Value added fish by-products - Nordic Innovation

2.6.5.2 Fat absorption
The absorption of fat into the fish cakes during frying was assayed. This was achieved by
determining the total lipid content of the fish cakes during lipid extraction. The lipid content
was compared to that of the unfried fish cakes, taking the differences in fat from the added
cream powder into consideration.
2.6.5.3 Water holding capacity
Water holding capacity (WHC) of the fish cakes was determined by a low speed
centrifugation method as described by Eide et al. (1982) except that the centrifugation was
carried out at 210 g for 5 minutes. Water content of the fish cakes was determined in triplicate
by weighing the cakes before and after drying at 105°C for 24 hours.
2.6.5.4 Texture analysis
Compression force on the fish cakes was measured using a TA.XT2 Texture Analyzer from
Stable Micro Systems, England. A 1/2” flat-ended cylindrical probe was used on whole fish
cakes, including its fried crust. The samples were compressed at 2 mm/s to a strain of 30% of
the sample thickness.
2.6.5.5 Storage trails
A storage experiment was conducted on the fish cakes after frying. The fish cakes were
stored in zip locked plastic bags in a cold storage room at 4ºC. The lamp in the ceiling was
kept on during the experiment to increase the rate of oxidation. The fish cakes were equally
exposed to light. Samples of the fish cakes were collected after 1, 4 and 8 days of storage.
Lipids from these samples were extracted following the method of Bligh & Dyer (1959) and
used for further analysis.
2.6.5.6 Analysis of lipids
2.6.5.6.1 Peroxide Value
Peroxide value (PV) was analyzed by the ferric thiocyanate method as described by the
International Dairy Federation 1991, and modified by Ueda et al. 1986 and Underland et al.
1998.
101