Evaluation of the Effects of Thermal Treatment on the Microbiological Quality of Passiflora cincinnata (Wild Passion Fruit) Flour

The aim of this study was to evaluate the effectiveness of thermal treatment in reducing the microbial load of wild passion fruit (Passiflora cincinnata) peel flour, aiming for its safe use as a food ingredient. Peels were sanitized with a 200 ppm chlorine solution for 15 min, dried at 55 °C, and ground; however, microbial counts remained above acceptable limits. A preliminary test at 65 °C confirmed the absence of contamination exceeding legal thresholds, and the flour was subsequently thermally treated at 65 °C for 24 h. Microbiological analyses were conducted for molds, yeasts, Escherichia coli, Bacillus cereus, and Salmonella. Fungal counts were log₁₀-transformed and statistically analyzed using analysis of variance and Tukey’s test (p < .05). Results showed a significant reduction in fungal load after thermal treatment, with Bacillus, E. coli, and Salmonella absent or below detectable limits. Enterobacter/Klebsiella group microorganisms were detected in raw peels and 55 °C dried flour, indicating contamination of the raw material. Thermal treatment at 65 °C reduced microbial loads to levels compliant with current Brazilian regulatory legislation. The study emphasizes the importance of validating thermal processes to ensure the microbiological safety of flours and recommends further research on the preservation of nutritional and bioactive compounds under these conditions.