Determination of antioxidant activity of surface‐treated PET films coated with rosemary and clove extracts

Abstract

Commercial PET films were surface treated and subsequently coated with either rosemary (RME) or clove (CE) extracts. Surface treatments involved (1) corona treatment, (2) chemical modification, and (3) plasma treatment. Radical scavenging activity (RSA) of both pure plant extracts and coated film extracts were determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. RME-coated films showed a % RSA of 25.6%, 22.4%, and 24.1% for plasma, chemical modification, and corona treatment, respectively, at an extract concentration of 1402 ppm, respectively, while pure RME showed a %RSA of 16.0%. Respective %RSA values for CE were 25.0% for plasma, 25.2% for chemically modified, and 25.2% for corona-treated films at 1402 ppm, while pure CE showed a %RSA of 47.6%. Thiobarbituric acid (TBA) test, performed on ground fish muscle wrapped in all types of employed films, showed a remarkable decrease in the degree of fish oxidation ranging between 50.0 and 80.0% after 6 days of storage. Contact angle measurements confirmed that surface chemically modified films had the highest adhesion strength followed by corona and plasma-treated films. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) data also supported contact angle measurements. Finally, the oxygen permeability of surface-treated films did not differ from untreated films indicating that surface treatment did not affect film barrier properties.

Improving Sodium Alginate Films Properties by Phenolic Acid Addition

“…The antioxidant activity increased with the increasing content of tannic acid. PET does not show the antioxidant activity but has to be modified by, e.g., the coating formation from rosemary and clove extracts [ 41 ]. Dou et al [ 42 ] modified adding sodium alginate gelatin and tea polyphenols.…”

Preparation and evaluation of antioxidant packaging films made of polylactic acid containing thyme, rosemary, and oregano essential oils

“…and synthetic [BHA, BHT, tert‐Butylhydroquinone (TBHQ), Propyl galate (PG)] antioxidant compounds have been introduced to polymeric packaging films to be used for this purpose (Li et al, ; Ramos, Beltran, Peltzer, Valente, & Garrigos, ). The most preferred option by consumers is the incorporation of natural rather than synthetic additives into packaging materials due to the potential health risk of the latter (Byun et al, ; López‐de‐Dicastillo, Gómez‐Estaca, Catalá, Gavara, & Hernández‐ Muñoz, 2012; Farghal, Karabagias, Sayed, & Kontominas, ).…”

Effect of Corona Treatment Method to Carvacrol Nanocoating Process for Carvacrol/Halloysite-Nanotube/Low-Density-Polyethylene Active Packaging Films Development

“…2 promising inhibitory action against a broad range of food spoilage microorganisms. In the literature there is a plethora of studies with EOs addition on polymers such as polyethylene (PE), low density polyethylene [7][8][9], polyethylene tetraphthalate (PET) [10], polystyrene (PS) [11] and biopolymers such as starch, chitosan, gelatin, alginates, poly-lactide acid (PLA) active packaging films [12][13][14][15][16][17][18][19][20]. In addition, there are many studies with use of EOs active components in active packaging systems such as limonene, eugenol, thymol, cinnamaldehyde and carvacrol [21][22][23][24][25][26][27][28].…”