Ultrasonication and Its Manifold Applications in Food Processing
Power ultrasound offers manifold possibilities for effective and reliable food processing applications. The most common applications in the food industry include mixing & homogenization, emulsification, dispersing, cell disruption and extraction of intra-cellular material, activation or deactivation of enzymes (which is dependent on the ultrasound intensity), preservation, stabilization, dissolving and crystallization, hydrogenation, meat tenderization, maturation, aging and oxidation, as well as degassing and spray drying.
Find below a list of specific applications.
Please click on the applications of your interest to read more about them!
Extraction of Flavours and Active Compounds
Fermentation of Yoghurt
The ultrasonic homogenization effects the break of the milk fat globules and a very fine-size distribution.
Ultrasonication can accerlerate the fermentation rate (reduction of total production time of up to 40%) and improve the quality characteristics of yogurt, resulting in higher viscosity, stronger coagulum and superior texture.
Homogenization of Milk
The study of Sfakianakis and Tzia (2012) shows that ultrasonic homogenization reduces the size of milk fat globules (MFG). Low amplitude (150W) had not a satisfactory homogenization effect (Fig.2) ; the MFG size and their distribution were similar to untreated milk (compare fig. 1 and 2). Medium amplitude ultrasound (267.5, 375 W) had a good homogenization effect; MFG average diameter was 2 μm (Fig. 3, 4). Higher amplitude (750W) ultrasound reduced the MFG size crucially (Fig. 6), making them barely visible at the optical microscope (100x magnification); their average diameter size was 0.3 μm.
Chandrapala et al. (2012) investigated the effect of ultrasonication on casein and calcium. They applied ultrasonic waves (20kHz) to samples of fresh skim milk, reconstituted micellar casein, and casein powder. They sonicated the samples until the milk fat globules were reduced to approx. 10nm. The analysis of the sonicated milk shows that the size of the casein micelles is unchanged. A small increase in soluble whey protein and a corresponding decrease in viscosity also occurred within the first few minutes of sonication. The study was determined that casein micelles are stable during sonication and the soluble calcium concentration is not affected by the ultrasonic treatment. [Chandrapala et al. 2012]
Sugar Crystallization for Confectionery
The ultrasonic modification of crystallization is interesting for the formulation of candies, confectionery, spreads, ice cream, whipped cream and chocolate.
Hydrogenation of Edible Oils
Liquefaction of Honey
Click here to learn more!
Stabilization of Juices and Smoothies
Read here more about the ultrasonic improvement of juices & smoothies!
Ageing of Wine & Liquor
Click here to learn more about the possibilities of ultrasonic wine treatment!
The fermentation process of wine, must, beer and sake can be increased substantially, too. Acceleration rates of 50% to 65% have been achieved!
To get more information about the ultrasonically assisted fermentation, please click here!
Ice Cream Freezing
During the freezing process, crystals are formed from supercooled water. The morphology of the ice crystals plays an important role regarding the textural and physical properties of frozen and half-frozen food. As size and distribution of the ice crystals are of special importance for the quality of thawed tissue products, for ice cream, smaller ice crystals are preferred because large crystals results in an icy texture. Nucleation is the most important factor to control the crystal size distribution during crystallization. Thereby, the freeze rate is usually the parameter used for controlling size and size distribution of the ice crystals in ice cream. During the whipping and freezing, air is injected to achieve the smooth texture of ice cream. The so-called “over-run”, the amount of air injected, is proportionated – specifically to the particular recipe – proportionally to the combined volume of solids and water. So, the over-run varies due to the different ice cream formulations and the processing streams. Standard ice cream shows an over-run of 100%, which means that the final product consists of an equal volume of ice cream mix and air bubbles.
The use of Hielscher’s high power ultrasound devices provides a better quality of ice cream by reducing the ice crystal size and avoiding the incrustation of a freezing surface. A better consistency and a more creamy mouth feeling is achieved due to the reduced ice cream crystal size and the enhanced air bubble distribution. Significantly shorter freezing times lead to a higher process capacity and a more energy-efficient production process.
Aeration of Batter
Ultrasound is an alternative technique to break the sugar crystals in chocolate and provides thereby similar effects as conching.
Tenderization of Meat
Sonication in the Kitchen
Click here, if you are interested in the recipe of his famous ultrasonic shrimp stock!
- Chandrapala, Jayani et al. (2012): The effect of ultrasound on casein micelle integrity. Journal of Dairy Science 95/12, 2012. 6882-6890.
- Chandrapala, Jayani et al. (2011): Effects of ultrasound on the thermal and structural characteristics of proteins in reconstituted whey protein concentrate. Ultrasonics Sonochemistry 18/5, 2011. 951-957.
- Dairy Processing Handbook. Published by Tetra Pak Processing Systems AB, S-221 86 Lund, Sweden. 387.
- Feng, Hao; Barbosa-Cánovas, Gustavo V.; Weiss, Jochen (2010): Ultrasound Technologies for Food and Bioprocessing. New York: Springer, 2010.
- Huang, B. X.; Zhou, W. B. (2009): Ultrasound Aided Yogurt Fermentation with Probiotics. NUROP Congress, Singapore, 2009.
- Keshava Prakash, M. N.; Ramana, K. V. R. (2003): Ultrasound and Its Application in the Food Industry. J. Food Sci Technol. 40/6, 2003. 563-570.
- Mortazavi, A.; Tabatabaie, F. (2008): Study of Ice Cream Freezing Process after Treatment with Ultrasound. World Applied Science Journal 4, 2008. 188-190.
- Petzold, G. and Aguilera, J. M. (2009): Ice Morphology: Fundamentals and Technological Applications in Foods. Food Biophysics Vol.4, No. 4, 378-396.
- Sfakianakis, Panagiotis; Tzia, Constantina (2011): Yogurt from ultrasound treated milk: monitoring of fermentation process and evaluation of product quality characteristics. ICEF 2011.