Effect of Carbon Dioxide (CO_2) Controlled Atmosphere on Superoxide Dismutase (SOD) Activity of Three Storage Pests in Chinese Medicinal Materials

[ Objective ] The paper was to study the effect of controlled atmosphere stress of carbon dioxide （ CO2 ） on Superoxide dismutase （SOD） activity of in- sect, so as to analyze the biological mechanism of the action of controlled atmosphere stress on insect. [ Method] Using nitrotetrazolium blue chloride （NBT） light reduction method, SOD activity of drugstore beetle （ Stegobium panlceum ）, cigarette beetle （ Lasioderma serricorne） and coffee bean beetle （Araecerus fasciculatus） was studied, and the stress response of the enzyme under controlled atmosphere stress of CO2 was analyzed. [ Result ] SOD activity of drugstore beetle, cigarette beetle and coffee bean beetle exposed to controlled atmosphere stress of high concentrations of CO2 for 3 and 6 h had certain degree of increase, and the activity sig- nificantly increased from 2.011±0.954,2.664±0.218 and 1.458±0.718 to 3. 135±0. 105,3.050±0.673 and 2.975±0.229 U/（per pest · 30 min） after treat- ment for 6 h. [ Conclusion] Controlled atmosphere stress of high concentrations of CO2 had certain activation effect on SOD activity of storage pest in Chinese me- dicinal material within the context of sub-lethal events. The results could enrich the insecticidal mechanism of controlled atmosphere and theoretical system of analy- sis on insect resistance to controlled atmosphere.

Effect of Controlled Atmosphere Storage(CAS)Technology of Flue-cured Tobacco Laminas on the Alcoholization Quality of Tobacco

To achieve the continuous maintainence of optimum quality state of flue- cured tobacco laminas and the effective regulation and control on alcoholization time for controlled atmosphere storage （CAS） method in the process of storage, the lam- ina samples of natural alcoholization for 1 year were selected. Comparable analysis on the appearance quality, chemical components and sensory quality of flue-cured tobacco laminas in the process of alcoholization was carried out by using the meth- ods of CAS and natural alcoholization. The results showed that appearance and color through the treatment of natural alcoholization were deep, browning and ac- companied by the phenomenon of oil, while color scale of flue-cured tobacco lami- nas through the treatment of CAS was uniform, fullness was better, and these two methods were close or identical after opening for 3 months. The contents of total sugar and reducing sugar during the process of alcoholization were also gradually decreased, but the ratio of reducing sugar to total sugar of laminas via CAS was higher than that of the natural alcoholization treatment. Compared with the natural alcoholization,the descending trends of total nitrogen and nicotine contents during CAS were gentler, the ratio via CAS was closer to 1, and the coordination of chemical components was more superior. During the period of alcoholization for 6 to 12 months, sensory quality of laminas via the natural alcoholization treatment was more superior than that of CAS treatment. However, after 18 months of alcoholiza- tion, sensory quality of laminas via the CAS treatment was more superior than that of the natural alcoholization treatment, and the CAS treatment could improve opti- mum sensory quality by 0.5 to 1.5 scores. Additionally, the CAS treatment could prolong the time of optimum alcoholization quality for 6 months, compared with the treatment of natural alcoholization. The CAS method could influence the alcohoJiza- tion quality of flue-cured tobacco laminas and prolong the retention period of opti- mum quality status for flue-cured tobacco laminas by regulating the environmental aas composition, thereby realizin.q quality control of flue-cured tobacco laminas.

The Relationship Between Resistance to Controlled Atmosphere and Insecticides of Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae)

The cross resistance of four resistant strains of Liposcelis bostrychophila Badonnel, an important stored-product insect pest, was investigated. These four strains included the HCO2-R (hypercarbia-resistant strain), HCLO-R (hypoxia and hypercarbia resistant strain), DDVP-R (DDVP-resistant strain) and PH3-R (PH3-resistant strain). The results indicated that there were cross-resistances between CA and insecticides, and the quantities of the cross-resistance were different. The cross-resistance factor (RF) of HCO2-R to hypoxia and hypercarbia was 3.2458, whilst, that of HCLO-R to hypercarbia was 1.8280. The RF of DDVP-R to PH3 was 3.9614, whilst, that of PH3-R to DDVP was 2.7852. The RF values of DDVP- R and PH3-R to hypercarbia were 1.3550 and 1.1816, respectively. However, the RF of HCO2- R to DDVP was 2.1372. There also was a low cross-resistance between DDVP-R and HCO2-R. The RF of HCO2-R to PH3 was 3.3698. This suggested that the insects resistant to high CO2 concentration atmosphere would develop significant resistance to PH3. However, the insects resistant to PH3 remain sensitive to hypercarbia atmosphere. Both DDVP-R and PH3- R developed resistance to high CO2 treatment. There was a low cross-resistance between DDVP-R and HCLO-R. The insects resistant to hypoxia and hypercarbia were very sensitive to DDVP. There also was cross-resistance between HCLO-R and PH3-R, but the resistance of PH3-R to hypoxia and hypercarbia was lower than that of HCLO-R to PH3. The difference of the overlapping and separate values indicated that there were differences in the intercross-resistance of four resistant strains.

Development and Performance Study of Controlled Atmosphere for Fresh Tomato

Development of a controlled atmosphere (CA) plant and shelf-life of fresh tomatoes at different storage conditions were studied in this research. The controlled chamber (4.5' × 4.5' × 4.5') with supplement of 1% L-ascorbic acid as antioxidant source was constructed using locally available materials. Fresh tomatoes were kept with wrapping by low density polyethylene under refrigerated and CA storage conditions. The maximum shelf-life of fresh tomato was 42 days under CA condition and followed by 35 days in refrigeration condition. Though initial cost of controlled atmosphere was high but it resulted in maximum shelf life of tomato. However, CA condition retained the physiological changes namely, color change, TSS, and weight loss of fresh tomatoes than that of stored in refrigerated condition. From nutritional point of view, it was concluded that developed CA plant could be used to extend the shelf-life of fresh tomatoes with minimum physico-chemical changes throughout the storage period.

外源乙烯对CA贮藏桃果实品质变化的影响

以"八月脆"桃果实为材料,研究了不同浓度外源乙烯(10～20、50～80μl/L)处理对桃果实气调贮藏(9%～11%CO2+9%～11%O2)期间及其回温3d后品质变化的影响。结果表明,外源乙烯处理可使贮藏后期桃果实及其回温果实正常软化,而未加乙烯处理的气调和冷藏对照处理果实在贮藏45d以后出现硬度升高,失去了后熟软化能力;外源乙烯处理使贮藏后期桃果实及其回温果实膜透性增加;外源乙烯处理使贮藏中后期桃果实总糖含量增加,但回温后桃果实总糖含量没有明显升高;外源乙烯处理加快了贮藏中期桃果实可滴定酸含量的下降,但可缓解回温桃果实可滴定酸的迅速下降。外源乙烯对气调贮藏桃果实各品质指标的影响主要表现在贮藏中后期。综合考虑不同浓度外源乙烯处理对桃果实各品质指标的影响,认为50～80μl/L外源乙烯处理对贮藏中后期桃果实的后熟及维持其品质有较好的作用。

外源乙烯对CA贮藏桃果实MDA含量、PPO和LOX活性变化的影响

以‘八月脆’桃果实为材料,研究了常温条件下,不同浓度外源乙烯(10～20μL.L-1和50～80μL.L-1)处理对气调贮藏(9%～11%CO2+9%～11%O2)期间以及在20℃回温3 d后桃果实MDA(丙二醛)含量、PPO(多酚氧化酶)和LOX(脂氧合酶)活性的影响。结果表明:常温贮藏条件下,桃果实MDA含量随着果实的成熟而升高,PPO和LOX活性在第4 d出现高峰。外源乙烯提高了气调贮藏果实MDA含量,贮藏60 d时,高浓度外源乙烯处理果实MDA含量明显升高。回温后,冷藏对照果实MDA含量随着贮藏时间的延长而增加,且在贮藏60 d时,MDA含量高于常温贮藏果实的MDA含量。外源乙烯对LOX的作用与其对MDA的作用一致。高浓度的外源乙烯可抑制贮藏前期桃果实PPO活性,低浓度外源乙烯则降低了贮藏后期桃果实PPO活性,但回温后,低浓度外源乙烯处理果实PPO活性明显升高。综合考虑不同处理对CA贮藏桃果实MDA含量、PPO、LOX活性的作用特点,认为50～80μL.L-1外源乙烯处理对减轻桃果实的低温冷害、抑制果实褐变有一定的作用。

黄花梨CA贮藏中气体成分对果实呼吸和发病率的影响

以黄花梨为试材,通过两年的气调贮藏（CA）试验,找到了该水果的适宜贮藏温度（1-4℃）及相应的O2和CO2气体浓度,它们分别为8%-11%和1%-4%;特别是对O2和CO2含量的动态监测数据及结果的分析对比,得出了反映呼吸变化的呼吸差Rd值与贮藏效果的关系,初步探明：随Rd值的增大,发病率增加,Rd值越小,越利于贮藏;还可通过Rd值的比较反推其临界氧含量.

