# Key Factors Influencing Bacillus cereus Contamination in Hot Ready-to-Eat Meal Delivery

## TL;DR

This study examines how meal types and packaging affect the risk of Bacillus cereus contamination during hot meal delivery.

## Contribution

The study identifies packaging materials as key factors influencing bacterial growth during food delivery.

## Key findings

- PP trays and PP boxes delayed temperature decrease, reducing B. cereus growth risk.
- Bacillus cereus counts remained below unsafe levels after four hours of simulated delivery.
- Meal type had no significant effect on temperature decrease or bacterial growth.

## Abstract

With increasing popularity of food delivery services, the microbial safety of transported meals should be ensured. An effect of the type of a meal (cooked rice; mashed potatoes; mushroom sauce), inner primary packaging (sugarcane bagasse [SB] tray; polypropylene [PP] tray), secondary container (polyester/polyethylene foam/aluminum foil [PPA] bag; PP box) on the time interval of the internal hot ready-to-eat (RTE) meal temperature decrease to the value critical for Bacillus cereus growth (40 °C) was tested during a simulated delivery; in aliquot samples of the same meals, B. cereus growth was quantified presuming a natural contamination of the meals. Type of a meal had no effect on the tested time interval (p > 0.05). Packaging a meal in the PP tray as compared to the SB tray and inserting primary trays into the PP box instead of PPA bag delayed (p < 0.05) the internal meal temperature decrease by 50 and 15 min, respectively. Average B. cereus counts in the naturally contaminated meals after the four-hour culturing at 40 °C was 2.99 log CFU·g−1. It was concluded that a hot RTE meal delivered up to four hours under the tested conditions is not likely to facilitate B. cereus growth above unacceptable levels.