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1.
采用喷雾式流态化液氮速冻及缓冻,研究了在不同的冻结工艺条件下白灵菇的冻结温度曲线及冻结速度与汁液流失率之间的关系等。结果表明:对白灵菇进行缓慢冻结时,有明显的冻结三阶段现象出现,而在液氮速冻时此三阶段不明显;建议采用-60℃以下温度进行冻结,冻品在-26℃冰箱中贮藏9个月后,解冻时的汁液流失率低于4.9%。  相似文献   

2.
采用喷雾式流态化液氮速冻及缓冻,探讨了在选用不同的筛板、风速和食品层高,以及不同的冻结温度下青头菌的流化状态、冻结速率及与解冻后冻品汁液流失率之间的关系等。结果表明:选用开孔率为50%、孔径为5mm的筛板,用3.5 m·s^-1循环风速,对床层高度为5 cm的新鲜青头菌进行流态化速冻效果最佳;建议采用-70℃以下温度进行冻结,冻品在-26℃冰箱中冻藏6个月,解冻后的汁液流失率低于2.3%。  相似文献   

3.
液态CO_2对香菇速冻的工艺研究   总被引:1,自引:0,他引:1  
采用喷雾式流态化液态CO2速冻和缓冻,探讨了在选用不同的筛板、风速和食品层高,以及不同的冻结温度下香菇的流化状态,冻结速率与解冻后冻品汁液流失率之间的关系等。结果表明,选用开孔率为50%,孔径为5mm的筛板,采用3.0m·s-1~3.5m·s-1循环风速对床层高度为6cm的新鲜香菇进行流态化速冻效果最佳。建议采用-60℃以下温度进行冻结,冻品在-26℃冰箱中贮藏6个月后,解冻时的汁液流失率低于3.3%。  相似文献   

4.
为了进一步开发利用鸡枞菌,对鸡枞菌进行深加工,以云南鸡枞菌为原料,采用真空冷冻干燥技术和超微粉碎技术,制得冻干鸡枞菌超微粉的工艺流程和技术要点。鸡枞菌最佳冻干工艺条件是:预冻温度为-26℃~-32℃,冻结平均速度1℃/min左右,冻结时间90~110 min,干燥仓真空度10 Pa以下,加热板温度25℃,冷阱温度为-35℃。得到的冻干鸡枞菌超微粉的平均直径9.02μm。  相似文献   

5.
采用喷雾式流态化液氮速冻及缓冻,研究了冻结温度、速度对黑牛肝菌多酚氧化酶(PPO)及过氧化物酶(POD)活性的影响。结果表明:冻结温度、速度对酶的活性有明显的影响,在-100℃、-80℃、-60℃及-35℃(缓冻)下进行冻结,黑牛肝菌的PPO活性分别下降了73.5%、70.6%、65.2%及18.0%,POD活性分别下降了68.4%、62.2%、51.7%及15,8%。  相似文献   

6.
李力  何永梅 《蔬菜》2009,(10):30-30
菠菜耐寒能力强,能忍受-7℃左右的低温,解冻后仍可恢复新鲜状态。因此,菠菜冻藏就是要求温度降到菠菜冰点以下,细胞中的游离水开始冻结,当外界温度逐渐升高时,细胞的生活功能开始恢复,即要在不致丧失蔬菜组织细胞生活功能的前提下冻结。同时,在这样的低温下,抑制酶的活性和病菌的活动,从而使蔬菜能长期贮藏。  相似文献   

7.
于12月取材的软枣猕猴桃侧芽通过酒精和次氯酸钠灭菌以后,以此为试材探讨了冻结保存液的组成、温度和浸泡时间对其冻结保存的影响。结果表明:最适的DMSO的浓度为15%,最适的浸泡温度为0℃。在侧芽预冷到-30℃后,再投入到液氮中,解冻后的生存率在含有甘油8 mol/L和11.5 mol/L区最高。用甘油预处理的实验结果表明:在处理浓度较高时可以获得较高的生存率。然而,在甘油预浸后,再用冻结保存液处理的最佳时间为小于1h。  相似文献   

8.
采用喷雾式流态化液态CO2速冻及缓冻技术,研究了冻结温度、速度对双孢蘑菇多酚氧化酶(PPO)和过氧化物酶(POD)活性的影响。结果表明:冻结温度、速度对酶的活性有明显的影响,在75℃、60℃、45℃及35℃(缓冻)下进行冻结时,双孢蘑菇的PPO活性分别下降了70.5%、66.3%、56.8%及19.6%,POD活性分别下降了74.3%、71.1%、64.5%及21.6%。  相似文献   

