Judul: Aktivitas Antibakteri Minyak Biji Pala (Myristica fragrans H) Terenkapsulasi pada Pure Jambu Biji Merah (Psidium guajava L)
Abstrak: Preservation of fruit puree is highly dependent on the chemical preservatives and frozen storage temperature. Some species of plants have inhibitory activity of microbes and could be developed as a natural preservatives, such as nutmeg seed oil. Antibacterial activity of nutmeg seed oil encapsulated against Staphylococcus aureus, Escherichia coli, dan Lactobacillus delbrueckii with concentrations 0,06%, 0,12%, and 0,60% (w/v) were analyzed and applied into red guava puree. The inhibitory activities were indicated by decreased amount of bacteria with certain time by pour plate methode. The result showed that S. aureus was the most sensitive bacteria while L. delbrueckii was the most resistant bacteria. Concentration MBPTe 0,6% and contact time 24 hours can decrease S. aureus (2,14 log CFU/ml), E. coli (0,92 log CFU/ml), and L. delbrueckii (0,44 log CFU/ml). Application in red guava pure showed concentration 1,2% and contact time 6 hours reduced S. aureus (3,20 log CFU/ml) and E. coli (2,59 log CFU/ml) while L. delbrueckii after contact 24 hours (1,17 log CFU/ml).
Keyword: red guava puree, preservative, nutmeg seed oil, encapsulation

Judul: Aktivitas Antifungi Minyak Biji Pala (Myristica fragrans) Terenkapsulasi pada Pure Jambu Biji Merah (Psidium guajava)
Abstrak: The purpose of this research was to study the antifungal activity of encapsulated nutmeg seed oil towards spoilage mold and yeast from red guava puree by contact method in 37 oC for 5 days. Yeast and mold were isolated from 5-days-storage of red guava puree and were identified as Rhodotorula sp., Aspergillus niger, and Aspergillus flavus. Those isolated yeast and mold and Saccharomyces cerevisiae were used as the tested fungi. The result showed that 1 % (w/v) of encapsulated nutmeg seed oil could reduce 8.67 log CFU/ml S. cerevisiae, 4.94 log CFU/ml Rhodotorula sp., 3.37 log CFU/ml A. niger, and 2.10 log CFU/ml A. flavus in PDB media. Encapsulated nutmeg seed oil with 2 % (w/v) concentration in red guava puree could reduce 6.27 log CFU/ml S. cerevisiae, 2.36 log CFU/ml Rhodotorula sp., 4.75 log CFU/ml A. niger, dan 7.04 log CFU/ml A. flavus
Keyword: red guava puree, encapsulated nutmeg seed oil, antifungal activity

Judul: Solusi Geometri Schwarzschild untuk Dimensi 4+1 dengan Invarian Rotasi Isotropik
Abstrak: Metrik Schwarzschild merupakan solusi eksak pertama dari persamaan medan Einstein dengan mangasumsikan metrik statik dan simetris. Metrik Schwarzschild yang ditemukan oleh Karl Schwarzschild masih dalam dimensi 3+1, namun seiring dengan teori-teori terbaru yang menunjukkan bahwa alam semesta tidak hanya di dimensi 3+1. Maka melalui penambahan dimensi, tujuan penelitian ini memperoleh solusi pada geometri Schwarzschild untuk dimensi 4+1 dengan memodifikasi koordinat bola yang invarian rotasi isotropik dan melalui penurunan rumus seperti koordinat bola, simbol Christoffel, dan tensor Ricci. Selain mendapatkan solusi ini, metrik Schwarzschild dimensi 4+1 dapat digunakan sebagai metrik dasar untuk memperoleh solusi blackhole dan wormhole pada dimensi 4+1. Hasil akhirnya, dengan memanfaatkan modifikasi koordinat bola, metrik Schwarzschild dapat dibentuk sehingga diperoleh solusi geometri Schwarzschild untuk dimensi 4+1.
Keyword: metrik Schwarzschild, persamaan medan Einstein, modifikasi koordinat bola, penambahan dimensi, invarian rotasi isotropik