EFFECTS OF MICROWAVE COOKING ON FISH QUALITY

Figures & data

Figure 1. The variation of proteolytic activity of trout during microwave cooking at different powers (⋄ 20%^a, ▪ 40%^a, ▴ 60%^b). Solid lines represent the model. Powers with different letters are significantly different (p ≤ 0.05).

Figure 2. The variation of texture of trout during microwave cooking at different powers (⋄ 20%^b, ▪ 40%^a,▴ 60%^a). Solid lines represent the model. Powers with different letters are significantly different (p ≤ 0.05).

Figure 3. The thermogram obtained for the trout cooked at 40% power for 10 s.

Figure 4. The thermogram obtained for the trout cooked at 40% power for 20 s.

Figure 5. The thermogram obtained for the trout cooked at 40% power for 30 s.

Figure 6. The thermogram obtained for the trout cooked at 40% power for 40 s.

Table 1. Analysis of DSC Thermograms

Power (%)	Time (s)	ΔH myosin (W/g)	ΔH actin (W/g)
Control		–	29.99
20	10	–	28.43
20	20	–	28.00
20	30	–	27.04
20	40	0.01	21.99
40	10	–	50.41
40	20	–	31.59
40	30	0.07	29.40
40	40	0.87	15.00
60	10	8.2	20.77
60	20	9.72	18.40
60	30	18.5	17.05
60 ^*	40	–	–

^* Many peaks were obtained and their corresponding proteins couldn't be determined due to burning of the tissue and adverse effects of high temperature.

Table 2. Fatty Acid Ester Composition (in Weight Percentages of Total Fatty Acid Methyl Esters) of Trout Processed in Microwave Oven for Different Powers and Times

	Power = 20%					Power = 40%				Power = 60%
	t = 0	t = 10 s	t = 20 s	t = 30 s	t = 40 s	t = 10 s	t = 20 s	t = 30 s	t = 40 s	t = 10 s	t = 20 s	t = 30 s	t = 40 s
C12	0.1	0.1	0.1	0.1	0.1	0.2	0.1	0.1	0.1	0.2	0.1	0.3	0.3
C14	4.0	3.9	3.8	4.0	4.0	3.8	4.2	4.5	4.6	4.9	4.5	4.4	4.3
C14.1 Tr	0.2	0.3	0.5	0.4	0.4	0.3	0.2	0.4	0.3	0.3	0.5	0.4	0.4
C14.1 Cis	0.6	0.5	0.6	0.7	0.6	0.8	0.6	0.7	0.8	1.0	0.8	1.0	1.1
C15	0.1	0.1	0.2	0.1	0.1	0.2	0.1	0.1	0.2	0.2	0.2	0.2	0.1
C16	17.7	17.5	19.2	20.4	19.7	18.4	18.3	19.6	18.8	18.5	18.6	18.7	18.4
C16.1 Tr	0.9	0.9	1.4	1.2	1.3	1.3	1.1	1.2	1.2	1.1	0.9	0.8	0.6
C16.1 Cis	5.7	7.1	6.6	5.4	7.0	6.9	5.8	5.7	6.4	6.2	6.1	6.8	6.4
C16.4	0.9	0.8	0.8	0.7	0.8	0.8	0.7	0.6	0.8	0.6	0.8	0.6	0.7
C17	0.2	0.2	0.5	0.4	0.4	0.3	0.2	0.3	0.4	0.2	0.3	0.2	0.3
C18	5.9	5.4	5.3	5.5	5.4	6.1	5.6	5.7	5.8	6.6	6.2	6.1	6.4
C18.1 Tr	0.3	0.4	0.6	0.5	0.3	0.2	0.4	0.3	0.4	0.2	0.3	0.4	0.3
C18.1 Cis	26.4	26.5	26.7	25.8	25.7	26.9	25.9	26.1	27.3	27.2	26.8	26.6	26.3
C18.2 Tr	0.2	0.3	0.5	0.4	0.4	0.3	0.4	0.3	0.2	0.4	0.3	0.4	0.3
C18.2 Cis	13.7	12.6	12.3	11.5	11.7	12.5	12.4	12.5	12.1	12.9	13.0	13.1	13.2
C18.3 Tr	0.9	0.7	0.8	0.9	0.7	0.8	0.8	0.9	0.8	0.5	0.3	0.7	0.6
C18.3 Cis	1.8	2.3	1.8	1.9	2.0	1.9	1.7	1.8	2.2	2.1	2.2	2.1	2.2
C20	0.3	0.3	0.2	0.1	0.2	0.5	0.6	0.4	0.7	0.4	0.3	0.5	0.4
C20.1	2.4	2.7	2.5	2.6	2.4	2.8	2.1	2.7	2.6	1.7	2.1	1.6	1.8
C20.2	0.8	1.3	0.9	0.9	1.0	0.9	0.8	1.2	1.1	0.9	1.0	0.9	0.8
C20.3	1.0	1.1	1.2	1.3	0.9	1.2	1.1	1.2	1.0	0.9	0.8	0.7	0.9
C20.4	1.1	0.6	0.5	0.3	0.7	0.6	0.6	0.7	0.8	0.4	0.5	0.4	0.4
C22	0.5	0.6	0.3	0.4	0.3	0.4	0.6	0.5	0.3	0.4	0.4	0.3	0.4
C22.1	1.7	1.8	1.7	1.9	1.9	1.8	1.9	2.0	1.9	1.5	1.6	1.7	1.8
C22.2	0.2	0.3	0.4	0.2	0.3	0.3	0.2	0.4	0.3	0.3	0.6	0.4	0.5
C22.3	0.6	0.8	0.5	0.9	0.8	0.7	0.5	0.7	0.8	0.5	0.6	0.5	0.6
C22.5	11.2	10.3	9.6	10.8	10.3	8.6	8.2	8.5	7.4	9.4	9.4	9.3	9.5
C22.6	0.6	0.6	0.5	0.7	0.6	0.5	0.4	0.9	0.7	0.5	0.8	0.9	1.0