Abstract: A study was made on the effects of ultra high pressure (0.1～500MPa) / mild temperature (19～58℃) treatmentson the microflora, mold and yeast and E.coli in Chinese Dangshan pear juices (pH5) with the sustaining time 10min. Results showedthat the residual microflora was 50cfu/ml under 19℃ (environmental temperature), with sustaining time 10min and 500MPa andthat the residual molds and yeasts were 10cfu/ml under 400MPa, However, the E.coli was completely sterilized under 19℃, withsustaining time 10min and 400MPa. On the other hand, results showed that the residual microflora was 70cfu/ml under 450MPa,with sustaining time 10min and ≥29℃, and the residual molds and yeasts were completely sterilized under the same conditions.The E.coli were completely sterilized under 450MPa with sustaining, dwell time 10min and 19℃.

Key words: pear juice, ultra high pressure, mild temperature, sterilization, microflora, yeast and mold, E.coli