Disinfection of fishmeal with radiofrequency heating for improved quality and energy efficiency

Abstract

Radiofrequency (RF) heating was investigated as an alternative to cooking, drying or chemical disinfection for the preservation of fishmeal and shown to be a highly effective process without any detectable effects, particularly on proteins, lipids or in vivo digestibility. The uniform and deep penetration of RF waves resulted in rapid and homogeneous heating allowing ∼4 times lower thermal loads to be used for >5 log 10 (>99.999%) reduction in infection levels for Salmonella spp and for Escherichia coli O157:H7. Simultaneously, the natural flora was reduced by >3 log 10 (>99.9%). The RF process can be operated in the 70-90 • C range and with high energy-use efficiency (∼50%), which compares well with the 10-15% efficiency for conventional surface heating methods. Industry and expert laboratories confirmed these results. RF heating is thus a new alternative thermal process that is particularly appropriate for disinfecting fishmeal or for reprocessing it rapidly and efficiently with full retention of its natural attributes.

Radiofrequency power disinfects and disinfests food, soils and wastewater

“…By industry standards, the fishmeal maintained its quality (e.g., protein and lipid contents, moisture) and in vivo digestibility (Lagunas-Solar et al 2005a) (fig. 4) …”

Dielectric properties of ground almond shells in the development of radio frequency and microwave pasteurization

“…Microwave (MW) and radio frequency (RF) treatments may be possible solutions. Those treatments have been proposed to control pathogens in other agricultural and food materials due to rapid volumetric heating (Nelson et al, 2002;Lagunas-Solar et al, 2005;Luechapattanaporn et al, 2005;Gao et al, 2011). In developing such treatments for almond pasteurization, determining the dielectric properties of almond shells is necessary to understand the interactions of the product with electromagnetic energy and estimating the penetration depth in industrial applications.…”

Analysis of radio frequency (RF) power distribution in dry food materials

“…Radio frequency (RF) technology has been explored in various food processing operations, such as pasteurization and sterilization (Bengtsson et al, 1970;Houben et al, 1991;Brunkhorst et al, 2000;Luechapattanaporn et al, 2005;Lagunas-Solar et al, 2005, 2007Byrne et al, 2010) and insect disinfestations in various agricultural commodities, such as fresh fruits (Birla et al, 2004(Birla et al, , 2005Wang et al, 2006;Tiwari et al, 2008) and dry nuts (Wang et al, 2001(Wang et al, , 2002(Wang et al, , 2003. A major obstacle for RF technology to be commercially applicable is its non uniform heating.…”