Effects of Different Whey Protein Concentrate Coating on Selected Properties of Rainbow Trout (Oncorhynchus mykiss) During Cold Storage (4°C)

Figures & data

FIGURE 1 The changes in microbiology characteristics rainbow trout samples (log cfu/g); a) Total aerobic mesophilic bacteria; b) total physcrophilic aerobic bacteria; c) lactic acid bacteria (in MRS); d) Enterobacteriaceae.

TABLE 1 The changes in chemical characteristics of rainbow trout samples during storage

Trout samples	Storage time (day)	Moisture (%)	Fat (%)	Protein (%)	pH	Ash (%)	Peroxide (meq O2/kg lipid)	TVB-N (mg 100/g)	TBARS µmol (MDA)/kg
	0	70.56 ± 0.37^a	7.61 ± 0.26^a	18.55 ± 0.09^a	6.31 ± 0.09^a	1.26 ± 0.02^ab	2.02 ± 0.04^a	12.41 ± 0.28^a	1.08 ± 0.05^a
C	3	69.49 ± 0.53^a	8.42 ± 0.43^a	19.38 ± 0.19^a	6.32 ± 0.09^a	1.34 ± 0.04^bc	2.20 ± 0.13^b	16.98 ± 0.15^a	3.13 ± 0.15^a
	6	68.43 ± 0.43^a	9.50 ± 0.12^a	19.90 ± 0.20^a	6.22 ± 0.08^a	1.32 ± 0.01^a	2.52 ± 0.08^ab	19.45 ± 0.14^a	4.78 ± 0.15^a
	9	67.48 ± 0.26^a	9.61 ± 0.15^a	19.94 ± 0.19^a	6.53 ± 0.08^a	1.32 ± 0.09^a	3.08 ± 0.12^ab	25.50 ± 0.11^a	6.14 ± 0.07^a
	12	66.60 ± 0.16^a	9.77 ± 0.18^a	20.54 ± 0.26^a	6.42 ± 0.12^a	1.44 ± 0.02^a	3.40 ± 0.09^a	29.50 ± 0.33^a	8.16 ± 0.79^a
	15	65.70 ± 0.38^a	10.25 ± 0.80^a	20.88 ± 0.05^a	6.69 ± 0.04^a	1.42 ± 0.01^a	3.92 ± 0.07^c	32.50 ± 0.18^c	9.20 ± 0.10^a
	0	69.36 ± 0.21^ab	9.57 ± 0.13^b	19.66 ± 0.20^b	6.31 ± 0.09^a	1.18 ± 0.02^a	2.06 ± 0.04^a	12.41 ± 0.28^a	1.08 ± 0.05^a
X	3	68.05 ± 0.09^ab	9.79 ± 0.13^b	20.06 ± 0.09^b	6.26 ± 0.01^a	1.14 ± 0.04^a	2.27 ± 0.08^b	16.80 ± 0.19^a	1.94 ± 0.10^b
	6	67.42 ± 0.19^b	10.33 ± 0.12^b	20.43 ± 0.05^b	6.34 ± 0.01^a	1.24 ± 0.06^a	2.72 ± 0.21^a	19.67 ± 0.12^a	3.17 ± 0.05^b
