Viabilitas dan Stabilitas Weissella sp. GMP12 Kering Beku yang Dipreparasi Menggunakan Rasio Krioprotektan Skim Milk dan Sukrosa Berbeda

Mutiara Zahra, Mgs. Muhammad Prima Putra, S.Pi., M.Sc., Ph.D.

2025 | Skripsi | TEKNOLOGI HASIL PERIKANAN

Penelitian ini dilakukan untuk mempelajari pengaruh konsentrasi krioprotektan tunggal skim milk serta kombinasi skim milk dan sukrosa terhadap viabilitas Weissella sp. GMP12 setelah pengeringan beku dan selama penyimpanan. Penelitian terdiri dari tiga tahap, yaitu: (1) optimasi konsentrasi skim milk (5%, 10%, 15%, 20%, dan 25% b/v) dengan akuades sebagai kontrol, (2) optimasi kombinasi skim milk optimal (10% yang diperoleh dari tahap pertama) dengan sukrosa (0%, 2,5%, 5%, 7,5%, 10%, dan 12,5% b/v), (3) pengujian stabilitas pada beberapa suhu selama penyimpanan. Suspensi dikering-bekukan pada suhu -55°C selama 24 jam, kemudian bubuk hasil pengeringan beku disimpan selama 4 minggu pada suhu -20°C, 4°C, dan 25°C. Hasil penelitian menunjukkan bahwa skim milk 10% menghasilkan viabilitas tertinggi (40,83%) pada perlakuan tunggal, sedangkan kombinasi skim milk 10% + sukrosa 5% menghasilkan viabilitas tertinggi (92,70%). Selama penyimpanan, viabilitas menurun seiring waktu, dengan suhu -20°C memberikan stabilitas terbaik dibanding suhu 4°C dan 25°C, dengan persentase penurunan viabilitas berturut-turut sebesar 16,95%; 28,95%; dan 97,65%.

This study aimed to investigate the effect of skim milk as a single cryoprotectant and its combination with sucrose on the viability of Weissella sp. GMP12 after freeze-drying and during storage. The research was conducted in three sequential stages: (1) optimization of skim milk concentrations (5%, 10%, 15%, 20%, and 25% w/v) with distilled water as the control, (2) optimization of combinations of the optimal skim milk concentration (10%, obtained from the first stage) with sucrose (0%, 2.5%, 5%, 7.5%, 10%, and 12.5% w/v), and (3) assessment of bacterial stability during storage in various temperature. The bacterial suspensions were freeze dried at -55°C for 24 hours, and the resulting powders were stored for 4 weeks at -20°C, 4°C, and 25°C. The results showed that 10% skim milk resulted in the highest viability (40.83%) among the single treatments, while the combination of 10% skim milk + 5% sucrose provided the highest viability (92.70%). During storage, viability decreased over time, with -20°C offering the best stability compared to 4°C and 25°C, with percentage reductions in viability of 16.95%, 28.95%, and 97.65%, respectively.

Kata Kunci : Weissella sp. GMP12, pengeringan beku, skim milk, sukrosa, viabilitas