Influence of ultrasound frequency and power on lactose nucleation

Abstract

This work was aimed at studying the effect of different ultrasound frequencies (20, 44, 98, 142 kHz) and ultrasound powers (10, 20, 30 W) on lactose nucleation. For this purpose, lactose solutions (25% w/v) with traces of whey proteins (0.3%) were sonicated 300 s. Crystallization was induced by reducing the temperature from 30 to 15 °C, which increased the absolute supersaturation of lactose (Cα-Cαs) from 0.19 to 8.25 g 100 g−1. The nucleation of lactose was monitored by light scattering. Results showed that application of ultrasound (US) modified both, the molecular-attachment frequency to form new nuclei (k) and the induction time. The ultrasound effect on lactose nucleation varied dependi..