Electronic Theses and Dissertation

Pliek u merupakan produk fermentasi tradisional khas aceh yang dihasilkan dari fermentasi daging buah kelapa, yang dimanfaatkan sebagai bahan pangan. tujuan penelitian adalah mengetahui keragaman mikroba berdasarkan identifikasi metagenomik, mengidentifikasi profil metabolit sekunder melalui analisis metabolomik menggunakan liquid-chromatography-high resolution mass spectrometry (lc-hrms), mengetahui karakteristik pliek u berdasarkan uji proksimat (kadar protein, kadar air, dan kadar lemak), serta aktivitas biologi (aktivitas antioksidan dan antibakteri). hasil analisis metagenomik menunjukkan bahwa keragaman mikroba yang terdapat pada pliek u didominansi oleh bakteri asam laktat, bakteri fermentatif dan khamir. sampel pliek u aceh besar (pa) didominansi oleh bakteri lactobacillus kitasatonis (12,79%), lactobacillus crispatus (10,90%), dan khamir pichia ethanolica (63,91%), pichia kudriavzevii (30,58%), sedangkan sampel pliek u bireun (pb) didominansi oleh bakteri bacillus subtilis (10,60%), lactobacillus amylovorus (8,30%) dan khamir pichia kudriavzevii (63,68%) dan candida tropicalis (16,89%). analisis metabolomik berhasil mengidentifikasi 44 senyawa bioaktif yang berperan dalam aktivitas biologi pliek u, terutama kelompok asam lemak, amida, dan peptida. kadar total fenol dan flavonoid lebih tinggi pada sampel pa dibandingkan pb. namun pengujian aktivitas antioksidan menunjukkan sebaliknya, sampel pb (12,74±1,15%) memiliki nilai persen inhibisi yang lebih tinggi dibandingkan sampel pa (9,86±1,13%). pengujian aktivitas antibakteri menunjukkan bahwa pliek u memiliki kemampuan menghambat pertumbuhan bakteri patogen. hasil uji proksimat menunjukkan bahwa kadar air, kadar lemak, dan protein pada sampel pa berturut-turut sebesar 7,43%, 41,15%, dan 17,65%, sedangkan pada sampel pb sebesar 11,97%, 46,37%, dan 15,57%. kata kunci : aktivitas antibakteri, aktivitas antioksidan, metabolomik, metagenomik, pangan tradisional, dan pliek u

Pliek U is a traditional fermented product native to Aceh made from the fermentation of coconut meat, which is used as a food ingredient. The objectives of this study were to determine microbial diversity based on metagenomic identification, to identify secondary metabolite profiles through metabolomic analysis using Liquid-Chromatography-High Resolution Mass Spectrometry (LC-HRMS), to determine the characteristics of Pliek U based on proximate analysis (protein content, moisture content, and fat content), as well as biological activity (antioxidant and antibacterial activity). Metagenomic analysis results showed that the microbial diversity in Pliek U was dominated by lactic acid bacteria and fermentative bacteria. Sample PA was dominated by Lactobacillus kitasatonis (12.79%), Lactobacillus crispatus (10.90%), and yeasts Pichia ethanolica (63,91%) and Pichia kudriavzevii (30,58%), while sample PB was dominated by Bacillus subtilis (10.60%), Lactobacillus amylovorus (8.30%), and the yeasts Pichia kudriavzevii (63,68%) and Candida tropicalis (16,89%). Metabolomic analysis successfully identified 44 bioactive compounds involved in the biological activity of Pliek U, particularly fatty acids, amides, and peptides. Total phenol and flavonoid levels were higher in the PA sample compared to the PB sample. However, antioxidant activity testing showed the opposite; the PB sample (12.74±1.15%) had a higher percentage inhibition value compared to the PA sample (9.86±1.13%). Antibacterial activity testing indicated that Pliek U possesses the ability to inhibit the growth of pathogenic bacteria. The proximate analysis results showed that the moisture, fat, and protein contents in the PA sample were 7.43%, 41.15%, and 17.65%, respectively, while those in the PB sample were 11.97%, 46.37%, and 15.57%. Keywords : Antibacterial activity, antioxidant activity, metabolomics, metagenomics, tradisional food, and Pliek U