Pengaruh Lakase-endospora dari Bacillus subtilis Pada Karakter Kimia Buah Ceri Kopi Arabika (Coffea arabica)

Putri, Arum Maulinda (2026) Pengaruh Lakase-endospora dari Bacillus subtilis Pada Karakter Kimia Buah Ceri Kopi Arabika (Coffea arabica). Masters thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Produksi lakase-endospora dari Bacillus subtilis menarik perhatian karena kemampuannya bertahan pada kondisi ekstrem, sehingga berpotensi digunakan sebagai biokatalis pada fermentasi buah kopi Arabika. Buah ceri kopi memiliki kandungan senyawa fenolik yang tinggi serta mucilage yang kaya gula pereduksi. Penelitian ini bertujuan untuk mengetahui pengaruh lakase-endospora B. subtilis terhadap kadar fenolik, kapasitas antioksidan, dan gula pereduksi pada buah ceri kopi Arabika. Lakase-endospora diproduksi pada media DSM, diuji aktivitasnya dengan substrat ABTS, lalu diaplikasikan pada inkubasi buah kopi selama 24 jam dengan konsentrasi 10⁹ sel/mL melalui pengolahan natural dan full-washed. Analisis fenolik, antioksidan, dan gula pereduksi masing-masing dilakukan menggunakan reagen Folin–Ciocalteu, DPPH, dan DNS. Hasil menunjukkan bahwa kontrol memiliki kadar fenolik lebih tinggi (33,56 mgGAE/mL pada 30°C, natural), sedangkan perlakuan lakase-endospora menurunkan kadar fenolik hingga 14,39 mgGAE/mL pada 70°C akibat oksidasi enzimatik yang tetap aktif pada suhu tinggi. Kapasitas antioksidan pada kontrol berada pada kisaran 47,4–64,5% inhibisi, sementara perlakuan lakase-endospora meningkat hingga 73,2% inhibisi pada 70°C (full-washed). Kadar gula pereduksi pada kontrol sebesar 20,32 mg/mL (natural 70°C), sedangkan pada perlakuan lakase-endospora meningkat sebesar 22,39 mg/mL (natural 70°C), menunjukkan perubahan dinamika gula selama proses inkubasi.
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The production of laccase–endospores from Bacillus subtilis has attracted considerable attention due to their ability to withstand extreme conditions, making them promising biocatalysts for use in Arabica coffee fruit fermentation. Coffee cherries are rich in phenolic compounds and contain mucilage with high levels of reducing sugars. This study aimed to evaluate the effect of B. subtilis laccase– endospores on phenolic content, antioxidant capacity, and reducing sugar levels in Arabica coffee cherries. Laccase–endospores were produced in DSM medium, and their activity was evaluated using ABTS as a substrate before being applied to coffee cherry incubation for 24 hours at a concentration of 10⁹ cells/mL under natural and full-washed processing. Phenolic content, antioxidant capacity, and reducing sugars were analyzed using the Folin–Ciocalteu, DPPH, and DNS methods. The results showed that the control treatment exhibited higher phenolic content (33.56 mg GAE/mL at 30°C under natural processing), whereas laccase– endospore treatment reduced phenolic levels to 14.39 mg GAE/mL at 70°C due to enzymatic oxidation that remained active at elevated temperatures. Antioxidant capacity in the control ranged from 47.4% to 64.5% inhibition, while laccase– endospore treatment increased antioxidant activity to 73.2% inhibition at 70°C under full-washed processing. The reducing sugar content in the control was 20.32 mg/mL (natural processing at 70°C), whereas laccase–endospore treatment increased reducing sugar levels to 22.39 mg/mL (natural processing at 70°C), indicating changes in sugar dynamics during the incubation process.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	Antioksidan, Bacillus-subtilis, Lakase-endospora, Kopi-Arabika, Fenolik.Antioxidants, Arabica-Coffee, Bacillus-subtilis, Laccase-Endospores, Phenolic
Subjects:	Q Science > QR Microbiology > QR74.8 Bacteria
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Biology > 46101-(S2) Master Thesis
Depositing User:	Arum Maulinda Putri
Date Deposited:	22 Jan 2026 09:54
Last Modified:	22 Jan 2026 09:54
URI:	http://repository.its.ac.id/id/eprint/130127

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