Some additional reading
Some chocolate manufacturers have implemented a precautionary pasteurization step for all of the raw ingredients, such as chocolate liquor, coming into the chocolate production plant (Cordier, 1994). However, others appear to be moving in the opposite direction in response to the consumer's increasing interest in 'superfoods', such as 'raw' chocolate, which is characterized by its low-temperature thermal processing (Nieburg, 2019). In the absence of a roasting step, the ability of Salmonella to survive the subsequent conching and tempering steps in chocolate-making i) presents a public health concern and ii) suggests that other bacterial pathogens with increased thermotolerance in low aw environments such as L. monocytogenes may also be able to survive the process (Sumner et al., 1991; Tsai et al., 2019; van Asselt and Zwietering, 2006).
https://atrium.lib.u...ed=y&sequence=3
https://www.scienced...362028X22103844
We used Salmonella detection in dark chocolate as a model to test the impact of different enrichment times (minimum and maximum validated times) and procedures on detection of low levels of difficult-to-detect Salmonella strains, for three PCR kits that were AOAC International Performance Tested Method certified for detection of Salmonella spp. in dark chocolate. Initial inclusivity studies with pure cultures showed that all three kits detected 70 of 70 Salmonella spp. strains at 1 log above the theoretical limit of detection, with some strains yielding later cycle threshold values or having variable detection among technical replicates, indicating reduced assay performance for these strains. Based on these data, we selected a S. enterica subsp. enterica serovar Poona strain as well as three non-subsp. enterica strains to test the ability of the three kits to detect Salmonella in dark chocolate inoculated at low levels (0.06 to 1.18 most probable number per 25 g). With primary enrichment in skim milk at 35°C, detection frequency for all assays did not significantly differ from the reference method for both the minimum and maximum validated enrichment times. However, a pilot study that used primary enrichment in buffered peptone water at 42°C yielded significantly fewer positive samples (13 of 80) than were obtained with the U.S. Food and Drug Administration Bacteriological Analytical Manual method using enrichment in skim milk at 35°C (40 of 80 positive samples); strains representing subsp. houtenae and salamae were detected in significantly fewer chocolate samples than enrichment with skim milk. Our data indicate that continued efforts to simplify rapid pathogen detection kits may reduce kit performance in a way that can only be detected with stringent evaluation protocols that are designed to identify kit failure modes.
https://www.research...t_and_Chocolate