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Linda J Harris - One of the best experts on this subject based on the ideXlab platform.
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a dry inoculation method for nut kernels
Food Microbiology, 2013Co-Authors: Tya Lessingto, Linda J Harris, Christopher G. TheofelAbstract:Abstract A dry-inoculation method for Almonds and walnuts was developed to eliminate the need for the postinoculation drying required for wet-inoculation methods. The survival of Salmonella enterica Enteritidis PT 30 on wet- and dry-inoculated Almond and walnut kernels stored under ambient conditions (average: 23 °C; 41 or 47% RH) was then compared over 14 weeks. For wet inoculation, an aqueous Salmonella preparation was added directly to Almond or walnut kernels, which were then dried under ambient conditions (3 or 7 days, respectively) to initial nut moisture levels. For the dry inoculation, liquid inoculum was mixed with sterilized sand and dried for 24 h at 40 °C. The dried inoculated sand was mixed with kernels, and the sand was removed by shaking the mixture in a sterile sieve. Mixing procedures to optimize the bacterial transfer from sand to kernel were evaluated; in general, similar levels were achieved on walnuts (4.8–5.2 log CFU/g) and Almonds (4.2–5.1 log CFU/g). The decline of Salmonella Enteritidis populations was similar during ambient storage (98 days) for both wet-and dry-inoculation methods for both Almonds and walnuts. The dry-inoculation method mimics some of the suspected routes of contamination for tree nuts and may be appropriate for some postharvest challenge studies.
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risk of salmonellosis from consumption of Almonds in the north american market
Food Research International, 2012Co-Authors: Elisabetta Lambertini, Donald W Schaffner, Michelle D Danyluk, Carl K Winter, Linda J HarrisAbstract:article i nfo Article history: Received 15 February 2011 Accepted 31 May 2011 Salmonellosis outbreaks from consumption of raw Almonds in 2001 and 2004 led to regulations that require mandatory treatment of Almonds sold in North America to give a minimum 4-log reduction of Salmonella .T his study aims to: 1) assess the risk of salmonellosis associated with Almond consumption in North America, with currenttreatmentsineffect;2)determinetheresilienceofthecurrentproductionsystemtoincreasesinprevalence or concentration of Salmonella on Almonds; 3) assess the impact of treating less than 100% of the crop; and 4) investigate conditions that could explain the number of cases associated with the 2001 outbreak. Risk was assessed using a Monte Carlo simulation, based on an established dose-response relationship. Data for Almond amounts sold, Salmonella prevalence and concentration on Almonds, storage time and temperature at different handling steps, population reductions during storage at various temperatures and with different treatments, and consumer handling were based on data from published sources and Almond industry or academic expert opinion. What-if scenarios were evaluated for Salmonella prevalence varying from 1 to 65%, concentrations of Salmonella varyingfrom 1to 120 MPN/100 g,and portionsofuntreated cropvaryingfrom 0to 10%.Theestimated incidenceof salmonellosis in North America from Almonds as currently treated is on average 0.008 cases per billion servings (with an estimated 6.6 billion servings consumed annually). Increases in Salmonella prevalence to 25%, mean concentrations above 25 MPN/100 g, or leaving 0.05% of the crop untreated all resulted in an arithmetic mean risk greater than 1 case/year (with geometric means remaining below 1 case/year for all variables). Assuming 4000 kg at a prevalence of 65% (observed in recalled lots) and an average concentration of 120 MPN/100 g in raw Almonds (back calculated from levels in recalled Almonds) predicted over the 2800 cases estimated for the 2001 outbreak. Applying a 4-log reduction to these Almonds reduced the average number of predicted cases to less than a single case. The current regulation is effective in maintaining the risk of salmonellosis from consumption of Almonds below an arithmetic mean of 1 case/year, although significant increases in either prevalence or concentration, or small increases in proportion of untreated Almonds would frequently lead to exceeding this threshold.
