Rapid Detection Of Fresh Vegetables, Irradiation Dose And Sample The Initial Bacterial Content

In order to keep greenness and quality, reduce expense and prolong store time, we often turn to the method of irradiation.Food irradiation is one method to sterilize, kill pest in food, refrain sprouting , delay ripeness and so on by y ray, in order to ensure fresh and quality, reduce loss and prolong storage time. The sensitivity of different samples to y ray are not the same.We wonder why there are such differences,and offer gist for food radiation,then find out one simple ,rapid method for the efficiency of sterilization with y ray on samples,so we did two aspects of work.First,the biological response of radiation on vegetables;second,the rapid bioluminescence assay method for the efficiency of sterilization with y ray .1 Study on the radiation biological effect of vegetable1.1 The dynamic change of leaf tissue resistance and the tolerance of vegetables to y rayWe studied the change rule of leaf tissue risistance and conductivity of irradiated vegetables.The result shows that: Radio damnification arosed by y ray appeared in leaves first, which indicated that leaf is more sensitive to y ray than the other tissue. Dynamic change curve of leaf tissue resistance is corresponding to its tolerance to y ray, which suggest that the curve peak value is a expective indictor of sensitiveness to y ray. The leaf tissue risitance is more sensitive to detect the difference of resistance to y ray between upper and lower leaf than the leaf conductivity. The vegetable's maximum tolerance dose to y ray could be obtained with the leaf tissue resistance and leaf conductivity.1.2 Relationship between the irradiation sensitive and ICL intensity in vegetableThe bioluminescence of several vegetable seeds induced by γ-ray was studied. The results show that there exist positive relativity between seed's bioluminescence and radiation dose, which fits with equation Y=Y₀e^KD. The higher the K value is, the more intense the bioluminescence induced by γ-rays is. Significant differences among K values different varieties were found. The bioluminescence and exterior measurement value of seed radiosensitivity showed good consistency.1.3 Regression analysis on the effect of γ ray on SOD, POD activities and MDA content in four vegetable leavesDynamic effects of γ ray on SOD, POD activities and MDA content in four vegetable varieties were studied quantificationally, with the method of curve fitting and establishing mathematical model. Solving and analyzing the parameters of the formula above, and the results suggested that the four vegetable varieties' sensitivity to radiation was in the orders as: Basella rubra > Lactuca sativa >Lactuca sativa Spp >Brassica chinensis.2 Study on the rapid bioluminescence assay method for the efficiency of estimating the initial sterilization with Y ray on dry vegetable and codimentIt is imperious for irradiation industry to apply a simple and rapid method for determining the primary number of bacteria, for it is a important tache during irradiation process.The results show that there is significant correlation between CFU and ATP bioluminescence, and the primary number of bacteria in dry vegetable and condiment can be rapidly obtained with the bioluminescence method.What we studied in this paper not only can ensure quality of irradiated samples, but also will offer elementary result about simple and rapid method ,which be used to test sample's sterilization effect.