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1.
该研究首次尝试利用双滚筒干燥技术来生产虾片饲料,考察了不同工艺参数及配方对虾片饲料性能的影响。研究中以成膜率和悬浮性为评价指标,采用正交试验设计考察蒸汽压力、滚筒转速和浆液浓度三个工艺参数对产品的成膜率和悬浮率的影响,优选出最佳工艺参数。同时,对比研究了虾片饲料生产过程中901、面粉、褐藻胶、蛋清粉4种成膜剂的成膜性能,并最终确定其最适的添加量。结果表明最佳工艺参数为蒸汽压力0.4MPa、浆液浓度30%、滚筒转速1000r/min; 901是最佳成膜材料,其最适添加量为7%。  相似文献   

2.
该研究首次尝试利用双滚筒干燥技术来生产虾片饲料,考察了不同工艺参数及配方对虾片饲料性能的影响。研究中以成膜率和悬浮性为评价指标,采用正交试验设计考察蒸汽压力、滚筒转速和浆液浓度三个工艺参数对产品的成膜率和悬浮率的影响,优选出最佳工艺参数。同时,对比研究了虾片饲料生产过程中901、面粉、褐藻胶、蛋清粉4种成膜剂的成膜性能,并最终确定其最适的添加量。结果表明最佳工艺参数为蒸汽压力0.4MPa、浆液浓度30%、滚筒转速1000r/min;901是最佳成膜材料,其最适添加量为7%。  相似文献   

3.
响应面分析优化枸杞浑浊汁饮料稳定工艺研究   总被引:1,自引:0,他引:1  
为得到以湖北杂交枸杞鲜果为原料制成的枸杞浑浊汁饮料,并探讨不同酶制剂和不同稳定剂对枸杞汁酶解稳定的作用效果,以可溶性固形物含量和感官评分为指标,确定酶制剂和稳定剂的种类及配比,并在单因素试验的基础上,通过Box-Behnken响应面分析法研究枸杞浑浊汁酶解及稳定的最佳工艺条件。结果表明,果胶酶与纤维素酶复配比2∶3时,可溶性固形物含量较大,卡拉胶与黄原胶复配比2∶3时,枸杞汁感官评分较好。通过响应面优化的枸杞浑浊汁饮料的最佳稳定工艺为复合酶添加量0.9‰(m/m)、酶解温度43℃、酶解时间72 min、酶解pH值4.5、复合稳定剂添加量0.2%(m/m),此时枸杞浑浊汁的感官评分最大(90±1.53分),与理论预测值相比,误差为0.089%,表明得到的产品感官效果最好。本研究结果为果蔬浑浊汁饮料的生产提供了理论参考。  相似文献   

4.
预糊化条件对萌芽糙米蒸煮质构特性及品质的影响   总被引:1,自引:1,他引:0  
为了解决萌芽糙米不易蒸煮且蒸煮后米饭口感较硬、黏弹性不足、粗糙感明显等问题,该文应用预糊化技术对萌芽糙米进行品质改良,评价了预糊化条件(米粒含水率43.21%±2.15%、34.64%±1.49%、29.83%±1.67%,蒸汽处理时间2、5、10、15、20、25 min)对萌芽糙米蒸煮特性、米饭质构特性及感官品质的影响。研究结果表明,随着米粒含水率的降低,预糊化萌芽糙米的蒸煮时间、蒸煮吸水率、体积膨胀率显著增大(P0.05),固形物损失率显著降低(P0.05);预糊化萌芽糙米的米饭硬度、黏附性、黏聚性、胶黏性、弹性、咀嚼性随米粒含水率降低的变化较为复杂。随着蒸汽处理时间的延长,预糊化萌芽糙米的蒸煮时间显著缩短(P0.05),蒸煮吸水率、体积膨胀率、固形物损失率变化较小且无明显规律;预糊化萌芽糙米的米饭硬度先减小后增大,黏附性、黏聚性先增大后减小,胶黏性、弹性、咀嚼性变化较为复杂。感官评定结果表明,预糊化萌芽糙米的米饭感官评分随米粒含水率降低的变化较为复杂,随蒸汽处理时间的延长先增大后降低。总体而言,米粒含水率29.83%±1.67%、蒸汽处理15 min的预糊化条件可以显著改善萌芽糙米的蒸煮特性、质构特性及感官品质,使其接近白米的品质指标。研究结果可为预糊化萌芽糙米的产业化开发提供依据。  相似文献   

