Dielectric Properties of Beverages (Tamarind and Green) Relevant to Microwave-Assisted Pasteurization.

• Autores: Arnold David González Monroy, Tejinder Kaur Kaur Kataria, José Luis Olvera-Cervantes, Alonso Corona-Chávez, César Ozuna, Gabriela Rodríguez-Hernández, María Elena Sosa Morales
• Localización: Journal of food science, ISSN 0022-1147, Vol. 83, Nº 9, 2018, págs. 2317-2323
• Idioma: inglés
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• Resumen

  • Dielectric properties (DPs) of two beverages, tamarind and a green drink (based on mix fruits of pineapple, guava, lemon, and nopal), were studied. The DPs were determined using the open-ended coaxial probe method in the frequency range from 0.25 to 25 GHz at 10, 30, 50, and 70 °C. The dielectric constant decreased when both frequency and temperature increased above 1000 MHz. For both beverages, the dielectric loss factor increased with increasing frequency and increasing temperature. In addition, dielectric constant values ranged from 59.7 to 82.5, and the dielectric loss factors were between 5.8 and 31.1. The penetration depth (dp ) of electromagnetic waves in the beverages increased proportionally to temperature at frequencies above 1000 MHz; dp values ranged from 0.2 to 7.5 cm. Because of its complexity and the amount of ingredients and the interactions between them, the green drink showed higher values of dielectric constants in comparison with the tamarind beverage.; Practical Application: The dielectric properties of the studied beverages, how they behave at different temperatures, and the penetration depth reached by microwave at the allocated frequencies, provide important parameters for further heating treatments, such as heating (microwave-assisted pasteurization) and for modeling/simulation purposes.; © 2018 Institute of Food Technologists®.