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survival of salmonella enteritidis pt 30 on inoculated Almond kernels in hot water treatments
Food Research International, 2012Co-Authors: Linda J Harris, Aaron R. Uesugi, Kathryn L. MccarthyAbstract:Abstract Almonds are blanched by exposure to hot water or steam-injected water to remove the pellicle (skin) from the kernel. This study evaluated the survival of Salmonella Enteritidis PT 30, Salmonella Senftenberg 775W and Enterococcus faecalis on whole raw Almond kernels exposed to hot water. Whole, inoculated (7 to 9 log CFU/g) Nonpareil Almonds (40 g) were submerged in 25 L of water maintained at 60, 70, 80 and 88 °C. Almonds were heated for up to 12 min, drained for 2 s, and transferred to 80 mL of cold (4 °C) tryptic soy broth. Almonds in broth were stomached at high speed for 2 min, serially diluted, plated onto tryptic soy and bismuth sulfite agars ( Salmonella ) or bile esculin agar ( Enterococcus ) and incubated at 37 °C for 24 and 48 h, respectively. D values of 2.6, 1.2, 0.75 and 0.39 min were calculated for exposure of S . Enteritidis PT 30 to water at 60, 70, 80 and 88 °C, respectively; the calculated z value was 35 C°. D values determined for Salmonella Senftenberg 775W and E. faecalis at 88 °C were 0.37 and 0.36 min, respectively. Neither Salmonella serovar could be recovered by enrichment of 1-g samples after Almonds inoculated at 5 log CFU/g were heated at 88 °C for 2 min. These data will be useful to validate Almond industry blanching processes.
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Survival of Salmonella Enteritidis PT 30 on inoculated Almond kernels in hot water treatments
Food Research International, 2012Co-Authors: Linda J Harris, Shirin J. Abd, Aaron R. Uesugi, Kathryn L. MccarthyAbstract:Abstract Almonds are blanched by exposure to hot water or steam-injected water to remove the pellicle (skin) from the kernel. This study evaluated the survival of Salmonella Enteritidis PT 30, Salmonella Senftenberg 775W and Enterococcus faecalis on whole raw Almond kernels exposed to hot water. Whole, inoculated (7 to 9 log CFU/g) Nonpareil Almonds (40 g) were submerged in 25 L of water maintained at 60, 70, 80 and 88 °C. Almonds were heated for up to 12 min, drained for 2 s, and transferred to 80 mL of cold (4 °C) tryptic soy broth. Almonds in broth were stomached at high speed for 2 min, serially diluted, plated onto tryptic soy and bismuth sulfite agars ( Salmonella ) or bile esculin agar ( Enterococcus ) and incubated at 37 °C for 24 and 48 h, respectively. D values of 2.6, 1.2, 0.75 and 0.39 min were calculated for exposure of S . Enteritidis PT 30 to water at 60, 70, 80 and 88 °C, respectively; the calculated z value was 35 C°. D values determined for Salmonella Senftenberg 775W and E. faecalis at 88 °C were 0.37 and 0.36 min, respectively. Neither Salmonella serovar could be recovered by enrichment of 1-g samples after Almonds inoculated at 5 log CFU/g were heated at 88 °C for 2 min. These data will be useful to validate Almond industry blanching processes.
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most probable number determination of salmonella levels in naturally contaminated raw Almonds using two sample preparation methods
Journal of Food Protection, 2010Co-Authors: Anika Bansal, Shirin J. Abd, Michelle D Danyluk, Thomas M Jones, Linda J HarrisAbstract:Pathogens occurring in particulate foods may be unevenly distributed, which may impact interpretation of most-probable-number (MPN) values. The MPN analysis of Salmonella in naturally contaminated raw Almonds was conducted using two sample preparation methods. Raw Almond kernels (3,698 samples) and inshell Almonds (455 samples) were collected from Almond processors throughout California during the 2006 and 2007 harvests, and 100-g samples were enriched for Salmonella. The prevalence of Salmonella on kernels and inshell Almonds was 1.6 and 0.9%, respectively, in 2006, and 0.83 and 2.2%, respectively, in 2007. Almond kernel samples from 2006 were further enriched for Salmonella, and levels of the organism were determined for positive samples by three-tube MPN analysis (25 g, 2.5 g, 0.25 g). Almonds were either divided into subsamples prior to blending and enrichment (method A), or samples were blended in enrichment broth prior to preparation of subsamples (method B). Salmonella was not isolated (<1.2 MPN/10...
Aaron R. Uesugi - One of the best experts on this subject based on the ideXlab platform.
