Application of ultrasonic waves for the improvement of particle dispersion in drinks
¹ South Ural State University, Higher Medical-Biological School, Department of Food and Biotechnologies, Lenin Ave 76, 454080 Chelyabinsk, Russia.
² ООVО IL Test-Puschino, 1g Gruzovaya Street, Puschino, Moscow Region 142290, Russia.
Dispersion is one of the most energy-costly processes in food production. Significant proportions of hard particles remain intact when traditional dispersion methods are used. The intensification of dispersion will lead to the more effective extraction of biologically active components from raw bulk. It will also expedite the ripening of products and will improve their consumer desirability. The goal of this research was to study the dispersing effect of low frequency ultrasound (US) on drinks which are of vegetable and animal origin (22 ± 0.6 kHz). The subjects of the research were raw cow’s milk, reconstituted milk, and cranberry drinks which had been produced with the use of traditional technology and employing ultrasonic power. An ultrasonic technological device with an umbrella-shaped working element was used as an ultrasound generator (Russian Federation patent No 2141386). A Nanotrac Ultra analyser (made by Microtrac Inc, USA) was used to study particle size, using the ISO 13321 standard. An analysis of particle size was based on the method which employs the dynamic dispersion of light, in which the minimal detectable particle size is 0.8 nm. It was found that the particles in raw cow’s milk, after ultrasonic processing at 180 W for dive minutes, decrease in size from 2,656 ± 72 nanometres to a prevailing particle size of 294.7 ± 24 nanometres. Following the US processing of reconstituted milk (with power at 180 W and action time at three minutes), the size of the particles decreases from 409.5 ± 62 nanometres to a prevailing particle size in the range of 202.2 ± 41 nanometres. With the cranberry drink, using ultrasound at 180 W for five minutes caused a decrease in particle size from 5,670 ± 62 nm to a prevailing size of 1,960 ± 42 nm. With an increase in ultrasound power and the duration of the application, an aggregation of particles was noted in both plant and animal-derived drinks. Therefore it can be seen that ultrasound can be used to regulate the dispersion processes in food manufacturing.