Optical, mechanical, and antimicrobial properties of bio‐based composites of poly(L‐lactic acid) and D‐limonene/β‐cyclodextrin inclusion complex

Abstract

Composites made of poly(L-lactic acid) (PLLA) and β-cyclodextrin/D-limonene inclusion complex (CD-Lim) are prepared to develop novel food packaging material with antibacterial properties. The composites are formulated with bio-based materials that are also biodegradable. The addition of CD-Lim to PLLA results in enhanced permeability and water uptake. Optical properties of PLLA/CD-Lim composites also significantly vary compared to plain PLLA, with partial loss of transparency and gloss, but sizably increased barrier to UV light, which imparts protection from oxidation to lipid-containing food. The mechanical properties of the composite films are also affected by composition. Most notably, PLLA films containing CD-Lim display significant antibacterial and antifungal properties, proving their potential as active food packaging films.

Thermal and Morphological Analysis of Linear Low-Density Polyethylene Composites Containing d-limonene/β-cyclodextrin for Active Food Packaging

“…Therefore, the authors proposed an effective route that enabled enhancing the thermal stability of an antimicrobial agent, i.e., the encapsulation of an essential oil, namely, d -limonene, within a cyclodextrin cage-like host (CD-lim inclusion complex). This has been widely discussed in our previous publications [ 20 , 21 , 22 ]. We proved that the CD-lim content in poly(butylene succinate) (PBS) and poly(lactic acid) (PLLA) matrices is able to extend shelf life and improve product quality by both preventing bacteria and fungi growth and enhancing UV protection.…”

“…An inclusion complex of β-cyclodextrin and d -limonene was obtained via precipitation, as detailed in our previous works [ 20 , 21 , 22 ]. PE pellets were mixed with CD-lim complex in a rotary mixer Retsch, type GM 200 for 3 min at a rotation speed of 2000 rpm.…”

“…To the best of our knowledge, such a coordinated system consisting of PE and the CD-lim inclusion complex has not been presented in the literature yet. The idea exploited the outstanding antibacterial properties of encapsulated d -limonene, as proved in our previous publications [ 20 , 21 , 22 ], which was further dispersed within the linear low-density polyethylene matrix. To our knowledge, only limited literature is available on polyethylene-based composites containing β-CD filled with an active compound: an essential oil, such as carvacrol and cinnamaldehyde [ 24 ], or Ferula asafoetida leaf and gum extract [ 25 ], but no data are available on PE containing the CD-lim inclusion complex.…”

Linear low‐density polyethylene modified with d‐limonene/β‐cyclodextrin inclusion complex: Antimicrobial composite for active food packaging

“…28 To improve thermal stability of D-limonene, an inclusion complex, where D-limonene molecules are trapped within β-cyclodextrin molecules (CD-lim) has been developed. [29][30][31][32] This procedure greatly limits the terpene evaporation during preparation of polymerbased composites via melt processing, as detailed in Dobrzy nska-Mizera et al, 32 also ensuring excellent germicidal properties retained upon inclusion with the efficiency against pathogen growth, as proven for CD-lim added as filler to poly(L-lactic acid). 30 The aim of this research is to investigate suitability of this polyethylene-based composite for active food packaging.…”

“…[29][30][31][32] This procedure greatly limits the terpene evaporation during preparation of polymerbased composites via melt processing, as detailed in Dobrzy nska-Mizera et al, 32 also ensuring excellent germicidal properties retained upon inclusion with the efficiency against pathogen growth, as proven for CD-lim added as filler to poly(L-lactic acid). 30 The aim of this research is to investigate suitability of this polyethylene-based composite for active food packaging. Melt processing via twin-screw extrusion was exploited to prepare PE/CD-lim composites without marked loss of the antimicrobial volatile essential oil.…”