Comparative shelf-life study in dehydrated plums: Use of potassium sorbate and its effect on microbial spoilage

Potassium sorbate is a preservative used to avoid microbial spoilage in dehydrated plums (prunes) during long travel distances and, therefore, improve the shelf life of prunes. In this study, prunes with and without sorbate were stored for 12 months at 4, 16, 20 and 37 °C. The physiological and biochemical indexes were measured and recorded monthly throughout the experimental period. The potassium sorbate was drastically desorbed from the fruit during the first months of the study. The results showed that 37 °C significantly affected the prunes quality, increasing the firmness and diminishing the moisture. While the other temperatures did not affect the quality of prunes. On the other hand, no significant differences were observed in the presence of mould and yeast for prunes with and without potassium sorbate independent of the storage temperature. Storage from 4 to 20 °C did not greatly affect the quality of the fruit stored for 12 months. However, storage at 37 °C significantly affected the quality of the prunes, mainly in terms of firmness.