TITLE:
Fatty Acid Composition in Freeze-Dried Chinese Mitten Crabs (Eriocheir sinensis)
AUTHORS:
Lihong He, Feng Li, Junyong Tang
KEYWORDS:
Eriocheir sinensis; Fatty Acid Composition; Freeze Drying; Frozen Storage; Rehydration Ratio; Viscera
JOURNAL NAME:
Open Journal of Marine Science,
Vol.2 No.3,
July
27,
2012
ABSTRACT: Freeze drying is reported to be the best method of dehydration. Live fresh Chinese mitten crabs (Eriocheir sinensis) were freeze dried. The moisture content, rehydration ratio, and fatty acid composition of freeze-dried crabs were analysed. The applicability of using freeze drying to process high-value E. sinensis, so as to prolong the time duration of their storage and marketing, were discussed. After lyophilisation, the average moisture content was 6%. The physical properties (shape, size, and colour) of the musculature and viscera were maintained well during freeze drying. The rehydration ratio was 2.15 when rehydrated for 30 min at room temperature. The levels of polyunsaturated fatty acids, especially eicosapentaenoic acid and docosahexaenoic acid, were higher in female freeze-dried crabs than in male crabs. After full rehydration, the fatty acid composition of freeze-dried crabs showed no significant differences to that of frozen crabs after thawing. In conclusion, freeze drying can well preserve the physical properties of the edible parts and fatty acid composition of the viscera in high-value E. sinensis. Rehydration has no destruction of the nutritional value regarding to the fatty acid composition. Therefore, freeze drying is a suitable technique for the processing of high-value E. sinensis.