不同气体成分处理对丰香草莓采后品质、SOD及CAT活性的影响

以采后"丰香"草莓为材料,研究了不同气体成分处理(11%O2+10%CO2,3%O2+5%CO2)及冷藏对照对果实采后品质参数(失重率、腐烂指数、pH值和可溶性固形物含量)、SOD和CAT活性的影响,旨在寻求适宜"丰香"草莓贮藏的气体成分。结果表明:较对照相比,3%O2+5%CO2处理可降低果实的腐烂指数和失重率,维持可溶性固形物含量,抑制SOD活性的升高,增强CAT活性和pH值,11%O2+10%CO2处理亦可降低果实的失重率、腐烂指数,维持可溶性固形物含量,但导致贮藏后期果实SOD活性的升高,同时降低了CAT活性。可见,3%O2+5%CO2处理对"丰香"草莓的保鲜效果较理想。

外源乙烯对CA贮藏桃果实内源乙烯生物合成的影响

以八月脆桃果实为试材,研究了不同浓度外源乙烯(0μL/L,20～50μL/L,50～80μL/L)对桃果实气调贮藏(9%～11%CO2+9%～11%O2)期间内源乙烯生成量、ACS和ACO活性变化的影响。结果表明,在整个贮藏过程中,外源乙烯处理果实的内源乙烯生成量显著高于未加外源乙烯的气调贮藏和冷藏对照果实;外源乙烯处理果实ACS活性亦高于气调和冷藏对照果实,但对ACO活性的影响不明显。

大蒜CA贮藏特性和参数优化研究

通过研究大蒜贮藏特性,以减少大蒜贮藏保鲜过程中的损失。采用静置法测定大蒜的呼吸强度,采用CA贮藏保鲜方法确定各组分气体的最优比例,采用真空低温贮藏保鲜方法确定贮藏最适温度,采用定硫法测定大蒜素含量。结果表明,大蒜的呼吸作用属于跃变型,贮藏7 d后,呼吸强度显著增强,出现1个呼吸峰,之后呈现下降趋势;CA贮藏最佳条件:充入体积分数4%O_2和14%CO_2,贮藏温度-4℃,相对湿度约80%;大蒜真空低温贮藏最佳贮藏温度-2℃,相对湿度约80%。

CA贮藏对新鲜石刁柏的影响

用9种不同的CA条件与低温空气贮藏进行比较,结果证明用CA贮藏法进行石刁柏的贮藏保鲜是可行的。在设定的10个试验区中,当O_2浓度保持在21％的前提下,适当提高CO_2的浓度可提高贮藏效果。以21％O_2,30％CO:_2的贮藏条件保鲜效果较好。当CO_2浓度为0％时,O_2的浓度在1～0％之间保鲜效果最好。在10个试验区中,以空气条件下贮藏效果最差。

气调技术在我国烟叶仓储养护上的研究与应用进展

气调技术是一种安全有效、绿色环保的仓储养护技术。近20年来,气调技术在烟叶仓储养护领域飞速发展,在烟叶杀虫防霉、保质等方面均取得了很多研究和应用成果。本文回顾了气调技术在烟叶仓储养护领域的发展历程,归纳了气调技术在烟叶杀虫防霉方面的研究和应用进展,综述了气调技术对烟叶醇化过程中质量变化的影响,认为应加强气调技术在原烟上的应用研究,构建“原烟-片烟”一体化养护体系;针对目前存在的气调杀虫周期过长、气调参数与烟叶醇化进程对应关系尚不明确等问题,指出应加强气调技术与其他手段联用快速杀虫技术研究,并进一步系统研究气调参数对烟叶醇化进程的影响规律及相关机理,从而实现烟叶醇化进程精准调控,使烟叶醇化质量高点和烟叶实际使用时间精准结合。

