Change of Nitrate Contents during Tomato Harvest and Potato Storage
摘要：
The aim of this study was investigate the nitrate contents of tomato fruits and potato tubers at various growing periods,testing parts and its change during a variety of storage time or temperature.Results obtained showed that amount of nitrate in tomato fruit was generally influenced by individual plant,maturity and harvest period.It was found that tomato nitrate increased at the beginning of harvest,then decreased gradually with ripening.Results also indicated that more nitrates were found in fruit side(16.47ppm),but less nitrates were measured in fruit flesh(5.37ppm).Nitrate contents in potato tubers varied considerably according to the size of tuber and individual plant.However,nitrate contents were nearly the same for potato tuber of similar size.Another finding was that,more nitrates in stolon part(80.18ppm)of potato than those found in bud end(33.10ppm).Generally speaking,potato tuber stored at 1°C show the lowest nitrate contents among three temperatures Potato packed with polyethylene showed a lower nitrate contents contents compared to those without packed package during storage.Nitrogen filling package caused a decrease in nitrate contents due to the inhibition of respiration action and big and mature potato tubers have lower concentration of nitrate.
