No abstract

The ultimate purpose of an investigation of physical properties and attempts to determine laws governing the processing of foodstuffs is to make available results which may be used in the improvement of a process leading to a safe and palatable product. I n this series of papers on heat processing of beef (5, 6, 7, 8, 9, 10, 12), Hurwicz and Tischer attempted to investigate the laws governing the thermal process and to determine some physical characteristics of beef. Objective measurements of quality were discussed in Part I11 (12), with only a brief consideration of the sterilizing effects of the process. Since these effects are of paramount importance, this investigation was undertaken to determine the sterilizing effects of high temperature processes. It is the purpose of the investigation to present and to evaluate data on the distribution of F, values in 300 X 308 cans packed with beef and processed in steam; and furthermore to evaluate the contribution of residual heating (10) to the sterilizing effect.Evaluation of the sterilizing effect of heat processing for the conditions prevailing during this experiment assumes two important aspects : (a) It furnishes information on the effects of high processing temperatures for short times on the sterilizing value of the process and (b) it makes available some information on the distribution of F, values within a container during heat treatment to permit the evaluation of the stsilizing effect for the whole contents of the can. I n both cases the information in the literature is either scarce or not available. EXPERIMENTAL PROCEDUREThe experimental procedure used in processing of round of beef and the design of the experiment were described in detail in P a r t s 111 and I V ( l a , 7) of this series and its description would be repetitious, as data presented here were gathered during the same experiment.The sterilizing values (F,) were determined graphically and also calculated by the "General Method'' ( 2 ) . The F, values were determined for the 6 temperatures investigated and for all of the processing times used: however, only 4 out of the 1 2 times within each temperature were presented in Table 1 for all 25 locations tested in the container. The locations are given in the table i n terms of their r and z cylindrical coordinates. Because of the variation observed, the results are given mostly in tabular and graphical form with the interpretation restricted to observation of trends or in some cases to approximate visual evaluation of functional relationships. No attempt was made to estimate parameters.