冬枣减压和臭氧联用保鲜技术研究

以冬枣为材料,研究减压、臭氧对冬枣贮藏期生理生化指标的影响。结果表明,减压和臭氧均能降低冬枣呼吸强度,抑制淀粉酶活性,减缓淀粉降解速度,抑制霉菌孢子繁殖,防止果实腐烂,保持果实硬度。减压还可减缓冷害,使贮藏温度较常压下(-1~0℃)降低2℃。正交试验结果表明,采用盛水加湿法,-2℃和40.5kPa条件下,每隔20d用300mg/m3O3处理30min,可使冬枣贮藏140d,好果率达92.4%。     

壳聚糖涂膜结合臭氧杀菌对冬枣果实贮期品质及抗病因子的影响

研究壳聚糖涂膜结合臭氧杀菌对冬枣果实贮期品质和抗病因子的影响,旨在为冬枣保鲜技术提供理论基础。结果表明:室温条件下贮藏,0.75%壳聚糖涂膜结合300μg/L臭氧处理冬枣,能防止果实可溶性固形物、可滴定酸和VC含量的下降速度;减缓还原糖含量的上升速度;防止酚类物质降解;激活保护酶POD活性,并在较高水平维持较长时间;贮藏初期抑制PAL活性下降而后期延缓其上升;推迟PPO活性高峰的到来。     

减压贮藏对冬枣果实呼吸及软化相关指标的影响

研究了在-1±1℃条件下不同减压强度(86.1、70.9、55.7、40.5、25.3 kPa)贮藏对冬枣果实呼吸强度、硬度、非水溶性果胶含量及多聚半乳糖醛酸酶(PG)活性的影响。结果表明,减压贮藏可以抑制冬枣的呼吸作用,保持冬枣的硬度,抑制非水溶性果胶的降解,但对PG活性的影响不明显。不同减压条件对冬枣贮藏期呼吸强度和软化相关指标的影响不同,其中55.7 kPa减压条件下冬枣的贮藏保鲜效果最好。     

减压对冬枣采后生理生化变化的影响

 以冬枣果实为试材 ,研究了减压对枣果贮藏生理生化变化的影响。结果表明 ,减压有效地保持了枣果的硬度和VC 含量 ,降低了果肉中乙醇、乙醛含量和枣果呼吸强度 ,抑制了抗坏血酸氧化酶和乙醇脱氢酶的活性 ,减慢了内源乙烯的释放速率。但是 ,减压对阻止果肉褐变无明显效果。     

臭氧气体处理对甜瓜和雪花梨果实贮藏品质及效果的影响

【目的】观察臭氧气体处理后甜瓜和雪花梨果实的贮藏品质变化,减少贮藏损失。【方法】以甜瓜和雪花梨为试材,经不同质量浓度臭氧气体处理后于4℃贮藏,定期分析果实品质变化。【结果】与对照相比,臭氧气体处理后甜瓜腐烂率降低50%,抗坏血酸含量下降10%、可滴定酸减少16%;有效维持雪花梨的硬度,延缓可溶性固形物变化,叶绿素含量下降47%;提高了两种果实可溶性蛋白质的含量,抑制丙二醛含量的上升。不同质量浓度的臭氧气体处理对甜瓜和雪花梨的腐烂率和品质的影响有所不同。甜瓜贮藏28d后,20mg/m3臭氧气体显著降低腐烂率,60mg/m3和100mg/m3次之;雪花梨贮藏40d后,100mg/m3臭氧处理的品质显著好于对照,而200mg/m3臭氧与对照的变化趋势相近。【结论】适当质量浓度的臭氧气体处理对甜瓜和雪花梨有一定的保鲜效果。     

冬枣酒软过程中呼吸强度和乙烯代谢的变化及1-MCP的处理效应

以半红果期的冬枣为材料 ,装入打孔的农膜袋中贮藏于 ( 2 0± 2 )℃和 ( 4± 0 5 )℃ ,研究其果实酒软的规律。结果表明 :随着贮藏时间的延长 ,果实乙醇含量持续上升 ,当乙醇含量达到 0 1%时 ,果实明显酒软 ;酒软过程中无呼吸高峰和乙烯释放高峰出现 ;果实的呼吸作用与乙醇积累呈正相关 ;降低温度可以抑制其呼吸强度 ,减缓酒软进程 ;室温下 1 0 0 μL·L-11 MCP密闭处理冬枣 12h ,明显抑制了乙烯释放量 ,但对呼吸作用的抑制效果不明显。冬枣贮藏期的酒软受呼吸代谢和乙烯代谢的双重调节 ,适宜的 1 MCP处理可以延缓酒软的发生     

低压条件下冬枣的膜脂过氧化变化

研究冬枣在低压下的膜脂过氧化变化规律,对冬枣果实在50.7和101.3kPa(常压)压力下的膜脂过氧化变化进行了测定。结果表明:低压贮藏显著抑制了脂氧合酶(LOX)活性的上升(P<0.05),减缓了果实果肉相对电导率的增加(P<0.05)和VC含量的下降。低压对抑制果实内丙二醛(MDA)的积累有显著作用(P<0.05)。相关性分析表明,冬枣果实的LOX活性与果肉相对电导率以及MDA含量之间均呈极显著的正相关(r电导率=0.74616及rMDA=0.91235),与果实VC含量的变化之间呈负相关。低压贮藏明显减缓了冬枣果实的成熟与衰老进程。     

积累的影响

 探讨冬枣的采后生理特性,为选择最佳气调贮藏条件和方法提供理论依据。以鲁北冬枣为试材,研究了不同气调指标对冬枣果实中乙醛和乙醇有害物质积累的影响。结果表明,适当的低O2可以有效抑制枣果果肉硬度的下降,维持细胞膜的完整性,减缓Vc的损失,同时没有引起果肉中乙醛和乙醇的大量积累,延缓了果实的衰老。而贮藏环境中的CO2会促使枣果无氧呼吸,加速了果实中乙醛和乙醇的积累,进而加强果肉伤害,破坏细胞膜的完整性,Vc损失加剧,加快了枣果的软化衰老进程。研究表明,2%O2+0%CO2的气调指标对冬枣贮藏最有利。     

不同气调包装对鲜食冬枣保鲜效果的比较

【目的】探究自发气调包装保鲜对鲜食的冬枣(果皮转红面积超过2/3)的保鲜效果。【方法】采用两种类型自发气调包装袋MP20(20 μm)和MP30(30 m)对冬枣进行包装处理,以微孔包装的冬枣作对照,研究在两种贮藏温度下(25 ℃和0 ℃)不同包装条件下冬枣的生理活性及营养成分的变化规律。【结果】冬枣在常温(25 ℃)贮藏15 d,低温(0 ℃)贮藏90 d,与微孔包装相比,两种自发气调包装内的冬枣在室温和低温下均能降低冬枣的腐烂率20%以上,同时能抑制冬枣的呼吸强度,保持果实硬度大于1 000 g/cm~2,降低其营养物质的损耗。【结论】冬枣自发气调包装产品透气率、透视率不宜过高。MP30气调包装袋的透氧率较低,小于6 000 cm~3/m~2·d·atm,在贮藏50 d后,结合冬枣的呼吸作用调节包装内气体,形成的5% O_2浓度、1.0%～2.0% CO~2浓度,能降低冬枣的生理代谢,保鲜期比微孔包装延长30 d以上,具有较好的市场应用前景。     

冬枣贮藏保鲜方法

综述了冷藏、速冻贮藏、气调贮藏、减压贮藏、臭氧保鲜贮藏、防腐保鲜、磁场杀菌保鲜、生物技术保鲜等冬枣贮藏保鲜的方法,并简述了保鲜纸箱、微波保鲜、加压保鲜、陶瓷保鲜袋等冬枣贮藏保鲜的新技术,以期为促进冬枣产业发展及提高经济效益提供一定的理论基础。     

