Judul: Aplikasi Plasma Dielectric Barrier DIscharge (DBD) untuk meningkatkan antioksidan dan senyawa fenol pada biji kopi Arabika (Coffea arabica)
Abstrak: Kopi Arabika Toraja merupakan salah satu kopi unggulan di Indonesia yang berasal dari Tana Toraja. Salah satu tahapan kritis kopi yaitu proses penyangraian yang mempengaruhi munculnya aroma dan rasa tetapi proses ini menyebabkan umur simpan pendek dan kandungan antioksidan berkurang. Penggunaaan teknologi plasma Dielectric Barrier Discharge (DBD) dengan menghasilkan ozon dan plasma lainnya yang dapat mempengaruhi sifat fisik dan kimia kopi. Dengan ozon tersebut diharapkan meningkatkan kualitas biji kopi, baik green bean maupun roasted bean melalui peningkatan antioksidan. Dalam penelitian dilakukan analisa pengaruh alat plasma DBD terhadap nilai antioksidan, total phenol content, kadar air, dan warna. Kadar ozon yang digunakan yaitu 5 ppm. Rancangan percobaan yang digunakan yaitu rancangan acak lengkap faktorial, dimana terdiri dari dua taraf, yaitu jenis tingkat roasting biji kopi (green bean, light roasted bean, medium roasted bean, dan dark roasted bean) dan waktu perlakuan (0 menit, 15 menit, 30 menit, 45 menit, 60 menit). Kombinasi antara dua taraf tersebut memiliki perbedaan signifikan terhadap persen inhibisi, TPC, kadar air, dan warna. Peningkatan persen inhibisi yang terjadi mencapai 22,1% dan peningkatan nilai TPC yang terjadi mencapai 19,1%., Toraja Arabica coffee is one of the leading coffees in Indonesia originating from Tana Toraja. One of the critical stages of coffee is the roasting process which affects the appearance of aroma and flavour but this process causes short shelf life and reduced antioxidant content. The use of Dielectric Barrier Discharge (DBD) plasma technology by producing ozone and other plasmas that can affect the physical and chemical properties of coffee. With ozone, it is expected to improve the quality of coffee beans, both green bean and roasted bean through increasing antioxidants. In this study, the effect of DBD plasma device on antioxidant value, total phenol content, moisture content, and colour was analysed. The ozone level used was 5 ppm. The experimental design used is a factorial complete randomised design, which consists of two levels, namely the type of roasting level of coffee beans (green bean, light roasted bean, medium roasted bean, and dark roasted bean) and treatment time (0 minutes, 15 minutes, 30 minutes, 45 minutes, 60 minutes). The combination of the two levels had significant differences in percent inhibition, TPC, moisture content, and colour. The increase in percent inhibition reached 22,1% and the increase in TPC value reached 19,1%.
