Effects of cinnamaldehyde on the germination and growth of Bacillus cereus spores in ready-to-eat boiled ground beef

Abstract

The study quantitatively described the effects of cinnamaldehyde on the germination and growth of Bacillus cereus spores in boiled ready-to-eat ground beef. With the combination of the concentrations of cinnamaldehyde 0, 0.1, 0.5, and 1.0% vol/wt at temperatures 12, 20, 28, and 36°C, the Huang model was successfully used as the primary model to predict the lag time (λ) and maximum growth rate (µmax). Thereafter, the cubic polynomial models were used to estimate the values of Ln λ and Ln µmax considering both the storage temperature and cinnamaldehyde concentration. The models were highly accurate, because they produced acceptable root mean squared error (RMSE) values that were close to 0, while the determination (R2), accuracy factor (Af), and bias factor (Bf) values were all close to 1. As indicated by the fitted models, the supplementary of cinnamaldehyde in samples increased the lag time of B. cereus significantly from 17.7 to 75.8 h at 12°C of storage. Increasing the storage temperature from 12 to 36°C led to only 0.80-fold prolongation of lag time from 1.6 to 2.9 h in the sample containing cinnamaldehyde. However, the µmax value declined most obviously at 20°C, while 66% decrease was determined. According to the results, the cinnamaldehyde can be used as a natural antimicrobial agent in boiled ready-to-eat ground beef in staple food industry by inhibiting the germination and growth of B. cereus. The results also provided regressing models that can be used for effectively designing the storage temperature and cinnamaldehyde concentration for a specific requirement.