Nile tilapia (Oreochromis niloticus) waste protein-based films

Figures & data

Table 1. Subjective evaluation of the Nile tilapia protein isolate films

	Composition				Characteristics
Treatment	FPI	GEL	GLY	SOR	C	H	M
T1	3.0	0.0	0.6	0.0	xxx	xx	xxx
T2	2.25	0.75	0.45	0.0	xxx	xx	xxx
T3	1.5	1.5	0.3	0.0	xxx	xx	xxx
T4	0.75	2.25	0.15	0.0	xxx	xxx	xxx
T5	0.0	3.0	0.0	0.0	xxx	xxx	xxx
T6	3.0	0.0	0.0	0.6	xxx	xx	xxx
T7	2.25	0.75	0.0	0.45	xxx	xx	xxx
T8	1.5	1.5	0.0	0.3	xxx	xx	xxx
T9	0.75	2.25	0.0	0.15	xxx	xxx	xxx

FPI = fish protein isolate, GEL = gelatin, GLI = glycerol, SOR = sorbitol, C = continuity, H = homogeneity, M = handling, xxx = excellent, xx = good, x = disabled.

Figure 1. Nile tilapia protein isolate films

T1 (3.0 g FPI, 0.6 g GLY), T2 (2.25 g FPI, 0.75 g GEL, 0.45 g GLY), T3 (1.5 g FPI, 1.5 g GEL, 0.3 g de GLY), T4 (0.75 g FPI, 2.25 g GEL, 0.15 g GLY), T5 (3.0 g GEL), T6 (3.0 g FPI, 0.6 g SOR), T7 (2.25 g FPI, 0.75 g GEL, 0.45 g SOR), T8 (1.5 g FPI, 1.5 g GEL, 0.3 g SOR), T9 (0.75 g FPI, 2.25 g GEL, 0.15 g SOR).FPI = fish protein isolate, GEL = gelatin, GLY = glycerol, SOR = sorbitol.

Table 2. Thickness (T), solubility in water (S_w), water vapor permeability (WVP), tensile strength (TS), and elongation (E) of the Nile tilapia protein isolate films

Treatment	T (mm)	Sw (%)	WVP (g mm day^−1 kPa^−1 m^−2)	TS (MPa)	E (%)
T1	0.09 ± 0.009ª	28.72 ± 2.39ª	16.36 ± 2.29^a	18.87 ± 1.65 ^g	125.33 ± 3.61^a
T2	0.05 ± 0.005^b	20.93 ± 0.48^b	8.74 ± 1.10^b	35.81 ± 3.35 ^f	2.24 ± 0.13^d
T3	0.05 ± 0.003^b	14.02 ± 2.79 ^c	9.66 ± 1.70^b	56.70 ± 2.67^e	3.42 ± 0.28 ^cd
T4	0.04 ± 0.003^b	4.11 ± 0.79^e	7.12 ± 0.82^b	83.03 ± 1.90 ^c	2.14 ± 0.33^d
T5	0.05 ± 0.004^b	22.32 ± 2.52^b	8.67 ± 0.53^b	155.57 ± 2.09^a	2.96 ± 0.11^d
T6	0.08 ± 0.009^a	17.79 ± 2.65^bc	9.12 ± 0.72^b	12.43 ± 1.51 ^h	14.96 ± 1.35^b
T7	0.04 ± 0.002^b	14.10 ± 2.37 ^c	8.38 ± 1.03^b	31.66 ± 2.88 ^f	6.26 ± 2.99 ^c
T8	0.05 ± 0.005^b	10.60 ± 1.12^d	7.94 ± 0.50^b	76.00 ± 2.92^d	3.09 ± 1.38^d
T9	0.04 ± 0.002^b	10.48 ± 2.42^d	7.58 ± 0.20^b	109.71 ± 1.72^b	3.79 ± 0.58 ^cd

Average of three replicates ± standard deviation. Different lowercase letters in the same column differ from each other by Tukey test (p ≤ 0.05).

Table 3. Color attributes and opacity of the Nile tilapia protein isolate films

Treatment	L*	a*	b*	∆E	Y
1	83.68 ± 0.43 ^f	1.25 ± 0.08^a	27.45 ± 0.59^a	88.08 ± 0.04	21.15 ± 0.33ª
2	92.12 ± 0.50^e	0.77 ± 0.02^b	12.53 ± 1.15 ^c	92.97 ± 0.32	15.65 ± 0.46 ^c
3	92.89 ± 0.09^d	0.68 ± 0.02 ^c	9.41 ± 0.63^e	93.37 ± 0.37	14.90 ± 0.41^e
4	93.35 ± 0.08 ^c	0.67 ± 0.02 ^c	7.81 ± 0.23 ^g	93.68 ± 0.07	14.03 ± 0.31 ^f
5	93.94 ± 0.09^a	0.40 ± 0.02^d	4.84 ± 0.13 ^h	94.07 ± 0.09	12.64 ± 0.17 ^g
6	84.72 ± 1.16 ^f	0.61 ± 0.36^bcd	25.03 ± 1.63^b	88.36 ± 0.64	18.24 ± 0.46^b
7	91.54 ± 0.39^e	0.69 ± 0.02 ^c	13.81 ± 0.26 ^c	92.58 ± 0.42	15.02 ± 0.51^d
8	92.49 ± 0.12^e	0.64 ± 0.06 ^c	9.61 ± 0.48^d	92.99 ± 0.08	14.13 ± 0.47 ^f
9	93.56 ± 0.02^b	0.61 ± 0.02 ^c	8.31 ± 0.05 ^f	93.93 ± 0.02	15.11 ± 0.48^d

L*: luminosity, a*: green-red chromaticity, b*: yellow-blue chromaticity, ΔE: color difference, Y: opacity.

Average of three replicates ± standard deviation. Different lowercase letters in the same column differ from each other by Tukey test (p ≤ 0.05).