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.

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.

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.

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.

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。

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。

南方地区立筒仓充氮控温气调储粮技术应用研究

立筒仓储粮具有储存量大、占地面积小、机械化程度高、节省人力、密闭防虫、防鼠雀和防火性能好等优点,缺点是装粮深、扦样处理粮情操作不易、使用磷化铝常规熏蒸投药难以杀死抗药性害虫及会出现杀虫不彻底等问题。为减少夏季外界环境对储粮的影响,提高南方高温高湿地区储粮稳定性,提高害虫防治作业的安全性及彻底性,实现绿色储粮,对本库立筒仓进行气调仓改造,开展充氮控温气调储粮杀虫试验。试验结果表明,气调杀虫效果良好,气调拆封后储粮品质稳定。既减轻了仓储保管人员的劳动工作量,又达到了“绿色、安全、有效、卫生”储粮的目的。

Effects of pre-storage dipping in calcium chloride and salicylic acid on the quality attributes of stored Khalal Barhi dates

Barhi is a high-quality date cultivar,typically harvested and consumed fresh at the Khalal maturity stage when the fruits are crispy and sweet with bright yellow color.The shelf-life of the Khalal stage(2-3 weeks)is very short for effective marketing.This study aimed at investigating the role of calcium chloride(CaCl2)and salicylic acid(SA)as pre-storage treatments in preserving the color and texture of the fruit during both cold and controlled atmosphere(CA)storage systems.Fresh-harvested Barhi fruits at the Khalal stage were treated with CaCl2(2%)or SA(2.0 mM),and then stored in cold and CA systems.The weight loss and decay percentages in the treated samples decreased,whereas the total soluble solids of the treated samples increased compared with those of the untreated ones.The best treatment in limiting changes in the color and texture of the fruits was CaCl2 treatment during CA storage.

不同浓度CO_(2)对玉露香梨贮藏品质的影响

【目的】以玉露香梨为试材,研究分析不同浓度CO_(2)气调贮藏对玉露香梨采后贮藏品质的影响。【方法】在低温贮藏(0℃)的0、60、120、180、240 d及常温贮藏(20℃)14 d时分别测定不同浓度CO_(2)处理下玉露香梨果实品质相关指标。【结果】各处理下玉露香梨果实随着贮藏时间的增加,硬度都呈下降的趋势,失重率呈升高趋势,2%CO_(2)处理的果实硬度较其他组最高,失重率较其他组最低。2%CO_(2)的气调贮藏在一定程度上可以延缓玉露香梨果实相对电导率、丙二醛含量、过氧化氢含量的升高,有效抑制了维生素C含量和抗坏血酸过氧化物酶活性的降低。当CO_(2)浓度为10%时,会对玉露香梨果实造成伤害,导致果实失重率、相对电导率增幅加大,果心果肉中过氧化氢积累过量。玉露香梨果心丙二醛的含量约为果肉的2倍,果心过氧化氢、维生素C的含量约为果肉的10倍。【结论】2%CO_(2)处理的玉露香梨保鲜效果最好。

气调小包装对去壳茭白品质的影响

研究了气调小包装对去壳茭白贮藏保鲜品质的影响。结果表明,去壳茭白气调贮藏适宜的气体成分为O2 0.5%～0.6%,CO2 10%～11%。气调小包装的去壳茭白在贮藏期中,呼吸强度和乙烯释放量均低于对照。气调包装可抑制茭白中PPO、POD活性和木质素含量的增加。在低氧、高二氧化碳环境中(温度0～3℃),去壳茭白贮藏期可以达到49 d。

果蔬气调贮藏国内外研究进展

综述了近年来国内外果蔬气调贮藏领域的研究进展,主要包括气调保鲜机理、气调贮藏环境模拟与优化、气调包装及气调库系统设计、气调保鲜寿命预测、气调环境下果蔬呼吸速率模型建立等方面的理论和实验研究情况,对气调贮藏新技术及其发展方向进行了总结。

不同气调贮藏方式对大久保桃冷藏后品质的影响

研究了不同气调贮藏方式(变动气调、间歇气调、常规(静态)气调)对大久保桃冷藏及货架期3d后果实品质变化的影响。结果表明,与冷藏对照相比,适宜的气调处理可明显降低果实冷害的敏感性、延缓果肉组织膜透性和褐变度的上升趋势、减轻出汁率的上升,有效保持了果实硬度、色泽、风味;对可溶性固形物和可滴定酸含量的影响不大;其中较适宜气体指标是5%O2+10%CO2;与常规(静态)气调相比,变动气调贮藏进一步降低了果实的冷敏感性,减轻了在低温条件下果实的冷害症状,贮藏70d,果肉无褐变,货架期间,仍保持了较好的后熟特性,改善了果实的贮后品质。

不同储藏温度及储藏方法对稻谷品质的影响

为了掌握不同储粮温度及储藏方法稻谷的发芽率、脂肪酸值、过氧化氢酶活动度等品质指标随储藏时间的变化规律,测定了不同储藏温度下常规和气调储藏稻谷的各项品质指标。结果表明:当储藏温度较低时,常规和气调储藏稻谷的各项检测指标较为接近;而高温储藏时,气调储藏稻谷的各项检测指标均优于常规储藏。因此,稻谷储藏时,低温储粮应是首选方案,当低温不易实现时,可选择气调储藏以减缓温度对稻谷品质的影响。

O_2联合CO_2气调对西兰花活性氧代谢及保鲜效果的影响

设置100%O2、80%O2+20%CO2、60%O2+40%CO2、40%O2+60%CO2、20%O2+80%CO2气体组合,以自然大气为对照(CK),对15℃贮藏过程中西兰花的活性氧代谢及品质指标进行测定。结果表明:100%O2处理促进西兰花呼吸和乙烯释放,加速过氧化氢(H2O2)和超氧阴离子自由基(O-2·)产生以及丙二醛(MDA)积累,促进叶绿素和VC含量的降低,缩短了保鲜期;而20%O2+80%CO2处理虽能很好的维持叶绿素含量,但易导致西兰花VC的迅速丧失并产生异味现象;40%O2+60%CO2处理显著降低呼吸速率和乙烯释放量,减少H2O2和O-2·产生,抑制MDA的积累,并较好的维持了叶绿素和VC含量,表现出很好的保鲜效果。