Dehydration of plant-based foods at moderate temperatures (≤60 °C) represents a growing interest in minimal processing. An article published in Foods 2021, 10(9), 2162 describes the effect of moderate-temperature (≤60 °C) dehydration of plant-based foods on pathogen inactivation. A model was created to reduce E. coli O157:H7 as a function of product-matrix, aw, and temperature under isothermal conditions. Apple, kale, and tofu were adjusted to aw 0.90, 0.95, or 0.99 and inoculated with an E. coli O157:H7 cocktail, followed by isothermal treatment at 49, 54.5, or 60.0 °C. Minimal microbial reductions, and in the case of tofu, initial growth, were achieved under dynamic drying conditions at 60 °C, indicating that moderate temperature dehydration does not provide an effective thermal inactivation treatment. While the isothermal data suggested that significant E. coli O157:H7 inactivation could be achieved, the model is only appropriately applied when the temperature is between 49 and 60 °C and when the aw is ≥ 0.90. Under dynamic dehydration treatments at 60 °C, these two conditions were never achieved simultaneously. Given the minimal lethality, additional treatments such as an initial acid wash, equipment modification to enhance thermal distribution and penetration, or an increase in the processing temperature may be necessary if a 5 log CFU/g reduction is targeted. @ https://www.mdpi.com/2304-8158/10/9/2162/htm
The effect of moderate-temperature (≤60 °C) dehydration of plant-based foods on pathogen inactivation is unknown. Here, we model the reduction of E. coli O157:H7 as a function of product-matrix, aw, and temperature under isothermal conditions. Apple, kale, and tofu were each adjusted to aw 0.90, 0.95, or 0.99 and inoculated with an E. coli O157:H7 cocktail, followed by isothermal treatment at 49, 54.5, or 60.0 °C. The decimal reduction time, or D-value, is the time required at a given temperature to achieve a 1 log reduction in the target microorganism. Modified Bigelow-type models were developed to determine D-values which varied by product type and aw level, ranging from 3.0–6.7, 19.3–55.3, and 45.9–257.4 min. The relative impact of aw was product dependent and appeared to have a non-linear impact on D-values. The root mean squared errors of the isothermal-based models ranged from 0.75 to 1.54 log CFU/g. Second, we performed dynamic drying experiments. While the isothermal results suggested significant microbial inactivation might be achieved, the dehydrator studies showed that the combination of low product temperature and decreasing aw in the pilot-scale system provided minimal inactivation. Pilot-scale drying at 60 °C only achieved reductions of 3.1 ± 0.8 log in kale and 0.67 ± 0.66 log in apple after 8 h, and 0.69 ± 0.67 log in tofu after 24 h. This illustrates the potential limitations of dehydration at ≤60 °C as a microbial kill step.
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The USDA/FSIS reported that Espi’s Sausage and Tocino Co (Seattle, WA) recalled approximately 2,048 pounds of frozen ready-to-eat chicken and pork hot dog products that may be adulterated with Listeria monocytogenes. The frozen ready-to-eat chicken and pork hot dog product in 12-oz vacuum-packed plastic packages was produced on May 19, 2021. These items were shipped to a distributor in California and further distributed to retail locations. FSIS discovered the problem during an assessment of the establishment’s sampling records that indicated the firm received confirmation from their third-party lab that a product contact surface had returned positive for Listeria monocytogenes. There have been no confirmed reports of adverse reactions due to the consumption of these products. @ https://www.fsis.usda.gov/recalls-alerts/espis-sausage-and-tocino-co.-recalls-ready-eat-chicken-and-pork-hot-dog-products-due
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According to the CFIA, Unisoya Inc. (Saint-Isidore-De-Laprairie, Quebec) has recalled from the Canadian marketplace Unisoya branded Organic Tofu Fine Herbs Flavour from the Canadian marketplace due to suspected Listeria monocytogenes contamination. Unisoya branded Organic Tofu – Fine Herbs Flavour was sold in 454 gram (one pound) vacuum packages with a best-before date code of 21OC04. These Organic Tofu products were distributed and sold in the Canadian province of Quebec. There have been no reported illnesses associated with the consumption of this product. @ https://healthycanadians.gc.ca/recall-alert-rappel-avis/inspection/2021/76505r-eng.php
Unisoya (1986) Inc. is recalling Unisoya brand Organic Tofu – Fine Herbs from the marketplace due to possible Listeria monocytogenes contamination.
The CDC continues to investigate a multistate outbreak of Salmonella Oranienburg infections. The update of September 24 indicates that there are 279 ill people in 29 states. While the investigation has not yet identified a food linked to illness, the outbreak strain of Salmonella Oranienburg was found in a sample taken from a takeout condiment cup containing cilantro and lime. The sick person reported that the condiment container also contained onions, but none were left in the cup when it was tested. However, cilantro seems like the most likely source of the contamination. The actual number of sick people in an outbreak is likely much higher than the number reported, and the outbreak may not be limited to the states with known illnesses. This is because many people recover without medical care and are not tested for Salmonella. @ https://www.cdc.gov/salmonella/oranienburg-09-21/details.html
Get the most up-to-date outbreak information here.