EVALUATION OF PROCESS DEVIATIONS, CONSISTING OF DROPS IN ROTATIONAL SPEED, DURING THERMAL-PROCESSING OF FOODS IN ROTARY WATER CASCADING RETORTS

Taking into account the similarities of broken-line heating curves and heat-penetration curves obtained when a product undergoes a drop in r otational speed during thermal processing in a rotary water cascading retort, a semiempirical method used for handling broken-line heating b ehaviour is suggested as a method of dealing with this type of process deviation. For this purpose, the possibility of extrapolating the emp irical heating rate parameter f(h), determined on the heat-penetration curve of white beans in brine processed in a still retort to the 'sti ll' conditions associated with a rotational speed drop in a rotary wat er cascading retort, was investigated. Following this approach, safe p roduct temperature predictions were obtained. The main criterion influ encing the quality of the evalution was the determination of the corre ct empirical parametric value to be used. This means when determining this parametric value, care is required when selecting the correct tem perature interval on the heat-penetration curve. Copyright (C) 1996 El sevier Science Limited