The effect of ultrasound treatment on characteristics of set yoghurt made from goat milk during storage

Abstract

Possibility treatment of ultrasound appliance in the production of goat milk's set yoghurt was investigated. Before inoculation milk was subjected to ultrasound treatment at the frequency of 35 kHz and 200 W powers during 5 and 10 minutes. As control, samples of goat milk's set yoghurt were produced by conventional treatment. Viscosity and physicochemical properties of produced samples were investigated on the 1st, 7th, 14th and 21st day of storage. Based on analysis of the collected data, samples made from goat milk treated by ultrasound during 5 minutes had the highest viscosity, water holding capacity and the least syneresis.

U radu je ispitivana mogućnost primene ultrazvučnog tretmana u proizvodnji čvrstog jogurta od kozijeg mleka. Mleko je pre inokulacije starter kulturom tretirano ultrazvukom frekvencije 35 kHz i snage 200 W u trajanju od 5 i 10 minuta. Kao kontrolni proizvedeni su uzorci čvrstog jogurta od kozijeg mleka standardnim tehnološkim postupkom. Ispitivanje viskoziteta i fizičko-hemijskih karakteristika proizvedenih uzoraka jogurta vršeno je 1, 7, 14 i 21- og dana skladištenja. Na osnovu dobijenih rezultata utvrđeno je da su najveće vrednosti viskoziteta, sposobnost vezivanja vode i najmanju sklonost ka sinerezisu, imali uzorci čvrstog jogurta proizvedeni od kozijeg mleka koje je tretirano ultrazvukom u trajanju od 5 minuta.