AKTIVITAS ANTIOKSIDAN, ANTIDIABETES, DAN PREBIOTIK IN VITRO EKSTRAK SERAI (Cymbopogon citratus) DENGAN PELARUT AIR DAN ETANOL

Yohana Laurencia, Dr. Ir. Muhammad Nur Cahyanto, M.Sc. ; Prof. Dr. Ir. Eni Harmayani, M.Sc.

2025 | Skripsi | TEKNOLOGI PANGAN & HASIL PERTANIAN

Metode ekstraksi dan jenis pelarut berperan penting dalam menentukan efektivitas senyawa bioaktif dalam serai  (Cymbopogon citratus), yang  memiliki potensi sebagai antioksidan, antidiabetes, dan prebiotik. Penelitian ini mengevaluasi pengaruh metode ekstraksi Ultrasonic Assisted Extraction (UAE) dan maserasi, serta jenis pelarut (air dan etanol 96%) terhadap aktivitas fungsional  ekstrak serai. Metode ekstraksi terbaik dipilih berdasarkan nilai Total Soluble Solid (TSS) dan aktivitas antioksidan. Uji antioksidan dilakukan dengan metode DPPH, uji antidiabetes berdasarkan penghambatan enzim alfa-glukosidase, dan uji prebiotik mengamati pertumbuhan Lactobacillus plantarum DAD-13 serta Escherichia coli.

Hasil penelitian menunjukkan bahwa metode UAE menghasilkan ekstrak dengan nilai TSS dan aktivitas antioksidan lebih tinggi dibandingkan metode maserasi. Ekstrak dengan pelarut etanol 96% menunjukkan aktivitas antioksidan lebih kuat (IC50 4,96 ppm) dibandingkan ekstrak air (IC50 8,25 ppm), serta memiliki aktivitas penghambatan enzim alfa-glukosidase lebih tinggi (IC50 2,50 ppm vs. 26,63 ppm). Uji prebiotik menunjukkan ekstrak etanol lebih mendukung pertumbuhan L. plantarum (aktivitas prebiotik 0,824) dibandingkan ekstrak air (0,341), menandakan selektivitasnya terhadap bakteri probiotik. Hasil penelitian ini menunjukkan bahwa metode UAE dengan pelarut etanol merupakan kombinasi terbaik untuk memperoleh ekstrak serai dengan aktivitas fungsional yang optimal. 

The extraction method and solvent type play a crucial role in determining the effectiveness of bioactive compounds in lemongrass (Cymbopogon citratus), which has potential as an antioxidant, antidiabetic, and prebiotic agent. This study evaluates the influence of Ultrasonic Assisted Extraction (UAE) and maceration methods, as well as solvent types (water and 96% ethanol), on the functional activity of lemongrass extract. The best extraction method was selected based on Total Soluble Solid (TSS) values and antioxidant activity. Antioxidant activity was assessed using the DPPH method, antidiabetic activity was evaluated based on alpha-glucosidase enzyme inhibition, and prebiotic activity was determined by observing the growth of Lactobacillus plantarum DAD-13 and Escherichia coli.

The results showed that the UAE method produced extracts with higher TSS values and stronger antioxidant activity compared to the maceration method. Extracts obtained ethanol exhibited stronger antioxidant activity (IC50 4.96 ppm) than water extracts (IC50 8.25 ppm) and had higher alpha-glucosidase enzyme inhibition (IC50 2.50 ppm vs. 26.63 ppm). Prebiotic tests indicated that 96% ethanol extracts better supported the growth of L. plantarum (prebiotic activity of 0.824) compared to water extracts (0.341), demonstrating their selectivity toward probiotic bacteria. These findings suggest that UAE method with ethanol as the solvent is the optimal combination for obtaining lemongrass extract with the highest functional activity.

Kata Kunci : antioksidan, antidiabetes, Cymbopogon citratus, ekstraksi, prebiotik.