Impact of long-term storage on the quality of selected sugar-based foods stored at different temperatures

The aim of the presented study was to evaluate the microbiological, chemical, physical and organoleptic properties of sugar-based foods (apricot-apple jam, flower meadow honey, sweetened hazelnut cocoa spread) stored at four different temperatures (−18, 5, 23 and 40 °C) for a period of 24 months. In addition, critical combinations of storage temperature and time were determined for maintaining food quality and food safety. Storage of all samples ≤23 °C appeared to be safe from a microbiology perspective, while in the case of storage at 40 °C it was not recommended to exceed a storage period of 6 or 12 months. The pH-values decreased and the dry matter, ammonia, TBARS content increased most intensively during the first 6 months of storage (P < 0.05). The amino acid content of sweetened hazelnut cocoa spread decreased significantly at 40 °C (P < 0.05). With the prolonged storage time, the organoleptic properties of the samples deteriorated. The changes were more intensive when an elevated storage temperature was used (P < 0.05). Moreover, under the above-mentioned conditions a marginal decrease of the total saccharide content in all samples was observed. In addition, the apparent viscosity of the honey and the firmness of the jam increased significantly at elevated temperatures of 40 °C (P < 0.05).