一氧化氮处理对冬枣贮藏期间乙醇代谢及相关品质的影响

 【目的】研究NO处理对冬枣贮藏期间乙醇代谢及相关品质的影响，探讨NO对冬枣褐变软化的作用机理,为NO应用于冬枣的贮藏保鲜提供理论依据。【方法】用0、10、20、30 µl•L-1 NO气体熏蒸4 h白熟期冬枣，研究了冬枣室温[（22±1）℃]贮藏和冷藏[（4±1）℃]期间外观品质变化的相关参数，丙酮酸、乙醇、乙醛等含量以及乙醇脱氢酶（ADH）和乳酸脱氢酶（LDH）活性的变化。【结果】20 µl•L-1 NO处理明显地减少了果实中乙醇、乙醛和丙酮酸的含量，且延缓了丙酮酸含量高峰的出现；显著抑制了乙醇脱氢酶（ADH）和乳酸脱氢酶（LDH）活性。30 µl•L-1 NO处理促进了冬枣果实在室温或冷藏期间的酒化软化。【结论】20 µl•L-1 NO处理可以减少乙醇积累对冬枣的毒害，有效抑制了冬枣果实贮藏期间的褐变软化。     

Effects of Hypobaric Storage on Physiological and Biochemical Changes in Postharvest Dong Jujube Fruit During Cold Storage

Effects of hypobaric storage on physiological and biochemical changes in Dong jujube fruit wereinvestigated. Hypobaric storage significantly delayed the decrease in firmness and maintained content of ascor-bic acid, reduced accumulation of ethanol and acetaldehyde in pulp and respiration, inhibited activities of as-corbic acid oxidase and alcohol dehydrogenase and slowed down the rate of ethylene production, but had littleeffect on flesh browning of the fruit.     

冬枣贮藏保鲜技术研究进展

从冬枣贮藏保鲜的方法和影响其贮藏保鲜的因素等方面,对冬枣贮藏保鲜技术研究现状进行了较为详细的论述。总体来看,冬枣贮藏保鲜的物理贮藏方法包括低温贮藏、气调贮藏和减压贮藏,化学方法中包括一些化学杀菌剂、保鲜剂和激素处理,考虑到化学药剂的残留对人体的影响,近几年来,科研人员逐步探索开发冬枣采后生物防治领域,并取得了一定的成绩;同时,也论述了影响冬枣保鲜效果的主要因素有冬枣自身因素、农业技术措施和环境条件等,并对当前研究工作存在的问题及今后的研究重点进行了讨论。     

Optimal storage temperature and 1-MCP treatment combinations for different marketing times of Korla Xiang pears

Maintenance of green color is the primary indicator of quality in the market evaluation of Korla Xiang pears at present and can generally be achieved through early harvesting and decreasing the storage temperature, but the fruit quality was reduced by early harvesting, and the decreasing storage temperature increased the risk of chilling injury. The objectives of this study were to determine the optimal storage parameters for different storage times and to find ways to preserve the green skin color of pears. Specifically, we analyzed the effects of the ethylene inhibitor, 1-methylcyclopropene(1-MCP), combined with low temperature on quality and maintenance of the green color of Korla Xiang pears during storage. We found that 1-MCP and/or low temperature reduced the loss of green color at 20°C after being removed from cold storage. In addition, 1-MCP significantly inhibited the decline of titratable acid and ascorbic acid but had no significant effect on fruit firmness and total soluble solids. Low temperature with or without 1-MCP inhibited the release of ethylene, inhibited the decline in the stalk preservation index, inhibited the increase in decay rate and weight loss rate during storage, and inhibited the increase in the core browning index after 225 days of storage. Different storage temperatures had different effects on the quality of Korla Xiang pears. Despite inhibiting ethylene release, a storage temperature of –1.5°C increased the respiration rate. Storage at –1.5°C caused core browning early during storage due to chilling injury, whereas at 2°C core browning occurred late during storage due to senescence. In late storage, 1-MCP had no significant effect on the maintenance of Korla Xiang pear quality at 2°C. Based on these results, we determined the optimal combinations of low temperature and 1-MCP treatment to maintain pear quality while avoiding chilling injury. For different marketing times, the optimal conditions for storage until New Year's Day(a storage duration of 90 days) are 2°C or 1-MCP combined with 2°C. For storage until the Spring Festival(a storage duration of 150 days), the optimal conditions are 0°C or 1-MCP combined with 0°C, and for storage until May(a storage duration of 225 days), the best conditions are 1-MCP combined with –1.5°C.     

