不同保鲜膜对双孢菇采后褐变及相关酶活性的影响

以双孢蘑菇为试材,研究了不同厚度的PE膜及微孔膜包装对双孢蘑菇贮藏中褐变及相关氧化酶活性的影响。结果表明:不同保鲜膜包装均能降低双孢蘑菇贮藏期间的褐变度、酶活性及衰老物质的积累。其中以0.050 mm PE膜对双孢蘑菇的贮藏效果最佳。     

不同厚度PE保鲜膜包装对'早金酥'梨果实品质和贮藏性的影响

以'早金酥'梨为试材,研究其采收后在(0±0.5)℃条件下,差压预冷4 h,分别用厚度为0.01、0.03、0.04 mm的PE保鲜膜包装,扎口,放入温度为(0±0.5)℃、空气相对湿度90%～95%的冷库中贮藏120d的品质变化情况。结果表明,用厚度为0.03 mm的PE保鲜膜包装的果实,在低温冷藏期间能有效抑制果实的呼吸强度,保持较高的可溶性固形物含量和果实硬度,减缓果皮色泽和感官品质的变化,且失重率和腐烂率也明显低于其他处理。     

不同保鲜膜包装对青椒保鲜效果的影响

以青椒为试材,采用5种不同的保鲜膜(0.04mm PE膜、0.018mm高渗出CO2保鲜膜、0.03mm纳米银保鲜膜、0.03mm PE膜、0.03mm PVC膜)包装处理青椒,测定青椒的感官品质和生理指标的变化,以筛选出适宜的膜包装。结果表明:室温下(20~25℃),0.03mm PVC膜处理组对青椒起到较好的保鲜效果,可有效抑制外观指数的下降,延缓果实转红和失重率的升高,抑制叶绿素、维生素C和可溶性蛋白质含量的减少,延缓MDA的积累,维持了细胞膜结构的完整性,同时,增强POD、CAT活性,减轻活性氧自由基对细胞组织的损伤,维持了较好的品质和商品性。     

双孢蘑菇软包装罐头加工工艺研究

对双孢蘑菇软包装罐头加工工艺进行了研究,确定了不合亚硫酸盐的护色剂配方及汤汁配方,并对制成的双孢蘑菇软包装罐头进行了感官评定和微生物指标检测。试验结果表明,采用不含亚硫酸盐的护色剂处理蘑菇,并用汤汁填充罐头能有效抑制双孢蘑菇的褐变,使菇体色泽浅黄,汤汁鲜味突出,较好地保持了双孢蘑菇的原有品质。     

双孢蘑菇软包装罐头加工工艺研究

对双孢蘑菇软包装罐头加工工艺进行了研究,确定了不舍亚硫酸盐的护色荆配方及汤汁配方,并时制成的双孢蘑菇软包装罐头进行了感官评定和微生物指标检测.试验结果表明,采用不含亚硫酸盐的护色荆处理蘑菇,并用汤汁填充罐头能有效抑制双孢蘑菇的褐变,使菇体色泽浅黄,汤汁鲜味突出,较好地保持了双孢蘑菇的原有品质.     

根用芥菜贮藏中品质和超微结构的变化

以根用芥菜为试材,采用PE包装的方法,在低温(2±1)℃下贮藏,研究0.01 mm PE保鲜膜包装对根用芥菜贮藏中品质和超微结构的影响,以期为根用芥菜的贮藏提供参考依据。结果表明:0.01 mm PE保鲜膜可以抑制根用芥菜失重率上升,减缓呼吸速率,延缓硬度下降,抑制纤维素含量上升,增加过氧化氢酶和超氧化物歧化酶活性,同时延缓细胞间隙的增加、改善其风味物质,有效延长其贮藏期。     

一氧化氮熏蒸处理对双孢蘑菇采后褐变及衰老的影响

以双孢蘑菇为试材,研究了在(10±0.5)℃条件下,不同浓度一氧化氮(NO) (30、60、90 μL/L)气体熏蒸处理对双孢蘑菇贮藏过程中感官品质、褐变度、多酚氧化酶(PPO)和过氧化物酶(POD)活性的影响.结果表明:外源NO熏蒸处理显著抑制了PPO活性的升高(8.90％～33.13％),减轻贮藏期的褐变程度.提高了贮藏后期POD活性(12.28％～76.27％),延缓了双孢蘑菇的衰老,有效延长了货架期(2 d).其中,NO浓度为60 μL/L时效果最好.     

