【作者】 李婷婷；

【导师】 宋述尧；

【作者基本信息】 吉林农业大学 ， 蔬菜学， 2008， 硕士

【摘要】 大蒜、洋葱和生姜是重要的香辛蔬菜,同时也是天然植物抗氧化物质的重要来源。但其所含抗氧化物质在贮藏过程中极易降解,影响贮藏品质和经济价值。总结传统贮藏保鲜技术,开发利用现代贮藏保鲜技术,寻求新兴的节能贮藏保鲜技术,提高蔬菜贮藏质量,是打破国际市场果蔬绿色壁垒的重要手段。果蔬电磁场保鲜是随生物电磁理论研究的深入而提出的一个全新的概念。本试验通过研究高压脉冲电场处理对大蒜、洋葱和生姜采后抗氧化物质(酶类抗氧化物质、非酶类抗氧化物质)的影响,探讨了高压脉冲电场处理对大蒜、洋葱和生姜采后生理的影响及调控作用,试验结果表明:1.高压脉冲电场不同强度处理大蒜、洋葱和生姜产生的影响效果不同,即存在“阈值”。2.高压脉冲电场处理不同品种的大蒜、洋葱和生姜,电场处理最佳剂量(电场强度×处理时间)与贮藏温度的组合不同。电场处理白皮大蒜场强是1.1kV/cm,处理时间10min,贮藏温度20℃时效果最好;电场处理紫皮大蒜2.0kV/cm,处理时间10min,贮藏温度5℃时效果最好;电场处理黄皮洋葱、紫皮洋葱场强是0.5kV/cm,处理时间10min,贮藏温度5℃时效果最好;生姜场强是2.0kV/cm,处理时间10min,贮藏温度5℃时效果最好。3.高压脉冲电场处理大蒜、洋葱和生姜均能明显的抑制相对电导率的上升,保持了细胞膜的完整性,同时也使含水量得到了较好的保持,对提高贮藏品质有利,延长了贮藏时间。处理后紫皮大蒜膜完整性优于白皮大蒜,紫皮洋葱的处理效果好于黄皮洋葱。4.高压脉冲电场在贮藏初期激活了大蒜、洋葱和生姜SOD、POD活性,抑制了PPO活性。提高了大蒜、洋葱和生姜防御自由基氧化损伤的能力,有效抑制了其酶促褐变,提高了贮藏品质,延长了贮藏时间。各处理电场处理10min的效果好于电场处理5min的效果,5℃贮藏酶活性变化趋势稳定,紫皮大蒜处理效果优于白皮大蒜,紫皮洋葱处理效果好于黄皮洋葱。5.高压脉冲电场处理能使大蒜、洋葱和生姜保持较高的抗氧化物质含量。高压脉冲电场处理大蒜、洋葱和生姜,贮藏初期能够促进黄酮类物质和多糖的合成和积累,在贮藏过程中能够有效抑制黄酮类物质、抗坏血酸和多糖的分解,使得在试验结束时大蒜、洋葱和生姜能够维持较高的抗氧化物质含量,增强其抗氧化能力,提高了贮藏品质。电场处理5min对黄酮类物质的影响效果最好,处理10min对抗坏血酸和多糖的影响效果最好。20℃下贮藏,抗氧化物质含量变化更稳定。更多还原

【Abstract】 The garlic,the onion and the ginger are the important vegetables,simultaneously is also the natural plant oxidation resistance material important origin.But the antioxidant substances are extremely easy to degrade in the process of store and affects the quality and the economic value.Summarising the technology can keep the vegetables fresh,developing and using the modern techology,seeking the new techology of store which can saving the energy,enhancesing the quality of the vegetables in store are the important methods to break the international markes of fruits and vegetables.The technology of store the fruits and vegetables in the electric field is a new concept which penetrates along with the biology electromagnetic theory research proposed.On the experiment of the studied on the predecessors,the effects of high intensity pulsed electric field(PEF) on the antioxidant substances of the garlics、the onions and the gingers were studied in this experiment,and discussed the effect and influence of the garlics、the onions and the gingers after treatmented by PEF.Experimental results in PEF show that:1.The effects on the garlics、the onions and the gingers treatmented by the different dlectrics field intensity of PEF are different,means that the PEF treatment existence the "value of threshold".2.They have different combinations of the dose(electric field intensity×treatment time) and the store temperature when different variety of the garlic、the onion and the ginger treated by PEF.The best treatment combination of the silver skin garlic is that the electric field intensity is 1.1kV/cm, the time is 10min and the store temperature is 20℃;The best treatment combination of the purple skin garlic is that the electric field intensity is 2.0kV/cm,the time is 10min and the store temperature is 5℃;The best treatment combination of the yellow skin onion and the purple skin onion is that the electric field intensity is 0.5kV/cm,the time is 10min and the store temperature is 5℃;The best treatment combination of the ginger is that the electric field intensity is 2.0kV/cm,the time is 10min and the store temperature is 5℃.3.PEF has a significant effect on restraining the relative electric conductivity of the garlics、the onion sand the gingers,maintaining the ceil membrane integrity,maintaining the high water content,keeping the qualities of store and lengthening the time of store.The effect on purple skin garlics are better than sliver skin garlics,and the effect of purple skin onions are better than yellow skin onions.4.The garlics,the onions and the gingers treated by PEF increase the activities of superoxide dismutase(SOD) and peroxidase dismutase(POD),and restrain the activities of Polyphenol oxidase.It can play a better role on enhancing the ability of defense free radical oxidation damage and the quality of store, also control the senescence of the garlics、the onions and the gingers.The activity of enzyme changing is stable when it stores in 5℃,the best time of treatment is 10min.After treated by the PEF,the effect of purple skin garlics are better than sliver skin garlics,and the effect on purple skin onions are better than yellow skin onions.5.PEF can restrain the reduction of antioxidant substances.The synthesis and accumulation of the flavonoids and the polyasccharides can be promoted by PEF in the initial period of stores,the dissolution of the flavonoids,ascorbic acids and polyasccharided can be suppressed in the process of stores.PEF has a significant effect on maintaining the content of antioxidant substances of the garlic、the onion and the ginger,strengthening the abilities of oxidation resistance and store.The best treanment time of flavonoids is 5min,the best treatment time of ascorbic acid and polyasccharide is 10min.The content of flavonoids changing is stabler when it storing under the 20℃.更多还原