Rice Starch Based Film Incorporated with Zinc Oxide Nanoparticles

Abstract

This study aimed to develop rice starch-based antimicrobial film with zinc oxide nanoparticles (ZnO-NPs) incorporation. ZnO-NPs were synthesized by hydrothermal method and their formation was confirmed by using XRD analysis. The synthesized ZnO-NPs showed an average diameter size of 79.25 ± 0.69 nm with spherical shape under the scanning electron microscope (SEM). The nanoparticles were tested against Gram-positive and Gram-negative bacteria; Staphylococcus aureus and Escherichia coli at different concentrations (1, 3, and 5 %, w/v) and found effective against both microorganisms. The ZnO-NPs (3 %, w/w) was selected for the incorporation into rice starch-based (5 %) antimicrobial film with sorbitol as plasticizer via solution casting method. Physical, mechanical, chemical and antimicrobial properties of the films were examined. Presence and distribution of nanoparticles in the film were confirmed with SEM and FTIR. Incorporation of ZnO-NPs significantly decreased (p<0.05) the transparency (2.64 ± 0.01), solubility (19.24 ± 0.78 %), WVP (0.04 ± 0.00 x 10-10 g m/m2 Pa s), and elongation at break (37.18 ± 2.71 %), while increased the lightness (89.72 ± 0.04) and tensile strength (9.14 ± 0.75 MPa) of the film were observed (p<0.05). The rice starch/ZnO-NPs film showed antibacterial activity against tested bacteria. These results suggest that rice starch/ZnO-NPs film had the potential to be used as an active packaging material. Keywords: antimicrobial packaging, nanocomposite film, nanoparticles, rice starch, zinc oxide

Studi bertujuan untuk mengembangkan film anti mikroba berbasis pati beras diinkorporasi dengan nano partikel ZnO (ZnO-NPs). ZnO-NPs disintesis dengan metode hidrotermal dan pembentukannya dikonfirmasi dengan menggunakan analisis XRD. ZnO-NPs yang disintesis menunjukkan ukuran diameter rata-rata 79.25 ± 0.69 nm dengan bentuk bulat dengan analisis SEM. Aktivitas antimikroba ZnO-NPs diuji terhadap bakteri Gram-positif dan Gram-negatif; Staphylococcus aureus dan Escherichia coli pada konsentrasi yang berbeda (1, 3, dan 5%, b/v) dan efektif terhadap kedua mikroorganisme. ZnO-NPs (3%, b/b) dipilih untuk diinkorporasikan ke dalam film anti mikroba berbasis pati beras (5%) dengan sorbitol sebagai plasticizer dengan metode solution casting. Sifat fisik, mekanik, kimia dan anti mikroba dari film diuji. Keberadaan dan distribusi partikel nano padafilm dikonfirmasi dengan SEM dan FTIR. Inkorporasi ZnO-NPs pada film berbasis pati beras secara signifikan menurunkan (p<0.05) transparansi film (2.64 ± 0.01), kelarutan film (19.24 ± 0.78 %), WVP (0.04 ± 0.00 x 10-10 g m/m2 Pa), dan elongation at break (37.18 ± 2.71 %), sementara terjadi peningkatan kecerahan film (89.72 ± 0.04) dan kekuatan tarik film (9.14 ± 0.75 MPa) (p <0.05). Film berbasis pati beras dengan inkorporasi ZnO-NPs menunjukkan aktivitas antibakteri terhadap bakteri yang diuji. Hasil ini menunjukkan bahwa film pati beras / ZnO-NPs memiliki potensi untuk digunakan sebagai bahan kemasan aktif. Kata kunci: film antimikroba, film nanokomposit, nanopartikel, pati beras, seng oksida