AKTIVITAS DAN STABILITAS AMILASE PADA EKSTRAK UBI JALAR ORANYE (Ipomoea batatas, L)

TIARA MURDANINGRUM, Dr. Ir. Tyas Utami, M.Sc.

2014 | Skripsi | TEKNOLOGI PANGAN & HASIL PERTANIAN

Penelitian ini bertujuan untuk mengetahui pengaruh pH dan suhu terhadap aktivitas enzim amilase ubi jalar oranye serta pengaruh suhu terhadap stabilitas enzim amilase ubi jalar oranye. Dilakukan ekstraksi ubi jalar oranye dan dilanjutkan dengan pengujian aktivitas amilase ekstrak ubi jalar oranye pada berbagai pH yaitu pH 3, 4, 5, 6, 7 dan 8 pada suhu 400 C selama 10 menit. Aktivitas amilase ekstrak ubi jalar oranye diuji juga pada berbagai suhu yaitu suhu 30, 40, 50, 60, 70, 80 dan 900 C menggunakan pH optimum yang diperoleh. Uji stabilitas enzim amilase ekstrak ubi jalar oranye dilakukan pada suhu 30, 40, 45, 50 dan 550 C selama 10, 20, 30, 40, 60, 90, 120, 240 dan 480 menit. Aktivitas enzim amilase ditentukan berdasarkan gula reduksi yang dihasilkan dan dianalisis dengan metode DNS. Hasil penelitian menunjukkan aktivitas enzim amilase ubi jalar oranye optimum pada pH 6. Aktivitas enzim amilase ubi jalar oranye meningkat seiring dengan meningkatnya suhu sampai dengan suhu 500 C kemudian menurun pada suhu diatasnya. Ubi Jalar oranye memiliki aktivitas enzim amilase tertinggi sebesar 2746.80 U/ g Ubi Jalar. Aktivitas enzim amilase stabil pada suhu 30, 40 dan 450 C dengan aktivitas diatas 65% pada inkubasi selama 480 menit.

This experiment was purposed to know the influence of pH and temperature on the orange flesh sweet potatoes amylase activity, and the influence of temperature on the orange flesh sweet potatoes amylase stability. The exctraction of orange flesh sweet potatoes produces the orange flesh sweet potatoes extract. The activity of the orange flesh sweet potatoes amylase was examined at varies pH condition i.e. are 4, 5, 6, 7 and 8 at 40o C for 10 minutes. Orange flesh sweet potatoes amylase was examined at varies temperature that were 30, 40, 50, 60, 70, 80, and 90oC at choosen pH. The stability pf orange flesh sweet potatoes amylase was studied at temperature of 30, 40, 45, 50, and 55oC for 0, 10, 20, 30, 40, 50, 60, 90, 120, 240, 480 minutes at choosen pH. The activity of amylase is done based on the sugar reduction which is produced and analyzed with DNS method. The result of this experiment showed that the optimum activity of orange flesh sweet potatoes was at pH 6. The orange flesh sweet potatoes amylase activity increase with the increasing of temperature until 50oC, then decreased at the higher temperature. Orange flesh sweet potatoes have the highest enzyme activity about 2746,80 U/g sweet potatoes. Amylase enzime was stable at 30, 40, and 45oC with the relative activity above and the activity above 65% for 480 minutes.

Kata Kunci : Ubi Jalar, Aktivitas Enzim Amilase, pH, suhu