. 2019 Aug 22;7(9):3093–3102. doi: 10.1002/fsn3.1171

Table 3.

The effect of different blanching methods on quality parameters of oil extracted from Rainbow trout wastes

Indices of oil spoilage		Blanching methods
Indices of oil spoilage		Control	Boiling water	Salt	pH shift
Peroxide value (meq O₂/kg oil)	BW	4.42 ± 0.38^Cb	20.8 ± 0.08^Ba	4.08 ± 0.23^Cb	76.7 ± 2.04^Ab
Peroxide value (meq O₂/kg oil)	SBW	16.7 ± 0.3^BCa	21.5 ± 1.1^Ba	11.5 ± 0.38^Ca	133 ± 6.1^Aa
Thiobarbituric acid (mg malondialdehyde/kg oil)	BW	1. 42 ± 0.002 ^Bb	1. 67 ± 0.001 ^Ab	1. 33 ± 0.003 ^Cb	1. 7 ± 0.001^Ab
Thiobarbituric acid (mg malondialdehyde/kg oil)	SBW	2. 43 ± 0.001^Ba	2. 41 ± 0.002 ^Ba	2. 06 ± 0.01^Ca	3. 18 ± 0.001^Aa
Free fatty acids (oleic acid %)	BW	0.323 ± 0.003^Bb	0.293 ± 0.005^Cb	0.314 ± 0.007^Bb	0.346 ± 0.01^Ab
Free fatty acids (oleic acid %)	SBW	0.623 ± 0.015^Ba	0.408 ± 0.011^Da	0.532 ± 0.015^Ca	0.698 ± 0.02^Aa
Anisidine value	BW	0.433 ± 0.01^Cb	2.36 ± 0.19^Ba	0.27 ± 0.01^Cb	3.26 ± 0.07^Aa
Anisidine value	SBW	1.19 ± 0.08^BCa	2.52 ± 0.13^Ba	0.76 ± 0.02^Ca	3.34 ± 0.11^Aa
Saponification value (mg KOH/g oil)	BW	124 ± 15^Db	284 ± 3.2^Ba	194 ± 35^Ca	444 ± 22^Aa
Saponification value (mg KOH/g oil)	SBW	290 ± 1.8^Ba	311 ± 14^Ba	218 ± 19.5^Ca	450 ± 29^Aa
Iodin value (g I₂. 100/g)	BW	46.86 ± 1.43^Aa	38.09 ± 2.54^Aa	38.04 ± 1.39^Aa	33.83 ± 1.47^Ba
Iodin value (g I₂. 100/g)	SBW	37.11 ± 2.72^Ab	37.83 ± 0.60^Aa	36.63 ± 2.55^Aa	25.98 ± 2.35^Bb
TOTOX	BW	9.28 ± 1.8^Ca	43.96 ± 1.4^Ba	8.43 ± 1.5^Ca	156.7 ± 5.5^Aa
TOTOX	SBW	34.6 ± 0.51^Ca	45.7 ± 2.3^Ba	23.8 ± 0.77^Da	268 ± 12.3^Aa

Control denotes nonblanched viscera, BW means oil immediately extracted from blanched or nonblanched waste, and SBW represents oil extracted from blanched or nonblanched waste after six hours of room temperature storage. Capital letters indicate statistical differences among various blanching methods, and small letters indicate statistical differences in oil quality indices of oil at different storage time (0 and 6 hr) (p < .05) Values are shown as means ± SD.