GLUCOMANNAN PURIFICATION FROM PORANG (Amorphophallus oncopyhlus) FLOUR BY ULTRASONIC AND ENZYMATIC LIQUEFACTION USING A THERMOSTABLE ALPHA AMYLASE

NABILA F. ISKANDAR, Dr. rer. nat. Lucia Dhiantika Witasari, S. Farm., Apt., M. Biotech; Prof. Dr. Ir. Eni Harmayani, M. Sc

2021 | Tesis | MAGISTER ILMU DAN TEKNOLOGI PANGAN

Porang (Amorphophallus oncophyllus) merupakan umbi yang mengandung glukomanan. Glukomanan dalam umbi porang diselubingi impurities berupa pati. Penelitian ini bertujuan untuk mengevaluasi efektivitas enzim alpha-amilase, ultrasonik, dan kombinasi kedua perlakuan untuk meningkatkan kemurnian dan rendemen tepung glukomanan selama pemurniannya; dan mengevaluasi pengaruh perlakuan tersebut terhadap karakteristik tepung glukomanan. Penelitian dilakukan dalam 4 langkah: 1) produksi dan preparasi alpha-amilase termostabil; 2) proses likuifaksi; 3) ekstraksi dan pemurnian glukomanan dengan etanol; dan 4) uji sifat glukomanan. alpha-amilase termostabil yang diproduksi menunjukkan aktivitas optimal pada 70° C. Aktivitas dari crude extract enzim adalah 0,025 U / µ mol. Kemurnian glukomanan tertinggi (89,96%) dan rendemen (64,11%) diperoleh pada sampel dengan perlakuan ultrasonik dan enzim (U + E), diikuti transparansi tertinggi (36,3%), kelarutan (46,16%), lightness (75,23) dan kadar gula pereduksi (2,4%). Meskipun demikian, sampel ini memiliki viskositas paling rendah (160 cP). Perlakuan ultrasonik dan enzim juga memiliki kadar pati dan abu yang rendah. Hasil tersebut didukung oleh hasil SEM pada sampel U + E yang memiliki granul dengan bentuk yang lebih halus dan teratur dibandingkan sampel kontrol. Namun, sampel dengan perlakuan ultrasonik dan enzim memiliki viskositas yang rendah, hal ini kemungkinan disebabkan oleh berat molekul yang rendah.

Porang (Amorphophallus oncophyllus) is a perennial plant which has a corm containing large amount of glucomannan. The impurities that encapsulated the glucomannan granule in its corm are dominated by starch. The main objective of this study was to evaluate the effectiveness of alpha-amylase enzyme, ultrasonic, and the combination of both treatments to improve purity and yield of glucomanann flour during its purification; and to evaluate the effect of those treatments on the characteristic of glucomannan flour. Research was conducted in 4 steps: 1) thermostable alpha-amylase production and preparation; 2) liquefaction process; 3) extraction and purification of glucomannan with ethanol; and 4) glucomannan properties assay. Thermostable alpha-amylase was produced and showed optimal activity at 70°C. Crude extract enzyme activity was 0.025 U / µ mol. The highest purity of glucomannan (89.96%) and yield (64.11%) was obtained in a sample with ultrasonic and enzyme treatment (U+E), followed by highest transparency (36.3%), solubility (46.16%), lightness (75.23) and reducing sugar content (2.4%). Nevertheless, this sample has the lowest viscosity (160 cP). The ultrasonic and enzyme treatment also have low starch and ash content. The finding was supported by SEM of U+E sample has a less rough and regular shaped granule than control sample. However, samples with ultrasonic and enzyme treatment have a low viscosity, this is probably due to the low molecular weight.

Kata Kunci : Glucomannan, Amorphophallus oncopylus, porang, thermostable Ã���Ã�ï&Acir