Simultaneous application of ultrasounds and firming agents to improve the quality properties of osmotic + freeze-dried foods
Research output: Contribution to journal › Article › peer-review
Authors
Colleges, School and Institutes
External organisations
- University of Birmingham, School of Chemical Engineering
Abstract
Dried foods generally show poor rehydration ability and changes in the product properties. In this work, strawberries, used as a model food, were processed using osmotic dehydration (OD) followed by freeze drying (FD) to investigate the effects on the sample colour, texture, microstructure and rehydration. For the first time, a new approach was implemented by adding firming agents (FA) in the osmotic solution to strengthen the cell walls and applying ultrasounds (US) during the pre-treatment to enhance the process mass transfer. FA and US have been implemented often separately but never combined. The resulting samples were then further dried using FD. This strategy revealed to be successful in improving the properties of dried foods compared to FD solely: rehydration capacity was enhanced; colour was better retained, showing colour coefficients closer to the fresh fruit; texture was largely improved, exhibiting the same mechanical properties of the raw material; microstructure was well preserved.
Details
Original language | English |
---|---|
Pages (from-to) | 402-410 |
Number of pages | 9 |
Journal | LWT |
Volume | 96 |
Early online date | 29 May 2018 |
Publication status | Published - 1 Oct 2018 |
Keywords
- Firming agent, Freeze-drying, Osmotic dehydration, Ultrasounds