	9	66.75 ± 0.16^ab	11.02 ± 0.04^b	21.00 ± 0.09^b	6.50 ± 0.00^a	1.37 ± 0.02^a	3.23 ± 0.08^b	22.32 ± 0.21^b	4.99 ± 0.14^b
	12	65.45 ± 0.06^b	11.17 ± 0.05^b	21.29 ± 0.11^b	6.43 ± 0.12^a	1.45 ± 0.04^a	3.35 ± 0.07^a	24.55 ± 0.33^a	6.34 ± 0.04^b
	15	64.33 ± 0.19^b	10.42 ± 0.13^a	21.81 ± 0.05^b	6.29 ± 0.01^b	1.52 ± 0.02^b	4.32 ± 0.06^b	27.36 ± 0.31^b	8.30 ± 0.20^b
	0	69.99 ± 0.12^b	11.40 ± 0.22^b	20.17 ± 0.22^b	6.31 ± 0.09^a	1.21 ± 0.01^ab	1.82 ± 0.04^b	12.41 ± 0.28^a	1.08 ± 0.05^a
Y	3	68.79 ± 0.20^bc	11.84 ± 0.08^c	20.37 ± 0.12^b	6.35 ± 0.07^a	1.28 ± 0.02^b	2.12 ± 0.06^ab	16.12 ± 0.20^a	2.06 ± 0.16^b
	6	67.08 ± 0.12^b	12.00 ± 0.05^c	20.97 ± 0.13^c	6.48 ± 0.01^b	1.35 ± 0.02^a	2.43 ± 0.05^ab	18.35 ± 0.14^b	3.06 ± 0.11^b
	9	66.40 ± 0.40^b	11.77 ± 0.14^c	21.79 ± 0.02^c	6.25 ± 0.03^a	1.43 ± 0.02^ab	2.89 ± 0.14^a	19.93 ± 0.07^c	3.90 ± 0.21^c
	12	65.03 ± 0.07^b	12.29 ± 0.12^b	21.82 ± 0.12^c	6.30 ± 0.02^a	1.45 ± 0.05^a	3.23 ± 0.06^a	20.61 ± 0.35^a	5.07 ± 0.11^c
	15	64.44 ± 0.24^b	12.05 ± 0.13^b	23.31 ± 0.16^c	6.24 ± 0.04^b	1.53 ± 0.01^c	3.21 ± 0.16^b	24.55 ± 0.33^a	6.89 ± 0.09^c
	0	68.35 ± 0.09^c	9.60 ± 0.12^c	19.76 ± 0.08^c	6.31 ± 0.09^a	1.37 ± 0.09^b	1.76 ± 0.04^b	12.41 ± 0.28^b	1.08 ± 0.05^b
Z	3	67.33 ± 0.12^c	9.98 ± 0.09 ^b	20.23 ± 0.07^b	6.24 ± 0.26^a	1.42 ± 0.01^c	1.92 ± 0.05^a	13.71 ± 0.38^b	1.75 ± 0.04^b
	6	66.24 ± 0.16^c	10.41 ± 0.11^b	20.88 ± 0.14^c	6.14 ± 0.04^b	1.47 ± 0.02^b	2.15 ± 0.11^b	16.14 ± 0.15^c	1.94 ± 0.10^c
	9	65.63 ± 0.15^c	10.71 ± 0.09^b	21.41 ± 0.11^d	6.23 ± 0.04^a	1.55 ± 0.02^b	2.90 ± 0.04^a	17.87 ± 0.26^d	3.31 ± 0.37^c
	12	64.44 ± 0.34^c	11.25 ± 0.03^c	21.82 ± 0.12^d	6.47 ± 0.01^a	1.73 ± 0.04^b	3.21 ± 0.16^a	19.71 ± 0.26^a	4.68 ± 0.09^c
	15	64.04 ± 0.07^b	11.65 ± 0.12^b	23.31 ± 0.16^d	6.32 ± 0.07^b	1.84 ± 0.02^d	3.28 ± 0.12^b	21.09 ± 0.60^a	5.50 ± 0.53^d

