Interfacial and foaming properties modifications of soy protein isolate by high ultrasound intensity

MORALES, ROCIO; MARTINEZ, KARINA D; PIZONES RUIZ-HENESTROSA, VICTOR ; PILOSOF, ANA

Cordoba

Congreso; IV Congreso Internacional de Ciencia y Tecnologia de los Alimentos; 2012

Ministerio de Ciencia y Tecnología de la Provincia de Córdoba

ABSTRACT The objective of this work was to explore the impact of high intensity ultrasound (HIUS) on the functionality of a denatured soy protein isolate sample (SPI) on foaming and interfacial properties. 6% w/w solutions at pH 6.9 were treated with HIUS for 20 min, in an ultrasonic processor at room and 75, 80 and 85°C of temperature. The operating conditions were: 20 kHz, 4.27 ± 0.71 W and 20% of amplitude. Before and after the HIUS treatment, the size of protein particles was measured by dynamic light scattering. Foaming by whipping method and interfacial measurement with an automated KSV Langmuir mini-trough were performed. The HIUS treatment improved the foaming capacity whereas stability was not modified significantly. The temperature treatment together with ultrasound (70 and 85ºC) showed a synergistic result on foaming capacity. The foaming capacity increase exhibited a good correlation with the particle size average decrease of SPI sample. While, the invariable stability of foams obtained was related to interfacial studies through elasticity results of films observed after treatments. Therefore, this technique is highly recommended to enhance the foaming properties by particle size control.