不同保鲜膜包装对低温储藏铁皮石斛的保鲜效果影响

将刚采收的铁皮石斛放置在0℃下进行储藏,研究不同保鲜膜包装对铁皮石斛保鲜效果的影响。采用薄膜自发气调包装保鲜技术（MAP）,分别使用PVC保鲜膜、PE保鲜膜及微孔膜对鲜石斛进行包装,以散装石斛作为对照,通过对石斛失重率、膜透性、丙二醛、可溶性固形物进行测定,探讨不同保鲜膜对石斛保鲜效果的影响。结果表明,PVC保鲜膜包装的石斛保鲜效果最好,有效地保持了石斛在低温储藏期间的品质,可以延长其货架期,为果蔬的贮藏保鲜提供技术参数。     

覆土添加硒对双孢蘑菇产量与品质的影响

为探讨覆土中硒对双孢蘑菇(Agaricus bisporus)子实体产量与品质的影响,采用在覆土中添加亚硒酸钠的方法,进行双孢蘑菇的栽培试验,测定了不同硒浓度处理下双孢蘑菇产量、子实体外观性状、主要营养成分和硒含量.结果表明,覆土中添加0.15 mg·kg-1～0.60 mg·kg-1浓度的亚硒酸钠可显著提高覆土中有效...     

不同包装材料对甘蓝的保鲜效果

以甘蓝为试材,采用编织袋和0.03、0.05mm PE包装袋对其进行包装的方法,研究不同包装材料对甘蓝品质的影响。结果表明:PE包装袋可保持甘蓝的外观品质、抑制失重率的上升、延缓可溶性固形物含量的下降,对甘蓝有较好的护色效果;0.03mm PE包装袋能在75d贮藏期内0℃冷库中维持甘蓝较好的品质。     

自发气调包装对‘新梨7号’果实品质及耐贮性的影响

【目的】明确不同厚度的保鲜袋自发气调包装对‘新梨7号’采后生理和贮藏品质的影响。【方法】将‘新梨7号’分别采用厚度为0.02、0.03、0.04和0.05 mm的PE袋扎口处理形成自发气调环境,于温度(0±0.5)℃、相对湿度90%~95%条件下贮藏,并以0.02 mm PE袋不扎口为对照处理,定期测定各处理相关指标,并统计果实腐烂率、果柄保鲜指数。【结果】不同厚度保鲜袋内气体成分在第30天时达到平衡,气调能力水平由高到低依次为0.05 mm>0.04 mm>0.03 mm>0.02 mm PE袋,采用上述包装进行自发气调处理均能够抑制果皮h°值、Fm、Fv和Fv/Fm的下降;果柄保鲜指数随保鲜袋厚度增加显著升高,果实腐烂率显著低于对照;显著降低果实维生素C含量,冷藏后期货架期间各处理果实硬度、可滴定酸含量显著高于对照。各处理乙醛含量极低,乙醇检测不出。【结论】‘新梨7号’为较耐CO2且极不易发生褐变的梨果品种。筛选出适合‘新梨7号’自发气调包装袋为0.03 mm PE袋,可有效保持果面绿色,降低果实腐烂率但显著降低维生素C含量。     

温度和PE袋包装对皖金猕猴桃果实采后品质变化的影响

【目的】探究猕猴桃新品种皖金的采后贮藏特点,明晰其适宜的贮藏温度及包装膜袋厚度。【方法】试验分为两部分:首先将部分果实分别放入(0±0.5)℃、(1±0.5)℃、(2±0.5)℃,相对湿度(90±5)%冷库以及常温(CK1)下贮藏,定期取样测定相关指标,确定皖金适宜贮藏温度;在上述适宜贮温基础上,进一步优化贮藏条件,采用不同厚度(0.01、0.03、0.05 mm)的聚乙烯(polyethylene,PE)膜袋密封包装果实,未包装果实为对照(CK2),筛选膜袋厚度。【结果】(1±0.5)℃贮藏温度下,果实贮藏保鲜效果较好,与(2±0.5)℃处理相比延长了有效贮藏期,与(0±0.5)℃处理相比显著降低了冷害的发生;在(1±0.5)℃下,不同厚度的膜袋包装处理与对照相比均可减缓果实硬度下降,延长有效贮藏期,延缓果实冷害的发生。其中0.03 mm PE膜袋处理果实贮藏效果更优。【结论】在(1±0.5)℃贮藏条件下,0.03 mm PE膜袋处理对延长皖金猕猴桃果实的贮藏保鲜期、减缓冷害发生效果最佳。     

薄膜包装对冷藏扁桃仁主要营养成分的影响

在(0±0.5)℃冷藏条件下,设裸果、0.03、0.05、0.08m m 的聚乙烯薄膜袋包装4个处理贮藏带壳扁桃仁,研究对其主要营养成分变化的控制。结果表明:适宜厚度的聚乙烯薄膜袋包装处理可明显降低呼吸强度,延迟呼吸跃变时期,能很好地保存蛋白质、粗脂肪、糖类以及维生素B1、B2等营养成分,同时有利于脂肪酸的转化,延长扁桃仁的保质期。其中0.03m m 厚度的效果最为显著,0.05m m 的次之,而厚度为0.08m m 的保藏效果最差,出现了生理伤害。     

