Storage Stability and Antibacterial Activity against Escherichia coli O157:H7 of Carvacrol in Edible Apple Films Made by Two Different Casting Methods

Abstract

The antimicrobial activities against Escherichia coli O157:H7 as well as the stability of carvacrol, the main constituent of oregano oil, were evaluated during the preparation and storage of apple-based edible films made by two different casting methods, continuous casting and batch casting. Antimicrobial assays of films and high-performance liquid chromatography (HPLC) analysis of film extracts following storage up to 49 days at 5 and 25 degrees C revealed that (a) optimum antimicrobial effects were apparent with carvacrol levels of approximately 1.0% added to the purees prior to film preparation, (b) carvacrol in the films and film weights remained unchanged over the storage period of up to 7 weeks, and (c) casting methods affected carvacrol concentration, bactericidal activity, physicochemical properties, and colors of the apple films. Carvacrol addition to the purees used to prepare the films reduced water vapor and oxygen permeability of apple films. The results indicate that carvacrol has a dual benefit. It can be used to both impart antimicrobial activities and enhance barrier properties of edible films. The cited observations facilitate relating compositional and physicochemical properties of apple puree films containing volatile plant antimicrobials to their use in foods.

Abscisic acid enhances the immune response in Apis mellifera and contributes to the colony fitness

“…Since augmented cellular immunocompetence was observed in ABA-supplemented bees, toxicity assays were performed to evaluate the aptitude of bees to confront pesticides. Carvacrol is a monoterpenoid phenol that inhibits the growth of several bacteria, e.g., Escherichia coli and Bacillus cereus (Du et al 2008). OA is an organic acid conventionally used in apiculture to control V. destructor , even though it has been demonstrated to have adverse effects on the survival of honey bee colonies (Hatjina and Haristos 2005).…”

Development of Edible Films and Coatings with Antimicrobial Activity

“…Regarding the performance of some EOs incorporated in edible films, it is important the study of their stability. Du et al (2008a) determined the destruction of carvacrol, the main constituent of oregano oil, during the preparation and storage of apple-based films made by continuous and batch casting methods. According to HPLC analysis, the relative concentration of carvacrol in cast films increased by 2.2 and 3.2 times the initial concentration in the solution used to cast the films, and carvacrol in the films remained unchanged over a storage period of up to 7 weeks.…”

Application of linear multivariate calibration techniques to identify the peaks responsible for the antioxidant activity of Satureja hortensis L. and Oliveria decumbens Vent. essential oils by gas chromatography–mass spectrometry

“…Carvacrol is a monoterpenoid phenol. It is the main compound in S. hortensis L. and has shown antibacterial properties against several bacterial strains such as Bacillus cereus and Escherichia coli through disrupting the bacterial membranes [34,35]. Thymol and carvacrol are the main compounds in O. decumbens Vent.…”