engleski

Microbiological quality assessment of rose hip nectars treated with high voltage electrical discharge during refrigerated storage

Conventional thermal processing technology for pasteurization of nectars ensuring microbiological safety and enzyme inactivation, but causes several physical and chemical changes and decreases the bioavailability of some nutrients. Therefore, an increasing effort has been made in applying novel technologies to preserve the sensory, nutritional and functional properties while providing safe products. High voltage electrical discharge (HVED) is one of such novel non-thermal processing technologies. This study aimed to investigate the microbiological quality of rose hip nectars treated with HVED (100 Hz, 20 minutes) during storage. Microbiological quality assessment of untreated, HVED treated nectars (prepared with/out purée blanching, low-calorie nectar), as well as pasteurised nectar, was performed on 0, 6 and day 12 of storage at 4 °C. Microbiological analysis was applied to determine the conformity of the samples according to the valid microbiological criteria. Aerobic mesophilic bacteria, Enterobacteriaceae and Escherichia coli count in all samples during 12 days were below the permitted levels for fresh fruits and vegetable juices. Salmonella spp. and Listeria monocytogenes were not detected in any of the samples. The total yeasts and moulds population level in the samples was above the regulatory limits, except for the pasteurised and nectar produced from blanched purée.

rose hip ; nectar ; HVED ; microbiological quality

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