Study of heat transfer in particulate food systems packaged metallic and flexible containers, submitted to sterilization process in a pilot retort operated in static and agitated mode

• Grant number: 19/22200-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: April 01, 2020
• End date: March 31, 2023
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Engineering
• Principal Investigator: Maria Isabel Berto
• Grantee: Luís Carlos Oliveira dos Santos Júnior
• Host Institution: Instituto de Tecnologia de Alimentos (ITAL). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil
• Associated research grant: 17/50349-0 - Plan of institutional development in research of the Institute of Food Technology - ITAL (PDIp), AP.PDIP

Abstract

The determination of the real intensity of the heat treatment, submitted to a low acidity canned food, is a critical factor for the guarantee of public health safety. This intensity or lethality depends on the time/temperature behavior measured at the slowest heating point of the product inside the package. This behavior is a function of the food's heat transfer characteristics that are related to its conductive or convective properties. (BLACK; BARACH, 2015). Studies had been conducted with particulate food systems, considering various types of grains immersed in brine and packaged in cylindrical metal cans which were heated in water bath to temperatures at most 100°C. The results showed that the lowest temperature inside package was measured on the radial axis at 1/4 of the package height diverging from the region indicated for conductive (1/2 package height) and convective (1/3 package height) products (CARA, et al., 2016). Since no other type or volume of packaging and temperatures of heating medium were tested, it is not possible to affirm that these results are valid to other processing conditions. The tests proposed in this project aim to study and evaluate the heat transfer in heating process of complex food systems with convective/conductive characteristics in metallic and flexible packages, and to define their slowest heating point. The heat treatment will be a sterilization process, performed in a cascade retort operated in the static, rotary and/or longitudinally shaking mode. The influence of the retort operation mode in heat transfer processing will be studied and so also the influence of other factors, such as: food composition and its conductive/convective properties, head space, filling operations, etc. The knowledge of this information is important and critical for an estimate and calculate the real intensity of thermal processing and consequently to produce foods that guarantee public health safety. (AU)