STUDI PELEPASAN ASAM GALAT DARI FILM KOMPLEKS POLIELEKTROLIT KITOSAN/CARBOXY METHYL CELLULOSE (CMC) DAN POTENSINYA SEBAGAI ANTIOXIDANT PACKAGING

FITRIA RAHMAWATI, Dr. Dwi Siswanta, M. Eng.; Prof. Dr. Mudasir, M.Eng.

2018 | Tesis | S2 Ilmu Kimia

Studi pelepasan asam galat dari film kompleks polielektrolit (KPE) kitosan/CMC dan uji aktivitas antioksidan telah berhasil dilakukan. Faktor-faktor yang mempengaruhi pelepasan asam galat berupa komposisi KPE kitosan/CMC, konsentrasi gliserol, dan konsentrasi asam galat, kinetika pelepasan asam galat serta aktivitas antioksidan asam galat telah dipelajari. KPE kitosan/CMC dibuat pada kondisi pH 5 dengan penambahan gliserol sebagai pemlastis dan asam galat sebagai antioksidan teremban. Film yang diperoleh dikarakterisasi dengan FTIR. Studi pelepasan asam galat dilakukan menggunakan fatty food simulant etanol 96% (v/v) selama 48 jam. Konsentrasi asam galat yang terlepas diukur menggunakan spektrofotometer UV-Vis pada panjang gelombang 266 nm. Untuk mengetahui kinetika pelepasan asam galat dipelajari melalui model kinetika orde nol, orde kesatu, model Higuchi, dan model Korsmeyer-Peppas. Uji aktivitas antioksidan dilakukan menggunakan radikal DPPH secara fix reaction time dan steady state selama 48 jam dan diukur absorbansinya pada panjang gelombang 517 nm. Hasil karakterisasi FTIR menunjukkan bahwa KPE kitosan/CMC terbentuk dari interaksi ionik antara kitosan -NH3+ pada kitosan dengan -COO- pada CMC. Hasil penelitian menunjukkan bahwa peningkatan komposisi KPE kitosan/CMC, konsentrasi gliserol, dan konsentrasi asam galat meningkatkan pelepasan asam galat. Persentase pelepasan asam galat terbesar sebesar 8,7%. Pelepasan asam galat dari KPE kitosan/CMC mengikuti kinetika model Korsmeyer-Peppas secara difusi Fickian (n<0,5). Hasil uji aktivitas antioksidan tertinggi sebesar 11,9% sebagai nilai Radical Scavenging Activity (RSA). Oleh karena itu, film KPE kitosan/CMC dapat digunakan sebagai pengemas antioksidan.

Study of gallic acid release from chitosan/CMC polyelectrolite complex (PEC) films and its potency as an antioxidant had been conducted. Some factors that affected the release of gallic acid including PEC chitosan/CMC composition, glycerol concentration, and gallic acid concentration, kinetic models of release, and antioxidant activity of various gallic acid concentrations in chitosan/CMC PEC films had been studied. Polyelectrolyte chitosan/CMC was synthesized at pH 5 with the addition of glycerol as plasticizer and gallic acid as loaded antioxidant. The synthesized films were characterized by FTIR spectrophotometer. Release of gallic acid was studied in ethanol 96% (v/v) as fatty food simulant for 48 hours. The kinetic models were studied by zero orde, first orde, Higuchi model, and Korsmeyer-Peppas model. The concentration of released gallic acid was measured by UV-Vis spectrophotometer at 266 nm. Antioxidant activity of gallic acid was measured using DPPH radical with fix reaction time method and steady state method for 48 hours and the absorbance was measured at 517 nm. The FTIR data showed that PEC chitosan/CMC films were formed by ionic interaction between -NH3+ of chitosan and -COO- of CMC. Results of this study shows that the increasing PEC chitosan/CMC composition, glycerol concentration, and gallic acid concentration increase the release of gallic acid. The highest percentage of gallic acid release is 8.7%. The release of gallic acid followed Korsmeyer-Peppas kinetic model through Fickian diffusion with n<0.5. The highest assay of antioxidant activity of gallic acid as Radical Scavenging Activity (RSA) value is 11.9%. From this results, it is concluded that PEC chitosan/CMC can be used as an antioxidant packaging.

Kata Kunci : KPE kitosan/CMC, asam galat, pelepasan antioksidan/PEC chitosan/CMC, gallic acid, antioxidant release