Judul: Physicochemical Properties of Fermented Cocoa Pulp and Its Ability on Starch Digestion Inhibition: In Vitro Gastrointestinal Digestion Analysis
Abstrak: Cocoa, a fruit consumed globally, is rich in bioactive compounds associated with numerous health benefits. This study investigated the chemical composition and functional properties of fermented cocoa pulp, as well as its capacity to inhibit starch digestion through in vitro gastrointestinal analysis. Cocoa pods underwent natural fermentation, producing cocoa pulp samples analyzed over the course of a week. The total phenol content reached its peak on day 7 at 294.94 µg GAE/mL, accompanied by high antioxidant activity. Gas chromatography-mass spectrometry detected the presence of acetic acid, reaching its peak on day 6. Ethanol content increased until day 7 (2.43 ppm). Statistical analyses confirmed significant daydependent effects. Fermentation time showed a positive correlation with αglucosidase and α-amylase inhibition, indicating potential for diabetes management. In vitro digestion analysis revealed decreased starch digestibility with longer fermentation, reaching optimal levels at around 60 minutes, providing insights for cocoa processing optimization.
Keyword: Cocoa pulp, fermentation, total phenol, antioxidant

Judul: Flavonoid Potential of Cacao Fermentated  Product (Theobroma cacao) by Pectinase Enzyme Induction in Inhibiting Alpha-Glucosidase Activity
Abstrak: Biji kakao banyak digemari karena memiliki cita rasa yang enak dan mengandung senyawa bioaktif berkhasiat untuk pencegahan maupun pengobatan penyakit degeneratif, seperti diabetes. Akan tetapi, fermentasi biji kakao, selain berfungsi membentuk cita rasa dan aroma khas, juga dapat mendegradasi senyawa bioaktif. Dalam penelitian ini, cairan enzim pektinase 1% ditambahkan pada biji kakao yang akan difermentasi untuk mempertahankan senyawa bioaktif yang mampu menginhibisi enzim alfa-glukosidase, yaitu polifenol dan flavonoid. Hasil fermentasi diekstraksi dengan pelarut metanol 80% kemudian dianalisis menggunakan spektofotometri dan diidentifikasi senyawa polifenol, yaitu katekin dan epikatekin, menggunakan kromatografi cairan kinerja tinggi. Hasilnya, total polifenol, flavonoid, kapasitas antioksidan, dan kamampuan inhibisi alfa-glukosidase biji kakao hasil fermentasi dengan induksi enzim pektinase meningkat masing-masing 11,44; 22,99; 38,03; dan 31,27%, Cacao beans are very popular because of good taste and contain bioactive compounds that are efficacious for preventing and treating degenerative diseases, such as diabetes. The cacao bean fermentation, in addition to functioning in the formation of distinctive flavors and aromas, can also degrade bioactive compounds. In this study, 1% pectinase enzyme liquid was added to cacao beans to be fermented to maintain bioactive compounds that can inhibit alpha-glucosidase, namely polyphenols and flavonoids. The fermented cacao beans were extracted in 80% methanol and then analyzed using spectrophotometry and identified the polyphenolic compounds, namely catechins and epicatechins, using the high-performance liquid chromatography. As a result, total polyphenols, flavonoids, antioxidant capacity, and alpha-glucosidase enzyme inhibition ability of the fermented cacao beans by pectinase induction increased by 11.44, 22.99, 38.03, and 31.27%, respectively.
Keyword: cacao beans, fermentation, pectinase enzymes, polyphenols

Judul: Penentuan Posisi Autonomous Underwater Vehicle (AUV) dengan Metode Dead Reckoning
Abstrak: AUV adalah wahana otonom bawah air yang memiliki berbagai sensor untuk akuisisi data. Alat ini dapat memudahkan survey bawah air karena bentuknya yang ringan. Misi AUV dibuat lalu disimpan ke dalam memori AUV. Penyelesaian misi memerlukan sistem navigasi yang akurat. GPS tidak bisa bekerja di dalam air sehingga dibutuhkan metode navigasi selain GPS. Dead reckoning adalah metode penentuan posisi dengan menghitung arah dan gerak AUV. Persamaan model kecepatan konstan digunakan untuk mengestimasi posisi pada saat t. Akurasi metode ini dipengaruhi banyak hal termasuk kesalahan sensor dan kondisi lingkungan. Misi dilakukan dalam 2 jalur berbeda sebanyak 3 kali. Jalur yang memiliki panjang lebih besar mempunyai kesalahan posisi yang tinggi. Ha ini disebabkan galat yang dihasilkan dead reckoning terakumulasi selama misi. Kesalahan tersebut dapat diatasi dengan memperhitungkan kondisi lingkungan pada program dead reckoning.
Keyword: AUV, DVL, Dead Reckoning, Navigasi