| Abstract | Uzorci pulpe i kore Hokkaido bundeve su sušeni u vakuumu (T = 60 °C i p = 100 mbar) sa ili bezpredobrade ultrazvukom, amplitudama 60 ili 90 % tijekom 15, 30 i 45 minuta, a potom im je određen kemijski sastav primjenom gravimetrijske i spektrofotometrijske analize. Rezultati su pokazali da predtretman od 30 minuta najviše snizi udio vlage uzoraka pulpe pri amplitudi 90 % (13,97 %), odnosno uzoraka kore pri 60 % amplitude (6,53 %). Amplituda od 60 % i vrijeme od 30 minuta povećavaju udio pepela u pulpi (7,28 %) tj., kori (9,62 %). Najviši udio šećera u pulpi (43.74 %), odnosno kori (16,80 %) dobiven je pri 90 % amplitudi i vremenu od 30, odnosno 15 minuta. Amplituda od 90 %, odnosno 60 % pri 30 minuta daje najviše udjele proteina: 23,94 % (pulpa), odnosno 45,89 % (kora). Predtretman efikasno povećava prinos analiziranih sastojaka, no parametri obrade ne mogu se primjenjivati jednako za sve analite.Prilagođavanjem uvjeta predobrade može se utjecati na količinu pojedinog sastojka čime se dobiva i namirnica raznolike nutritivne vrijednosti. |
| Abstract (english) | Samples of Hokkaido pumpkin pulp and peel were vacuum dried (T = 60 °C and p = 100 mbar) with or without ultrasonic pretreatment at amplitudes of 60 or 90 % and times of 15, 30 and 45 minutes, then the chemical composition of the samples was determined by gravimetric and spectrophotometric methods. The results showed that the 30-minute pretreatment caused the greatest reduction in moisture content in the pulp samples at 90 % amplitude (13.97 %) and in the peel samples at 60 % amplitude (6.53 %). The 60 and 90 % amplitude and the duration of 30 minutes increased the ash content in the pulp (7.28 %) and peel (9.62 %) samples. The highest sugar content in the pulp (43.74 %) and in the peel samples (16.80 %) was achieved with a 90 % amplitude and a time of 30 and 15 minutes, respectively. The amplitude of 90 % and 60 % at 30 minutes results in the highest content of protein: 23.94 % (pulp) and 45.89 % (peel). Ultrasonic pretreatment effectively increases the yield of analysed components, but the processing parameters cannot be applied equally to all analytes. Manipulation of ultrasonic pretreatment conditions can affect the amount of an individual ingredient, ultimately resulting in foods with different nutritional value. |
