Avaliação da redução do tempo no processo térmico e da temperatura interna de presunto cozido com manutenção da segurança microbiológica no produto final

Abstract

In recent years, the consumption of pork and ready-to-eat meat products has witnessed significant growth in Brazil. Within the cooked meat product manufacturing industry, there is a constant pursuit of alternatives to minimize processing time, aiming to enhance productivity and profitability on the production line. For cooked meat products like ham, studies have confirmed that a cooking temperature of 68 °C to 70 °C at the product's center ensures microbiological safety. The effectiveness of the thermal treatment applied to the product is assessed based on the thermal lethality of the process for a target microorganism. Among microorganisms, Listeria monocytogenes survives in adverse environmental conditions longer than other foodborne pathogens. This study aimed to evaluate the influence of reducing the internal temperature of cooked ham and the processing time on the microbiological safety of the final product. The experiment was conducted using a randomized block design, organized in a 7x2 factorial scheme as follows: (7) cooling tanks and (2) internal ham temperature (71 °C and 68 °C), resulting in 14 evaluated samples, utilizing a temperature sensor (ibbuton). One sample from each tank for 71°C and one sample from each tank for 68 °C were microbiologically assessed, totaling 14 samples. Official references were employed as the methodology for microbiological analyses, carried out in the company's in-house laboratory, where the analysis results complied with legal requirements. Additionally, the number of logarithmic reductions for the target microorganism, L. monocytogenes, was determined following the thermal treatment of the product. In the cooking process with a target internal temperature of 71 °C, tank number 7 reached the standard temperature in the shortest time, 236 minutes, while tank number 3 took 253 minutes to reach the final temperature of 71 °C, which was the longest time among all tanks. Both tank number 7 and tank number 3 reached a final temperature of 78.4 °C. The average cooking time for the seven tanks was 243 minutes. The average accumulated F-value per tank was 33.74, and the maximum number of logarithmic reductions achieved in the tanks was 114.46, with this value attained in the tank with the longest cooking time. When comparing the two combinations of time and temperature, a temperature variation of 3 °C (from 68 °C to 71 °C) and an average time reduction of 25 minutes was obtained, representing an average reduction of N = 56.75 (102.25 – 45.50) across the seven cooking tanks. In conclusion, the thermal process applied with a temperature of 68 °C at the geometric center of the cooked ham ensured the microbiological safety of the final product when evaluated with the target microorganism, Listeria monocytogenes, having an average reduction in cooking time of 17.86 minutes.