Effects of temperature and packaging types on ergosterol and Howard mold count values of tomato paste during storage.

The objective of the present study was to investigate the effects of temperature and packaging on ergosterol and Howard mold count (HMC) changes of tomato paste during storage. The other purpose of this study was to determine whether the measurement of ergosterol stability in tomato paste can be useful for the assessment of microbiological quality of tomato paste as related to the storage temperature (4, 20, 28, or 37°C) and time. Ergosterol analysis was done by using high-performance liquid chromatography. Tomato paste samples were packaged in either aseptic bags or tin boxes and stored at 4, 20, 28, or 37°C for a period of 10 months. The detection limit of ergosterol was 0.1 mg/kg. Measurements showed that packaging and storage temperatures of 28 and 37°C have a considerable influence on ergosterol and HMC changes in the product. The poor precision of the "percentage of discarded fruits" and HMC methods has increased the importance of ergosterol for the microbiological quality evaluation of tomato and tomato products. This article reports the data from what we believe to be the first survey for the influence of storage temperature and packaging material on ergosterol and HMC changes of tomato paste during storage.