Abstract
Freeze-drying (lyophilization) has many advantages. The color of the freeze-dried product resembles that of the fresh tissue, in contrast to the frequently darker color resulting from conventional oven-drying. However, freeze-dried non-blanched potato slices suffer from considerable browning following rehydration. Electrical treatment of the fresh tissue (40V/cm for 1min) without heating and before lyophilization reduced its browning after rehydration: L* values (lightness) of the untreated and electrically treated rehydrated tissues were 50.4±0.3 and 84.3±0.8, respectively. Image processing revealed that the porosity of the freeze-dried potato is not significantly influenced by the prior electrical treatment. Compression of any of the treated freeze-dried specimens always yielded characteristic sigmoid stress-strain curves. The freeze-dried blanched potato specimen was tougher than both the freeze-dried fresh potato and its electrically treated counterparts.
| Original language | English |
|---|---|
| Pages (from-to) | 194-199 |
| Number of pages | 6 |
| Journal | LWT |
| Volume | 56 |
| Issue number | 1 |
| DOIs | |
| State | Published - Apr 2014 |
| Externally published | Yes |
Keywords
- Blanching
- Browning prevention
- Electrical fields
- Freeze-dried
- Potato