【作者】 王颉；

【导师】 李里特；

【作者基本信息】 中国农业大学 ， 食品科学， 2003， 博士

【摘要】 自从1963年Murr发现模拟电场对鸡足草生长的影响，近40年来，高压静电场生物效应研究工作十分活跃，主要研究领域涉及促进种子萌发，影响植物生长等。有关高压静电场处理对果品采后品质的影响也有一些研究，表明高压静电场对番茄、豇豆和黄瓜采后品质具有一定的影响，但其对多种果品采后品质的影响是否具有普遍规律，高压静电场影响果品采后品质的机理仍不清楚。 本研究利用自制的高压静电场保鲜实验台产生的-50kV／m和-100kV／m高压静电场处理冬枣、鸭梨、草莓、番茄和苹果果实，在贮藏过程中测定了果实内源多胺含量、果实多聚半乳糖醛酸酶和羧甲基纤维素酶活性、鸭梨黑心率、草莓腐烂率、果实硬度、可溶性固形物含量、果实颜色变化、冰点变化等指标，并在贮藏结束时，对果实品质进行感官评定，实验结果表明： 1．高压静电场处理对鸭梨、番茄和草莓果实内源多胺含量变化影响不同。贮藏前期高压静电场处理对鸭梨和番茄内源多胺含量的影响较小，贮藏后期除鸭梨内源腐胺含量上升外，其他内源多胺的含量均低于对照。草莓果实在12d的贮藏过程中，除第6d外，对照的腐胺含量总是处于较高水平。但贮藏后期高压静电场处理的亚精胺含量显著高于对照，贮藏6d时，100kV／m高压静电场处理的亚精胺含量是对照组的1.76倍，对照同高压静电场处理的精胺含量无显著差异。 2．高压静电场处理可以抑制番茄和草莓果实多聚半乳糖醛酸酶和羧甲基纤维素酶活性，抑制草莓和番茄果实软化。 3．高压静电场处理鸭梨贮藏240d时，果实黑心率显著低于对照。 4．高压静电场处理草莓贮藏12d时，果实腐烂率显著低于对照。 5．感官评定结果表明高压静电场处理贮藏84d的冬枣，贮藏12d的草莓，贮藏24d的金冠苹果和贮藏24d的红元帅苹果，果实新鲜程度、硬度、甜味等主要感官指标比对照好。 6．本文实验结果还证明短期高压静电场处理对果实冰点温度没有影响。 7．高压静电场处理对保持果实可溶性固形物含量具有显著作用；对金冠苹果和番茄果实颜色的变化具有显著的抑制作用。采用高压静电场处理可以显著抑制冬枣、鸭梨、草莓、番茄和苹果的成熟衰老速度，对保持果实采后品质具有较好的作用。更多还原

【Abstract】 Since Murr discovered that simulated electric field could affect the growth of orchard grass in 1963, the research on the effect on bio-effective in high voltage electrostatic field (HVEF) is quiet active for nearly 40 years, such as improving seed germination, affecting the growth of plants, affecting post-harvest qualities of fruits and so on. Some research results showed that post-harvest qualities of tomato, cucumber and cowpea had been affected in HVEF. However, whether the influence on post-harvest quality of other fruits in HVEF has a general principle or not, as well as its mechanism has not been clear yet.’Dongzao’, ’Ya’ pear, strawberry, tomato and apple have been investigated in -50kV/m and -100kV/m HVEF produced by the self-made storage device. Some indexes of post-harvest qualities have been measured during storage such as the content amount change of endogenous polyamine, activity of polygalacturonase and carboxymethylcellulase, black heart rate of ’Ya’ pear, rot rate of strawberry, fruit firmness, soluble solids content and the change of freezing point. At the late period of storage, sensory evaluation of qualities of fruits was measured. Experimental results in HVEF show that:1. They have a different effect on the content amount change of endogenous polyamine of’Ya’ pear, tomato and strawberry in HVEF. HVEF treatment has a little effect on the content of endogenous polyamine of ’Ya’ pear and tomato at the early period of storage, except the content amount of endogenous putrescine of ’Ya’ pear, others content amount of endogenous polyamine are lower than the control at the later of storage. During the 12 days storage of strawberry, except the sixth, the content amount of putrescine of the control are always kept in a higher level. However, during the late period of storage, the spermidine content in HEVF was significantly higher than the control. When stored for 6 days in -lOOkV/m HVEF, the spermidine content was 1.76 times than that of the control. The spermine content in HEW had not a significant difference with the control.2. The activity of polygalacturonase and carboxymethylcellulase of tomato and strawberry is restrained in HVEF, and therefore the soften of tomato and strawberry are restrained.3. ’ Ya’ pear black heart rate in HEVF is obviously lower than the control when stored for 240 days.4. Strawberry rot rate in HEVF is obviously lower than the control when stored for 12 days.5. Sensory evaluation results showed that the main sensory indexes such as fruits fresh degree, firmness and sweetness are better than the control when ’Dongzao’ stored for 84 days, strawberry stored 12 days, Gold delicious apple stored 24 days and Red delicious apple stored 24 days in HVEF.6. The experiment results also proved that short HVEF treatment had no effect on fruit freezing point.7. HEVF has a significant effect on keeping fruit soluble solids content, and on restraining the color change of gold delicious apple and tomato. The maturation and senescence speed of ’Dongzao’, ’Ya’ pear, strawberry and apple are obviously restrained in HEVF, and it can play a better role on keeping the post-harvest qualities of fruits in HVEF.更多还原