Impact of ozone on quality of strawberry during cold storage

The postharvest physiology of strawberry was investigated to study the effects of ozone on weight loss rate, ascorbic acid, respiration rate, peroxdase (POD) activity, catalase (CAT) activity, and malondialdehyde (MDA) content during cold storage. The strawberries were treated with ozone of 0 ppm (control), 2 ppm, 4 ppm, and 8 ppm, respectively. The results indicated that the treatment of 4 ppm ozone could inhibited the decrease of ascorbic acid, POD activity, and CAT activity, and reduced weight loss rate and MDA content. The treatment delayed the senescence of strawberry, with a significantly lower respiration rate. Thus, the best concentration of ozone was 4 ppm, and ozone treatment could be a good candidate for maintaining postharvest quality of strawberry and provide a longer storage life.     

减压处理对梨枣果实采后生理及贮藏效果的影响

以梨枣为试材,研究了减压处理对梨枣果实呼吸强度、CAT活性、MDA含量、果肉组织相对电导率、VC含量和果肉硬度的影响。结果表明,减压处理在一定程度上降低了梨枣的呼吸强度,有效地保持了CAT活性,减少了MDA的积累,显著降低了果肉组织相对电导率,有效地保持了果肉硬度和VC含量,从而延缓了果实的成熟衰老。     

不同保鲜剂处理对灵武长枣贮藏品质的研究

灵武长枣是宁夏银川地区主要栽培枣品种,采后在自然条件下果肉快速疏松变质,鲜食期很短,为了延长灵武长枣采后鲜果的市场供应期,特开展此试验.采用6种不同保鲜荆贮藏,研究不同保鲜荆贮藏后的生理变化及品质变化.结果表明采用5 g/m''4.5%TBZ(噻苯咪唑)熏蒸的处理为好.该处理能有效地延缓枣果含酸量的下降速率和还原糖含量的变化,较好地保持Vc含量,枣果贮藏105天硬果率37.5%,商品果率94.34%.用5 g/m3 4.5%TBZ熏蒸,在温度为(-0.5±0.5)℃、相对湿度(90±3.0)%的条件下贮藏,能减缓枣果含酸量的下降速率和还原糖含量的变化,贮藏效果要明显好于其他保鲜剂.     

Study on the Mechanism of Browning of Pomegranate （Punica granatum L. cv. Ganesh） Peel in Different Storage Conditions

Peel browning of pomegranate fruit is the key problem during storage. The mechanism of it during storage in relation to the technology of the browning control was studied in this paper. The effects of storage temperature, gas component and pH value on peel browning of sweet pomegranate fruit in Lintong, Shaanxi Province, China, were investigated. Change in tannin content was measured and the relationship between the activities of ascorbic acid oxidase （AAO）, polypenoloxidase （PPO）, peroxidase （POD）, catalase （CAT） and peel browning was analysed. The results showed tannin was the basic substance of pomegranate peel browning. The activities of the browning index of peel were correlated positively with AAO, PPO and POD, correlated negatively with CAT activity. Application of intermittent warming for 24 h at （15 ± 0.5）℃ every 5 days for pomegranate fruit storage under the conditions of pH 4.0, （5.0± 0.5）℃ and 5.0% CO2 ＋ 8.0% O2 ＋ 87.0% N2 gas component could delay browning, with the browning index being 0.15 after 120 days of storage. Enzymatic tannin denaturation was the main cause that led to peel browning of pomegranate fruit during storage. The browning control of pomegranate fruit peel was effective using intermittent warming storage with suitable pH, temperature and gas component.     

抗坏血酸对丽江雪桃贮藏品质的影响

为探索延长丽江雪桃贮藏期的可行方法,以丽江雪桃为材料,研究了低温贮藏条件下(1～2.5℃)不同浓度抗坏血酸(2g/L,6g/L,10g/L)处理对可溶性固形物、可滴定酸和褐变的影响。结果表明:6g/L抗坏血酸能有效延缓丽江雪桃可溶性固形物和可滴定酸含量的升高,能有效抑制果实褐变。