猕猴桃大帐气调气流组织的数值模拟及优化

为确定合理的猕猴桃大帐气调参数,提高大帐气调贮藏性能,该研究通过模拟猕猴桃在果筐内的自然堆叠状态,建立了单个猕猴桃尺度的大帐气调微环境模型,采用数值模拟方法,分析猕猴桃大帐气调过程中N_(2)纯度、流量、管径、出口高度4个关键参数对降氧时间及气体分布均匀性的影响。基于Box-Behnken原理设计四因素三水平正交仿真试验,利用Design-Expert软件建立响应指标回归模型,对所选取的4个因素进行响应面分析和参数优化。对优化参数组合进行仿真试验,对比优化参数组合条件下响应面回归模型预测值与仿真试验数值模拟值。结果表明:各因素对降氧时间影响由大到小顺序为出气口高度、流量、N_(2)纯度、管径;对不均匀系数影响由大到小顺序为N_(2)纯度、出气口高度、管径、流量。猕猴桃大帐气调的最优气调参数组合为N_(2)纯度96.0%、流量23.0 m^(3)/h、管径50 mm、出气口高度3 126 mm,对应的降氧时间、不均匀系数分别为989 s、6.1%。降氧时间响应面回归模型预测值与仿真值之间的相对误差为3.1%,不均匀系数响应面回归模型预测值与仿真值之间的相对误差为8.4%。研究对于大帐气调装备的研发及性能提升具有重要的理论和实际意义。

CO_(2)气调对不同品种哈密瓜采后品质特征的影响

以2个山东哈密瓜品种‘晓蜜25号’及‘玫珑’为材料,研究不同CO_(2)浓度气体调控(controlled atmosphere,CA)下不同品种哈密瓜的采后品质特征变化。结果表明:随着贮藏时间的延长,不同CO_(2)浓度处理能够有效延缓不同品种哈密瓜失重率的上升,保持果实的硬度,延缓可溶性固形物以及可滴定酸含量的下降,提高过氧化物酶和过氧化氢酶的活性,延缓丙二醛含量的上升,保持抗氧化能力并在贮藏结束时仍维持较好的品质。这些结果表明,采后维持CA条件有助于改善哈密瓜的品质,延长贮藏期。

气调贮藏对唐古特大黄品质的影响

目的:探究气调贮藏对唐古特大黄后期养护的影响。方法:以干燥后唐古特大黄为对照,研究气调养护贮藏2年与常温贮藏2年的唐古特大黄中主要活性成分含量的变化。结果:相比于干燥后唐古特大黄,气调养护储藏与常温储藏的唐古特大黄中总蒽醌、没食子酸、番泻苷A、番泻苷B以及游离蒽醌(大黄素、大黄酚、芦荟大黄素、大黄素甲醚、大黄酸)的含量均出现损失,气调养护贮藏的唐古特大黄中有效成分含量明显高于常温储藏的含量,表明气调养护贮藏能够有效减少唐古特大黄中有效含量的损失。结论:气调养护有利于唐古特大黄的后期贮藏。该研究为青藏高原道地药材的储藏提供了一定的科学依据。

不同厚度保鲜袋包装对“广丰”青皮核桃保鲜效果的影响

为探究不同厚度保鲜袋包装对青皮核桃保鲜效果的影响,用简便、环保的保鲜方法达到延长其贮藏期的目的,以四川产“广丰”青皮核桃为试材,以不使用保鲜袋包装为对照,采用25μm、45μm、70μm三种厚度的保鲜袋包装,于(4±1)℃条件下贮藏,每7 d测定一次各组青皮核桃贮藏期间的表皮褐变指数、腐烂率、色差、呼吸强度、失重率、乙烯释放速率、MDA含量等指标。结果表明:与对照相比,不同厚度的保鲜袋包装均能抑制青皮核桃的呼吸强度、乙烯释放速率,延缓呼吸高峰和乙烯高峰的到来,从而延缓失水、表皮褐变和腐烂的进程,抑制MDA含量的增加,较好地维持青皮核桃表皮色泽;其中,45μm厚度保鲜袋包装的青皮核桃贮藏第57 d时,色差a^(*)值2.65,失重率5.03%,腐烂率28.57%,综合来看保鲜效果最好。

