Pengaruh pewarna makanan sintetik terhadap stabilitas fotooksidatif L-Asam Askorbat
REDHA, Abdi, Dr.Ir. Umar Santoso, M.Sc
2007 | Tesis | S2 Teknologi Hasil PerkebunanTelah dilakukan penelitian mengenai efek pewarna makanan sintetik komersial, yaitu brilliant blue FCF, fast green FCF, erythrosine B, ponceau 4R, phloxine B, rose bengal, sunset yellow FCF dan tartrazine terhadap stabilitas fotooksidatif Lasam askorbat dalam suatu sistem model. Tujuan penelitian adalah 1) mengetahui jenis pewarna makanan sintetik yang berperan sebagai sensitiser, 2) menentukan pengaruh jenis sensitiser dan pH terhadap aktivitas fotosensitasi sistem model dan 3) menentukan pengaruh konsentrasi awal asam askorbat dan sensitiser terhadap tingkat kerusakan fotooksidatif Lasam askorbat. Penelitian terdiri 3 tahap yaitu 1) fotooksidasi Lasam askorbat dengan berbagai pewarna makanan sintetik; 2) fotosensitasi oksidasi Lasam askorbat dengan pewarna yang berperan sebagai sensitiser pada berbagai pH (buffer sitrat); 3) fotosensitasi oksidasi pada berbagai konsentrasi awal asam askorbat (10, 20, 30 ppm) dan sensitiser (1, 2, 3 ppm). Hasil penelitian menunjukkan rose bengal, erythrosine B, dan phloxine B (5 ppm) dapat berperan sebagai sensitiser dalam kondisi terpapar cahaya 4000 lux, sedangkan brilliant blue FCF, fast green FCF, ponceau 4R, sunset yellow FCF dan tartrazine tidak memiliki aktivitas fotosensitasi. Peningkatan aktivitas fotosensitasi sistem model terjadi seiring bertambahnya pH untuk semua sensitiser (5 ppm). Urutan aktivitas fotosensitasi pada berbagai pH yaitu: erythrosine B > phloxine B > rose bengal pada pH 4; erythrosine B > rose bengal > phloxine B pada pH 5; rose bengal > erythrosine B > phloxine B pada pH 6 dan 7. Peningkatan konsentrasi awal asam askorbat dan sensitiser dalam sistem model mampu memicu kehilangan asam askorbat yang lebih besar setelah penyinaran 15 menit. Penurunan konsentrasi asam askorbat maksimum pada sistem model yang disensitasi rose bengal, erythrosine B dan phloxine B berturutturut adalah 98, 95 dan 98 %.
Effects of eight commercially available synthetic food colorants i.e. brilliant blue FCF, fast green FCF, erythrosine B, ponceau 4R, phloxine B, rose bengal, sunset yellow FCF and tartrazine on photooxidative stability of Lascorbic acid in a model system were investigated. The aims of this research were 1) to determine synthetic food colorants that can role as sensitizers, 2) to determine the effects of kind of sensitizer and pH on photosensitization activity of model system and 3) to determine the effects of initial concentration of ascorbic acid and sensitizer on photooxidative degradation of Lascorbic acid. The research consisted of three parts i.e. 1) photooxidation of Lascorbic acid using various synthetic food colorants; 2) photosensitized oxidation of Lascorbic acid by food colorant sensitizers at various pH values (citrate buffer); 3) photosensitized oxidation at various initial concentration of Lascorbic acid (10, 20, 30 ppm) and food colorant sensitizers (1, 2, 3 ppm). The result of research showed rose bengal, erythrosine B and phloxine B (5 ppm each) could act as sensitizers under a 4000 lux light exposure. In contrast, the other food colorants i.e. brilliant blue FCF, fast green FCF, ponceau 4R, sunset yellow FCF and tartrazine showed no photosensitization activity. The increase of pH values caused system model to undergo the increase of photosensitization activity at the same sensitizer concentration (5 ppm). The photosensitization activity order at various pH values were: erythrosine B > phloxine B > rose bengal at pH 4; erythrosine B > rose bengal > phloxine B at pH 5; rose bengal > erythrosine B > phloxine B at pH 6 and 7. The increase of initial concentration of ascorbic acid and sensitizer induced larger loss of ascorbic acid in a fifteen minutes illumination. The maximum depletion of ascorbic acid concentration on rose bengal, erythrosine B and phloxine Bsensitized model system were 98, 95 and 98 % respectively.
Kata Kunci : Pewarna Makanan Sintetik,Sensitiser,Asam Askorbat, synthetic food colorant, ascorbic acid, photosensitization, sensitizer
