Changes in texture, microstructure and nutritional quality of carrot slices during blanching and freezing
✍ Scribed by Kidmose, Ulla; Martens, Helle J
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 225 KB
- Volume
- 79
- Category
- Article
- ISSN
- 0022-5142
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✦ Synopsis
Thermal processing of vegetables has pronounced effects on the cell structure, often lowering the ®nal textural properties of the product. In order to investigate the effect of thermal processing on carrot, slices were subjected to different blanching and freezing treatments before frozen storage. Microwave-, steam-or water-blanched material was frozen and then stored at À24 °C. Steamblanched carrots were subjected to blast freezing or cryogenic freezing at different temperatures before frozen storage. The in¯uence of these process conditions on the texture (maximum load and slope), microstructure, dry matter, sugars, carotene and drip loss was investigated. Microwave blanching differed from the other blanching methods by resulting in a heterogenic cell structure. The content of dry matter, carotene and sucrose was higher following microwave blanching. Blast freezing resulted in low maximum load which seemed to be caused by major tissue damage. Concerning cryogenic freezing, lowering the temperature from À30 °C to À70 °C resulted in better preservation of the native microstructure together with an increase in maximum load, which was most pronounced after one month of storage. No signi®cant effect was observed when lowering the temperature from À30 °C to À70 °C for any of the other measured parameters.