Application of crude bacteriocins based on LC₅₀ values to prolong the shelf life of white shrimp: Aplikasi bakteriosin kasar berdasarkan nilai LC₅₀ untuk memperpanjang daya simpan udang putih

Abstrak

Bahasa Indonesia

Produk perikanan, khususnya udang putih, mudah mengalami penurunan mutu akibat kontaminasi mikrob pascapanen sehingga diperlukan pengawet alami yang aman dan efektif. Bakteriosin merupakan senyawa antimikrob hasil metabolit bakteri yang berasal dari fermentasi terasi udang rebon dan berpotensi sebagai kandidat bioaktif. Penelitian ini menganalisis toksisitas bakteriosin melalui uji LC₅₀ pada Artemia sp. selama 24 jam, serta efektivitasnya menekan angka lempeng total (ALT) bakteri pada udang putih segar. Sampel bakteriosin (TRS1, TRS2, TRS3) diuji. Nilai LC₅₀ dihitung dengan analisis probit berbasis regresi linear logaritmik, sedangkan efektivitas dihitung dari pengamatan ALT selama 24 jam (interval 3 jam) dan dianalisis dengan uji Kruskal-Wallis dilanjutkan uji Dunn’s. Hasil menunjukkan TRS1 memiliki LC₅₀ terendah (0,22 µL/mL), diikuti TRS3 (2,48 µL/mL) dan TRS2 (4,40 µL/mL), menandakan TRS1 paling toksik terhadap Artemia sp. Dari sisi efektivitas, TRS1 dan TRS2 mampu mempertahankan ALT di bawah ambang SNI (5×10⁵ koloni/g) hingga jam ke-24. TRS3 hanya efektif hingga jam ke-12, lalu ALT meningkat mendekati kontrol (8,0×10⁶ koloni/g pada jam ke-24). Pola ALT TRS1 dan TRS2 berfluktuasi di awal sebelum menurun drastis, menunjukkan adaptasi mikrob dan aktivitas bakteriosin yang optimal setelah jam ke-6, hal ini disebabkan oleh aktivasi bakteriosin dan adapatasi mikrob, tetapi belum ada bukti kuat untuk menyatakannya. Kesimpulannya, TRS1 dan TRS2 memiliki potensi terbaik sebagai pengawet alami udang putih segar dengan kemampuan menekan pertumbuhan bakteri secara efektif selama penyimpanan.

Inggris

Fishery products, including white shrimp, are highly perishable due to microbial contamination during postharvest handling. To address this, natural preservatives, such as bacteriocins, which are antimicrobial compounds produced by bacteria, including those from fermented shrimp paste, are being explored. This study aimed to evaluate the toxicity and preservative potential of three bacteriocin samples (TRS1, TRS2, and TRS3) using a 24-hour LC₅₀ test on Artemia sp. and antibacterial activity based on total plate count (TPC) in shrimp during storage. A completely randomized design (CRD) was used. Toxicity levels were assessed using probit analysis with log-linear regression to determine LC₅₀ values, and TPC was measured at 3-hour intervals over 24 h. Data were analyzed using the Kruskal-Wallis test and Dunn’s post-hoc test. TRS1 exhibited the highest toxicity, with an LC₅₀ of 0.22 µL/mL, followed by TRS3 (2.48 µL/mL) and TRS2 (4.40 µL/mL). Despite its higher toxicity, TRS1, along with TRS2, effectively suppressed microbial growth in shrimp, maintaining TPC values below the Indonesian National Standard (5×10⁵ CFU/g) throughout 24 h. In contrast, TRS3 maintained TPC below the threshold only up to 12 h, with counts nearing control levels (8.0×10⁶ CFU/g) by 24 h. TRS1 and TRS2 treatments initially showed fluctuating TPC patterns, followed by a sharp decline, possibly due to delayed bacteriocin activation and microbial adaptation; however, the exact reason remains unclear. Overall, TRS1 and TRS2 exhibited strong potential as natural preservatives for extending the shelf life of fresh white shrimp by effectively controlling bacterial growth during storage.

Kata kunci

• food safety
• microbe
• natural preservative
• probit analysis
• TPC
• ALT
• analisis probit
• mikrob
• pengawet alami
• keamanan pangan