5.
油豆腐是深受中国人民喜爱的传统食品,为了提高原料利用率和产品功能性,该试验以全豆为原料,研究新型全籽粒油豆腐的制备工艺。首先研究并优化了纤维素酶酶解豆浆工艺,以还原糖浓度为指标,建立了优化工艺的Box-Behnken模型。其次,以感官评价为标准,研究油炸工艺对全籽粒油豆腐色泽、含油率和硬度的影响,最后,对全籽粒油豆腐的成分进行了测定。结果表明:最佳酶解条件为加酶量0.53%、酶解温度50℃、酶解时间160 min,在此条件下还原糖浓度约为2.9433 mg/m L;在油炸温度为170℃,油炸时间为4 min时,全籽粒油豆腐的感官品质最好(感官评价95分),在此条件下制得的全籽粒油豆腐的白度L*值为60.22,红度a*值为10.85,黄度b*值为37.80,含油率为15.6%,硬度为2 972 g。与传统豆腐相比,全籽粒豆腐和全籽粒油豆腐中总黄酮和总酚等生物活性成分含量均有提高,总黄酮质量分数分别提高14.53%和7.93%,总酚质量分数分别提高18.95%和82.11%。  相似文献   

6.
糠醛渣的纤维素酶水解及其最优纤维素转化条件   总被引:6,自引:2,他引:4  
仉磊  李涛  王磊  李十中 《农业工程学报》2009,25(10):226-230
该文对糠醛渣的纤维素酶水解特性进行了研究,探索利用玉米芯制糠醛联产燃料乙醇工业化生产的可行性。分析糠醛渣组分,表明其半纤维素质量分数为3.1%,纤维素为31.6%,说明糠醛生产过程对玉米芯的预处理基本满足高效酶解糖化糠醛渣并转化乙醇的要求;通过纤维素酶用量、温度、pH值、固液比、转速等因素进行条件优化,确定最佳水解条件:每克底物酶用量为6.7FPU,固液质量体积比1︰6,pH5.2,转速80 r/min;在糠醛渣水解体系中加入吐温80,结果表明在酶施用量较低情况下(6.7 FPU/g),吐温80对提高糠醛渣水解转化率效果更为明显;通过最优化水解条件,使糠醛渣纤维素转化率达到78%,据此初步判定以糠醛渣为原料转化乙醇的工业化生产具有较大潜力。  相似文献   

7.
蒸汽爆破过程麦秆木质纤维素的转化   总被引:4,自引:1,他引:4  
采用低压蒸汽爆破技术处理小麦秸秆木质素。通过单因素试验,考察蒸汽爆破过程汽爆压力、液固比、物料粒度、维压时间对木质纤维素降解的影响,木质素的降解率达到22.67%。设计L9(34)正交试验,上述因素影响主次顺序为汽爆压力>液固比>维压时间>物料粒度,优化条件为汽爆压力0.6 MPa,液固比为20︰1,维压时间为30 min,物料粒度为20~60目,且对优化结果进一步验证。红外光谱分析表明,经汽爆后麦秆木质素结构受到了一定程度的破坏;扫描电镜观察,麦秆的纤维束受到了破坏,发生了断裂,且出现了多孔的结构。  相似文献   

8.
绿茶电磁滚筒-热风耦合杀青工艺参数优化   总被引:1,自引:4,他引:1  
为探究电磁滚筒-热风耦合杀青对绿茶品质的影响,该文运用响应面设计,以杀青样生化成分含量和成茶感官品质为指标,对电磁滚筒-热风耦合杀青工艺参数(热风温度、热风风量、筒体前段温度等)进行优化,并与电热管滚筒杀青、微波杀青、热风杀青、电磁内热滚筒杀青等进行比较,结果表明:当投叶量为150 kg/h时,电磁滚筒-热风耦合杀青的最佳参数组合为热风温度104℃,热风风机转速920 r/min,筒体前段温度270℃;此工艺下所制成茶香气、滋味、色泽等品质最好,感官总分达到91.0,较其他杀青方式要高2.7~4.0分,杀青叶茶多酚、氨基酸、可溶性糖、儿茶素、咖啡碱和黄酮的质量分数分别为13.849%、2.057%、8.412%、9.724%、2.172%、1.336%,品质物质加权值达7.018%;该杀青工艺能耗成本较电热管滚筒杀青减少1/2,热能利用率达45%~55%,克服了传统滚筒杀青的不足,可为绿茶生产提供指导。  相似文献   

9.
蒸汽式扇贝开壳装置工作参数优化   总被引:3,自引:3,他引:0  
为了得到蒸汽式扇贝开壳装置蒸汽工作参数的最优匹配,提高扇贝深加工的产品品质,以开壳效果感官评分值为考察目标进行单因素试验,明确影响开壳效果的蒸汽喷射时间、喷射距离和蒸汽排量的最佳取值范围。采用Box-Behnken design试验设计方法进行了扇贝开壳组合试验,建立了扇贝开壳效果感官评分值与喷射时间、喷射距离和蒸汽排量之间的数学模型,并采用响应面优化分析法,得到了蒸汽式扇贝开壳装置的最佳工作参数匹配。结果表明:采用蒸汽发生器,压强控制在0.3~0.4 MPa、温度控制在142.92~151.11℃,当喷射时间设定在3.5 s、喷射距离设定在30 mm和蒸汽排量设定6 mm球阀门开度为90°,扇贝开壳率为93.3%,开壳效果感官评分值为94.53分。该研究为即食扇贝加工设备的设计提供参考。  相似文献   

