Antimicrobial, mechanical, and physicochemical properties of ethylene vinyl alcohol (EVOH) extruded films blended with propolis

Figures & data

Table 1. Characteristics of crystallization and melting behaviour of EVOH pure sample and EVOH films containing 0%, 5%, 10%, 15%, and 20% (w/w) propolis

Xc (%)	∆Hm °C	T m °C	∆Hc J/g	Tc °C	Tonset °C	Propolis %
46.22	72.94	189.6	63.97	164.1	157.7	0
51.48	81.31	180.3	71.93	157.6	152.1	5
54.24	78.06	179.7	63.04	156.3	149.9	10
54.89	69.05	178.5	61.5	155	148.9	15
54.96	69.29	178.2	60.88	154.5	147.7	20

Figure 1. TGA thermograms of propolis, EVOH pure film and EVOH/Propolis (20%w/w) mixed film

Figure 2. SEM images of pure EVOH film (a) and blended films of EVOH and propolis with different percentages: (b) 5%(W/W), (c) 10% (W/W), (d) 15% (W/W), (e) 20% (W/W)

Figure 3. FTIR spectra of propolis, EVOH film and EVOH/Propolis 20% (W/W) blended film

Figure 4. Mechanical properties of EVOH/propolis blended films containing different percentages of propolis: a) elongation to tear b) tensile strength at break point c) elastic modulus

Table 2. Results of permeability to moisture and oxygen for EVOH films containing different concentrations of propolis

Percentage of propolis (%)	Moisture permeability (g d^−1 m^−1)	Oxygen permeability (m^2 s^−1 Pa^−1)	Percentage of permeability decrease (%)
0%	1.19E-4	0.035 ± 0.011a	0 ± 0e
5%	1.13E-5	0.033 ± 0.019a	4.16 ± 0.033d
10%	1.32E-5	0.030 ± 0.01a	12.5 ± 0.030 c
15%	1.22E-5	0.029 ± 0.01a	16.66 ± 0.041b
20%	1.68E-5	0.028 ± 0.01a	20.83 ± 0.039a

Figure 5. Antimicrobial results of EVOH films containing different concentrations of propolis

The dissimilarity in lowercase Latin letters indicates a significant difference between different concentrations of propolis at 95% level. The discrepancy in uppercase Latin letters indicates a significant difference between the different microorganisms at the 95% level.