Effect of Gamma Radiation on the Reduction of Salmonella strains, Listeria monocytogenes, and Shiga Toxin-Producing Escherichia coli and Sensory Evaluation of Minimally Processed Spinach (Tetragonia expansa).

• Grant number: 14/17280-9
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: September 01, 2014
• End date: February 28, 2015
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Science
• Principal Investigator: Mariza Landgraf
• Grantee: Mariza Landgraf
• Host Institution: Faculdade de Ciências Farmacêuticas (FCF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

This study evaluated the effects of irradiation on the reduction of Shiga toxin-producing Escherichia coli (STEC), Salmonella strains, and Listeria monocytogenes, as well as on the sensory characteristics of minimally processed spinach.Spinach samples were inoculated with a cocktail of three strains each of STEC, Salmonella strains, and L. monocytogenes, separately, and were exposed to gamma radiation doses of 0, 0.2, 0.4, 0.6, 0.8, and 1.0 kGy. Samples that were exposed to 0.0,1.0, and 1.5 kGy and kept under refrigeration (4uC) for 12 days were submitted to sensory analysis. D10-values ranged from 0.19 to 0.20 kGy for Salmonella and from 0.20 to 0.21 for L. monocytogenes; for STEC, the value was 0.17 kGy. Spinach showed good acceptability, even after exposure to 1.5 kGy. Because gamma radiation reduced the selected pathogens without causingsignificant changes in the quality of spinach leaves, it may be a useful method to improve safety in the fresh produce industry. (AU)