富氮气调--磷化氢的可供替换技术

在粮食储藏上利用氮气的方法已经有30多年的历史,但直到最近经济有效的变压吸附(PSA)和膜分离(MS)制氮设备的出现,才使得该技术在储粮上使用成为可能。本研究首先在25、30和35℃、99%、98%和97%氮气的环境下,对小麦、大麦、燕麦、羽扇豆和油菜籽中的花斑皮蠹、赤拟谷盗、谷蠹和米象成虫和非成虫虫态进行了为期4、3和2周的实验室生物测定。然后在终端用户LakeGrace和CBH(Cooperative BulkHandling)谷物进出口公司Albany出口港码头开展实仓验证,测定小麦、大麦和油菜籽中不同储粮害虫虫种和油菜籽瓢虫和肖叶甲类两种田间害虫的防治效果。同时对处理后的粮食品质进行了测定。实验结果表明,害虫死亡率随着氧气浓度降低、暴露时间和温度的增加而增加,富氮低氧在低温条件下不能100%致死花斑皮蠹幼虫。氮气处理对磷化氢抗性和敏感品系储粮害虫防治效果没有差异。与其他粮种相比,在油菜籽中的防治效果更好。各种粮种的水分含量、蛋白质、含油量、淀粉和籽粒颜色品质指标均未受到影响。成功开发了富氮低氧商业规模应用模式,为磷化氢高抗性害虫治理提供了解决方案,满足市场日益增长对无害虫和无化学残留粮食的需求。

不同环境因子下茶籽油在储藏过程中的品质变化

该研究评估茶籽油在不同温度和气体环境下的储藏稳定性,分析其质量指标变化情况。结果显示,高温条件下茶籽油的甘油三酯结构稳定性下降,氧化程度加深。然而,经过CO_(2)和N_(2)气调处理后的茶籽油的酸价和过氧化值显著降低,证明气调处理可以有效抑制甘油三酯结构的破坏。此外,在高温条件下,茶籽油中的生育酚、油酸和亚油酸损失严重,而气调处理可以保护上述活性物质不被破坏。因此,低温和无氧气调处理将是茶籽油质量控制的重要手段。

Effects of Gibberellic Acid (GA_(3)) and Salicylic Acid (SA) postharvest treatments on the quality of fresh Barhi dates at different ripening levels in the Khalal maturity stage during controlled atmosphere storage

Barhi dates at Khalal maturity stage are well-known with their pleasant taste,crispy texture,and bright yellow color.It is necessary to extend the duration of Barhi Khalal stage which is too short for effective marketing.This study aimed to inspect the effects of Gibberellic Acid(GA_(3))and Salicylic Acid(SA)postharvest treatments on retaining the high quality of Khalal Barhi fruits during controlled atmosphere storage.Fresh samples of Barhi fruits at Khalal stage harvested at three different ripening levels were dipped after harvesting in GA3(150 ppm)or SA(2.0 mmol/L)and subsequently stored in controlled atmosphere(0°С,5%O_(2),5%CO_(2),80%±5%RH).The results revealed that the GA_(3) and SA treatments reduced the percentage of weight loss and decay in the fruits,while the total soluble solids increased.Moreover,GA_(3) and SA treatments were significantly efficient in limiting the changes in fruit color and texture of Barhi dates compared to the control.Sensorial results support the experimental data and disclosed that the GA_(3)(150 ppm)treatment in the controlled atmosphere(CA)storage was better in conserving the quality of Barhi at the Khalal maturity stage and delaying ripening process.

常压储罐氮封系统的设计

氮封流程是储罐工艺设计的常用流程,为防止储罐内物料因与进入的外界气体(空气)接触而被污染变质或与外界进入的气体(空气)发生化学和(或)生物反应,常需设置气封系统。储罐设置氮封系统是降低油品蒸发损耗必不可少的重要措施。在石油、化工等行业,储罐是必不可少的储存设备,对储罐进行氮封可以有效减少油品蒸发损耗,提高储罐的使用寿命,避免环境污染等问题。对于不同性质的物料,氮封系统方案需要根据物料性质进行改进。例如,对于轻质油品储罐,需要增加氮气流量,保持储罐内部压力稳定,防止油品挥发;对于高温易结晶的液硫,需要增加氮气流动速度,防止液硫结晶,影响储罐使用寿命;对于顺酐,需要增加氮气流量,减少顺酐受潮,防止产生燃爆事故。基于此,本文主要针对氮封系统设计展开相关探讨分析。