Perfume and Flavor Engineering: A Chemical Engineering Perspective.

In the last two decades, scientific methodologies for the prediction of the design, performance and classification of fragrance mixtures have been developed at the Laboratory of Separation and Reaction Engineering. This review intends to give an overview of such developments. It all started with the question: what do we smell? The Perfumery Ternary Diagram enables us to determine the dominant odor for each perfume composition. Evaporation and 1D diffusion model is analyzed based on vapor-liquid equilibrium and Fick's law for diffusion giving access to perfume performance parameters. The effect of matrix and skin is addressed and the trail of perfumes analyzed. Classification of perfumes with the perfumery radar is discussed. The methodology is extended to flavor and taste engineering. Finally, future research directions are suggested.

Separation of tartronic and glyceric acids by simulated moving bed chromatography.

The SMB unit developed by the Laboratory of Separation and Reaction Engineering (FlexSMB-LSRE®) was used to perform tartronic acid (TTA) and glyceric acid (GCA) separation and to validate the mathematical model in order to determine the optimum operating parameters of an industrial unit. The purity of the raffinate and extract streams in the experiments performed were 80% and 100%, respectively. The TTA and GCA productivities were 79 and 115 kg per liter of adsorbent per day, respectively and only 0.50 cubic meters of desorbent were required per kilogram of products. Under the optimum operating conditions, which were determined through an extensive simulation study based on the mathematical model developed to predict the performance of a real SMB unit, it was possible to achieve a productivity of 86 kg of TTA and 176 kg of GCA per cubic meter of adsorbent per day (considering the typical commercial purity value of 97% for both compounds) with an eluent consumption of 0.30 cubic meters per kilogram of products.

Instrumental aspects of Simulated Moving Bed chromatography.

The Simulated Moving Bed (SMB) is one of the greatest illustrations of the potential of continuous multicolumn counter-current chromatographic processes. Although it was initially developed for the purification of petrochemicals, the advances that this technology has experienced during more than 50 years of existence were at the basis of its successful expansion into the food and pharmaceuticals industries. In this context, the present work provides an overview of the evolution of SMB focused on the most relevant instrumental aspects related with this technology. For that purpose, the details of the design and construction of this equipment will be reviewed, with special attention to the valves design. Due to its increasing interest, the technical requirements imposed by unconventional operating modes will be addressed together with the design adaptations that allow the operation of SMB units with compressible fluids and the implementation of Hybrid-SMB processes. Finally, as SMB technology has been unable to meet all the process specifications within the growing biopharmaceuticals industry, the development of alternative multicolumn counter-current units has intensified over the last few years. Hence, examples of the design and application of these new units will be provided.