Development and characterization of corn starch/PVA active films incorporated with carvacrol nanoemulsions

• Published in: International journal of biological macromolecules 2020-12, Vol.164, p.1631-1639
• Main Authors: Kong, Ruiqi, Wang, Juan, Cheng, Meng, Lu, Wenqian, Chen, Menglin, Zhang, Rongfei, Wang, Xiangyou
• Format: Article
• Language: English
• Subjects: Active film; Anti-Infective Agents - chemistry; Anti-Infective Agents - pharmacology; Antifungal Agents - chemistry; Antifungal Agents - pharmacology; Antioxidants - chemistry; Biphenyl Compounds - chemistry; Carvacrol; Corn starch; Cymenes - chemistry; Cymenes - pharmacology; Emulsions - chemistry; Free Radical Scavengers - chemistry; Nanoemulsions; Nanoparticles - chemistry; Permeability; Picrates - chemistry; Polyvinyl Alcohol - chemistry; PVA; Spectroscopy, Fourier Transform Infrared - methods; Starch - chemistry; Steam; Tensile Strength; Trichoderma - drug effects; Water - chemistry; X-Ray Diffraction - methods; Zea mays - chemistry
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2020.08.016

An active film was prepared by corn starch (CS), polyvinyl alcohol (PVA) and carvacrol nanoemulsions (CNE). The microstructure and properties of CNE/corn starch/PVA (CNE/CSP) films were characterized and investigated. Scanning electron microscopy (SEM) revealed the uniform distribution of CNE and discontinuity of the film matrix. Fourier transform infrared (FT-IR) and rheological analysis indicated that CNE could weaken molecular interaction of the film matrix. X-ray diffraction (XRD) show that the films are amorphous and CNE has no effect on crystal structure of the films. Incorporation of CNE significantly increased the tensile strength, Young's modulus, elongation at break, barrier (water vapor and ultraviolet), antioxidant and antifungal activity. With the CNE incorporated, the optimal tensile strength, Young's modulus, elongation at break and antioxidant activity of the films can reach 12 MPa, 11 MPa, 133%, 81%, respectively. Minimum water vapor permeability was 3.1 × 10−12 gd−1m−1Pa−1. Notably, films incorporated with CNE (≥20%) had good DPPH free radical scavenging ability (>50%) when stored up to 6 days. Films with 25% CNE exhibited excellent antifungal activity against Trichoderma sp. and its inhibitory zone was 47 mm. Overall, the CSP films loaded with CNE (>15%) could be used as food packing materials with good antioxidant and antimicrobial activities. •Active corn starch/PVA films were prepared by incorporating carvacrol nanoemulsions.•Carvacrol nanoemulsions droplets were evenly distributed in film matrix.•DPPH assays revealed the excellent antioxidant properties of the films loaded more than 15% CNE.•The films showed excellent antifungal effects against Trichoderma sp.