The relation between the survivors of micro-organisms and the processing pressure and the pulse pressure processing was investigated in UHP treatment to watermelon juice. And species of baroduric bacteria were discriminated. Processing pressure is between the atmosphire pressure and 500 MPa, and the pressurized duration 10 min in this experiment. Results show that under the ambient temperature (30 ℃) and pressure equal to or above 400 MPa the number of natural microflora, yeast, mold and coliform bacteria meets the requirement of National Food Hygienic Standard of China. When the times of pulse pressure processing increases, the survivors of micro-organisms decreases. Gram positive bacteria are the main part, ≈70%, of the survived bacteria, and the rests are the Gram negative bacteria and molds.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |