# Application of Ultrasound Homogenization in Milk Ice Cream Mixes
## 3 Results and Discussion
### The Analysis of Particle Sizes of Milk Ice Cream Mixes  
It is a generally accepted fact that a higher stability of the emulsion is connected with smaller sizes of particles, which may contribute to being homogenously distributed. Therefore, the particle sizes of the dispersed phase are pivotal in the stability parallel to [PERSON]'s law [28]. In the presented study, the particle sizes are expressed as median D\({}_{50}\) in Table 2, respectively, before and after maturation. The estimation of the median D\({}_{50}\) ranged from 22.97 to 39.72 \(\upmu\)m before the maturation. The lowest value of median D\({}_{50}\) was observed for the control sample after the mechanical homogenization (CH) whereas the highest score was noted for the sample after the ultrasound homogenization and with the addition of an enzymatic hydrolyzate of iota carrageenanan (LU) (Tables 1 and 2). Considering the influence of the sort of homogenization,in all samples after the mechanical homogenization, the median D\({}_{50}\) had the lowest values compared to in samples after the ultrasound homogenization. In accordance with the statistical analysis (Table 2), significant differences between samples were noticed (\(p<0.05\)). The range of D\({}_{50}\) was from 22.97 to 25.41 \(\upmu\)m for samples after the mechanical homogenization while for samples after the ultrasound treatment, it ranged from 28.92 to 39.78 \(\upmu\)m. Moreover, taking into account the sort of used stabilizers, the combination of mechanical homogenization with the addition of an enzymatic hydrolyzate of iota carrageenanan was the most effective of all added stabilizers (sample LH) (Tables 1 and 2). On the other hand, it can be seen that in all added stabilizers in the milk ice cream mixes, the combination with the traditional mechanical homogenization was more effective in decreasing the sizes of particles than ultrasound homogenization. In view of all the results and observations mentioned so far, it is vital to explain that during conventional, mechanical homogenization, the created turbulence in the medium and cavitation forces are generated by the high pressures. Therefore, the fat globules are disrupted and disintegrated, which leads to a reduction in their sizes [33]. The power of ultrasound by acoustic vibration results in the formation, growth, and collapse of air cavities. It leads to highly localized turbulence, which breaks up and disperses particles. Additionally, the ultrasound treatment besides disrupting particles can promote chemical reactions. This effect is strictly dependent on the intensity of ultrasound treatment [32; 34]. In the investigation into the particle sizes of the peanut protein-stabilized emulsions after the ultrasound treatment, [PERSON] et al. [35] observed that the sizes of particles decreased in comparison to the control sample without ultrasound treatment. Additionally, it was concluded that with the increasing time of ultrasound, the particle size decreased. This could have been explained in that the longer ultrasonic time means higher energy input. Therefore, oil droplets were broken into smaller ones with the increasing duration of ultrasound. In the same vein, [PERSON] et al. [31] proved that increasing the pressure amplitude might have led to intensive cavitation by increasing the number of bubbles generated by the pronounced breaking of liquid threads. The examination of emulsions that contain whey protein and stabilizers showed that a longer duration of ultrasound and a two-stage method (with changing the amplitude from 70 to 90% in the second stage) could have decreased the sizes of particles and narrowed droplet size distribution. Therefore, presumably, using the longer-time ultrasound may have been influenced by improving the effect on decreasing the sizes of particles. After the maturation, the median D\({}_{50}\) ranged from 18.63 to 39.75 \(\upmu\)m (Tables 1 and 2).