9.
超低温冻结草菇菌种床栽试验   总被引:1,自引:0,他引:1  
草菇对低温的忍耐度较差,菌丝体在5℃下易丧失活力。但我们用超低温-196℃冻结草菇菌种,不但没有冻死,反而在超低温下生活得很好。我们将草菇菌种V_((?)3)在液态氮超低温-196℃冻结120天后,解冻复活,恢复培养,进行室内小区床式堆料栽培,用稻草10kg,收鲜菇2.33kg,生物  相似文献   

10.
冻结速率对松茸PPO和POD活性的影响   总被引:6,自引:0,他引:6  
采用喷雾式流态化液氮速冻及缓冻.研究了冻结速率对松茸多酚氧化酶(PVO)及过氧化物酶(POD)活性的影响。结果表明:冻结速率对醇的活性有明显的影响,在-80℃、-60℃及-35℃(缓冻)下进行冻结,松茸的PPO活性分别下降了72.5%、67.7%及24.6%.POD活性分别下降了62.8%、53.5%及17.6%。  相似文献   

11.
AIM: Although endovascular radiotherapy inhibits neointimal hyperplasia, the exact alterations induced by β-particles irradiation remain to be elucidated. The objective of this study was to investigate the ability and the cellular mechanism of local β-particles emission from 188Re to inhibit vascular smooth muscle cells (SMCs). METHODS: The SMCs in vitro were irradiated by 188Re with single doses of 2.6 Gy-25.8 Gy. The effects of β-particles on SMCs, such as effective irradiate doses, the period of inhibition for SMCs proliferation, the changes of cell proliferation rate and DNA synthesis rate, cell cycle progression and related gene expression, were investigated by cell count, [3H]-TdR incorporation, cell cycle progression analysis, cell viability and immunocytochemistry, respectivecy. RESULTS: β-particles irradiation with dose of 5.2 Gy could inhibit significantly SMCs proliferation. At dose of 20.6 Gy DNA synthesis inhibitory rate was 92%, SMCs proliferation rate was only 3%. Renoval of 188Re did not abolish the inhibitory effects of β-particles on SMCs proliferation. The expression of P53 was up regulation and PCNA was down regulation after irradiation. CONCLUSION: β-particles from 188 Re was significantly effective and permanent in inhibiting SMCs proliferation, and inhibitory effect was in dose-dependet manner ED50was 5 Gy, the best dose to inhibit SMCs proliferation was 20 Gy. β-particles irradiation induced SMCs to occur G0/G1 arrest, damaged the ability of SMCs reproliferation and led to cell clonogenic death. P53 and PCNA had regulatiory effects on SMCs proliferation after β-particles irradiation.  相似文献   

12.
AIM:To study the effect of L-Arg on plasma content of endothelin (ET) and the expression of proto-oncogene c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy. METHODS: The level of c-fos mRNA were measured by in situ hybridization. The ET in plasma were measured by radioimmunoassay. RESULTS:After eight weeks of treatment with L-Arg, the expression of c-fos decreased markedly (P<0.01). The ET content in plasma also decreased significantly by L-Arg(P<0.01).CONCLUSION: Plasma ET content and the expression of c-fos in the left ventricle of rats with renovascular hypertensive hypertrophy could be decreased by L-Arg administration.  相似文献   

