Release kinetics of carvacrol and eugenol from poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) films for food packaging applications

Abstract

Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) films, plasticized with PEG, incorporating 13 wt. % of active compounds (carvacrol-CA, eugenol-EU) were obtained by spraying the active between PHBV layers and their subsequent adhesion. Release kinetics of CA and EU in food simulants of different polarity was analysed and the films' antimicrobial activity was predicted, taking the minimal inhibitory concentration against some foodborne pathogens into account. Overall migration values were also determined. At equilibrium, an almost total release of both CA and EU occurred in 50% ethanol, about 20 and 50 % of CA and EU, respectively, was delivered in the more aqueous simulants and 65-70 % in fatty systems. The release rate increased when the polarity of aqueous simulants decreased, but it fell markedly in fatty systems. EU was released faster than CA in the less polar simulants, but more slowly in the more aqueous systems.

Bioactive Starch Foam Composite Enriched With Natural Antioxidants from Spent Coffee Ground and Essential Oil

“…The diffusion of active compound consisted of three steps that is, (i) the diffusion of solvent into polymer matrix; (ii) polymer network relaxation by solvation and plasticization; and (iii) the diffusion of active compound through the relaxed polymer network until the thermodynamic equilibrium phase. The active compound diffusion was affected by pH and polarity of the impregnated solvent . The rate constant of diffusion was summarized in Table .…”

“…The release profile of polyphenols can be determined by Korsmeyer‐Peppas model . This model was widely applied to study the possible coupling of the relaxation of polymer in contact with the solvent with the diffusion of the active compound through the polymer matrix,, as shown in Eq . where is the fraction of active compound release at time (t), k is the rate constant of diffusion and n is the difusional exponent related to release process.…”

“…This mechanism indicated that the major diffusion is release of active compound whereas the relaxation of polymer matrix in contact with the solvents was not coupled with the release process . The observation is in good agreement with other active compounds in various polymer matrices such as Satureja hortensis essential oil in alginate, lemongrass oil in alginate film, carvacrol and eugenol in poly (hydroxybutyrate‐co‐hydroxyvalerate) . Many approaches were studied to explain the phenomenon occurred in the release of active compound in polymer matrix.…”

Release kinetics and antimicrobial properties of carvacrol encapsulated in electrospun poly-(ε-caprolactone) nanofibres. Application in starch multilayer films

“…The kinetic study of CA release from the electrospun PCL fibres was carried out in four types of solvents, acting as food simulants of different polarities or pH (Regulation 10/2011/EC). As described by Requena et al (2017), ethanol 10% (v/v) (simulant A) and acetic acid 3% (w/v) (simulant B) were chosen to emulate aqueous foodstuffs neutral and acidic (pH<4.5) in character, respectively. Ethanol 50% (v/v) (simulant D1) was used to imitate foods with alcohol content higher than 20% or oil-in-water emulsions, whereas isooctane (simulant D2) was used for foods with a highly lipophilic surface.…”

Designing for effective controlled release in agricultural products: new insights into the complex nature of the polymer–active agent relationship and implications for use

“…The present study builds on our previous work, 13 where DCD was extruded as a composite material within a biodegradable polymer matrix, namely poly(3‐hydroxybutyrate‐ co ‐3‐hydroxyvalerate) (PHBV). This bacterial polyester has been studied extensively for the controlled release of drugs, 14–16 food packaging additives 17 and agrichemicals 18–22 due to its ability to slow the rate of water diffusion, biocompatibility and biodegradability in almost any environment, including soils, fresh water systems and oceans. Our previous study revealed that, at loading of 250 g kg −1 mobilization of DCD from the PHBV matrix occurs via four distinct mechanisms: (i) initial rapid dissolution of surface available DCD, (ii) channelling of water through voids and pores in the PHBV matrix, (iii) gradual diffusion of water and DCD through layers of PHBV, and (iv) biodegradation of the PHBV matrix 13 .…”