Effect of drying parameters on physiochemical and sensory properties of fruit powders processed by PGSS-, vacuum- and spray-drying

Aim of this experimental work was to investigate the possibility of producing fruit powders without employing drying aid and to investigate the effect of drying temperature on the final powder characteristics. Raw fruit materials (banana puree, strawberry puree and blueberry concentrate) were processed using three different drying techniques each opera- ting at different temperature conditions: vacuum-drying (–27–17 °C), spray-drying (130–160 °C) and PGSS-drying (112–152 °C). Moisture content, total colour difference, antioxidant activity and sensory characteristics of the proces- sed fruit powders were analysed. The results obtained from the experimental work indicate that investigated fruit pow- ders without or with minimal addition of maltodextrin can be produced. Additionally, it was observed that an increase in process temperature results in a higher loss of colour, reduced antioxidant activity and intensity of the flavour profile.Raziskovalno delo je zajemalo proučitev možnosti upraševanja sadnih pripravkov brez uporabe sušilnih sredstev ter raziskati vpliv procesne temperature na kvaliteto uprašenih sadnih pripravkov. Sadne pripravke (bananin in jagodni pire ter koncentrat borovnice) smo procesirali z uporabo vakuumskega sušenja pri temperaturi –27–17 °C, sušenja z razprševanjem pri temperaturi 130–16 °C ter z uporabo postopka za pridobivanje delcev iz raztopin nasičenih s plinom v temperaturnem območju 112–152 °C. Dobljenim praškastim produktom smo določili vsebnost vode, razliko v barvi ter vsebnost antioksidantov. Ugotovili smo, da je s predlaganimi postopki možno pripraviti sadje v prahu brez oziroma z minimalnim dodatkom maltodekstrina. Dodatno smo opazili, da temperatura procesiranja vpliva na kvaliteto končnega produkta in sicer višja temperatura negativno vpliva na obstojnost barve, antioksidativih lastnosti ter organoleptičnih značilnosti sadnih pripravkov