Encapsulation of orange terpenes investigating a plasticisation extrusion process

Abstract

Extrusion is widely used for flavour encapsulation. However, there is a lack of process understanding. This study is aimed at improving the understanding of a counter rotating twin screw extrusion process. Orange terpenes as model flavour, maltodextrin and sucrose as matrix materials, and a water feed rate between 4.0% and 5.7% were applied. Product temperatures < 80 °C and specific mechanical energy inputs <260 Wh/kg resulted. Amorphous and partly crystalline samples were obtained. The loss of crystalline sucrose was linked to a dissolution process of the sugar in the available water amount. Melting of the excipients did not arise, resulting in a plasticisation extrusion process. Maximally 67% of the flavour was retained (corresponding to a 4.1% product flavour load). The flavour loss correlated with insufficient mixing during the process and flavour evaporation after extrusion. Based on these results, recommendations for an improved encapsulation process are given.

• Flavour encapsulation
• melting
• maltodextrin
• plasticisation
• sucrose
• twin screw extrusion

Acknowledgements

The authors thank Dr. Andreas Marmann, Heinrich-Heine-University for the determination of the orange terpene contents, Dr. Elena Reitz, Heinrich-Heine-University for the microscope images, Andrea Butterbrodt, Karlsruhe Institute of Technology for various DSC measurements, Bonifaz Endrass, HB-Feinmechanik GmbH & Co KG and Prof. Dr. Markus Thommes, formerly Heinrich-Heine-University, now TU Dortmund University for the discussion about the extrusion process.

Declaration of interest

The research presented in this article has been conducted in the context of the AIF ZIM project (AiF Projekt GmbH, Projekttraeger des BMWi) KF2256805WZ1 in cooperation with the company HB-Feinmechanik GmbH & Co KG, Metten, Germany and in context of a scholarship of the Max Buchner Research Foundation (Project 2898). Furthermore the authors thank the company Roquette Frères for donation of the maltodextrin.