To judge whether retort sterilization is fully completed by physical parameters, three core indicators must reach and stay at the qualified standard at the same time: temperature, pressure and constant holding time.
- Sterilization TemperatureThe internal chamber temperature and product cold-point temperature must reach the required sterilization temperature and keep stable.Common standard: 121°C, 135°C or customized temperature according to food formula.Allowable fluctuation range: ±0.5°C ~ ±1°C, no obvious temperature drop during the holding stage.
- Matching Working PressureMaintain the saturated steam pressure corresponding to the sterilization temperature.Stable pressure ensures balanced inside and outside of packaging, prevents bag expansion, cracking or tank deformation, and guarantees continuous heat transmission.No sudden pressure drop or overpressure alarm during the whole sterilization process.
- Effective Constant Temperature Holding TimeOnly the time after the temperature reaches the set sterilization standard can be counted as effective sterilization time.The cumulative holding time must fully meet the technological requirement.If temperature or pressure drops in the middle, the timing will be invalid, and supplementary holding time is required.
- Complete Data RecordingContinuous temperature and pressure curve without interruption, blank point or abnormal fluctuation.Complete heating, constant temperature, cooling and pressure relief process in sequence.
- Qualified Cooling & Pressure ReliefAfter sterilization holding finished, complete gradual cooling and pressure relief.Product core temperature drops to below 40°C, to avoid thermal over-cooking and secondary bacterial breeding.