Test Methods for Measuring Minimum Holding Times in Continuous Egg Pasteurizers1

Abstract

Two test methods that may be used in commercial egg pasteurizers while in normal operation are described. Either may be used without damage to the product and with almost no disturbance to regular plant procedures. These tests have been needed to help determine the degree of compliance with pasteurization requirements. The first method requires injection of a cold shot into the flow stream entering the holding tube and determination of the time required for the first of this material to arrive at the outlet of the holding tube. The cold shot is introduced into the line by use of a by-pass loop. The arrival of the cold shot at the end of the holding tube is detected by use of a sensitive recorder to indicate the temperature change. The second method is based on the use of a fluorocarbon compound as a tracer. The compound is dissolved in yolk, which is injected into the flow stream entering the holding tube. Samples taken at the end of the holding tube are checked with a fluorocarbon leak detector of the type used in the refrigeration industry. The first positive sample is taken as the time of arrival of the injected tracer. Fluorocarbon compound 12 which is permitted in the immersion freezing of foods may be used and has no effects on the functional properties of the products.