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1.
为确定羊肚菌最适宜的干燥方式,研究了不同温度(45、50、55 ℃)条件下的热风干燥(hot air drying,HAD)、以及50 ℃条件下的碳纤维远红外干燥(carbon fiber far-infrared drying,CFFD)、热泵干燥(heat pump drying,HPD)、碳纤维远红外联合热泵干燥(carbon fiber far-infrared combined heat pump drying,CFFD-HPD)与真空脉动干燥技术(vacuum pulsed drying,VPD)对羊肚菌干燥时间、干燥能耗、色泽、品质(复水比、质构特性、电子舌、感官评价)以及营养指标(氨基酸、蛋白质、粗多糖、脂肪含量)的影响,并对上述指标做出综合评分。结果表明:CFFD-HPD组的干燥时间最短,与HAD(55 ℃)组无显著性差异(P>0.05),与其他组差异性显著(P?0.05)。VPD组的干燥时间最长、能耗最高,显著高于其他组(P?0.05)。在外观品质方面,HAD(50 ℃)的L*值显著高于其他组(P?0.05),VPD组的L*、b*值显著低于其他组(P?0.05),a*值显著高于其他组(P?0.05)。在感官品质方面,CFFD组的羊肚菌最终复水比最大,VPD组的最终复水比最小,复水20min 时,CFFD-HPD组的羊肚菌复水速率最高。复水后的羊肚菌HAD(55 ℃)组的弹性和咀嚼性最大,VPD组的硬度最小。对干燥后的羊肚菌进行感官评价,HAD与CFFD-HPD组的得分较高,且两者无显著性差异(P>0.05),VPD的感官评价得分最低。在营养品质方面,VPD组的总氨基酸和蛋白质含量高于其他组,但是CFFD-HPD的综合评价得分最高,其次是HAD(55 ℃)(P?0.05),VPD的综合评价得分最低,说明CFFD-HPD与HAD(55 ℃)适合用于羊肚菌干燥。研究结果为羊肚菌干燥技术提供了数据支持。  相似文献   

2.
风味豆制品辐照贮藏保鲜技术研究   总被引:3,自引:1,他引:3  
用聚乙烯复合膜抽真空包装 (5 0g 袋 )的风味豆制品经 5~ 1 0kGy照射 ,在常温(2 5℃ )条件下贮藏 30d,0~ 7℃条件下贮藏 90d ,经感官品评和微生物检测 ,结果表明 ,细菌总数低于 5× 1 0 4 个 g,大肠菌群 <30个 1 0 0g,符合国家卫生质量标准(GB2 71 1 -81 ) ,保持豆制品原有的色泽、香味 ,无异味 ,质地细腻 ,有弹性 ,无胖袋。蛋白质、脂肪含量辐照前后无明显变化 ,包装材料厚度为 0 0 7~ 0 1 0mm为宜。  相似文献   

3.
为探索不同食品加工工艺及条件对肉制品中共轭亚油酸(Conjugated Linoleic Acid,CLA)的影响,在110只5月龄的内蒙古苏尼特绵羊宰杀后取背最长肌肉(Longissimus Dorsi,LD)为样品,采用气—质联用技术分析研究辐射、冻藏、加热、腌制等加工对背最长肌中共轭亚油酸稳定性的影响。结果表明,空气包装、-2℃贮藏条件下,2 kGy的γ射线可降低肌肉中共轭亚油酸含量(P<0.05),但同样的辐射条件下,真空包装、-2℃贮藏30 d肌肉中共轭亚油酸含量很稳定。经2 kGy的γ射线灭菌,采用真空或空气包装,-18℃贮藏45 d后共轭亚油酸仍然很稳定。贮藏时间对CLA含量的影响不显著。紫外线灭菌不会引起共轭亚油酸损失。低温巴氏杀菌(70~72℃、82~86℃)可使共轭亚油酸含量降低(P<0.05)。腌制中氯化钠和亚硝酸钠的浓度对共轭亚油酸含量的影响作用显著(P<0.05)。该研究对于实际生产中确定合理的工艺参数,保持肉类产品天然成分具有指导意义。  相似文献   

4.
苹果液氮降温排氧打浆技术研究   总被引:2,自引:0,他引:2  
为了抑制苹果制汁过程中的褐变,提高产品质量,该文首次采用自行设计的液氮降温排氧打浆机,对苹果打浆工艺进行了初步研究。具体研究了打浆时添加液氮后苹果浆温度、溶解氧含量、果浆颜色以及多酚氧化酶(PPO)和过氧化物酶(POD)活力等的变化。结果表明:添加1%~2%液氮后,苹果浆温度迅速降低为原来温度的50%,氧气含量降低为对比组的47.7%;果浆色泽L值为53.96,较对比组的L值高44.1%;同时可减少维生素C损失,提高苹果出汁率。  相似文献   

5.
发芽条件对发芽糙米中γ-氨基丁酸含量的影响   总被引:12,自引:3,他引:12  
以糙米为原料,研究浸泡温度、发芽温度和发芽时间对发芽过程中γ-氨基丁酸(GABA)含量变化的影响,建立基于GABA含量的糙米发芽动力学模型,以获得富含GABA发芽糙米的最佳工艺条件。结果表明:浸泡温度、发芽温度和发芽时间对GABA的含量有显著影响,采用Logistic生长模型建立的糙米发芽动力学方程能较好地描述GABA含量的变化规律。在30~40℃浸泡和33~38℃发芽,GABA的增长速率常数b和积累极限k均达到较高水平;基于GABA含量的最佳发芽条件为33.0℃浸泡12 h,35.1℃发芽26 h,此条件下GABA的含量可达32.23 mg/(100 g)。  相似文献   

