Effect of Bay Leaves Essential Oil Concentration on the Properties of Biodegradable Carboxymethyl Cellulose-Based Edible Films

Abstract

Films containing bay leaves essential oils (BEOs) were prepared and evaluated for edible packaging applications. The BEOs were extracted by the Soxhlet method, using ethanol or methanol as organic solvent. Then, films were prepared by “solvent casting” technique using carboxymethyl cellulose (CMC), with different concentrations for the as-obtained BEOs (from 1% to 30% wt.). The resulting films were characterized to evaluate their physical (thickness, moisture content, water solubility and water vapor permeability), optical (transparency and UV-light barrier), mechanical (tensile strength and elongation at break), antioxidant and antimicrobiological properties Attractive films were obtained for food active packaging applications, as they presented a high antioxidant activity (up to 99%) and total phenolic content, and good barrier properties against water vapor (50% improved of CMC) in the case of CMC-film containing 15% wt. ethanolic extract. Related to optical properties, UV-light barrier effect was increased (almost 100% of protection) avoiding typical lipids oxidation in food systems. High water solubility (93%) was also found, ensuring also their biodegradability. Moreover, it was demonstrated that developed films inhibit microorganisms’ growth (Escherichia coli and Candida glabrata), this avoiding an early food oxidation.

Characterization of Carboxymethyl Cellulose Films Incorporated with Chinese Fir Essential Oil and Their Application to Quality Improvement of Shine Muscat Grape

“…The band at 2931 cm −1 represents the saturated C-H stretching of -CH3. Antisymmetric vibrations of the COO-groups are evident in the peak at 1592 cm −1 [33]. The bands at 1413 and 1320 cm −1 in the enlarged image on the right are attributed to the bending vibrations of -CH2 or -CH3 and those of -OH, respectively [45].…”

“…In the wavelengths of 1500-1000 cm −1 , no significant fluctuation occurred among these points owing to the physical incorporation of the added CFEO and CMC. In addition, the spectra of films containing CFEO showed no relationship with the concentration, indicating that CFEO can be effectively combined with CMC [33].…”

“…The water solubility (WS) was determined following the method of Rincon [33]. The films were placed into an oven at 110 • C to obtain the original constant weight (W 0 ) and were then immersed in 50 mL distilled water for 6 h at room temperature under constant magnetic stirring.…”

“…With an increase of CFEO concentration, the thickness of the film gradually increased from 0.095 to 0.195 mm as the film matrix began to be occupied by small molecules of CFEO microdroplets [33]. In previous research, the difference in thickness depended on the concentration of the material and the pouring rate on the surface [25,32,33]. The letters after the numbers in the same column are not the same, indicating that there is a significant (p < 0.05) difference.…”

Cellulose Nanofibers from Olive Tree Pruning as Food Packaging Additive of a Biodegradable Film

“…The light transmittance of the film in the UV-VIS regions (200–800 nm) was determined with a Perkin Elmer UV/VIS Lambda 25 spectrophotometer (Waltham, MA, USA), using the following equations to assess the UV barrier (Equation (1)) and transparency properties (Equation (2)) of the films by means of the transmittance values of the films at wavelengths of 280 nm and 660 nm, which are consistent with the UV-VIS absorption spectra [ 25 ]. UV-barrier = 100 − (% T 280 /% T 660 ) × 100 where % T 280 and % T 660 are the transmittance percentage at 280 nm and 660 nm, respectively.…”