210 J.F.Martucci et aL Industrial Crops and Products 71(2015)205-213 Table 4 est water uptake(i.e,26.0±6.8‰)，in accordance to its hydrophilic Mechanical properties,water vapor permeability (WVP)and water uptake (WUeg) nature (Martucci and Ruseckaite,2009:Martucci et al.,2012: of Ge films with and without essential oils. Kavoosi et al.,2013).The incorporation of LEO into gelatin matrix Mechanical properties WVP'1013 WUeq reduced the water absorption capacity (14.8+1.0%for 6000 ppm). e(3 TS(MPa) (Kg.m/Pa.s.m2)() It is hypothesized that non polar EOs interact favorably with Ge 10.8±3.0 17.7±2.8m 1.46±0.13 26.0±6.8m hydrophobic domains in gelatin inducing conformational changes 0E02000-Ge 8.3±3.7° 14.0±1.6b 121±0.45 23.8±3.7加 in gelatin chains that cannot promote protein-water interaction 0E03000-Ge 92±3.4 13.9±1.8 0.88士0.019 202±1.90 (Djagny et al.,2001:Kavoosi et al.,2013).Nevertheless,no signifi- 0E04000-Ge 9.7±2.6° 12.2±2.8hc 1.10±0.20° 21.0±2.1a cant differences were noted in OEO incorporated films(P>0.05) 0E05000-Ce 10.1±2.2° 8.9±3.3 0.81±0.039 19.5±1.70 The different behavior could be due to the differences in the 0E06000-Ge 10.0±1.99 113±3.2c 0.84±0.01 18.1±2.3 LE02000-Ge 43±0.8y 88±2.2z 127±0.07r 203±3.1x hydrophobic nature of the oils used,which resulted in a different LEO3000-Ge 7.6±3.09 15.4±2.1w 0.97±0.10 19.6±2.3 ability to attract water to the film network. LE04000-Ge 6.3±2.0￥ 12.1±1.9w 1.05±0.03 17.8±1.69y LE05000-Ge 4.6±0.3 11.7±2.4w 1.02±0.04 17.5±1.4 LE06000-Ge 73±2.09.12.8±2.82w 0.68±0.02W 14.8±1.0 3.2.4.Water vapor permeability WVP values of LEO-Ge films were slightly decreased when Any two means in the same column followed by the same letter are not signifi- cantly different(P>0.05)based on the Turkey test. lavender concentrations remained above 2000 ppm (Table 4, P<0.05).Nevertheless,in OEO-Ge films,no significant differences (Table 4.P20.05)were found among samples with different occurred during dehydration (Hosseini et al..2009;Atares et al., contents of oregano oil phase.Lavender and oregano oil incor- 2010b:Tongnuanchan et al.,2012). poration affected WVP of gelatin film in a different way.due to the hydrophobic nature of essential oils,which affects the 3.2.3.Water uptake hydrophilic/hydrophobic balance of the film(Ojagh et al..2010; Water uptake at the equilibrium of gelatin films incorporated Teixeira et al..2014)based on the water uptake capacity.Sim- with EOs is summarized in Table 4.Gelatin films exhibited the high- ilar results were obtained by Ahmad et al.(2012)in fish skin 15kU X508 5OMm 25/APR/13 15kU X500 58wm 13 31 SEI C D 15k0 X500 58Mm 15 31 SEI 31sE1 E Fig.2.Scanning electron microscopic images of cross sections of Ge(a):LEO3000-Ge(b):LEO6000-Ge(c):OEO3000-Ge(d)and OEO6000-Ge (e)films.210 J.F. Martucci et al. / Industrial Crops and Products 71 (2015) 205–213 Table 4 Mechanical properties, water vapor permeability (WVP) and water uptake (WUeq) of Ge films with and without essential oils. Mechanical properties WVP*1013 WUeq  (%) TS (MPa) (Kg.m/Pa.s.m2) (%) Ge 10.8 ± 3.0ax 17.7 ± 2.8ax 1.46 ± 0.13ax 26.0 ± 6.8ax OEO2000-Ge 8.3 ± 3.7a 14.0 ± 1.6ab 1.21 ± 0.45a 23.8 ± 3.7a OEO3000-Ge 9.2 ± 3.4a 13.9 ± 1.8bc 0.88 ± 0.01a 20.2 ± 1.9a OEO4000-Ge 9.7 ± 2.6a 12.2 ± 2.8bc 1.10 ± 0.20a 21.0 ± 2.1a OEO5000-Ge 10.1 ± 2.2a 8.9 ± 3.3c 0.81 ± 0.03a 19.5 ± 1.7a OEO6000-Ge 10.0 ± 1.9a 11.3 ± 3.2bc 0.84 ± 0.01a 18.1 ± 2.3a LEO2000-Ge 4.3 ± 0.8y 8.8 ± 2.2yz 1.27 ± 0.07x 20.3 ± 3.1x LEO3000-Ge 7.6 ± 3.0xy 15.4 ± 2.1xw 0.97 ± 0.10y 19.6 ± 2.3x LEO4000-Ge 6.3 ± 2.0y 12.1 ± 1.9zw 1.05 ± 0.03y 17.8 ± 1.6xy LEO5000-Ge 4.6 ± 0.3y 11.7 ± 2.4zw 1.02 ± 0.04y 17.5 ± 1.4y LEO6000-Ge 7.3 ± 2.0xy 12.8 ± 2.8zw 0.68 ± 0.02w 14.8 ± 1.0z * Any two means in the same column followed by the same letter are not signifi- cantly different (P > 0.05) based on the Turkey test. occurred during dehydration (Hosseini et al., 2009; Atarés et al., 2010b; Tongnuanchan et al., 2012). 3.2.3. Water uptake Water uptake at the equilibrium of gelatin films incorporated with EOs is summarized in Table 4. Gelatin films exhibited the high￾est water uptake (i.e., 26.0 ± 6.8%), in accordance to its hydrophilic nature (Martucci and Ruseckaite, 2009; Martucci et al., 2012; Kavoosi et al., 2013). The incorporation of LEO into gelatin matrix reduced the water absorption capacity (14.8 ± 1.0% for 6000 ppm). It is hypothesized that non polar EOs interact favorably with hydrophobic domains in gelatin inducing conformational changes in gelatin chains that cannot promote protein-water interaction (Djagny et al., 2001; Kavoosi et al., 2013). Nevertheless, no signifi- cant differences were noted in OEO incorporated films (P ≥ 0.05). The different behavior could be due to the differences in the hydrophobic nature of the oils used, which resulted in a different ability to attract water to the film network. 3.2.4. Water vapor permeability WVP values of LEO-Ge films were slightly decreased when lavender concentrations remained above 2000 ppm (Table 4, P < 0.05). Nevertheless, in OEO-Ge films, no significant differences (Table 4, P ≥ 0.05) were found among samples with different contents of oregano oil phase. Lavender and oregano oil incor￾poration affected WVP of gelatin film in a different way, due to the hydrophobic nature of essential oils, which affects the hydrophilic/hydrophobic balance of the film (Ojagh et al., 2010; Teixeira et al., 2014) based on the water uptake capacity. Sim￾ilar results were obtained by Ahmad et al. (2012) in fish skin Fig. 2. Scanning electron microscopic images of cross sections of Ge (a); LEO3000-Ge (b); LEO6000-Ge (c); OEO3000-Ge (d) and OEO6000-Ge (e) films