13.
Zusammenfassung Die Leistungsprüfungen wurden im Zeitraum 1997 bis 2003 mit den Unterlagen Gisela 4 und 5, den Klonnummern 195/20 und 497/8 aus der Gisela-Serie sowie Weiroot 10, 13, 53, 72 und 158 durchgeführt. Dabei dienten Sämlinge von P1 (bulgarische Selektion aus Prunus mahaleb) als Kontrolle. Alle Unterlagen waren mit der Sorte Stella veredelt und im Dezember 1996 in der Versuchsanlage der Agraruniversität in Plovdiv, Bulgarien, im Abstand von 6 m×4,5 m gepflanzt worden. Dabei erfolgte ein Pflanzschnitt. Nach Abschluss der natürlichen Kronenentwicklung wurde jedes Jahr ein Winterschnitt vorgenommen. Der Boden wurde durch mechanische Bearbeitung offen gehalten und nach dem 4. Standjahr wurden die Baumstreifen mit Herbiziden behandelt. Die Wasserversorgung erfolgte durch eine dem natürlichen Gefälle folgende Überflutung, allerdings nicht immer zum optimalen Zeitpunkt, da keine eigene Wasserquelle zur Verfügung stand.Basierend auf den Ergebnissen bis zum Anfang des 7. Standjahres können die untersuchten Unterlagen in zwei Gruppen differenziert werden: starkwüchsig—Weiroot 10, P1 und Weiroot 13; mittelstarkwachsend bis schwachwüchsig—Gi 497/8, Gisela 4, Weiroot 53, Weiroot 158, Gi 195/20, Weiroot 72 und Gisela 5. Letztere zeichnete sich durch besondere Schwachwüchsigkeit aus. Die meisten Wurzelschosser bildeten Gisela 4, Weiroot 10 und Weiroot 13. Weiroot 53, Weiroot 72 und Weiroot 158 entwickelten deutlich weniger und P1, Gisela 5, Gi 195/20 sowie Gi 497/8 keine Wurzelschosser. Den frühesten Blühbeginn induzierte Gisela 4. Die anderen Unterlagen führten, in Abhängigkeit von den Temperaturbedingungen des jeweiligen Jahres, zu einer Verspätung der Blüte: P1 und Weiroot 10 um 1–2 Tage; Gi 497/8, Weiroot 13 und Weiroot 158 um 2–4 Tage; Weiroot 72 um 2–7 Tage; Gi 195/20 um 3–6 Tage; Weiroot 53 um 3–8 Tage und Gisela 5 um 3–10 Tage. Die Reifezeit der Früchte war bei den Bäumen auf Gisela 5 im Vergleich zu den anderen Varianten um 2–3 Tage verspätet. Gisela 5, Weiroot 72 und Gisela 4 induzierten bei der aufveredelten Sorte die höchsten Ertragsleistungen, P1 die geringsten. Bei den Bäumen auf Gisela 5 war die Fruchtgröße geringer als bei den anderen Unterlagen. Bäume auf Gisela 5 brauchen intensive Pflege. Nur wenn alle Produktionsfaktoren und kulturtechnischen Maßnahmen optimiert werden, kann das hohe Ertragspotenzial dieser Unterlage ausgeschöpft werden.  相似文献   

14.
多效唑对猕猴桃离体试管苗生长及内源激素的影响   总被引:18,自引:0,他引:18  
多效唑(PP333)处理猕猴桃试管苗,降低了其生长强度;植株体内的GA3、IAA和ZT含量下降,ABA的含量上升,乙烯释放率增加;并且能降低外源的GA3和IAA促进生长的作用,而外源的GA3和IAA又能不同程度地逆转多效唑的抑制作用,使植株恢复生长。  相似文献   

15.
AIM: To investigate and screen the sensitive proteins in the formation mechanism of pathological scars by comparing the results of differential proteomic analysis between pathological scars and normal skin.METHODS: Two-dimensional gel electrophoresis was used to detect the protein expression profiles in 8 keloid patients, 8 hypertrophic scar patients and 3 matched normal skin patients.The proteins that showed differential expression of over 4-fold change were cut and analyzed by MALDI-TOF/TOF mass spectrometry.RESULTS: A two-dimensional protein profiling comparison between pathological scars and normal skin was successfully established.On average, 2 978 spots in keloid, 2 975 spots in hypertrophic scar and 3 053 spots in normal skin were identified using gel analysis software.Compared with normal skin, there were totally 36 differentially-expressed proteins in keloid and hypertrophic scar identified from the spots of over 4-fold change, including 16 proteins in both keloid and hypertrophic scar (8 up-regulated and 8 down-regulated), 11 only in keloid (9 up-regulated and 2 down-regulated) and 9 only in hypertrophic scar (4 up-regulated and 5 down-regulated).CONCLUSION: Proteomic analysis can identify the proteins with variance of pathological scars versus normal skin, thus providing probable new clues to reveal the formation mechanism of pathological scars.  相似文献   

16.
Abstract

Saskatoon berry (Amelanchier alnifolia Nutt., Rosaceae) and blueberry (Vaccinium corymbosum L., Ericaceae) are substantially equivalent in all characteristics that are important to the consumer, including fruit color, shape, size, nutrition, texture, and uses. In addition, both fruits are native to North America and they have practically identical historical uses and known health benefits. Their composition, processing, nutritional value and metabolism, intended uses, and levels of undesirable substances are compared.  相似文献   

