CS240860B1 - A method for determining the thermodestructive effect of a sterilizing or pasteurizing procedure - Google Patents

Abstract

The method of determination consists in subjecting a crystalline test body, which has previously been converted into an excited state by ionizing radiation, to a thermal treatment together with the sterilized or pasteurized substance, and evaluating the thermodestructive effect from the difference in the concentrations of excited states in the crystalline structure of the test body before and after the sterilization or pasteurization treatment. The solution has applications in canning.

Description

The invention relates to a method for determining the value of the thermodestructive effect of a sterilization or pasteurization procedure in the thermal treatment of a food material.

The sterilization of food by heating remains a basic canning operation that has not yet been overcome by any better method. The sterilization effect is achieved by various combinations of sterilization temperatures and duration of the procedure. Current methods of detecting the thermo-destructive effect are based on the experience that the course of inactivation of microorganisms can be described by relations for the kinetics of 1-order reactions and that the dependence of the inactivation rate constant on temperature is governed by a modified Arhenius function. For most microorganisms limiting sterilization regimens, the parameters of thermo-inactivation curves in the range of temperatures of 70 to 140 ° C used in sterilization are tabulated in the literature.

The prior art methods of determining the sterilization effect based on the above assumptions generally require the measurement of temperature variations within the can at the worst-heated point during the sterilization procedure.

From these courses, the specific achieved value of the sterilization effect, which can be compared with the required values, is then determined by various methods and thus determine the effectiveness of the thermal treatment. Various sensors and measuring instruments are used to measure the temperature inside the can during sterilization, which converts the temperature data into an electrical signal. This is then recorded and processed until a result indicating a sterilizing effect is obtained. These methods are either unusable on continuous lines or too demanding on the instrumentation and its mechanical resistance, which makes the measurement considerably more expensive.

- 2 240 860

The aforementioned drawbacks are eliminated by the method of determining the thermodestructive effect according to the invention, which consists in subjecting, together with the sterilized or pasteurized substance, a crystalline test specimen in the excited state to the heat treatment. The initial concentration of excited states is achieved by irradiating the test specimen with a dose of ionizing radiation. During sterilization, the test specimen is placed at a suitably selected point in the can, which may be any number. The ratio of the excited state concentration before and after the heat treatment is a measure of the thermodestructive effect. Detection of the concentration of excited states in the test specimen is performed, for example, by measuring the optical density of the specimen before and after sterilization using a densitometer or measuring the thermoresistance of the test specimen in response to a known dose of radiation received by the test specimen before sterilization.

The advantage and higher effect of the new solution lies in the fact that the measuring body placed before the sterilization procedure in the tested can does not require connection to the evaluation device, it practically does not disturb the temperature conditions in the can, can be placed anywhere inside the can. placing test cans in a sterilization apparatus. No emissions are produced during the measurement. The method of determining the thermodestructive effect is simple and reliable and the device for its realization is readily available. The purchase costs are lower than in all known methods for continuous or discontinuous devices.

Example

The can with an inlet density of 1.40 was fitted with a thermocouple sensor located inside the can to monitor the temperature during sterilization. It was then subjected to a sterilization procedure in a 90 ° C water bath for 38 min. After rapid cooling of the can to below sublethal temperature, the body was removed and the density measured. The input and output density differences were 0.24. The experiment was repeated with a new density measure 1.40 in an autoclave water bath for 28 minutes at 105 ° C. At the end of the experiment, the density difference in this case was 0.28. In both cases, the sterilization effects of the procedures, whose values showed a good agreement with

- 3,240,861 obtained from ratios of input and output densities of specific bodies The time required to measure the density of a single body on the MEODENZI TRD-04 densitometer is about 6 seconds.

The method can be used to measure thermal processes in the food, pharmaceutical and healthcare industries.

Claims (2)

SUBJECT OF THE INVENTION 240 860 CLAIMS 1. A method for determining the thermodestructive effect of a sterilization or pasteurization procedure, comprising, in conjunction with a sterilized or pasteurized substance, subjected to a heat treatment of a crystalline test specimen which has been previously excited by ionizing radiation and and the thermodestructive effect is evaluated after sterilization or pasteurization. 2. The method of claim 1, wherein the concentration of excited states is determined by measuring optical density or thermoresistance.