| Fresh-cut vegetables and fruits are processed by selecting, washing, centrifugation, grading and packaging, sometimes peeling and slicing are needed. As people's life step quicken and more attention to food safety, Consumer's trends in fresh-cut vegetables and fruits are dramatic increased, and further research and development in this area are expected. Broccoli is one of the most popular vegetables worldwide, and is not only high in nutrient values, but also in medicinal values. And we all know that broccoli is really suitable for fresh-cut processing. However, its respiration rate is so high that may induce deteriorating after harvest easily. So the objective of this dissertation was to investigate the effect of sanitizer, temperature and packaging on keeping quality of fresh-cut broccoli.We chose ozone and chlorine dioxide that may be alternatives to chlorine as sanitizing agents for fresh-cut broccoli in an aqueous form. Results indicated that ozone treatments were effective in controlling the microbes in broccoli. Treatment with 1.20 mg · L-1, 1.80 mg ·L-1 and 2.40 mg ·L-1 resulted in about 0.85 log, 1.00 log and 1.19 log reductions of total bacteria before storage respectively. The sterilizing effect was related with the concentration of aqueous ozone. Ozone treatments inhibited the reducing of chlorophyll and enzyme activity significantly, maintained ascorbic acid, but decreased the reducing sugar. The best effect of preservation of fresh-cut broccoli appeared to be the treatment of water ozonated to a 2.40mg · L-1 of concentration in this dissertation.Chlorine dioxide treatments were also effective in controlling the microbes in broccoli. Treatment with 50 mg · L-1,75 mg · L-1 and 100 mg · L-1 resulted in about 2.00 log, 2.52 log and 2.97 log reductions of total bacteria before storage respectively. The sterilizing effect was related with the concentration of aqueous chlorine dioxide. However, at the end of storage, the population of total bacteria on fresh-cut broccoli treated with 100 mg·L-1 reached most. Chlorine dioxide treatments reduced chlorophyll, and their blanching effects affected sensory qualities of fresh-cut broccoli seriously. In addition, ascorbic acid and the reducing sugar in fresh-cut broccoli were oxidated to different extent by differentconcentration. The best effect of preservation of fresh-cut broccoli appeared to be the treatment of 50 mg ? L"1 concentration in this dissertation.Besides, effects of temperature and packaging on qualities of fresh-cut broccoli were studied. Results showed that the senescence of fresh-cut broccoli stored at room temperature was very fast. The content of ascorbic acid, chlorophyll and sugar decreased rapidly, and the microbes increased fast which resulted in the spoilage of tissue. Low temperature is very effective for preservation of fresh-cut broccoli. Chlorophyll degradation was delayed, and the reducing sugar and ascorbic acid losses were reduced, and also water in fresh-cut broccoli was kept well. The fresh-cut broccoli stored at 0°C was better in quality than that at 4°C.All the packaging treatments had better results than the control while thicker bags had better results than thinner ones. The respiration rate and ethylene production and water loss could be inhibited and delayed by the packaging treatments, thus had good sensory qualities. But fresh-cut broccoli packaged in thick bags would have peculiar smell. The best effect of preservation of fresh-cut broccoli appeared to be the packaging treatment of "nanya" film in this dissertation.
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