17.
The objective of this study was to establish a cryopreservation protocol for hawthorn shoot apices (Crataegus pinnatifida Bge.). Cryopreservation was carried out via encapsulation–dehydration, vitrification, and encapsulation–vitrification on shoot apices excised from in vitro cultures. We began by showing that cold-acclimation enhanced the regrowth of cryopreserved apices from 10.0 to 65.5% in encapsulation–dehydration. We then decided that the encapsulation–dehydration method was an optimal cryopreservation method for hawthorn shoot apices in terms of its high recovery after cryopreservation as well as its ease of use compared with vitrification and encapsulation–vitrification. In encapsulation–dehydration, the protocol leading to optimal regrowth was as follows: after cold-acclimation at 5 °C in the dark for 2 weeks, excised shoot tips were pretreated for 24 h at 25 °C on hormone-free Murashige and Skoog [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue culture. Physiol. Plant. 15, 473–497] (MS) basal medium with 0.4 mol/L sucrose, then encapsulated and precultured in liquid MS medium with 0.8 mol/L sucrose for 16 h at 25 °C. Precultured beads were dehydrated for 6 h at 25 °C in the dessicator containing 50 g silica gel to a moisture content of 15.3% (fresh-weight basis) before cryostorage for 1 h. In addition, we examined the effect of adding glycerol to both the alginate beads and loading solution to enhance regrowth after cryopreservation in encapsulation–dehydration. In the present study, it was shown that adding 0.5 mol/L glycerol resulted in high regrowth percentages (82.5–90.0%) in four Crataegus species.  相似文献   

18.
Historic landcover dynamics in a scrubby flatwoods (Tel-4) and scrub landscape (Happy Creek) on John F. Kennedy Space Center were measured using aerial images from 1943, 1951, 1958, 1969, 1979, and 1989. Landcover categories were mapped, digitized, geometrically registered, and overlaid in ARC/INFO. Both study sites have been influenced by various land use histories, including periods of range management, fire suppression, and fire management. Several analyses were performed to help understand the effects of past land management on the amount and spatial distribution of landcover within the study sites. A chi-squared analysis showed a significant difference between the frequency of landcover occurrence and management period. Markov chain models were used to project observed changes over a 100-year period; these showed current management practices being effective at Tel-4 (restoring historic landscape structure) and much less effective at Happy Creek. Documenting impacts of past management regimes on landcover has provided important insight into current landscape composition and will provide the basis for improving land management on Kennedy Space Center and elsewhere.  相似文献   

19.
AIM: Previous studies performed with XBP-01 in vitro indicated that XBP-01 could inhibit vascular smooth muscle cells from being transformed into foam cell and could eliminate the atherosclerotic plaque in C57BL/6J mouse. This experiment is to investigate its mechanism of eliminating plaques in vitro. METHODS: The cultured porcine artery smooth muscle cells incubated with XBP-01 of 0.1 mg/L for 24 h after preincubated with oxidized low density lipoprotein of 15 mg/L for 72 h in vitro. The samples were analyzed by fluorescence microscope, confocal microscope system and flow cytometry. RESULTS: Apoptosis was triggered by being incubated with oxidized low density lipoprotein and this process was accelerated additionally by being incubated with XBP-01. CONCLUSION: XBP-01 can be effective in eliminating atherosclerotic plaque by accelerating the process in which oxidized low density lipoprotein induced smooth muscle cell apoptosis.  相似文献   

20.
AIM:To investigate the effect of metallothionein(MT) on proliferation of rat vascular smooth muscle cells (VSMCs) stimulated by homocysteine and its mechanism. METHODS:VSMCs proliferation was measured by [3-H]-TdR incorporation, mitogen-activated protein kinase(MAPK)activity were determined by immunoprecipitation method, the intracellular contents of MT and malondialdehyde (MDA)were assayed by -hemoglobin saturation method and TBA reaction, respectively, and lactate dehydrogenase (LDH) leakage was measured by NADH oxidation. RESULTS:Hcy(10-6-10-4 mmol/L) stimulated [3-H]-TdR incorporation by the VSMCs in a concentration-dependent manner. Compared with control, [3-H]-TdR incorporation in VSMCs treated with 0.1 mmol/L Hcy was increased by 4.2 fold (P<0.01). Meanwhile, Hcy enhanced MAPK activity, MDA formation and LDH release (P<0.01)in a concentration-dependent manner. Treatment of VSMCs with MT alone did not change above parameters, compared with control. However, MT (10-6-10-4 mol/L)attenuated significantly Hcy-stimulated proliferation of VSMCs (P<0.01)in a concentration-dependent manner. And MT inhibited obviously Hcy-induced activation of MAPK activity, MDA formation and LDH release. Preincubation of VSMCs with 0.5 mmol/L ZnCl2 for 6 h induced an increase cellular MT content by 5.7-fold (P<0.01). The MT-overexpressed VSMCs resisted Hcy-stimulating action on MAPK activity, MDA formation and LDH leakage (P<0.01). CONCLUSION:These results show that MT has an inhibitory effect on Hcy-induced VSMCs proliferation, and that MT could inhibit Hcy-stimulated MAPK activity and lipid peroxidation.  相似文献   

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