Influence of operating conditions on residence time distributions in a scraped surface heat exchanger during aerated sorbet production

Estimation of Ice Cream Mixture Viscosity during Batch Crystallization in a Scraped Surface Heat Exchanger

“…In addition, the results at temperatures of 0, −1, and −2 °C ( Figure 6) show that the apparent viscosity of the mixture is dependent on the shear rate, this being a typical characteristic of a non-Newtonian fluid. This dynamic crystallization process is similar to that described by several authors, who have studied ice cream crystallization in SSHE [2,7,10,13,15,25,[27][28][29][30]. The evolution of the temperature and therefore the ice fraction were similar in all the tests carried out at different agitation rates.…”

Shrinkage in frozen desserts

“…Overrun and aeration are initially determined by the foamability of the matrix, where fat, ice, and serum phases all play a role in the development of air cells during freezing (Chang & Hartel, 2002b). The exact process by which air cells are formed and stabilized is difficult to quantify without real-time imaging and rheological measurements during the freezing process, but recent researchers have applied the principles of thermodynamics, fluid dynamics, and other engineering principles to predict and validate experimental conditions for ice crystal and air cell structure development during freezing (Arellano et al, 2013;Hernández Parra et al, 2018a, 2018bNdoye et al, 2018). In the case of frozen desserts, the foamability of proteins and LMWS, the process by which fat networks form, and the increasing viscosity of the serum phase as water freezes to ice aid in creating the initial frozen foam and determine the compositional properties of the air/serum interface.…”

“…The frozen foam is created by the high shear forces in the freezer barrel through the development of ice, air, and fat phases, and the freezing process also alters the functionality of the ingredients within the serum phase. Researchers have begun to study the specific design and operation of continuous freezers on development of ice crystals and air cells in sorbets (Hernández Parra et al, 2018a;Ndoye et al, 2018) and have used complex modeling to explain development of a more complex microstructure (Inoue et al, 2008), but additional research is needed to explain the effects of continuous freezer design on the complete microstructure of the frozen foam.…”

“…Whipped creams provide insights into aerated dairy-based systems containing no ice crystals and can be analyzed by confocal microscopy staining of protein and fat to understand air cell structuring (Cheng et al, 2020;Han et al, 2018). Aerated sorbets can be also studied for the effects of ice crystal and air cell co-development during the dynamic freezing process without the effects of fat, protein, or LMWS (Hernández Parra et al, 2018a;Ndoye et al, 2018).…”

“…The fat phase cannot be well distinguished from the serum phase due to the small size and low phase boundary contrast, and many structural elements below 20 µm are difficult to measure accurately (Guo et al, 2017;Mo et al, 2018). Focused beam laser reflectance (FBRM) has been used to approximate online measurements of ice crystal and air cell size distributions during freezing but cannot distinguish the two dispersed phases nor describe morphology of the structures (Hernández Parra et al, 2018a;Ndoye et al, 2018).…”