Keyword: Antioksidan, arabika, plasma DBD, dielectric barrier discharge, total phenol content, fenol

Judul: Comparison of Total Phenol and Total Phenolic Acid of Bogor Arabica Coffee from Different Postharvest and Roasting Processes
Abstrak: Kopi mengandung senyawa fenolik, yang dapat dianalisis dari kandungan total fenolik atau senyawa fenolik tertentu. Komposisi dan konsentrasi fenolik dalam kopi dipengaruhi oleh proses pascapanen dan tingkat penyangraiant. Penelitian ini bertujuan untuk membandingkan rasio asam fenolat (diukur sebagai asam klorogenat) terhadap total kandungan fenolik dalam kopi arabika Bogor, dengan mempertimbangkan perlakuan pascapanen dan tingkat penyangraian yang berbeda. Sampel kopi diberikan perlakuan pascapanen (kering, basah, dan madu) dan penyangraian (ringan dan gelap). Proses penyangraian melibatkan pemanasan kopi pada suhu antara 147,9°C hingga 178,8°C untuk penyangraian ringan, dan 190,2°C hingga 200°C untuk penyangraian gelap (masing-masing selama 10 menit). Biji kopi hijau digunakan sebagai kontrol. Warna biji kopi, konsentrasi asam fenolik dalam ekstrak kopi, dan konsentrasi fenolik total dalam ekstrak kopi dianalisis dengan colorimeter, HPLC, dan spektrofotometer secara berturut-turut. Hasil penelitian menunjukkan bahwa penyangraian secara signifikan memperkuat warna gelap kopi arabika Bogor. Di antara asam fenolat, isomer 5-CQA muncul sebagai yang paling dominan dan juga paling rentan terhadap degradasi selama penyangraian. Seiring dengan peningkatan tingkat penyangraian, konsentrasi asam fenolat secara konsisten menurun. Kandungan total fenolik pada awalnya meningkat pada kopi ringan namun kembali menurun pada kopi gelap. Biji kopi hijau memiliki proporsi asam fenolat tertinggi (83%), sedangkan kopi gelap memiliki proporsi terendah (19%). Meskipun kopi ringan memiliki kandungan total fenolik tertinggi, konsentrasi asam fenolat menurun secara signifikan dibandingkan dengan biji kopi hijau., Coffee contains abundant phenolic compounds, which can be evaluated either collectively as total phenolics or individually as specific phenolic components. The presence and amount of phenolics in coffee are influenced by various factors, including postharvest treatments and the roasting process. This study aimed to compare the ratio of phenolic acid, specifically chlorogenic acid, to the total phenolic content in Bogor arabica coffee, considering different postharvest treatments and roasting levels. The coffee samples underwent different postharvest treatments (dry, wet, and honey) and were subjected to two types of roasting processes (light and dark). Green coffee beans were used as the control. The roasting procedure involved heating the coffee within the temperature range of 147.9°C to 178.8°C for light roasting and 190.2°C to 200°C for dark roasting (each for 10 minutes). The color of the coffee beans, the concentration of phenolic acid in the coffee extract, and the total phenolic content in the coffee extract were analyzed using a colorimeter, high-performance liquid chromatography (HPLC), and spectrophotometer, respectively. The findings revealed that roasting significantly intensified the dark color of Bogor arabica coffee. Among the phenolic acids, the 5-CQA isomer emerged as the most dominant and was also the most susceptible to degradation during the roasting process. As the roasting level increased, the concentration of phenolic acid consistently decreased. Interestingly, the total phenolic content initially increased in light-roasted coffee but decreased in dark-roasted coffee. Green coffee beans exhibited the highest proportion of phenolic acid (83%), whereas dark-roasted coffee had the lowest proportion (19%). Although light-roasted coffee had the highest total phenolic content, its phenolic acid concentration decreased significantly compared to green coffee beans.
Keyword: asam fenolat, kopi arabika, penyangraian, perlakuan pascapanen, total fenolat

Judul: Posisi Filogenetik Kura-Kura Carettochelys Insculpta  (Reptillia: Testudinata)
Abstrak: Carettochelys insculpta is an endemic freshwater turtle of southern Papua and northern Australia. Phylogenetic position of this turtle is remain unresolved until now. Most of the research conducted show close relationships of C. insculpta and members of Trionychidae family. However, some of the research show distance between C. insculpta and members of Trionychidae family. This research is conducted to analyze phylogenetic relationship between C. insculpta and other members of Testudinata using 12S rRNA, 16S rRNA, and both gene as markers. DNA samples were obtained from three different organisms of C. insculpta. Two species used as outgroups were Alligator mississippiensis and Iguana iguana. Phylogenetic analysis was carried out using Neighbor-Joining method with Felsenstein 1981 (F81) modeltest. A polytomy tree of Testudinata was produced by using 12S rRNA gene. However, analysis using 16S rRNA and both genes as markers confirmed that C. insculpta was located between the Chelonidae and the Trionychidae family.
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