This study examines the lipid characteristics in king mackerel fillets after cooking and chill-reheating. Cooking using methods like shallow fat frying and grilling increased the total lipid content due to moisture loss. Cooking also altered the fatty acid composition and increased lipid oxidation. Reheating the cooked fillets after two days of chilling did not significantly further impact the lipid content or stability. The changes caused by cooking and reheating depended on the original lipid levels and cooking methods used.

2. Lipid characteristics in cooked, chill-
reheated fillets of indo-pacific king
mackerel.
Scomberomorous guttatus

3. Why do we study lipid characteristics in cooked,
chill-reheated fillets of indo pacific king mackerel?
 Seafoods are very important due to their health benefits.
 Fish lipid contains long-chain fatty acids, which are highly
unsaturated with five or six double bond.
 Heating such as cooking methods causes some reactions
in food, such as lipid oxidation which changes the food
composition.
 Little or no fat was lost during cooking; however, the lipid
content increased instead due to moisture loss.
 Losses of polyunsaturated fatty acids due to oxidation
during cooking have been reported.

4. Material and Methods
Sample
preparation
Cooking
methods

5. Cooking
methods
Shallow
fat frying
Microwave
cooking

6. Reheating method
 All samples were reheated at medium power by
microwave set at a frequency of 2450 MHZ for 4 min.
 The internal temperature of all reheated samples
were monitored to achieve a temperature of 75- 80
Degree C.
 The initial temperature of the fish slices was 10± 2
Degree C.

7. Lipid extraction
Lipid chemical
characteristics
Fatty acid analysis Lipid fractionation
Analytical
techniques

8. Lipid extraction
 The procedure used for the lipid extraction was based on Kinsella,
Shimp, Mai, & Weihrauch (1977).
Fatty acid analysis
 Lipid samples were converted to their constituent fatty acid methyl esters by the method of
Timms (1978).
Lipid chemical characteristics
 The free fatty acid value was measured with the method mentioned by Cocks and Rede
(1966).
 Peroxide value was measured according to PORIM (1995) and TBA was measured according
Kim (1992).
Lipid fractionation
 Lipids were separated into neutral and polar fractions on a 20X1.8 cm column of Silica Gel 60
(70-230; Merck).
 Samples (0.1-0.2 g) were dissolved in 2 mL chloroform and applied to the column.

9. Statistical analysis
 The data were analyzed using the one and two-way
analysis of variance test (ANOVA).
 The one-way ANOVA was used to analysis the effect of
cooking by different methods on the control and two-
way ANOVA was used to analyze the effect of chill-
reheating on the cooked samples.

10. Results and discussion
 The content of total lipid (TL), lipid classes and chemical
characteristics of S. guttatus are as shown in Table 1

11. Effect of cooking by different methods
 All cooking methods significantly (P < 0.05) increased
the TL content with the exception of steaming where a
slight decrease was obtained.
 The highest increase was obtained for grilled samples,
although the increase was not significantly different
from that of shallow fat fried fish slices.

12. Effect of cooking by different methods on fatty acid composition (g/100 g
of total fatty acids) of S. Guttatus.
 Table 2

17. Conclusion
 Cooking affects the total lipid, FA profile and the lipid
stability of samples.
 Reheating after chilling for two days do not
significantly affect the lipid composition and stability.
 The changes on lipid content, chemical characteristics
and fatty acid composition during cooking and
followed by chill-reheating are dependent to original
lipid content and methods of cooking.