PENGARUH PERLAKUAN PERKECAMBAHAN DAN HIDROLISIS ENZIMATIS PROTEIN BIJI SEMANGKA (Citrullus lanatus) TERHADAP AKTIVITASNYA SEBAGAI KOAGULAN ALAMI PENJERNIHAN AIR - Suryanadi, O.; Ratnayani, K.; Bawa, I G. A. G.; Wirajana, I N. (Jurnal Kimia (Journal of Chemistry); Vol. 19 Issue 2, Juli 2025, 2025)
Biji semangka ( Citrullus lanatus ) mengandung protein dengan gugus amina bebas yang dapat berperan sebagai bahan aktif koagulan alami penjernihan air. Penelitian ini bertujuan untuk mengetahui pengaruh perlakuan perkecambahan dan hidrolisis enzimatis protein biji semangka terhadap aktivitasnya sebagai koagulan alami penjernihan air. Analisis kekeruhan air dengan metode turbidimetri pada koagulan biji semangka dilakukan dalam berbagai variasi perlakuan, yaitu serbuk biji semangka tidak berkecambah (BTB), serbuk biji semangka berkecambah (BB), hidrolisat biji semangka tidak berkecambah (HBTB), dan hidrolisat biji semangka berkecambah (HBB). Hasil penelitian menunjukkan koagulan HBB memiliki daya koagulasi terbaik dengan tingkat penurunan kekeruhan air sebesar (76,62±0,072)%, dibandingkan HBTB, BB, dan BTB dengan tingkat penurunan kekeruhan air masing-masing sebesar (66,57±0,135)%, (60,70±0,214)%, dan (48,08±0,286)%. Hasil ini didukung oleh data analisis parameter kadar protein dan gugus amina bebas yaitu kadar protein terlarut dan kadar ?-amino bebas dari HBB lebih tinggi dibandingkan kadar protein terlarut dan kadar ?-amino bebas dari HBTB, serta kadar protein total dari BB lebih tinggi dibandingkan kadar protein total dari BTB. Peningkatan daya koagulasi berbanding lurus dengan peningkatan jumlah gugus amina bebas dalam protein biji semangka. Berdasarkan hasil penelitian dapat disimpulkan bahwa perlakuan perkecambahan dan hidrolisis enzimatis protein biji semangka dapat meningkatkan daya koagulasi dalam menurunkan kekeruhan air. K ata kunci : Citrullus lanatus , Hidrolisis Enzimatis, Kekeruhan, Perkecambahan ABSTRACT         Watermelon seeds ( Citrullus lanatus ) contain proteins with free amine groups that can act as active substances for natural water purification coagulants. This research aims to determine the effect of germination treatment and enzymatic hydrolysis of watermelon seed protein on its activity as a natural coagulant for water purification. Water turbidity analysis using the turbidimetric method on watermelon seed coagulant was conducted using treatment variations of non-germinated watermelon seed powder (BTB), germinated watermelon seed powder (BB), non-germinated watermelon seed hydrolysate (HBTB), and germinated watermelon seed hydrolysate (HBB). The results showed that HBB coagulant had the best coagulation power with a water turbidity reduction rate of (76.62±0.072)%, compared to HBTB, BB, and BTB with water turbidity reduction rates of (66.57±0.135)%, (60.70±0.214)%, and (48.08±0.286)%, respectively. These results were supported by data analysis of protein content parameters and free amine groups, which showed that the content of soluble protein and free ?-amino of HBB was higher than that of HBTB, as well as the total protein content of BB was higher than that of BTB. The higher coagulation power is directly proportional to the increase in the number of free amine groups in watermelon seed protein. Based on the results, it can be concluded that the treatment of germination and enzymatic hydrolysis of watermelon seed protein can increase the coagulation power in reducing water turbidity. Keywords : Citrullus lanatus , Enzymatic Hydrolysis, Turbidity, Germination