This study aims to reduce the incubation period (commercial sterility test) of tomato paste cans before the bacteriological inspection in quality control laboratories. 62 cans of tomato paste were incubated under temperatures (mesophilic 25,37°C and thermophilic 55°C) to accelerate potential spoilage. Chemical indicators(pH, titratable acidity, and lactic acid) and microbial indicators (Total plate count and yeast/molds) were monitored daily to identify the earliest reliable spoilage signals. Incubation at elevated temperatures accelerated acid buildup. D+L lactic acid levels measured using a rapid enzyme assay increased with titratable acidity, while pH decreased. Meanwhile, total platelet counts remained at very low levels, while yeasts and molds were undetectable. Significant spoilage indicators appeared within 3–5 days at 55°C compared to 7–10 days at 37°C. These results indicate that acidification may be detectable within 5-6 days of incubation at 37°C. However, microbial growth was not consistently identified. We recommend an improved incubation procedure before culture, together with quick lactic acid measurement, to provide an early warning for microbial deterioration in tomato paste.
Shaghati et al. (Wed,) studied this question.