中甘21号

AIM: To observe the pathological role of 3-nitrotynosine (3-NT) on Escherichia coli LPS-induced vascular hyporeactivity in rats and the therapeutic effect of antioxidants. METHODS: Forty male SD rats weighting from 200 g to 250 g were randomly divided into four groups: the control group (n=10); LPS shock group (n=10); uric acid-treated group (n=10); melatonin-treated group (n=10). 6 h after LPS shock, phenylephrine (0.5-2.5 μg·kg-1) was applied intravenously to all groups and the percentage increase in MAP was detected, respectively. The concentration-response curve of aorta rings from all groups rats were obtained by cumulative addition of phenylephrine (PE), and PE Emax, EC50 were calculated. The concentrations of plasma malondialdehyde (MDA), nitrate/nitrite and 3-NT were assayed in all groups 6 h after LPS shock. RESULTS: The MAP level induced by PE significantly decreased to 54.60% in LPS shock rats compared with the control (P<0.05). However, PE induced MAP level increased 37.70% and 43.05% in uric acid and melatonin treated rats, respectively, compared with the LPS shock rats (P<0.05). The maximum response and EC50 to PE were significant reduced in LPS shock rats ［Emax, 35.30%±9.80%; EC50, (15.70±4.50)nmol/L］ compared with control group ［Emax, 100%; EC50, (4.71±2.04)nmol/L, P<0.05］; but the reactivity of aorta to PE was improved obviously in uric acid and melatonin treated groups (P<0.05). The plasma concentration of MDA, nitrate/nitrite and 3-NT were much lower in uric acid and melatonin groups than those in LPS shock group (P<0.05). CONCLUSIONS: 3-NT is an important pathological factor on vascular hyporeactivity in LPS shock. Antioxidants effectively improve α-adrenergic receptor-mediated vascular reactivity in LPS shock rats partially by removing lipid peroxidative production, reducing nitric oxide and 3-NT biosynthesis in LPS shock. These results suggest that antioxidants have potential beneficial therapeutic effect for septic shock patients.     

Effect of heat shock protein 70 expression induced by glutamine on vascular hyporeactivity in rats caused by LPS

AIM: To observe the effect of heat shock protein 70(HSP70) expression induced by glutamine on Escherichia coli lipopolysaccharides(LPS)-induced vascular hyporeactivity in rats.METHODS: Twenty four healthy male Sprague-Dawley rats were randomly divided into: the control group (n=8);LPS shock group (n=8);glutamine(Gln) treated group (Gln 0.75 g·kg-1 iv,n=8).6 h after LPS shock,phenylephrine (PE,0.5-2.5 μg·kg-1 ) was applied intravenously to all groups and the percentage increase in mean arterial pressure(MAP) was detected,respectively.The concentration-response curves of aorta rings were obtained by cumulative addition of phenylephrine (PE),and PE Emax,EC50 were calculated.The blood concentration of malondialdehyde (MDA),TNF-α and IL-6 were assayed in all groups 30 min and 360 min after LPS shock,respectively.The expressions of HSP70 from heart and aorta were also assayed after 6 h LPS shock.RESULTS: The MAP level induced by PE significantly decreased by 51.4% in LPS shock group compared with the control (P<0.05).However,PE induced MAP level increased by 17.5% in Gln group compared with LPS shock group (P<0.05).Emax and EC50 to PE were significant reduced in LPS shock group compared with control group (P<0.05),but significantly improved in Gln group (P<0.05).The expressions of HSP70 from heart and aorta were much higher in Gln group than those in LPS shock group (P<0.05).The blood concentrations of TNF-α,IL-6 and MDA were much lower in Gln group than those in LPS shock group.CONCLUSION: Glutamine effectively improves α-adrenergic receptor-mediated vascular reactivity through inducing the expression of HSP 70,reducing inflammatory cytokine release and peroxide biosynthesis in LPS shock.These results suggest that glutamine have potential beneficial therapeutic effect for septic shock patients.     

