Abstract: High pressure processing,heat processing and freezing processing were adopted to treat pure pineapple juice respectively,and their effects on the sensory qualities and preservation properties of the pure pineapple were investigated. The results showed that high pressure processing,heat processing and freezing processing have no significant effects on the color and appearance of the pure pineapple juice; There are no significant differences on flavor,taste and overall score between the pure pineapple juice processed by heat processing or freezing processing,and the untreated pure pineapple juice. Significant differences on flavor,taste and overall score of the pure pineapple juice processed by high pressure processing are tasted out compared with the untreated pure pineapples juice. Both heat processing and high pressure processing can lower down the viable count significantly,and freezing processing can lower down the viable count after the storage of 7 days at -18℃,but has no obvious effect on the viable count at the beginjing. So freezing processing is more suitable for processing pure pineapples juice.

Key words: pineapple juice, preservation, high pressure processing, total plate colony