Judul: Aktivitas Antioksidan Hasil Fermentasi Media Padat Berbasis Gandarusa (Justicia gendarussa Burm. f.) oleh Aspergillus oryzae
Abstrak: Gandarusa menghasilkan metabolit sekunder yang memiliki potensi sebagai senyawa antioksidan. Penelitian ini bertujuan menentukan aktivitas antioksidan serta menentukan pelarut terbaik untuk mengekstraksi hasil fermentasi media padat berbasis kedelai dan gandarusa oleh Aspergillus oryzae. Kadar total fenolik dan flavonoid tertinggi diperoleh pada ekstrak etil asetat fermentasi campuran media kedelai dan gandarusa (1:1) serta gandarusa (16,668 mg GAE/g ekstrak dan 21,822 mg QE/g ekstrak). Aktivitas antioksidan DPPH dan ABTS tertinggi diperoleh pada ekstrak metanol fermentasi gandarusa dan campuran kedelai dan gandarusa (1:1) (4,964 mg TE/g ekstrak dan 63,35 mg TE/g ekstrak). Aktivitas antioksidan FRAP tertinggi diperoleh pada ekstrak etil asetat gandarusa tanpa fermentasi dengan nilai 106,004 mg TE/g ekstrak. Kadar total fenolik dan flavonoid menunjukkan korelasi positif dengan aktivitas antioksidan FRAP dan ABTS namun tidak berkorelasi dengan aktivitas antioksidan DPPH. Pelarut terbaik untuk mengekstraksi hasil fermentasi media padat berbasis kedelai dan gandarusa yaitu metanol., Gandarusa produce many secondary metabolites that have potential as antioxidant. This research aims to measured the activity of antioxidant and determining the best solvent to extract soybean and gandarusa-based solid media fermentation by Aspergillus oryzae. The highest phenolic and flavonoid content was obtained by ethyl acetate extract of fermented soybean-gandarusa (1:1) and gandarusa, respectively (16,668 mg GAE/g extract, 21,822 mg QE/g extract). The highest antioxidant activity of DPPH and ABTS methods was obtained by methanol extract of fermented gandarusa and soybean-gandarusa (1:1), respectively (4,964 mg TE/g extract, 63,35 mg TE/g extract). The highest activity antioxidant of FRAP method was found in ethyl acetat extract of non-fermented gandarusa (106,004 mg TE/g extract). Total phenolic and flavonoid content had a strong positive and significant correlation with antioxidant activity of FRAP and ABTS methods, while there is no significant correlation with antioxidant activity of DPPH method. The best solvent to extract secondary metabolite of fermented soybean and gendarussa-based solid media is methanol.
Keyword: antioxidant, flavonoid, gandarusa, phenolic, solid-state fermentation

Judul: Optimasi Fermentasi Justicia gendarussa Burm.f. oleh Aspergillus oryzae Berdasarkan Respon Kapasitas Antioksidan, Total Fenolik dan Flavonoid
Abstrak: Gandarusa mempunyai aktivitas antioksidan yang diduga berasal dari senyawa flavonoid dan fenolik. Faktor-faktor yang mempengaruhi hasil fermentasi padat oleh Aspergillus oryzae belum diketahui, sehingga diperlukan penelitian mengenai optimasi fermentasi untuk memaksimalkan potensi tersebut. Proses fermentasi diberi perlakuan seperti suhu, waktu, konsentrasi inokulum, dan kelembaban. Faktor suhu dan kelembaban mempengaruhi proses selama pertumbuhan jamur pada media, parameter tersebut tidak lepas dari parameter waktu fermentasi. Semakin lama waktu fermentasi maka kandungan total fenolik dan kapasitas antioksidannya semakin tinggi. Fermentasi tanaman gandarusa dengan Aspergillus oryzae mengalami peningkatan nilai kandungan total fenolik dan flavonoid, kapasitas antioksidan metode DPPH dan FRAP dibandingkan dengan tanaman gandarusa yang tidak difermentasi. Rancangan fermentasi optimal yang diperoleh adalah, waktu fermentasi 14 hari, suhu fermentasi 45°C, kelembaban 20% total kadar air, dan konsentrasi inokulum 20%., Gandarusa has antioxidant activity that is believed to come from flavonoid and phenolic compounds. Factors influencing solid-state fermentation outcomes by Aspergillus oryzae are not yet known, so research is needed to optimize fermentation to maximize this potential. The fermentation process involves variables such as temperature, time, inoculum concentration, and humidity. Temperature and humidity factors affect the process during fungal growth in the media, and these parameters are closely linked to fermentation time. The longer the fermentation time, the higher the total phenolic content and antioxidant capacity. Fermentation of Gandarusa plants with Aspergillus oryzae leads to increased total phenolic and flavonoid content, as well as antioxidant capacity using DPPH and FRAP methods compared to non-fermented Gandarusa plants. The optimal fermentation design obtained includes a fermentation time of 14 days, fermentation temperature of 45°C, humidity of 20% total moisture content, and inoculum concentration of 20%.
Keyword: antioxidant, Aspergillus oryzae, Justicia gendarusssa, phenolic, solidstate fermentation

Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model