| Abstract | Povećana potrošnja industrijski prerađenih proizvoda od avokada rezultira proizvodnjom velike količine nusproizvoda (kora, sjemenka). Kora avokada bogat je izvor fitokemikalija, minerala i pigmenata, a zbog visokog sadržaja vlage brzo se kvari. Sušenje predstavlja važan korak u valorizaciji ovog industrijskog nusproizvoda. Cilj ovog rada bio je ispitati učinak kondukcijskog vakuum sušenja pri različitim temperaturama (40, 60 i 80 °C) i tlakovima (10, 40 i 70 kPa) na fizikalna (boja, tekstura, nasipna gustoća) i kemijska (sadržaj ukupnih fenola, pigmenata i mineralnih elemenata) svojstva kore avokada sorte Hass. Prema dobivenim rezultatima, viša temperatura i tlak sušenja skraćuju vrijeme sušenja (80 °C i tlak 10 kPa). Sušenjem ne dolazi do značajne promjene boje, teksturnih svojstava i nasipne gustoće. Kora avokada sušena pri niskoj temperaturi i tlaku može biti dobar izvor fenola i pigmenata, iako se njihova koncentracija značajno smanjuje u odnosu na svježu koru avokada. Sušena kora avokada dobar je izvor mikroelemenata (Cu, Fe, Mn, Zn) i makroelemenata (Ca, K, Mg i Na) čija se koncentracija sušenjem značajno ne mijenja. Dobiveni rezultati ukazuju da se uz pravilan izbor uvjeta, vakuum sušenje može smatrati dobrom metodom za valorizaciju kore avokada, nusproizvoda industrije prerade avokada. |
| Abstract (english) | Increased consumption of industrially processed avocado products results in the production of a large quantity of by-products (peel, seed). Avocado peel is a rich source of phytochemicals, minerals, and pigments, but due to its high moisture content, it deteriorates rapidly. Drying is an important step in the valorization of this industrial by-product. The aim of this study was to investigate the effect of conduction vacuum drying at different temperatures (40, 60, and 80 °C) and pressures (10, 40, and 70 kPa) on the physical (color, texture, bulk density) and chemical (total phenolic content, pigments, and mineral elements) properties of Hass avocado peel. According to the results obtained, higher drying temperature and pressure shorten the drying time (80 °C and 10 kPa pressure). Drying does not significantly change the color, texture properties, and bulk density. Avocado peel dried at low temperature and pressure can be a good source of phenols and pigments, although their concentration significantly decreases compared to fresh avocado peel. Dried avocado peel is a good source of microelements (Zn, Cu, Fe, Mn) and macroelements (Ca, K, Mg, and Na) whose concentration does not significantly change during drying. The obtained results indicate that with the proper selection of drying conditions, vacuum drying can be considered a good method for valorizing avocado peel, a by-product of the avocado processing industry. |
