Ultrasonic processing of dairy systems in large scale reactors

Abstract

High intensity low frequency ultrasound was used to process dairy ingredients to improve functional properties. Based on a number of lab-scale experiments, several experimental parameters were optimised for processing large volumes of whey and casein-based dairy systems in pilot scale ultrasonic reactors. A continuous sonication process at 20 kHz capable of delivering up to 4 kW of power with a flow-through reactor design was used to treat dairy ingredients at flow rates ranging from 200 to 6000 mL/min. Dairy ingredients treated by ultrasound included reconstituted whey protein concentrate (WPC), whey protein and milk protein retentates and calcium caseinate. The sonication of solutions with a contact time of less than 1 min and up to 2.4 min led to a significant reduction in the viscosity of materials containing 18% to 54% (w/w) solids. The viscosity of aqueous dairy ingredients treated with ultrasound was reduced by between 6% and 50% depending greatly on the composition, processing history, acoustic power and contact time. A notable improvement in the gel strength of sonicated and heat coagulated dairy systems was also observed. When sonication was combined with a pre-heat treatment of 80 degrees C for 1 min or 85 degrees C for 30s, the heat stability of the dairy ingredients containing whey proteins was significantly improved. The effect of sonication was attributed mainly to physical forces generated through acoustic cavitation as supported by particle size reduction in response to sonication. As a result, the gelling properties and heat stability aspects of sonicated dairy ingredients were maintained after spray drying and reconstitution. Overall, the sonication procedure for processing dairy systems may be used to improve process efficiency, improve throughput and develop value added ingredients with the potential to deliver economical benefits to the dairy industry.

Spiral computed tomography evaluation of rabbit VX2 hepatic tumors treated with 20 kHz ultrasound and microbubbles

“…The application of low-frequency (20 kHz) US has been demonstrated to be useful for increasing the efficiency and consumer safety in food processing (2), removing heavy metal (lead, mercury and arsenic) contamination in milk (3), decreasing the viscosity and particle size of milk (4) and improving the functional properties of dairy ingredients (5). US at a frequency of 20 kHz has been used to degrade the antibiotic ofloxacin in water (6).…”

Thermosonication as an Upcoming Technology in the Dairy Industry: An Overview

“…Yogurts made from thermosonicated milk were found to have improved consistency, texture, gel strength, viscosity and water holding capacity compared to yogurts prepared from pasteurized milk, also a drop in fermentation time of around 40% was seen [18,19]. The heat stability and gelling properties of whey proteins was improved when sonication was combined with heat treatment [20]. One of the concerns in using ultrasound in dairy is: ultrasound processing of milk may lead to the formation of volatiles due to lipid oxidation in milk.…”

Research of Sonochemistry of the Dairy Systems to Improve the Properties of Milk Semis

“…3), developed in the homeland of one of the first researchers the mechanical disintegration in rotary apparatus of Dr. J. Hint [16] as well as the sonochemical reactor For example, an industrial processor UIP4000 company Hielscher Systems GmbH [17]. This requires uploads dried whole or skim milk or whey powder or dry milk protein concentrate According to patent application WO 2007111524.…”