leaf gas exchange of these trees, measured as transpiration and diffusive resistance, when these trees were cultivated without water restrictions.  相似文献   

20.
Inoculation of wheat seedlings with the plant growth-promoting bacterium Azospirillum brasilense Cd was immobilized in alginate microbeads and, without applying any stress, significantly increased the quantity of several photosynthetic pigments, such as chlorophyll a, chlorophyll b, and the auxiliary photoprotective pigments violaxanthin, zeaxanthin, antheroxanthin, lutein, neoxanthin, and β-carotene. This resulted in greener plants with no apparent visible stress. After monitoring the quantity of photosynthetic pigments for 4 weeks, we observed that inoculated plants had higher quantities of pigments in shoot and stem. The greatest difference in the quantity of all pigments between inoculated and noninoculated plants occurred in the first week of growth. Regardless of treatment, the quantity of pigments in stems was three to four times less than the quantity of these pigments in shoots. Application of Azospirillum, either as liquid inoculant or as alginate microbeads, did not alter the positive effect of the bacteria on pigment production or the positive response of the plants towards A. brasilense Cd inoculation.  相似文献   

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