VARIATION OF QUALITY ATTRIBUTES IN SERIALLY CONNECTED INDEPENDENT FOOD REACTOR UNITS .1.

The author has developed new calculation methods for serially connecte d flow-through type food reactor units, working on the macro-mixing pr inciple and being independent regarding the residence time of macro-el ements. Constant temperatures and 'closed behaviour' (a concept from t he dispersion models) are also conditioned for the units. Quality attr ibutes include concentration of surviving microbes, activity of enzyme s, concentration of vitamins or other constituents, sensory attributes and related physical properties. Their variations at constant tempera ture, however, should be dependent only on the product of a rate const ant and time, and moreover based on previous knowledge of the residenc e time distributions (RTDs) in the units. A rather simple convolution integral has been deduced for the calculation of the overall change of a quality attribute. Further simplifications are possible for first o rder changes. As an example, details of treatment of three units at di fferent temperatures and figures illustrating some basic ideas and the difference between original and modified RTD functions are given.