10.
山核桃坚果热风干燥特性及其工艺参数优化   总被引:5,自引:4,他引:1  
针对山核桃坚果热风干燥质量难以控制、干后品质差等问题,采用单因素试验方法,研究了热风温度、装载量及风速对山核桃坚果干燥特性的影响。通过3因素5水平的二次回归正交试验,分析了热风温度、装载量及风速与干燥过程单位时间干燥速率、单位质量干燥能耗以及干后物料蛋白质保存率、不饱和脂肪酸保存率、感官品质指标综合分值的关系,建立了二次回归数学模型,分析了3因素对各指标影响的显著性;利用多目标非线性优化方法,确定了山核桃坚果热风干燥的最佳工艺参数组合,即热风温度为72℃,装载量为0.08 kg,风速为65 m/min。在此条件下,单位时间干燥速率为0.458%/min、单位质量干燥能耗为5.986 kWh/kg、蛋白质保存率为92.12%、不饱和脂肪酸保存率为90.65%、感官品质指标综合分值为32.89分,综合评分为0.802。研究结果为山核桃坚果的干燥和工业化生产提供一定的理论依据。  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.
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   

18.
We examined the community composition of microbes that colonized atrazine-containing beads buried in agricultural soils that differed in atrazine treatment history. Bacterial abundance was 5-40-fold greater in atrazine-fortified beads. In beads containing 20 mg atrazine kg−1 buried in soil with a history of atrazine application (conditioned soil), the abundance of Actinobacteria increased approximately 80-fold whereas in control soil, Actinobacteria were enriched only 10-fold and the gamma-Proteobacteria and Planctomycetes increased by 60- and 25-fold, respectively. The gamma-Proteobacteria were enriched by 120- and 230-fold in beads containing 200 mg atrazine kg−1 in conditioned and control soil, respectively. The results demonstrate that BioSep® beads are a suitable matrix for recruiting a diverse subset of the bacterial community involved in atrazine degradation.  相似文献   

19.
Arbitrary oligonucleotides were used as primers to amplifygenomic DNA of 48 wild Spanish populations of Agropyroncristatum, Elymus hispanicus,E. caninus,E. repens,Thinopyrum curvifolium, Th.junceum and Th.intermedium. Genetic diversity was analysedusing nineteen primers. The number of amplified products ranged from8 to 18 per primer and a total of 240 markers were scored. Differentlevels of intraspecific genetic diversity were found, the allogamousspecies E. repens andTh. intermedium being themost variable. Jaccard's similarity coefficients for internalmeasure within and between populations were used to produce a clusterdiagram. The results demonstrate differences in the degree ofsimilarity between taxonomic units. Interpopulational variability andinterspecific genomic relationships of these species arediscussed.  相似文献   

20.
The effects of three commonly used fungicides on the colonization and sporulation by a mixture of three arbuscular mycorrhizal (AM) fungi consisting of Glomus etunicatum (Becker & Gerd.), Glomus mosseae (Nicol. & Gerd.) Gerd. & Trappe, and Gigaspora rosea (Nicol. & Schenck) in symbiosis with pea plants and the resulting response of the host-plant were examined. Benomyl, PCNB, and captan were applied as soil drenches at a rate of 20 mg active ingredient kg-1 soil 2 weeks after transplanting pea seedlings in a silty clay-loam soil containing the mixed inocula of AM fungi (AM plants). Effects of fungicides were compared to untreated plants that were inoculated with fungi (AM control). The effect of mycorrhizal inoculation on plant growth was also examined by including nonmycorrhizal, non-fungicide-treated plants (non-AM control). Fungicides or inoculation with AM fungi had only a small effect on the final shoot weights of pea plants, but had greater effects on root length and seed yield. AM control plants had higher seed yields and lower root lengths than the corresponding non-AM plants, and the fungicide-treated AM plants had intermediate yields and root lengths. Seed N and P contents were likewise highest in AM control plants, lowest in non-AM plants, and intermediate in fungicide-treated AM plants. All three fungicides depressed the proportion (%) of root length colonized by AM fungi, but these differences did not translate to reductions in the total root length that was colonized, since roots were longer in the fungicide-treated AM plants. Pea plants apparently compensated for the reduction in AM-fungal metabolism due to fungicides by increasing root growth. Fungicides affected the population of the three fungi as determined by sporulation at the final harvest. Captan significantly reduced the number, relative abundance, and relative volume of G. rosea spores in the final population relative to the controls. The relative volume of G. etunicatum spores was greater in all the fungicide-treated soils, while G. mosseae relative volumes were only greater in the captan-treated soil. These findings show that fungicides can alter the species composition of an AM-fungal community. The results also show that AM fungi can increase seed yield without enhancing the vegetative shoot growth of host plants.  相似文献   

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