Isolation of Protein and Lactic Acid Bacteria from Modified Dali Ni Horbo Traditional Food as Probiotic Candidates / Isolasi Protein dan Bakteri Asam Laktat dari Pangan Tradisional Dali Ni Horbo yang Dimodifikasi sebagai Kandidat Probiotik

Background: Dali ni horbo is a traditional North Sumatran food made from buffalo milk that has potential as a source of protein and lactic acid bacteria (LAB). Its high nutritional content and fermentation process make it a promising candidate for functional food development with probiotic properties. Objective: This study aimed to isolate and characterize proteins and LAB from dali ni horbo produced using different treatments, namely pure buffalo milk, the addition of pineapple juice, and the addition of citrus juice. Methods: Protein isolation was carried out using the ammonium sulfate precipitation method, while LAB were isolated on MRS agar supplemented with CaCO₃. Protein characterization was performed using biuret, ninhydrin, and xanthoprotein tests. LAB characterization included Gram staining, catalase test, and bile salt tolerance test. Results: The results showed that the protein isolate obtained using pineapple as a coagulant had the highest yield (2.3321 g) compared to citrus (1.8516 g). All protein isolates tested positive for biuret, ninhydrin, and xanthoprotein, indicating the presence of peptide bonds, amino acids, and aromatic groups. A total of 18 LAB isolates were obtained, all of which were Gram-positive, rod-shaped, catalase-negative, and tolerant to bile salts. Conclusion: Dali ni horbo has strong potential as a source of protein and probiotic candidates, indicating its applicability as a functional food to support health.

Latar belakang: Dali ni horbo merupakan pangan tradisional khas Sumatera Utara berbasis susu kerbau yang berpotensi sebagai sumber protein dan bakteri asam laktat (BAL). Kandungan nutrisi yang tinggi serta proses fermentasi menjadikan produk ini berpotensi dikembangkan sebagai pangan fungsional berbasis probiotik. Tujuan: Penelitian ini bertujuan untuk mengisolasi dan mengkarakterisasi protein serta BAL dari dali ni horbo yang dibuat dengan variasi perlakuan, yaitu susu kerbau murni, penambahan perasan nanas, dan penambahan perasan jeruk. Metode: Isolasi protein dilakukan menggunakan metode presipitasi amonium sulfat, sedangkan isolasi BAL menggunakan media MRS agar yang diperkaya CaCO₃. Karakterisasi protein dilakukan melalui uji biuret, ninhidrin, dan xantoprotein. Karakterisasi BAL meliputi pewarnaan Gram, uji katalase, serta uji toleransi terhadap garam empedu. Hasil: Hasil penelitian menunjukkan bahwa isolat protein dari perlakuan koagulan nanas memiliki berat tertinggi (2,3321 g) dibandingkan jeruk nipis (1,8516 g). Seluruh isolat protein menunjukkan hasil positif pada uji biuret, ninhidrin, dan xantoprotein yang mengindikasikan adanya ikatan peptida, asam amino, dan gugus aromatik. Isolasi BAL menghasilkan 18 isolat murni dengan karakteristik Gram positif, berbentuk batang, katalase negatif, serta mampu tumbuh pada media yang mengandung garam empedu. Kesimpulan: Dali ni horbo berpotensi sebagai sumber protein dan kandidat probiotik lokal, sehingga dapat dikembangkan lebih lanjut sebagai pangan fungsional yang mendukung kesehatan.