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Survival of Salmonella in peanut butter and peanut butter spread
Author(s) -
Burnett S.L.,
Gehm E.R.,
Weissinger W.R.,
Beuchat L.R.
Publication year - 2000
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1046/j.1365-2672.2000.01138.x
Subject(s) - peanut butter , food science , salmonella , inoculation , sugar , biology , food preservation , chemistry , bacteria , horticulture , genetics
In 1996, the first documented outbreak of salmonellosis associated with the consumption of peanut butter was reported. This study was undertaken to determine survival characteristics of high (5·68 log 10 cfu g −1 ) and low (1·51 log 10 cfu g −1 ) inocula of a five‐serotype mixture of Salmonella in five commercial peanut butters and two commercial peanut butter spreads. Populations in samples inoculated with 5·68 log 10 cfu g −1 and stored for 24 weeks at 21 or 5 °C decreased 4·14–4·50 log 10 cfu g −1 and 2·86–4·28 log 10 cfu g −1 , respectively, depending on the formulation. The order of retention of viability was: peanut butter spreads > traditional (regular) and reduced sugar, low‐sodium peanut butters > natural peanut butter. Differences in rates of inactivation are attributed to variation in product composition as well as size and stability of water droplets in the colloidal matrix, which may influence nutrient availability. With the exception of natural peanut butter, products initially inoculated with 1·51 log 10 cfu of Salmonella g −1 (32 cfu g −1 ) were positive for the pathogen after storage for 24 weeks at 5 °C. At 21 °C, however, with the exception of one peanut butter spread, all products were negative for Salmonella after storage for 24 weeks. Post‐process contamination of peanut butters and spreads with Salmonella may to result in survival in these products for the duration of their shelf life at 5 °C and possibly 21 °C, depending on the formulation.