Reduction of on Inoculated Almonds Exposed to Hot Oil

Abstract

The heat resistance of Salmonella inoculated onto almonds was determined after immersion in hot oil. Whole almonds were inoculated with Salmonella Enteritidis PT 30 or Salmonella Senftenberg 775W and heated in oil. After heating, almonds were drained, transferred to cold tryptic soy broth, and mixed with a stomacher, and samples were plated onto tryptic soy and bismuth sulfite agars. Salmonella survivor inactivation curves were upwardly concave. Rapid reductions of 2.9, 3.0, or 3.6 log CFU/g for Salmonella Enteritidis were observed after 30 s of exposure to oil at 116, 121, or 127 degrees C, respectively. Thereafter, reduction occurred at a much slower rate. Similar reductions were observed at 127 degrees C for Salmonella Senftenberg. The Weibull model was used to predict 4- and 5-log reductions of Salmonella Enteritidis after 0.74 and 1.3 min at 127 degrees C, respectively. Neither Salmonella serovar could be recovered by enrichment of 1-g samples after almonds inoculated at 5 log CFU/g were exposed to oil at 127 degrees C for 1.5 min. Standard oil roasting times and temperatures that achieve acceptable kernel color and texture should result in much greater than 5-log reductions of Salmonella in almonds.

Effect of moisture on salmonella spp. heat resistance in cocoa and hazelnut shells

“…4% w/w moisture), which gives rise to concerns about the efficacy of roasting at mild processing conditions that maybe insufficient to eliminate salmonellae in nut processing. S. Enteritidis PT30 exhibited reasonably linear inactivation at the temperatures tested, which is in contrast to the results of Du et al (2010) where thermal inactivation results for S. Enteritidis PT30-inoculated almonds, immersed in hot oil, gave non-linear results. In addition, a study in peanut butter (Shachar & Yaron, 2006), also reported non-linear curves for the thermal inactivation of salmonellae (including S. Enteritidis).…”

“…In addition, a study in peanut butter (Shachar & Yaron, 2006), also reported non-linear curves for the thermal inactivation of salmonellae (including S. Enteritidis). Both Du et al (2010) and Shachar and Yaron (2006), modelled the non-linear curves with the Weibull model. Different shapes of inactivation curves have been reported, including linear, sigmoidal ('shoulders' and 'tails'), concave and convex.…”

“…Goepfert and Biggie (1968) demonstrated the high heat resistance of salmonellae in cocoa liquor, while showed that heat resistance could be substantially lowered in this matrix, by addition of small amounts of water (1-4% w/w). Whilst data is available on the effectiveness of heat treatments and heat resistance of salmonellae in almonds (Bari et al, 2010(Bari et al, , 2009Chang, Han, Reyes-De-Corcuera, Powers, & Kang, 2010;Du, Abd, McCarthy, & Harris, 2010), pecan nutmeats (Beuchat & Mann, 2011) and other low a W foods, such as peanut butter (Ma et al, 2009;Shachar & Yaron, 2006), no similar data in other low a W confectionery raw materials is currently in the public domain. This study addresses the apparent lack of such data by determining the heat resistance of several strains of Salmonella in crushed shells of cocoa and hazelnut at low and elevated water content.…”

Survival of Salmonella Enteritidis PT 30 on inoculated almond kernels in hot water treatments

“…Since September 2007, in response to these outbreaks, almonds grown in California and sold in North America (U.S., Canada and Mexico) must be processed to achieve a minimum 4-log reduction of Salmonella using a validated process (Federal Register 2007). These processes may either induce desirable sensory characteristics (e.g., roasting or blanching) (Du, Abd, McCarthy, & Harris 2010) or may be designed to retain attributes of the raw almond (e.g., propylene oxide, high pressure, infrared heating, moist air impingement, steam or combination treatments) (ABC, 2007a;Bari et al 2009; Bari et al 2010;Brandl, Pan, Huynh, Zhu, & McHugh 2008;Chang, Han, Reyes-De-Corcuera, Powers, & Kang 2010;Jeong, Marks, & Orta-Ramirez 2009;Lee et al 2006;Willford, Mendonca, & Goodridge 2008;Yang et al 2010).…”

Atımlı Işık Uygulaması ile Bademde Salmonella Enteritidis İnaktivasyonu

“…Almonds, in particular, were associated with two recorded outbreaks of salmonellosis [2,19], which led to the establishment of U.S. regulations that require treatment achieving a minimum 4-log reduction in Salmonella for California-grown almonds [10]. There are several treatments that can be used to meet the minimum reduction requirement including blanching [14], oil roasting [8], and propylene oxide fumigation [5,6]. However, blanching and oil roasting technologies may lead to undesirable loss of nutritional and physical quality and propylene oxide fumigation was found less attractive treatment for pathogen reduction due to its toxicity.…”