Patent ID: 6462546
Filing Date: 2002-10-08
Classification: G01R

Abstract:
A method for investigating the imperishability of liquid foodstuffs by means of electron spin resonance (ESR), wherein a sample of the foodstuff is exposed to an elevated temperature, as compared to room temperatures, for an extended period of time, wherein during the period of time an ESR signal of the sample is measured in predetermined time intervals (&Dgr;T), the intensity (I) of the ESR signal is plotted vs. time and the moment in time (t01, t02, t03) is detected when the Intensity (I) shows a super proportional increase, wherein a predetermined number n of samples each of different foodstuffs is investigated interlocked in time relative to each other by executing the following steps within a same sample container (22):a) filling a first sample of a first foodstuff into the sample container (22); b) investigating the first sample by means of ESR and measuring the intensity (I) of the ESR signal; c) plotting the intensity (I) measured in step b) as a first measuring point (P11) in a first diagram (75/1); d) discharging the first sample of the first foodstuff; e) repeating nâˆ’1 times steps a) through d) with the nâˆ’1 samples of the foodstuffs, wherein in step c) the measured intensities of each foodstuff are plotted into separate diagrams (75/2 through 75/n) as first points (P21 through Pn1), the number n being dimensioned such that executing steps a) through d) n times corresponds essentially to the predetermined time interval (&Dgr;T); f) filling a second sample of the first foodstuff in to the sample container (22); g) investigating the second sample by means of ESR and measuring the intensity (I) of the ESR signal; h) plotting the intensity measured in step g) as a second measuring point (P12) into the first diagram (75/1); i) discharging the second sample; j) repeating nâˆ’1 times steps e) through i) with the nâˆ’1 samples of the nâˆ’1 other foodstuffs, wherein in step h) the measured intensities of each foodstuff are plotted into separate diagrams (75/2 through 75/n) as second points (P22 through Pn2) into the separate diagrams and k) repeating steps e) through j) for third and more measuring points until a predetermined number m of measuring points per diagram has been attained.