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survival of salmonella enteritidis pt 30 on inoculated Almond kernels in hot water treatments
Food Research International, 2012Co-Authors: Linda J Harris, Aaron R. Uesugi, Kathryn L. MccarthyAbstract:Abstract Almonds are blanched by exposure to hot water or steam-injected water to remove the pellicle (skin) from the kernel. This study evaluated the survival of Salmonella Enteritidis PT 30, Salmonella Senftenberg 775W and Enterococcus faecalis on whole raw Almond kernels exposed to hot water. Whole, inoculated (7 to 9 log CFU/g) Nonpareil Almonds (40 g) were submerged in 25 L of water maintained at 60, 70, 80 and 88 °C. Almonds were heated for up to 12 min, drained for 2 s, and transferred to 80 mL of cold (4 °C) tryptic soy broth. Almonds in broth were stomached at high speed for 2 min, serially diluted, plated onto tryptic soy and bismuth sulfite agars ( Salmonella ) or bile esculin agar ( Enterococcus ) and incubated at 37 °C for 24 and 48 h, respectively. D values of 2.6, 1.2, 0.75 and 0.39 min were calculated for exposure of S . Enteritidis PT 30 to water at 60, 70, 80 and 88 °C, respectively; the calculated z value was 35 C°. D values determined for Salmonella Senftenberg 775W and E. faecalis at 88 °C were 0.37 and 0.36 min, respectively. Neither Salmonella serovar could be recovered by enrichment of 1-g samples after Almonds inoculated at 5 log CFU/g were heated at 88 °C for 2 min. These data will be useful to validate Almond industry blanching processes.
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Survival of Salmonella Enteritidis PT 30 on inoculated Almond kernels in hot water treatments
Food Research International, 2012Co-Authors: Linda J Harris, Shirin J. Abd, Aaron R. Uesugi, Kathryn L. MccarthyAbstract:Abstract Almonds are blanched by exposure to hot water or steam-injected water to remove the pellicle (skin) from the kernel. This study evaluated the survival of Salmonella Enteritidis PT 30, Salmonella Senftenberg 775W and Enterococcus faecalis on whole raw Almond kernels exposed to hot water. Whole, inoculated (7 to 9 log CFU/g) Nonpareil Almonds (40 g) were submerged in 25 L of water maintained at 60, 70, 80 and 88 °C. Almonds were heated for up to 12 min, drained for 2 s, and transferred to 80 mL of cold (4 °C) tryptic soy broth. Almonds in broth were stomached at high speed for 2 min, serially diluted, plated onto tryptic soy and bismuth sulfite agars ( Salmonella ) or bile esculin agar ( Enterococcus ) and incubated at 37 °C for 24 and 48 h, respectively. D values of 2.6, 1.2, 0.75 and 0.39 min were calculated for exposure of S . Enteritidis PT 30 to water at 60, 70, 80 and 88 °C, respectively; the calculated z value was 35 C°. D values determined for Salmonella Senftenberg 775W and E. faecalis at 88 °C were 0.37 and 0.36 min, respectively. Neither Salmonella serovar could be recovered by enrichment of 1-g samples after Almonds inoculated at 5 log CFU/g were heated at 88 °C for 2 min. These data will be useful to validate Almond industry blanching processes.
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growth of salmonella enteritidis phage type 30 in Almond hull and shell slurries and survival in drying Almond hulls
Journal of Food Protection, 2006Co-Authors: Aaron R. Uesugi, Linda J HarrisAbstract:Traceback investigation of a 2000 to 2001 outbreak of salmonellosis associated with consumption of raw Almonds led to isolation of the outbreak strain Salmonella enterica serovar Enteritidis phage type (PT) 30 on three geographically linked Almond farms. Interviews with these growers revealed that significant rain fell during the 2000 harvest when many Almonds were drying on the ground. The objectives of this study were to document weather conditions during the 2000 harvest, determine the potential for growth of Salmonella Enteritidis PT 30 in hull or shell slurries, and evaluate survival of Salmonella Enteritidis PT 30 on wet Almond hulls during drying. Dry Almond hulls and in-shell kernels wetted for 24 h increased in weight by 250 to 300% and 100%, respectively. Both hull and shell slurries supported rapid growth of Salmonella Enteritidis PT 30 at 24 degrees C; slurries containing hulls also supported growth at 15 degrees C. Maximum Salmonella Enteritidis PT 30 concentrations of 6.2 and 7.8 log CFU/ml were observed at 15 and 24 degrees C, respectively. Salmonella Enteritidis PT 30 grown in wet hulls that were incubated at 24 degrees C survived drying at either 15 or 37 degrees C. Reductions of 1 to 3 log CFU/g of dry hull were observed during drying; reductions generally declined as incubation time increased from 2 to 7 days. Evaluation of shipping records revealed that approximately 60% of outbreak-associated Almonds had not been exposed to rain, eliminating this factor as the sole cause of the outbreak. However, the data provide evidence that wet Almonds may be a greater risk for high concentrations of Salmonella, and specific guidelines should be established for harvesting and processing Almonds that have been exposed to rain or other water sources.
Kathryn L. Mccarthy - One of the best experts on this subject based on the ideXlab platform.
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survival of salmonella enteritidis pt 30 on inoculated Almond kernels in hot water treatments
Food Research International, 2012Co-Authors: Linda J Harris, Aaron R. Uesugi, Kathryn L. MccarthyAbstract:Abstract Almonds are blanched by exposure to hot water or steam-injected water to remove the pellicle (skin) from the kernel. This study evaluated the survival of Salmonella Enteritidis PT 30, Salmonella Senftenberg 775W and Enterococcus faecalis on whole raw Almond kernels exposed to hot water. Whole, inoculated (7 to 9 log CFU/g) Nonpareil Almonds (40 g) were submerged in 25 L of water maintained at 60, 70, 80 and 88 °C. Almonds were heated for up to 12 min, drained for 2 s, and transferred to 80 mL of cold (4 °C) tryptic soy broth. Almonds in broth were stomached at high speed for 2 min, serially diluted, plated onto tryptic soy and bismuth sulfite agars ( Salmonella ) or bile esculin agar ( Enterococcus ) and incubated at 37 °C for 24 and 48 h, respectively. D values of 2.6, 1.2, 0.75 and 0.39 min were calculated for exposure of S . Enteritidis PT 30 to water at 60, 70, 80 and 88 °C, respectively; the calculated z value was 35 C°. D values determined for Salmonella Senftenberg 775W and E. faecalis at 88 °C were 0.37 and 0.36 min, respectively. Neither Salmonella serovar could be recovered by enrichment of 1-g samples after Almonds inoculated at 5 log CFU/g were heated at 88 °C for 2 min. These data will be useful to validate Almond industry blanching processes.
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Survival of Salmonella Enteritidis PT 30 on inoculated Almond kernels in hot water treatments
Food Research International, 2012Co-Authors: Linda J Harris, Shirin J. Abd, Aaron R. Uesugi, Kathryn L. MccarthyAbstract:Abstract Almonds are blanched by exposure to hot water or steam-injected water to remove the pellicle (skin) from the kernel. This study evaluated the survival of Salmonella Enteritidis PT 30, Salmonella Senftenberg 775W and Enterococcus faecalis on whole raw Almond kernels exposed to hot water. Whole, inoculated (7 to 9 log CFU/g) Nonpareil Almonds (40 g) were submerged in 25 L of water maintained at 60, 70, 80 and 88 °C. Almonds were heated for up to 12 min, drained for 2 s, and transferred to 80 mL of cold (4 °C) tryptic soy broth. Almonds in broth were stomached at high speed for 2 min, serially diluted, plated onto tryptic soy and bismuth sulfite agars ( Salmonella ) or bile esculin agar ( Enterococcus ) and incubated at 37 °C for 24 and 48 h, respectively. D values of 2.6, 1.2, 0.75 and 0.39 min were calculated for exposure of S . Enteritidis PT 30 to water at 60, 70, 80 and 88 °C, respectively; the calculated z value was 35 C°. D values determined for Salmonella Senftenberg 775W and E. faecalis at 88 °C were 0.37 and 0.36 min, respectively. Neither Salmonella serovar could be recovered by enrichment of 1-g samples after Almonds inoculated at 5 log CFU/g were heated at 88 °C for 2 min. These data will be useful to validate Almond industry blanching processes.
Michelle D Danyluk - One of the best experts on this subject based on the ideXlab platform.
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risk of salmonellosis from consumption of Almonds in the north american market
Food Research International, 2012Co-Authors: Elisabetta Lambertini, Donald W Schaffner, Michelle D Danyluk, Carl K Winter, Linda J HarrisAbstract:article i nfo Article history: Received 15 February 2011 Accepted 31 May 2011 Salmonellosis outbreaks from consumption of raw Almonds in 2001 and 2004 led to regulations that require mandatory treatment of Almonds sold in North America to give a minimum 4-log reduction of Salmonella .T his study aims to: 1) assess the risk of salmonellosis associated with Almond consumption in North America, with currenttreatmentsineffect;2)determinetheresilienceofthecurrentproductionsystemtoincreasesinprevalence or concentration of Salmonella on Almonds; 3) assess the impact of treating less than 100% of the crop; and 4) investigate conditions that could explain the number of cases associated with the 2001 outbreak. Risk was assessed using a Monte Carlo simulation, based on an established dose-response relationship. Data for Almond amounts sold, Salmonella prevalence and concentration on Almonds, storage time and temperature at different handling steps, population reductions during storage at various temperatures and with different treatments, and consumer handling were based on data from published sources and Almond industry or academic expert opinion. What-if scenarios were evaluated for Salmonella prevalence varying from 1 to 65%, concentrations of Salmonella varyingfrom 1to 120 MPN/100 g,and portionsofuntreated cropvaryingfrom 0to 10%.Theestimated incidenceof salmonellosis in North America from Almonds as currently treated is on average 0.008 cases per billion servings (with an estimated 6.6 billion servings consumed annually). Increases in Salmonella prevalence to 25%, mean concentrations above 25 MPN/100 g, or leaving 0.05% of the crop untreated all resulted in an arithmetic mean risk greater than 1 case/year (with geometric means remaining below 1 case/year for all variables). Assuming 4000 kg at a prevalence of 65% (observed in recalled lots) and an average concentration of 120 MPN/100 g in raw Almonds (back calculated from levels in recalled Almonds) predicted over the 2800 cases estimated for the 2001 outbreak. Applying a 4-log reduction to these Almonds reduced the average number of predicted cases to less than a single case. The current regulation is effective in maintaining the risk of salmonellosis from consumption of Almonds below an arithmetic mean of 1 case/year, although significant increases in either prevalence or concentration, or small increases in proportion of untreated Almonds would frequently lead to exceeding this threshold.
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most probable number determination of salmonella levels in naturally contaminated raw Almonds using two sample preparation methods
Journal of Food Protection, 2010Co-Authors: Anika Bansal, Shirin J. Abd, Michelle D Danyluk, Thomas M Jones, Linda J HarrisAbstract:Pathogens occurring in particulate foods may be unevenly distributed, which may impact interpretation of most-probable-number (MPN) values. The MPN analysis of Salmonella in naturally contaminated raw Almonds was conducted using two sample preparation methods. Raw Almond kernels (3,698 samples) and inshell Almonds (455 samples) were collected from Almond processors throughout California during the 2006 and 2007 harvests, and 100-g samples were enriched for Salmonella. The prevalence of Salmonella on kernels and inshell Almonds was 1.6 and 0.9%, respectively, in 2006, and 0.83 and 2.2%, respectively, in 2007. Almond kernel samples from 2006 were further enriched for Salmonella, and levels of the organism were determined for positive samples by three-tube MPN analysis (25 g, 2.5 g, 0.25 g). Almonds were either divided into subsamples prior to blending and enrichment (method A), or samples were blended in enrichment broth prior to preparation of subsamples (method B). Salmonella was not isolated (<1.2 MPN/10...
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migration of salmonella enteritidis phage type 30 through Almond hulls and shells
Journal of Food Protection, 2008Co-Authors: Michelle D Danyluk, Maria T Brandl, Linda J HarrisAbstract:The ability of Salmonella to migrate from an external aqueous environment through the Almond hull and shell, and to colonize the kernel, was evaluated in two ways. First, the outer surface of shell halves from five varieties of Almonds that differed in shell hardness were placed in contact with a suspension of Salmonella enterica serovar Enteritidis phage type 30 for 24hat24°C. Salmonella Enteritidis was isolated from the inside of these Almond shells in 46 and 100% of the samples, by direct swabbing of the inner surface of the shell and by enrichment from the swab, respectively. These findings suggested that hardness of the shell is not a significant factor in the migration of the pathogen through that tissue. In addition, both motile and nonmotile strains of S. enterica serovar Typhimurium migrated through the Almond shells to the same extent under the conditions of this assay, indicating that bacterial migration through the wet shell may be a passive process. Second, whole Almonds (intact hull, shell, ...
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migration of salmonella enteritidis phage type 30 through Almond hulls and shells
Journal of Food Protection, 2008Co-Authors: Michelle D Danyluk, Maria T Brandl, Linda J HarrisAbstract:The ability of Salmonella to migrate from an external aqueous environment through the Almond hull and shell, and to colonize the kernel, was evaluated in two ways. First, the outer surface of shell halves from five varieties of Almonds that differed in shell hardness were placed in contact with a suspension of Salmonella enterica serovar Enteritidis phage type 30 for 24 h at 24 degrees C. Salmonella Enteritidis was isolated from the inside of these Almond shells in 46 and 100% of the samples, by direct swabbing of the inner surface of the shell and by enrichment from the swab, respectively. These findings suggested that hardness of the shell is not a significant factor in the migration of the pathogen through that tissue. In addition, both motile and nonmotile strains of S. enterica serovar Typhimurium migrated through the Almond shells to the same extent under the conditions of this assay, indicating that bacterial migration through the wet shell may be a passive process. Second, whole Almonds (intact hull, shell, and kernel) were soaked for 24 to 72 h at 24 degrees C in a suspension of Salmonella Enteritidis phage type 30 labeled with the green fluorescent protein. Green fluorescent protein-labeled Salmonella cells were observed on the outer and inner surfaces of both the Almond hull and shell, and on the kernel, by confocal laser scanning microscopy. Our data provide direct evidence that wet conditions allow for Salmonella migration through the hull and shell and onto the Almond kernel, thus providing a means by which Almond kernels may become contaminated in the field.
Maria T Brandl - One of the best experts on this subject based on the ideXlab platform.
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feasibility of using sequential infrared and hot air for Almond drying and inactivation of enterococcus faecium nrrl b 2354
Lwt - Food Science and Technology, 2018Co-Authors: Chandrasekar Venkitasamy, Maria T Brandl, Franz J A Niederholzer, Ruihong Zhang, Tara H MchughAbstract:Abstract This study was aimed to develop a sequential infrared and hot air (SIRHA) drying method for whole Almonds and evaluate its effectiveness on decontamination of Almonds. Wet Almonds with hull and shell were dried using different time-combinations of infrared (IR) radiation and hot air (HA) to determine the optimum drying conditions. Almonds were inoculated with Enterococcus faecium, a surrogate for Salmonella enterica. The SIRHA drying (1h IR at 70 °C and 2h HA) reduced the moisture content of Almonds to 7% in 3 h, with a saving of 2 h (40%) of drying time compared with HA drying alone. The population sizes of E. faecium showed the largest size reductions of 4.69 ± 0.71, 1.82 ± 0.39, 1.52 ± 0.31 log CFU/nut on hulls, shells and kernels, respectively, after SIRHA drying combined with tempering (T) (2h IR with 2h T and 1h HA). The peroxide value and free fatty acids content of Almond oil samples from all drying treatments were within accepted level for the Almond industry.
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Shelf-life of infrared dry-roasted Almonds
Food chemistry, 2012Co-Authors: Jihong Yang, Gokhan Bingol, Zhongli Pan, Maria T Brandl, Tara H Mchugh, Gary R. Takeoka, Bruce E. Mackey, Karine Garcin, Hua WangAbstract:Infrared heating was recently used to develop a more efficient roasting technology than traditional hot air roasting. Therefore, in this study, we evaluated the shelf-life of Almonds roasted with three different approaches, namely infrared (IR), sequential infrared and hot air (SIRHA) and regular hot air (HA). Nine medium roasted Almond samples produced by the aforementioned heating methods were processed at three different temperatures (130, 140 and 150 C), packed in paper bags and then stored at 37 C for three, six or eight months. Shelf-life of the roasted Almonds was determined by measuring the changes in colour, peroxide value, moisture content, water activity, volatile components and sensory quality. No significant difference was observed in moisture content and water activity among the Almond samples processed with different roasting methods and stored under the same conditions. GC/MS analysis showed that aldehydes, alcohols, and pyrazines were the main volatile components of Almonds. Aliphatic alde- hydes such as hexanal, (E)-2-octenal, and nonanal were produced as off-odours during storage. Although the overall quality of roasted Almonds produced with SIRHA and HA heating was similar during the first three months of storage, their peroxide value and concentration of aliphatic aldehydes differed signifi- cantly for different roasting methods and increased significantly in all roasted samples during storage. We postulate that hexanal and nonanal might be better indicators of the shelf life of roasted Almonds than the current standard, peroxide value.
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Review of Current Technologies for Reduction of Salmonella Populations on Almonds
Food and Bioprocess Technology, 2012Co-Authors: Zhongli Pan, Gokhan Bingol, Maria T Brandl, Tara Habig MchughAbstract:After the 2001 and 2004 Salmonellosis outbreaks that were associated with raw Almonds, ensuring the microbial safety of Almonds by treating them to achieve a minimum 4-log reduction of Salmonella population became mandatory in California, the world’s largest Almond producer. In this paper, we summarize potential pathways of microbial contamination during Almond production and manufacturing. Furthermore, we review sanitization technologies, including chemical, thermal, and non-thermal methods, as well as proprietary systems with regard to microbial and sensory quality of Almonds and compare various aspects of their use during Almond processing.
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migration of salmonella enteritidis phage type 30 through Almond hulls and shells
Journal of Food Protection, 2008Co-Authors: Michelle D Danyluk, Maria T Brandl, Linda J HarrisAbstract:The ability of Salmonella to migrate from an external aqueous environment through the Almond hull and shell, and to colonize the kernel, was evaluated in two ways. First, the outer surface of shell halves from five varieties of Almonds that differed in shell hardness were placed in contact with a suspension of Salmonella enterica serovar Enteritidis phage type 30 for 24hat24°C. Salmonella Enteritidis was isolated from the inside of these Almond shells in 46 and 100% of the samples, by direct swabbing of the inner surface of the shell and by enrichment from the swab, respectively. These findings suggested that hardness of the shell is not a significant factor in the migration of the pathogen through that tissue. In addition, both motile and nonmotile strains of S. enterica serovar Typhimurium migrated through the Almond shells to the same extent under the conditions of this assay, indicating that bacterial migration through the wet shell may be a passive process. Second, whole Almonds (intact hull, shell, ...
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migration of salmonella enteritidis phage type 30 through Almond hulls and shells
Journal of Food Protection, 2008Co-Authors: Michelle D Danyluk, Maria T Brandl, Linda J HarrisAbstract:The ability of Salmonella to migrate from an external aqueous environment through the Almond hull and shell, and to colonize the kernel, was evaluated in two ways. First, the outer surface of shell halves from five varieties of Almonds that differed in shell hardness were placed in contact with a suspension of Salmonella enterica serovar Enteritidis phage type 30 for 24 h at 24 degrees C. Salmonella Enteritidis was isolated from the inside of these Almond shells in 46 and 100% of the samples, by direct swabbing of the inner surface of the shell and by enrichment from the swab, respectively. These findings suggested that hardness of the shell is not a significant factor in the migration of the pathogen through that tissue. In addition, both motile and nonmotile strains of S. enterica serovar Typhimurium migrated through the Almond shells to the same extent under the conditions of this assay, indicating that bacterial migration through the wet shell may be a passive process. Second, whole Almonds (intact hull, shell, and kernel) were soaked for 24 to 72 h at 24 degrees C in a suspension of Salmonella Enteritidis phage type 30 labeled with the green fluorescent protein. Green fluorescent protein-labeled Salmonella cells were observed on the outer and inner surfaces of both the Almond hull and shell, and on the kernel, by confocal laser scanning microscopy. Our data provide direct evidence that wet conditions allow for Salmonella migration through the hull and shell and onto the Almond kernel, thus providing a means by which Almond kernels may become contaminated in the field.