Judul: Pengembangan Bionanokomposit Film Berbasis Tapioka/Nanopartikel Perak dan Tapioka/Nanopartikel Seng Oksida dengan Plasticizer Gliserol.
Abstrak: Cassava starch can be formed into bioplastic film which is transparance as synthetic plastic films. However, pure cassava starch film has some drawbacks such as brittle, poor barrier to water vapour, sensitive to humidity and not stable during the application. The addition of nanoparticles in film was intended to increase the elongation and tensile strength, moisture stability and to provide antimicrobial activity. Meanwhile, the addition of glycerol was intended to increase the plasticity of films so they will not be easily cracked. The main purpose of this research is to elaborate the functional packaging characteristics of bionanocomposites films made from cassava starch with or without silver nanoparticles (Ag-Np) of zinc oxide nanoparticles (ZnO-Np) with glycerol as plasticizer. The addition of nanoparticles was conducted at the amount of 0%, 0,5%, and 1% by weight of the starch, whereas glycerol was used at the amount of 0% and 20% by weight of the solids (starch only or starch+nanoparticles). The value of water vapor transmission decreased significantly with the addition of Ag-Np and ZnO-Np at the concentration of 1% (from 18,0569 g/hm2 to 12,0574 g/hm2) so it enhance the water barrier of the films as packaging materials. The addition of Ag-Np and ZnO-Np at the amount of 1% with 20% of glycerol was also able to inreased the value of elongation (from 1,2% to 88,8%), but decreased the value of tensile strength (from 22,93 MPa to 4,03 MPa). The addition of glycerol gave contrary effect to the tensile strength because it produces low tensile strength values. Moreover, the results show that films made with ZnO-Np had a stronger antimicrobial activity than those made with Ag-Np for both gram positive and gram negative bacteria. In overall, it seems that the formulation of 1% ZnO-Np is the best formulation for developing bionanocomposite film based on cassava starch.
Keyword: Bionanocomposite Films, Silver Nanoparticle (Ag-Np), Zinc Oxide Nanoparticle (ZnO-Np), Cassava Starch, Antibacterial Films

Judul: Film Berbasis Pati Beras Diinkorporasi dengan Nanopartikel ZnO
Abstrak: 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
Keyword: Bogor Agricultural University, Institut Pertanian Bogor, IPB, Antimicrobial packaging, Nanocomposite film, Hidrotermal, Sorbitol, Inkorporasi

Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh.
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. ,,,
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular.