STORAGE IMPACT ON THE QUALITY OF RASPBERRY AND PEACH JAMS

Abstract The aim of this study is to evaluate the quality properties of raspberry and peach jams during storage. Jams were prepared with a reduced amount of sucrose, citric acid and low-estrified pectin with the addition of calcium ions in the form of calcium citrate. Physico-chemical parameters, such as total dry matter, soluble solids, sugars, total acids, pH, vitamin C, fats, proteins and ash after storage of 15 and 90 days were tested. The jams were exposed to microbiological analysis also. Results showed that the values of ash, fats and vitamin C were not changed regardless the storage period of the analysed raspberry and peach jams. The period of storage increased the values of total dry matter from 44.97% to 45.86%, soluble solids from 40.17 °Brix to 41.5 °Brix and total acids from 1.47% to 1.49% in raspberry jam. In peach jam these results changed from 42% to 44.1%, from 41.92 °Brix to 42.9 °Brix, and from 0.92% to 0.97% respectively. Microbiological examinations indicate that jams are microbiologically proper according to standards. From the overall results it can be concluded that the storage period has effect on the prepared raspberry and peach jams, but their quality remains good and has maximum consumer acceptance