PERBANDINGAN KADAR ETANOL HASIL FERMENTASI UWI VARIETAS PUTIH, UNGU, DAN ORANGE (Dioscorea alata L.)

Abstract

ABSTRAK Telah dilakukan Perbandingan Kadar Etanol Hasil Fermentasi Uwi Varietas Putih, Ungu dan Orange (Dioscorea alata. L). Penetapan kadar etanol digunakan alat spektrofotometer UV-Vis secara mikrodifusi dengan alat cawan Conway. Panjang gelombang maksimum yang didapat pada 446 nm, persamaan garis regresi yang diperoleh y = -0,3765x + 0,7835. Hasil validasi metode diperoleh akurasi metode dan presisi alat yang baik dengan koefisien korelasi (r) -0,9983, dengan limit deteksi 0,0546 g/dL, limit kuantitasi 0,1821 g/dL. Dari hasil penetapan kadar uwi diperoleh kadar rata-rata sebesar 3,2998%; 2,6152%; 2,6947% berturut-turut untuk sampel uwi putih, uwi orange dan uwi ungu. Kadar etanol uwi sampel berbeda bermakna sesuai hasil uji anava, dimana diperoleh nilai signifikan P lebih kecil dari α (0,000 < 0,05). Kata kunci : Uwi (Dioscorea alata L.), etanol, spektrofotometri UV-Vis, cawan Conway, fermentasi, perbandingan kadar, mikrodifusi. ABSTRACT Has been done a comparation about Ethanol from Fermentation White, Purple, and Orange Uwi Variety. Determination of ethanol using UV-VIS spectophotometry according to microdifusion and using Conway dish. Beer’s law is obeyed maximum length at 446 nm and equality of regretion line obtained by y = -0.3765x + 0.7835. The result of validation method obtained accuration of method and good precision appliance with the correlation coefficient ( r ) -0.9983. Limit of detection 0.0546 g/dL. Limit of quantitation 0.1821 g/dL. From result determination of uwi’s sampels obtained by 3.2998%; 2,6152%; 2,6947% continued for white, orange and purple uwi’s samples. Rate of uwi’s samples have different meaning of according to result of ANAVA test obtained by meaning value (P) smaller than α value (0,000<0,05). Key words : Uwi (Dioscorea alata L.), ethanol,UV-VIS Spectrophotometry, Conway dish, fermentation,comparation, microdifusion.