Mean values followed by different letters in the same column are significantly different (p < 0.05).

Control (C; without edible films), whey protein concentrate (X; without any addition), WPC + glycerol (Y; 1:1), and WPC + glycerol (Y; 2:1).

TABLE 2 The changes in sensory characteristics of rainbow trout samples during storage

Trout samples	Storage time (day)	Appearance	Odour	Taste	Geneal acceptability	Firmness
C	0	8.20 ± 0.14^a	8.20 ± 0.14^a	8.20 ± 0.14^a	8.20 ± 0.14^a	8.20 ± 0.14^a
	3	3.50 ± 0.42^a	2.40 ± 0.56^a	2.40 ± 0.56^a	2.50 ± 0.70^a	2.30 ± 0.42^a
	6	2.20 ± 0.28^b	1.90 ± 0.14^a	1.90 ± 0.14^a	1.70 ± 0.14^a	1.80 ± 0.04^a
	9	1.40 ± 0.28^a	1.40 ± 0.28^a	1.40 ± 0.28^a	1.60 ± 0.00^a	1.30 ± 0.14^a
	12	1.30 ± 0.14^a	1.40 ± 0.00^a	1.30 ± 0.14^a	1.30 ± 0.14^a	1.40 ± 0.00^a
	15	1.10 ± 0.14^a	1.00 ± 0.14^a	1.30 ± 0.14^a	1.30 ± 0.14^a	1.30 ± 0.14^a
	0	8.70 ± 0.014^b	8.90 ± 0.14^b	8.90 ± 0.14^b	8.70 ± 0.014^b	8.18 ± 0.02^a
	3	5.90 ± 0.14^b	5.70 ± 0.42^b	5.70 ± 0.42^b	5.70 ± 0.42^b	5.80 ± 0.28^b
X	6	1.90 ± 0.14^a	3.00 ± 0.28^b	3.00 ± 0.28^b	3.00 ± 0.28^b	2.30 ± 0.14^b
	9	2.20 ± 0.14^d	2.10 ± 0.14^b	2.10 ± 0.14^b	2.10 ± 0.14^b	1.90 ± 0.14^b
	12	1.90 ± 0.14^c	1.50 ± 0.00^b	1.30 ± 0.14^a	1.70 ± 0.14^b	1.40 ± 0.00^a
	15	1.30 ± 0.14^b	1.40 ± 0.00^b	1.30 ± 0.14^a	1.40 ± 0.00^b	1.30 ± 0.14^a
	0	8.90 ± 0.14^c	8.90 ± 0.14^b	8.90 ± 0.14^b	8.90 ± 0.14^c	8.90 ± 0.14^b
	3	6.80 ± 0.28^d	6.60 ± 0.28^c	6.60 ± 0.28^c	6.60 ± 0.28^c	6.50 ± 0.14^c
Y	6	4.50 ± 0.42^c	4.00 ± 0.28^c	4.00 ± 0.28^c	4.00 ± 0.28^c	2.90 ± 0.14^c
	9	2.00 ± 0.00^b	2.10 ± 0.14^b	2.10 ± 0.14^b	2.10 ± 0.14^b	2.10 ± 0.42^c
	12	2.20 ± 0.00^d	1.80 ± 0.00^c	2.20 ± 0.00^b	1.90 ± 0.14^c	2.10 ± 0.14^c
	15	1.90 ± 0.20^d	1.90 ± 0.14^c	2.10 ± 0.14^c	1.90 ± 0.14^c	1.70 ± 0.14^b
	0	8.67 ± 0.32^b	8.90 ± 0.14^b	9.00 ± 0.00^c	8.90 ± 0.14^c	8.90 ± 0.14^b
	3	6.70 ± 0.12^c	7.10 ± 0.14^d	7.10 ± 0.14^d	7.10 ± 0.14^d	6.90 ± 0.14^d
Z	6	5.60 ± 0.56^d	4.4 ± 0.28^d	5.00 ± 0.28^d	4.4 ± 0.28^d	4.10 ± 0.14^d
	9	2.10 ± 0.14^c	2.10 ± 0.14^b	2.10 ± 0.14^b	2.10 ± 0.14^b	2.90 ± 0.14^d
	12	1.65 ± 0.41^b	1.80 ± 0.00^c	2.70 ± 0.14^c	1.70 ± 0.14^b	1.90 ± 0.14^b
	15	1.40 ± 0.28^c	1.40 ± 0.00^b	1.40 ± 0.14^b	1.40 ± 0.28^b	2.00 ± 0.00^c

Mean values followed by different letters in the same column are significantly different (p < 0.05).

Control (C; without edible films), whey protein concentrate (X; without any addition), WPC + glycerol (Y; 1:1), and WPC + glycerol (Y; 2:1).