Judul: Karakterisasi Sistem Multifase yang Terdiri atas Minyak Sawit Merah dan Air dengan dengan Partikel Nano Seng Oksida sebagai Penstabil
Abstrak: This study investigated the stability and rheological properties of multiphase systems comprising red palm oil and water, with zinc oxide nanoparticles (ZnO NPs) as stabilizers. Multiphase systems with 60% and 70% oil contents exhibited excellent physical stability. To achieve a stable multiphase system, a 60% v/v oil content required 1.50% w/t ZnO NPs. However, when the oil content was increased to 70% v/v, only 0.75% w/t ZnO NPs were required. Increasing ZnO NPs concentration enhanced system stability, as demonstrated by minimal changes in the total carotenoid content and reduced lipid oxidative product formation. Based on rheological characterization, these multiphase systems exhibited shear-thinning flow behavior and viscoelastic properties. The multiphase system consisting of 70% v/v RPO stabilized by 1.50% w/t ZnO NPs was identified as the best multiphase formulation. Conclusively, the findings in this study are valuable insights for formulating stable multiphase systems, composed of red palm oil and water.
Keyword: multiphase system, red palm oil, ZnO nanoparticles, physicochemical stability

Judul: Experimental Investigation on Physical Stability of RPO-in-Water  Emulsion Stabilized by Protein and SiO2 Nanoparticles
Abstrak: As a source of Vitamin-A precursor, the stability of red palm oil (RPO) against oxidation was addressed to be improved. Emulsion containing 10% (v/v) RPO was produced using two-step homogenization, namely at 9000 rpm and 18000 rpm. This research aims to study the effect of emulsification process of RPO to enhance its stability. The used emulsifiers are whey protein concentrate (WPC), soy protein isolate (SPI), and SiO2 nanoparticles with concentration from 2.5% to 15%. The physical stability of the resulting emulsion is analyzed based on the parameters of surface colour, separation index, flow properties, and droplet size distribution. Results showed that higher emulsifier concentration (c) contributes to improve emulsion stability during storage. In this study, emulsion stabilized by SiO2/SPI 15% (SSP15) and SPI 5% (SPI5) were found as the most stable emulsion based on tested physical attributes.
Keyword: emulsion, red palm oil, SiO2 nanoparticle, whey protein concentrate, soy protein isolate

Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf