Feasibility of Aseptic Processing of a Low-Acid Multiphase Food Product (salsa con queso) Using a Continuous Flow Microwave System


  • Paper nr FSR-06-10 of the Journal Series of the Dept. of Food Science, North Carolina State Univ., Raleigh, NC 27695-7624, U.S.A.

  • The use of trade names in this publication does not imply endorsement by the North Carolina Agricultural Research Service of the products named nor criticism of similar ones not mentioned.


ABSTRACT:  Aseptic processing of a low-acid multiphase food product using a continuous flow microwave heating system can combine the advantages of an aseptic process along with those of microwave heating. Dielectric properties of 2 different brands of 1 such product (salsa con queso) were measured under continuous flow conditions at a temperature range of 20 to 130 °C. At 915 MHz, the dielectric constant ranged from 58.7 at 20 °C to 41.3 at 130 °C with dielectric loss factor ranging from 41.0 at 20°C to 145.5 at 130 °C. The loss tangent at 915 MHz ranged from 0.61 at 20 °C to 3.52 at 130 °C. The temperature profiles at the outlet during processing of salsa con queso in a 5-kW microwave unit showed a narrow temperature distribution between the center and the wall of the tube. The study showed the feasibility of aseptic processing of salsa con queso using a continuous flow microwave system.