Comparison of the effect of ultraviolet light, ozone and heat treatment on muesli quality
Felici LLC, Rigas gatve 8, LV-2164, Adazi, Adazu novads, Latvia
Various muesli processing technologies can be used to lower microbiological parameters. It is necessary to find the best treatment technology to ensure that the product can meet various regulatory limits and to increase the shelf life of the product. The aim of this study was to compare the effect of ultraviolet light, ozone treatment and sterilisation on muesli quality. Muesli samples with dried fruits were tested, comparing the change in total plate count, yeast count and mould count. Short-wave ultraviolet (UV-C) light with a wavelength of 254 nm was used for ultraviolet light treatment, and the product was treated for 1, 2, and 5 minutes. As for ozone treatment, the samples were treated with an ozone concentration of 35 ppm for 30 minutes. Heat sterilisation was performed using sterilisation mode 25-30-50 (heating, holding, cooling), 119 °C, 2.2×105 Pa. Ultraviolet light and ozone treatment did not have a significant impact on total plate count, yeast count and mould count. Heat sterilisation had the most significant effect on muesli sample microorganism level, total plate count, yeast count and mould count level were 10 log cfu g-1.