| 主权项 |
1. A preservative efficacy testing method for testing efficiency of at least one preservative material present in a consumable product to reduce or eliminate living microorganisms, the testing method comprising the steps of:
(a) inoculating a sample of the consumable product at time zero with initial number of living microorganisms, the living microorganisms derived from at least one pure culture of the respective living microorganisms to produce an inoculated sample, wherein the living microorganisms in the inoculated sample are present as a volumetric portion of the respective pure culture; (b) allowing the at least one preservative material in the consumable product to interact with the inoculated microorganisms in the inoculated sample for a predetermined standard exposure time in order to reduce concentration of living microorganisms in the inoculated sample; (c) terminating interaction between the at least one preservative material and the living microorganisms at a predetermined standard exposure time, wherein the interaction termination step occurs by mixing the inoculated sample with at least one neutralizing agent, wherein the neutralizing agent is at least one compound that is capable of eliminating the microorganism reduction effect of the preservative material to produce a neutralized sample; (d) introducing a portion of the neutralized sample into a testing system, the testing system including at least one testing container, wherein the testing container contains liquid growth media and sensor means capable of monitoring microorganism growth by sensing the metabolic by-products generated by growth of microorganisms present in the liquid growth media and producing an output signal; (e) incubating the at least one testing container at a temperature sufficient to effect growth of the microorganisms and monitoring microorganism growth as a function of time, wherein microorganism growth monitoring occurs by measuring the output signal of the sensor means at specific time increments to yield a microorganism growth value curve; (f) determining concentration of the microorganisms in the neutralized sample at the predetermined standard exposure time based on the output signal of the sensor means, determination of concentration determination occurring by applying a survival calibration function to the concentration of the surviving microorganisms in the neutralized sample, wherein the survival calibration function correlates the output of the sensor means with concentration of the surviving microorganisms; (g) at time zero introducing a portion of the at least one pure culture from which the living microorganisms are derived into at least one container in the testing system; (h) incubating the at least one testing container containing living microorganisms from the at least one pure culture at a temperature sufficient to effect growth of the microorganisms and monitoring microorganism growth as a function of time, wherein microorganism growth monitoring occurs by measuring the output signal of the sensor means at specific time increments; (i) determining microorganism concentration in the pure culture from output of the sensor means, the determination step occurring by applying a pure-culture-calibration function to the concentration of the microorganisms in the pure culture, wherein the pure-culture calibration function correlates the output of the sensor means with concentration of the pure-culture microorganisms; (j) calculating concentration of the microorganisms in the inoculated sample immediately after the inoculation step by calculating the volumetric proportion of the pure culture in the inoculated sample of the consumable product to yield a reference-microorganisms concentration value; (k) calculating reduction in the concentration of the microorganisms in the inoculated sample at the predetermined standard exposure time relative to the reference-microorganisms-concentration value in the reference sample; (l) determining whether the preservative material is efficient in reducing the concentration of the microorganisms in the consumable product by comparing said calculated reduction at said exposure time to a predetermined reduction standard for identical standard exposure time. |
