A quantitative risk assessment of Bacillus cereus in tofu treated with carbon quantum dots derived from tangerine...

Carbon quantum dots (CQDs) were synthesized using a one-step hydrothermal process developed in our previous study. The novelty of this study lies in being the first to estimate the effect of CQDs on reducing foodborne diarrheal illness from Bacillus cereus after consuming retail packaged tofu. The research objectives were 1) to prepare sustainable CQDs from tangerine peels and 2) to use a quantitative microbial risk assessment (QMRA) approach to evaluate the effect of CQDs on the microbial risk of illness from B. cereus in packaged tofu. Growth and survival secondary models were developed for B. cereus grown on tofu in water with and without CQDs and were used for QMRA evaluation. Monte Carlo simulation was used to evaluate the probability risks by combining exposure assessment data, consumption data, and the minimum infective B. cereus dose. The final probability of the risk of diarrheal B. cereus foodborne illness by consumption of tofu was significantly different at 2.58 × 10^-5 for the control group (19/100,000 total cases) and 0 in the CQD group (0/100,000 total cases). Sensitivity analysis showed that the infectivity of the control retail tofu was influenced by all external factors except the time for transportation and the amount consumed. In contrast, the CQD-treated tofu was not affected by any external factors. Therefore, the application of CQDs as a water solution shows a high potential for reducing microbial risk of foodborne illness from tofu consumption.