Experimental study on ultraweak luminescence value of damaged apple

In order to explore a new method for identifying damaged fruits using ultraweak luminescence(UL) characteristics, the variation laws of the UL values of Fuji apples with bump damage and static pressing damage were investigated. The experimental results show that both kinds of damages can affect the UL values and the effect is especially noticeable at the damaging moment. The change of the UL values is more remarkable when the damage is in a larger area or at a deeper level. Test results also show that the UL values of Fuji apples with bump damage change sharply within eight hours after bump damage, and UL values of apples without damages keep constant in this period. During the storage period, the UL values of apples with bump damage fluctuated continuously and UL values of apples with pressing damage decrease slowly in earlier storage period and keep constant rapidly in later period. Contrasted with damaged apples, the absorbency of undamaged apples changes very slowly. Experimental results show that as a sensitive test technology, UL value can be used to distinguish damaged apples from undamaged ones.