Denaturation of Algal Phycobiliproteins Can be Used as a Thermal Process Indicator

  • A. Orta-Ramirez
  • D. M. Smith
  • J. E. Merrill


Thermal processing is a very common method of food preservation. The thermal treatment consists of applying heat to a food product at a specific temperature for a determined interval of time. The process time is calculated to achieve sufficient microbial destruction to comply with public health standards and prevent spoilage of the food product. The thermal processing kinetics can be defined in terms of D, z and F values (Teixeira, 1992; Singh and Heldman, 1993; Hendrickx et al., 1995). D value is the time in minutes required to decrease a quality attribute by 90% at a constant temperature. The z value is the temperature increase necessary to reduce the D value by 90%. The F value is the time required to achieve a stated reduction in a population of microorganisms or spores. This time is usually expressed as a multiple of the D value. Many thermal processes have been standardized, and published recommendations for specific conditions are available (National Canners Association, 1968). Even with reliable thermal processing schedules and equipment, though, there is a need to determine process compliance to ensure food safety. The evaluation of thermal processes in foods can be done using in situ methods, physical-mathematical models or time-temperature integrators (TTIs). These TTIs are devices capable of predicting the time-temperature response of a quality or safety index in a food product without the need for extensive mathematical modeling of the thermal process. This occurs when the thermal destruction of both TTI and target index are identical (ZTTI = Ztarget) (Hendrickx et al., 1995; Van Loey et al., 1996).


Thermal Inactivation Safety Index Ensure Food Safety Public Health Standard Thermal Inactivation Kinetic 
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  1. Davis, B.J. 1964, Ann. N.Y. Acad. Sci. 121: 404–427.PubMedCrossRefGoogle Scholar
  2. Hendrickx, M., Maesmans, G., De Cordt, S., Noronha, J., Van Loey, A., and Tobback, P. 1995, Rev. Food Sci. Nut. 35: 231–262.CrossRefGoogle Scholar
  3. National Canners Association. 1968, Laboratory Manual for Food Canners and Processors. Vol. 1. AVI Publishing Company, Inc. Westport, CT.Google Scholar
  4. Orta-Ramirez, A., Price, J.F., Hsu, Y-.C., Veeramuthu, G.J., Cherry-Merritt, J.S. and Smith, D.M. 1996, J. Food Prot. 60: 471–475.Google Scholar
  5. Singh, R.P. and Heldman, D.R. 1993, Introduction to Food Engineering. 2nd ed. Academic Press Inc. New York, NY.Google Scholar
  6. Teixeira, A. 1992, Thermal process calculations. Ch.11, In Handbook of Food Engineering. D.R. Heldman and D.B. Lund (Ed.), 563–620. Marcel Dekker, Inc., New York.Google Scholar
  7. USDA-FSIS. 1996, Performance standards for the production of certain meat and poultry products. Federal Register. 61 (86), 19–564.Google Scholar
  8. US Department of Agriculture, Food Safety Inspection Service, Washington, DC.Google Scholar
  9. Van Loey, A., Hendrickx, M., De Cordt, S., Haentjens, T. and Tobback, P. 1996, Trends Food. Sci. Tech. 7 (1): 1–33.CrossRefGoogle Scholar
  10. Veeramuthu, G.J. 1996, Personal communication.Google Scholar

Copyright information

© Springer Science+Business Media New York 1998

Authors and Affiliations

  • A. Orta-Ramirez
    • 1
  • D. M. Smith
    • 1
  • J. E. Merrill
    • 2
  1. 1.Department of Food Science and Human NutritionEast LansingUSA
  2. 2.Department of MicrobiologyMichigan State UniversityEast LansingUSA

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