Establishment Of MA-ULO System And Effects Of ULO On Fuji Apple During Storage

ULO(ultra low-oxygen) is a new method to store the fruits and vegetables at the condition of oxygen below 2%.This method of ULO treatment was studied less at home, especially on Fuji Apple. The ULO conditions need airproof coolroom, the cost is very high, so it is limited to use. This research aimed to choose this kind of package film for the MA-ULO storage for the Fuji apples, and establish MA-ULO system. The effect of ULO treatment on storage quality of Fuji Apples was studied in this paper. The main conclusions are as follows:1 The PVDC of 0.02mm and 0.08mm were chosen and proved to be fit for Fuji apples through this research. The conclusion that the oxygen concentration could keep stabilization was educed by the experiment filling nitrogen in the storage entironment. By using oxygen concentration and carbon dioxide concentration, the oxygen concentration was 1.6±0.1% and 1.0±0.1% of PVDC of 0.02mm and 0.08mm. So the MA-ULO system was established by the method.2 The respiration rate of Fuji apples stored at ULO(1.6%) were decreased, so the contents of total soluble solid, tirable acid and sugar were better maintained. The activities of PE and PG were debased in the ULO condition, the pectin content were well kept, so the firmness was higher and the inteneratment was slowered conparae with the control.3 At the beginning, the qualities of Fuji Apples stored at 1.0% were higher than the control. After eighty days'storage, the MDA and ethanol content of Fuji Apples stored at 1.0% were higher and the quality falled compared with the control.4 The degrees of scald development of ULO(1.6%) were lower than the control and ULO(1.0%). The control of CA, low-temperature and ULO(1.0%) were respectively 7.69%, 16.67% and 2.17%. The results showed that at 1.6% concentration of oxygen superficial scald was restrained obvisily, but that at 1.0% concentration of oxygen superficial scald(15.2%) was higher than CA and ULO(1.6%)5 At the last storage, the results showed that the effect of ULO(1.6%) was better than the control(P<0.01) in keeping the firmness. The content of total soluble solid of ULO(1.6%) was higher than the control. The pulp tasted pleasant sweetness and sourness. The unique fragrance of apple was rich.6 After fifteen days shelf life at 27.2℃～31℃, the quality of apples storaged in ULO and the control descended in different degree. But the quality of Fuji Apple after ultra low-oxygen treatment was better than other conditions.