Evaluation of hydration with lactoferrin on late-instar Tenebrio molitor larvae performance and functional properties of obtained meal

Figures & data

Table 1. Substrate consumed per gram of diet on a fresh matter (DM) basis, feed conversion efficiency (ECI) on a dry matter basis and feed conversion ratio (FCR) on a fresh matter basis.

Group	Consumed substrate (%)	ECI (%)	FCR
Control	96.93 ± 0.25	10.10 ± 5.78	13.02 ± 6.76
Treatment	96.90 ± 0.10	11.81 ± 6.44	9.24 ± 4.74
p-Value	0.704	0.492	0.111

All values are listed as mean ± standard deviations.

Figure 1. Percentage of survival rate of larvae in control (CTRL) and treatment (TRT) group over 14 days of the trial. All values are listed as mean ± standard deviations. *Asterisk indicates statistically significant differences between tested groups (Unpaired Student’s t-test p < 0.05).

Table 2. Chemical analysis of control (CTRL) and treatment (TRT) group growing substrates administered at day 0 of the trial and residual growth substrates collected at day 14.

	Type of substrate	Dry matter (%)	Ash (%)	Ether Extract (%)	Crude fibre (%)	Crude protein (%)	Non-Structural Carbohydrates (%)
Growing substrate at day 0	Wheat Bran	90.62 ± 1.26	5.50 ± 1.59	2.66 ± 0.88	10.76 ± 3.94	15.40 ± 0.17	56.30 ± 3.78
Residual substrate at day 14	CTRL	92.04 ± 0.41*	8.46 ± 0.09*	1.39 ± 0.28*	17.83 ± 1.54	22.03 ± 2.23	42.33 ± 2.51
	TRT	91.57 ± 0.31*	7.97 ± 0.07*	0.66 ± 0.26*	15.85 ± 2.97	23.15 ± 1.11	43.94 ± 2.85
	p-Value	0.0225	<0.0001	<0.0001	0.2981	0.2267	0.2507

All values are listed as mean ± standard deviations on fresh matter basis. * Asterisk indicates statistically significant differences between tested groups (Unpaired Student’s t-test p < 0.05).

Figure 2. Antioxidant activity of residual growing substrates extracts at three different concentrations (100%; 50%; 25%) in the treatment (TRT) and the control (CTRL) groups. All values are listed as mean ± standard deviations. * Asterisks indicate statistically significant differences between tested groups (p < 0.05).

Table 3. Nutritional composition of insect meals in the control (CTRL) and the treatment (TRT) groups.

	CTRL	TRT	p-Value
Dry matter (%)	93.3 ± 3.35	90.74 ± 1.85	0.080
Ash (%)	7.44 ± 4.52	8.91 ± 2.58	0.439
Ether extract (%)	30.75 ± 2.33*	27.49 ± 0.94*	0.003
Crude protein (%)	44.02 ± 3.12*	46.66 ± 1.34*	0.045

Data are listed as means ± standard deviations on dry matter. * Asterisk indicates statistically significant differences between tested groups (Unpaired Student’s t-test p < 0.05).

Table 4. Lightness (L*), red/green (a*) and yellow/blue (b*) results of control and treatment insect meals groups.

Insect meals		L*	a*	b*
	Control	33.07 ± 1.32	6.19 ± 0.49*	13.68 ± 0.87*
	Treatment	31.88 ± 0.90	5.68 ± 0.38*	12.64 ± 0.52*
	p-Value	0.0530	0.0384	0.0121

Data are shown as means and standard deviations. * Asterisk indicates statistically significant differences between tested groups (Unpaired Student’s t-test p < 0.05).

Figure 3. Evaluation of growth inhibition of O138 E. coli of insect meals in the control (CTRL) and the treatment (TRT) groups for six hours after the inoculation. Data were analysed using two-way ANOVA, and shown as means and standard deviations. * Asterisks indicate statistically significant differences among tested groups (p < 0.01). T0: 0 hours; T1: 1 hour; T2: 2 hours; T3: 3 hours; T4: 4 hours; T5: 5 hours; T6: 6 hours.

Figure 4. SDS-PAGE of soluble proteins extracted from insect meals and residual substrates at day 14 of the control (CTRL) and treatment (TRT) groups. (A) Soluble proteins extracted from insect meals. M: Molecular weight marker (Precision Plus Protein, Bio-Rad, Hercules, CA, USA); Lane 1: 8 µg of soluble proteins of the CTRL group; Lane 2: 4 µg of soluble proteins of the CTRL group; Lane 3: 8 µg of soluble proteins of the TRT group; Lane 4: 4 µg of soluble proteins of the TRT group. (B) Soluble proteins extracted from residual substrates after 14 days of trial. M: Molecular weight marker (Precision Plus Protein, Bio-Rad, Hercules, CA, USA); Lane 1: 5 µg of soluble proteins of the CTRL group; Lane 2: 2.5 µg of soluble proteins of the CTRL group; Lane 3: 5 of soluble proteins of the TRT group; Lane 4: 2.5 of soluble proteins of theTRT group.

Data availability statement

All data are available within the manuscript.