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New Automated Microwave Heating Process for Cooking and Pasteurization of Microwaveable Foods Containing Raw Meats
Author(s) -
Huang Lihan,
Sites Joseph
Publication year - 2010
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1750-3841.2009.01482.x
Subject(s) - pasteurization , microwave , microwave heating , food science , dielectric heating , microwave oven , tray , microwave cavity , defrosting , chemistry , heating system , analytical chemistry (journal) , materials science , chromatography , biology , mechanical engineering , physics , botany , quantum mechanics , air conditioning , engineering , thermodynamics
A new microwave heating process was developed for cooking microwaveable foods containing raw meats. A commercially available inverter‐based microwave oven was modified for pasteurization of mechanically tenderized beef, inoculated with Escherichia coli O157:H7 (approximately 5 log 10 CFU/g) and packaged in a 12‐oz CPET tray containing 150‐mL de‐ionized water. The new microwave heating system was equipped with an infrared sensor and a proportional feedback mechanism to allow temperature controlled microwave heating. A 2‐stage heating strategy was adopted to cook the product. In the primary heating stage, the sample surface temperature was increased to an initial temperature set‐point (ITSP, 65, 70, 75, or 80 °C). In the secondary heating stage, the heating was continued with a small fraction of microwave power. The effect of ITSP, hold time (0 to 3 min), and sample elevation (0, 0.03, and 0.07 m above turntable) on inactivation of E. coli O157:H7 and background microflora was evaluated. It was observed that only a small number (approximately 1.3 logs) of E. coli O157:H7 and background microflora were inactivated in the primary heating stage. The elevation 0.07 m, which was in the proximity of the geometric center of the metal cavity, was more effective in inactivating both E. coli O157:H7 and background microflora. Substantially more bacteria were inactivated in the secondary heating stage. Complete inactivation of E. coli and background microflora was observed with heating at temperatures above 70 °C for more than 1 min. This study demonstrated a new approach for ensuring the safety of microwaveable products containing raw meats.