6.
2016年7月2—11日,在麻妹子农业科技有限公司(四川省丹棱县)冷藏库,试验研究(3±1)℃、(6±1)℃、(9±1)℃三种贮藏温度下鲜藤椒的感官品质变化。结果表明:1)冷藏温度与鲜藤椒气味、油腺、新鲜度等感官指标关系密切,与色泽、滋味等感官指标有一定关系。在贮藏过程中先出现油腺发黑、芳香味减弱、新鲜度下降的劣变,然后出现色泽发黄变黑、麻度减弱的情况。2)鲜藤椒在(3±1)℃的冷藏温度下,贮藏4 d感官品质无明显变化;在(6±1)℃的冷藏温度下,贮藏3 d感官品质无明显变化;在(9±1)℃的冷藏温度下,贮藏2 d感官品质无明显变化。  相似文献   

7.
以两种不同抗旱性的玉米品种("陕单21"和"郑单958")和高粱品种("晋中405"和"晋杂12")为对象, 研究了土壤渐进干旱过程中茎木质部水分传输能力与光合作用之间的协调关系, 试图揭示玉米和高粱品种抗旱性差异的水力生理机制。结果表明: (1)相同土壤干旱程度下, 玉米品种"郑单958"的叶水势、净光合速率(Pn)、最大光化学量子效率(Fv/Fm)和PSⅡ实际量子效率(ΦPSⅡ)高于"陕单21", 其气孔导度(Gs)及蒸腾速率(Tr)则低于"陕单21"。高粱品种"晋杂12"的Pn和ΦPSⅡ高于"晋中405"。表明玉米品种"郑单958"和高粱品种"晋杂12"的抗旱性相对较强。(2)土壤渐进干旱过程中, 玉米和高粱光合气体交换参数(Pn、Gs及Tr)的下降早于叶绿素荧光参数(Fv/Fm、ΦPSⅡ)的下降, 表明气孔关闭比PSⅡ活性受损要早。(3)抗旱性强的玉米品种"郑单958"和高粱品种"晋杂12"同时具有相对高的水分传输能力, 其抵抗气穴化形成的能力更强, 但高粱抵抗气穴化的能力不如玉米, 高粱通过快速的栓塞来减少水分散失。(4)玉米Pn和Gs对茎木质部水分传输能力下降的敏感性高于高粱, 抗旱性强的玉米和高粱品种Gs对木质部水分传输能力下降的敏感性更强。高粱能在低水分传输能力的情况下, 维持较高的光合作用, 反映了高粱保守性的水分利用策略。  相似文献   

8.
热泵干燥北极虾的物理和感观特性研究   总被引:3,自引:0,他引:3  
对分别在(-2~0)℃和20℃两种温度下热泵干燥北极虾(整虾、去头北极虾、去壳北极虾)的物理和感官特性进行了研究.结果显示,当热泵干燥温度由(-2~0)℃增加到20℃时,干燥虾的收缩率和所需的剪切力增大.干燥温度对干燥虾的色泽影响不显著.所有热泵干燥虾均具有高的复水能力和水分保持能力(WHC).研究结果还显示,虾的处理状态(有壳或无壳、有头或无头、解冻处理)对其物理和感官特性有着显著影响.解冻处理不利于虾色泽的保持并使之收缩增加.在所有的干燥虾样品中,在20℃下干燥的冷冻去头虾(B-2)具有最好的综合表现.与热风干燥相比,利用热泵干燥虾可获得高质量干燥产品.  相似文献   

9.
以马铃薯为辅料的黄酒发酵条件优化   总被引:2,自引:1,他引:2  
采用响应面方法对以马铃薯为辅料的黄酒发酵条件进行了优化。通过单因素试验、正交试验及中心组合试验优化得到以马铃薯为辅料酿造黄酒的最佳发酵条件为:酵母添加量0.114%(原料量的0.114%)、主发酵温度28℃、麦曲添加量14.0%(原料量的14.0%)、料水比1∶0.7、每100 g原料添加425μL糖化酶、发酵初始pH值4.0。在优化得到的发酵条件下酿造得到的以马铃薯为辅料的成品黄酒,其酒精度、酸度、色、香、味等各项理化指标和感官指标均符合国家黄酒标准GB/T 13662-2000,成品酒的感官品质得到了改善,且所含游离氨基酸含量为7063.4 mg/L,是普通黄酒游离氨基酸含量的1.2~2.5倍。  相似文献   

10.
为了使嗜酸乳杆菌微胶囊得到较好的应用,并为其保质期提供理论依据,根据其活菌数,对嗜酸乳杆菌微胶囊的热稳定性和热动力学进行分析研究。结果显示:在试验温度为45~60℃下,微胶囊的失活常数随温度的升高逐渐增大,90%微胶囊中的菌失活所需要的时间(D)分别为140.85 h、64.52 h、31.06 h及14.40 h,且在45~60℃范围内,D值变化90%时的温度变化量(Z)为15.20℃;利用Arrhenius方程计算出表观活化能(E)为124.43 kJ/mol。  相似文献   

11.
低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响   总被引:2,自引:2,他引:0  
【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.
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   

13.
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   

14.
We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass, soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration, N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially (<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils, indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea.  相似文献   

15.
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   

16.
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   

17.
“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.  相似文献   

18.
Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.  相似文献   

19.
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   

20.
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   

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