Evaluation of freshness in fruit and vegetable base on their active oxygen scavenging systems -in sweet pepper fruit model-

低温贮藏是延长新鲜园艺商品保质期的最有效的贮藏方法，因为它减缓了它们的新陈代谢。然而，低于临界阈值温度但高于冰点的低温会导致新鲜园艺商品的冷害。近年来，低温可诱导植物组织的氧化应激，越来越多的证据表明，低温提高了活性氧的水平。在本研究中，我们已经确定了在低温贮藏过程中，甜椒果实，梅果实，甘薯和马铃薯的抗氧化系统的变化。1 ℃贮藏的甜椒和甘薯果实出现并加重了表面麻点等冷害症状，7 ℃贮藏的梅果实出现并加重了表面麻点等冷害症状。1 ℃贮藏的甜椒、甘薯和7 ℃贮藏的乌梅过氧化氢含量增加。然而，在马铃薯中，过氧化氢水平不受贮藏滕佩的影响 ...更多信息 在整个储存过程中保持不变。甜椒果实中抗坏血酸含量不受贮藏温度的影响，在贮藏过程中呈上升趋势，脱氢抗坏血酸含量在1 ℃下贮藏4d时出现短暂上升，随后下降。甜椒果实中还原型谷胱甘肽含量在整个贮藏过程中均低于其他处理，但氧化型谷胱甘肽含量不受贮藏温度的影响，在贮藏过程中呈下降趋势。1 ℃贮藏7d后，甜椒和甘薯的超氧化物歧化酶活性升高，梅果实在7 ℃贮藏7d后超氧化物歧化酶活性升高。而马铃薯超氧化物歧化酶活性不受贮藏温度的影响，在整个贮藏过程中保持不变，表明低温贮藏期间，除马铃薯外，甜椒、梅、甘薯果实的冷害症状可能与抗氧化系统的活性有关。少

Low temperature storage is the most effective storage for extending the shelf life of fresh horticultural commodities because it slows down their metabolism. However, low temperature below the critical threshold temperature but above freezing causes chilling injury for fresh horticultural commodities. Recently, it is reported that chilling may induce oxidative stress in plant tissues, and there is increasing evidence that chilling elevates the levels of active oxygen species.In this study, we have determined changes in the antioxidant system in sweet pepper fruit, mume fruit, sweet potato and potato during storage at low temperature. Chilling injury symptoms such as surface pitting appeared and increased in sweet pepper fruit and sweet potato stored at 1 ℃, and in mume fruit stored at 7 ℃. Hydrogen peroxide levels increased in sweet pepper fruit and sweet potato stored at 1 ℃, and in mume fruit stored at 7 ℃. However, in potato, hydrogen peroxide level was not affected by storage tempe … More rature and remain unchanged throughout storage. In sweet pepper fruit ascorbate level was not affected by storage temperature and increased during storage, while dehydroascorbate level showed significant transient increase on day 4 at 1 ℃, and then decreased subsequently. Level of reduced glutathione in sweet pepper fruit was found to be lower at 1 ℃ than the other treatments throughout storage but the levels of oxidized glutathione in sweet pepper fruit were not affected by storage temperature and decreased during storage. Superoxide dismutase activity increased in sweet pepper fruit and sweet potato stored after days 7at 1 ℃, and in mume fruit stored at 7 ℃ . But, in potato superoxide dismutase activity level was not affected by storage temperature and remain unchanged throughout storage.These findings indicate that the development of chilling injury symptoms may be related to the activity of the antioxidant system in sweet pepper fruit, mume fruit and sweet potato expect in potato during storage at low temperature. Less