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: Optimization of Extraction of Phenolic Content and  Antioxidant Activity of Gandarusa (Justicia gendarussa Burm f.) Leaf with  Response Surface Methodology (RSM)
Abstrak: Ektraksi daun gandarusa (Justicia gendarussa Burm f.) dapat dipengaruhi oleh pelarut, suhu, dan waktu ekstraksi. Penelitian ini bertujuan menentukan suhu, waktu, dan konsentrasi pelarut optimum kadar total fenolik dan aktivitas antioksidan ekstrak etanol daun gandarusa dengan metode Respon Surface Methodology (RSM). Parameter uji yang dilakukan terhadap ekstrak daun gandarusa antara lain penentuan kadar total fenolik dengan metode Folin-Ciocalteu serta aktivitas antioksidan DPPH dan FRAP. Variabel bebas yang digunakan dalam desain eksperimen adalah konsentrasi etanol (10%, 50%, dan 90%), suhu (30℃, 45℃, dan 60℃) dan waktu ekstraksi (60, 120, dan 180 menit). Kadar total fenolik menunjukan korelasi yang positif dan signifikan terhadap aktivitas antioksidan FRAP daun gandarusa. Kondisi optimal untuk kadar total fenolik dan aktivitas antioksidan DPPH dan FRAP ekstrak daun gandarusa yaitu pelarut etanol 16,8%; suhu 30℃; dan waktu 180 menit. Nilai prediksi dan nilai verifikasi kadar total fenolik dan aktivitas antioksidan DPPH tidak berbeda secara signifikan., Extraction of gandarusa leaves (Justicia gendarussa Burm f. ) can be affected by solvent, temperature, and extraction time. This study aimed to determine the optimum temperature, time, and concentration of solvents, the total phenolic contents and antioxidant activity of gandarusa leaf ethanol extract by the Response Surface Methodology (RSM). Parameters of the test carried out on the extract of gandarusa leaf include determination of total phenolic contents using the Folin-Ciocalteu method as well as the antioxidant activity of DPPH and FRAP. The independent variables used in the experimental design were ethanol concentration (10%, 50%, and 90%), temperature (30℃, 45℃, and 60℃) and extraction time (60, 120, and 180 minutes). Total phenolic content showed a positive and significant correlation to the antioxidant activity of FRAP gandarusa leaves. Optimal conditions for total phenolic content and antioxidant activity of DPPH and FRAP of gandarusa leaf extract are 16,8% ethanol solvent; temperature 30℃; and time 180 minutes. The predictive value and verification value of the total phenolic content and antioxidant activity of DPPH did not different significantly.
Keyword: Antioxidant activity, gendarussa, independent variables, phenolic, RSM

Judul: : Persamaan Tunggal sebagai Representasi Kurva Komposit
Abstrak: A mathematical method is introduced to represent a composite curve based on an extension of analytic geometry. The representation is given either with a single equation or with two equations, in the case of parametric representation. This method permits the representation of composite curves in similar manner to the conventional representation of non-composite curves. Some mathematical tools, including Heaviside unit step function and periodizer function, are used in the establishment of a single equation. In this paper, regular equations of regular and irregular polygon, as well as composite curves of two dimensions, are implemented using a computer algebraic system, Mathematica.
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