3类生境下脐橙果实细胞壁酶、瓤囊壁超微结构和品质变化的研究

为改进脐橙果实质地和科学生态区划与高品质栽培技术提供理论依据,研究了四川3类不同生境下脐橙果实果胶甲酯酶(PE)、多聚半乳糖醛酸酶(PG)、纤维素酶(CX)、瓤囊壁超微结构及主要品质指标的变化。结果表明:果实生长发育期细胞壁酶活性逐渐升高,但不同生境类型的变化趋势不同。超微结构中,南亚热带攀枝花脐橙的线粒体明显,中胶层清晰,细胞壁形态结构较完整;中亚热带江安和中北亚热带雅安脐橙细胞壁的中胶层明显裂解,线粒体膜分解,细胞器空泡化。不同生境SSC和可溶性糖差异显著。PG酶活性与≥10℃积温、1月份平均气温、年平均气温显著负相关,与年降雨量显著正相关。固酸比与≥10℃积温、年平均气温、1月均气温极显著正相关,与日照时数极显著正相关,与降雨量显著负相关。     

Effects of Ginkgo leaf extract and dipyridamole injection on tension of thoracic aorta rings of rats with hyperkalemia

AIM: To investigate the effects of Ginkgo leaf extract and dipyridamole injection (GD) on the tension of thoracic aorta rings isolated from hyperkalemia rats(HKR).METHODS: After the model of HKR was established and the preparation of the thoracic aorta rings was made, the tension of the rings was measured by a biological signal analytical system. The thoracic aorta rings were exposed to the medium containing GD at different concentrations and the vaso-constrictive tension was observed after stimulated with phenylephrine (PE) or KCl. RESULTS: Stimulated with PE or KCl, the tension of the thoracic aorta rings in HKR group was significantly higher than that in normal group (P<0.05). GD at the concentrations used in the experiment did not affect the basal tension in the resting rings prepared from both HKR and normal rats. In HKR group, pretreatment of the endothelium-intact thoracic aorta rings with GD at different concentrations showed no significant effect on KCl-induced vessel constriction (P>0.05). However, GD at the concentration of 16 mg/L significantly attenuated the vessel constriction induced by PE (P<0.05), which was inhibited by the pretreatment with N^ω-nitro-L-arginine methylester or methylene blue. GD at different concentrations did not show significantly inhibitory effect on PE-induced tension of endothelium-denuded thoracic aorta rings in HKR group (P>0.05). CONCLUSION: GD causes endothelium-dependent relaxation in the thoracic aorta rings of HKR. This effect may be mediated by the nitricoxide-guanylyl cyclase pathway.     

Effects of P38 MAPK signaling pathway on anacardic acid attenuating mouse cardiomyocyte hypertrophy induced by phenylephrine

AIM: To investigate the roles of P38 mitogen-activated protein kinase (P38 MAPK) in the process of anacardic acid (AA) attenuating mouse cardiomyocyte hypertrophy induced by phenylephrine (PE). METHODS: Cardiomyocyte hypertrophy was induced by PE in primary neonatal mouse myocardial cells. According to random number table method, the experiments were designed in 6 groups as following: control group, PE+ DMSO group, PE group, PE+ AA group, PE+ AA+ P38 inhibitor group and PE+ P38 inhibitor group. Mouse myocardial cells were collected after intervention for 48 h. The protein levels of p-P38, acetylated histone H3 at lysine 9 (H3K9ac) and atrial natriuretic peptide (ANP) were determined by Western blot. The interaction between p-P38 and H3K9ac was verified by co-immunoprecipitation (Co-IP). The mRNA expression of myocyte enhancer factor 2C (MEF2C) were tested by RT-qPCR. Mouse myocardial cell surface area was observed by immunofluorescence staining. RESULTS: The results of Western blot showed that the protein levels of p-P38 and H3K9ac in PE group were significantly increased compared with control group (P<0.05), and the levels of MEF2C mRNA and ANP protein in PE group were apparently increased compared with control group (P<0.05). However, P38 inhibitor and histone acetylase inhibitor AA attenuated P38 phosphorylation and H3K9 acetylation induced by PE, and down-regulated the over-expression of MEF2C and ANP in the mouse myocardial cells (P<0.05). The results of immunofluorescence staining showed that PE apparently increased mouse myocardial cell surface area (P<0.05), while P38 inhibitor and AA attenuated cardiomyocyte hypertrophy induced by PE (P<0.05). CONCLUSION: The mechanism of AA attenuating cardiomyocyte hypertrophy induced by PE may be related to the regulation of histone acetylation modification imbalance mediated by P38 MAPK signaling pathway.     

不同施肥处理对“醉人香”葡萄产量和品质的影响

以“醉人香”葡萄为试材,在秋施基肥的基础上,通过展叶期株施磷酸二铵0.5、0.75、1.0 kg、袋控缓释肥0.6kg和不施肥5种处理,研究不同施肥处理对“醉人香”葡萄生长、产量和品质的影响.结果表明:不同施肥处理对“醉人香”葡萄生长、产量和品质较CK均有不同程度的提高.其中,袋控缓释肥0.6 kg/株的效果最好,新梢粗度、单粒重、单株产量、可溶性固形物含量、有机酸和糖酸比分别为9.7mm、9.7g、4.37 kg、21.1％、和47.85,较CK分别提高1.6mm、1.9g、0.66 kg、1.O％和5.87,达到显著性差异.