| Abstract | Cilj ovog rada bio je ispitati utjecaj ultrazvuka visokog intenziteta primjenom sondi različitih promjera na stabilnost sojinog mlijeka izražene pomoću indeksa stabilnosti emulzije (ISE)[h]. Istraživanje je provedeno uređajima maksimalne izlazne snage od 100 W i 400 W. Kod uređaja snage 100W, konstantne frekvencije 30 kHz korištene su sonde promjera 7, 10 i 14 milimetara pri slijedećim procesnim parametrima: amplituda (A = 20, 60, 100 %), vrijeme obrade (t = 2, 6, 10, 15 minuta) te primjenjeni ciklus: (c = 0,6; 0,8; 1). Istraživanje utjecaja uređaja snage 400 W, frekvencije 24 kHz te sondi promjera od 7 i 22 milimetra provedeno je pri procesnim parametrima: amplituda (A = 37,5; 50; 62,5; 75; 87,5; 100 %), vrijeme obrade: (t = 2, 6, 10, 15 minuta) te primjenjeni ciklus (c = 0,6; 0,8; 1). Praćen je utjecaj ultrazvuka na apsorbanciju, apsorbanciju nakon 24 sata te indeks stabilnosti emulzije koji je izračunat preko izmjerenih vrijednosti apsorbancije. Rezultati su statistički obrađeni u programu „Statistica 8“. Promjer sonde značajno utječe na sve promatrane vrijednosti. Kod intenziteta od 100 W povećanje promjera pokazuje utjecaj na smanjenje indeksa stabilnosti emulzije ISE [h], a kod 400 W na povećanje. |
| Abstract (english) | The purpose of this thesis was to examine the influence of high intensity ultrasound with different probe diameters on the stability of soy milk expressed by the emulsion stability index (ESI). The research was conducted with devices of maximum output power of 100 W and 400 W. With the device of power of 100 W at constant frequency of 30 kHz were used probes with diameters of 7, 10 and 14 millimetres under the following conditions: amplitude (A = 20, 60, 100 %); processing time (t = 2, 6, 10, 15 minutes); applied cycle (c = 0,6; 0,8; 1). The research of the influence of the device at power of 400 W and frequency of 24 kHz with probes of diameters of 7 and 22 millimetres was conducted under conditions: amplitude (A = 37,5; 50; 62,5; 75; 87,5; 100 %); processing time (t = 2, 6, 10, 15 minutes); applied cycle (c = 0,6; 0,8; 1). It was observed the influence of ultrasound on absorbance, absorbance after 24 hours and ESI that was calculated over measured values of absorbance. The results were statistically analyzed with the program "Statistica 8". Changes in probe diameter have significant influence on all observed values. With the device of power of 100 W the increase of diameter influences on decreasing ESI, while with power of 400 W on increasing. |
