The effect of thyme and elderflower extract addition on the properties and shelf life of fresh cheese from raw milk

Trajnost svježeg sira proizvedenog od sirovog mlijeka je vrlo kratka i može se reći da je riječ o dnevnom proizvodu. Stoga je cilj ovog rada bio ispitati hoće li se dodatkom vodenih ekstrakata majčine dušice i cvjetova bazge produljiti trajnost svježeg sira. Svježi sir je proizveden od sirovog mlijeka iz mljekomata, a fizikalno-kemijska, mikrobiološka i senzorska analiza su provedene određene dane čuvanja. Vodeni ekstrakti majčine dušice i cvjetova bazge su dobiveni visokotlačnom tekućinskom ekstrakcijom (eng. Pressurized Liquid Extraction, PLE) pri temperaturi od 160 °C, statičkom vremenu od 5 minuta kroz 3 ciklusa, a u mlijeko su dodani u koncentraciji od 2 % i 5 % (v/v). Na temelju mikrobiološke i senzorske analize, može se zaključiti kako su najbolji rezultati postignuti kod svježeg sira s 2 %-tnim dodatkom ekstrakta majčine dušice.The shelf life of fresh cheese produced from raw milk is very short and it can be said that it is a daily product. Therefore, the aim of this thesis was to examine whether the addition of water extract of thyme and elderflower will extend the shelf life of fresh cheese. Fresh cheese was produced from raw milk purchased at vending machines, and physico-chemical, microbiological and sensory analysis were determined for certain storage days. The water extracts of thyme and elderflower were produced by pressurized liquid extraction (PLE) at the temperature of 160 °C, static time of 5 minutes over 3 cycles and were added in milk at the concentration of 2 % and 5 % (v/v). Based on microbiological and sensory analysis, it can be concluded that the best results were achieved by adding of thyme extract in the fresh cheese in the quantity of 2 %