Time-dependent evolution of properties of fish gelatin edible films enriched with carvacrol during storage

L.M. NEIRA; J. F. MARTUCCI; R. A. RUSECKAITE

FOOD HYDROCOLLOIDS

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2019

0268-005X

The temporal stability of the physicochemical, antibacterial and antioxidant properties of fish gelatin (FG) filmsplasticized by glycerol (20 % w/w) and supplemented with carvacrol (CRV) obtained by casting and stored at 65 % RHand 25 ºC, was investigated over 15 days. The level of CRV incorporated into FG film was determined from minimuminhibitory concentration (MIC) values against E. coli and S. aureus. The incorporation of 0.6 % w/v CRV reduced themoisture content (MC), and water vapor permeability (WVP) while kept invariable the tensile and light barrierproperties, compared to the control. Additionally, CRV increased the in vitro antibacterial and antioxidant effectivenessof films. Upon storage, the sustained loss of moisture and glycerol provoked the drop of MC and WVP values of bothfilms. Control film became stiffer and less stretchable while the active film remained mechanically time-stable. Suchdifference was ascribed to the increased contribution of triple helical structures in the control, as revealed by ATRFTIR and XRD. Antibacterial effectiveness (based on disc diffusion assay) decayed from 3.1 ± 0.1 and 2.7 ± 0.3 cm forE. coli and S. aureus, respectively, to undetectable levels for both pathogens. Antioxidant power in terms of radicalscavenging activity (RSA) declined to about 1.96 % of the initial value, in line with the decline of CRV level up to 13 %of its initial concentration. Overall this study proves the significance of assessing the stability of the properties of ediblefilms before proposing any technical application.