KARAKTERISASI DAN POTENSI PREBIOTIK GLUKOMANAN DARI UMBI PORANG (Amorphophallus muelleri Blume syn Amorphophallus oncophyllus Prain)

Veriani Aprilia, Dr. Ir. Eni Harmayani, M.Sc

2012 | Tesis | S2 Ilmu dan Teknologi Pangan

Porang (Amorphophallus oncophyllus) merupakan tanaman lokal yang dikembangkan untuk mendukung program konservasi hutan. Umbinya mengandung glukomanan dengan banyak kegunaan, baik sebagai bahan tambahan pangan maupun pangan fungsional. Tujuan penelitian ini mempelajari karakteristik glukomanan yang diekstrak dari umbi porang serta pengaruhnya terhadap pertumbuhan sel Lactobacillus acidophilus dan Bifidobacterium longum in vitro serta potensi prebiotik in vivo. Tahapan penelitian terdiri dari skrining umbi porang dan produksi glukomanan, uji karakteristik fisikokimiawi glukomanan porang, uji pengaruh glukomanan porang terhadap pertumbuhan sel Lactobacillus acidophilus dan Bifidobacterium longum in vitro, serta potensi prebiotik in vivo. Glukomanan dikarakterisasi kelarutan, water holding capacity, dan viskositas. Uji in vitro dengan menginkubasi kultur dalam media MRS broth dengan substitusi sumber C menggunakan glukomanan kemudian dienumerasi menggunakan MRS agar pada jam ke-0, 24, dan 48. Uji in vivo menggunakan 32 tikus Wistar jantan yang dipelihara selama 14 hari, dianalisis populasi mikrobiologi serta karakteristik fisikokimiawi digesta (pH, kadar air, berat, dan SCFA digesta) di akhir penelitian. Karakteristik glukomanan menunjukkan nilai kelarutan 86,43 ± 1,32%, WHC 34,50 ± 2,32 gram air/gram glukomanan, dan viskositas gel 5400 ± 40,82 cps. Glukomanan porang mampu mempengaruhi jumlah sel Lactobacillus acidophilus pada jam ke-48 dan Bifidobacterium longum pada jam ke-24 dan 48. Suplementasi glukomanan mampu menekan pertumbuhan E. coli kolon, namun tidak mampu menstimulasi pertumbuhan lactobacilli dan bifidobacteria kolon. Glukomanan porang juga dapat meningkatkan total SCFA dan menurunkan pH digesta tikus. Dengan demikian glukomanan umbi porang dapat dikembangkan sebagai pangan fungsional.

Porang (Amorphophallus oncophyllus) is a local plant that has been developed for the forest conservation. The tuber of the porang is rich in glucomannan that may be used as food ingredient as well as functional food. The aim of this study was to determine the characteristic of glucomannan extracted from porang tuber, its ability to increase cell number of Lactobacillus acidophilus and Bifidobacterium longum as well as its potency as prebiotic in vivo. The research stages consisted of screening the best porang and production of glucomannan, characterization of porang glucomannan physico-chemical properties, the ability of porang glucomannan to increase cell number of Lactobacillus acidophilus and Bifidobacterium longum in vitro, and exploration of prebiotic activity of porang in vivo. Glucomannan was characterized the solubility, water holding capacity, and viscosity. Prebiotic potency in vitro was studied by incubating cultures on MRS broth during 48 hours then the cells was enumerated on MRS agar on 0, 24, and 48 hours of incubation, while in vivo study was evaluated by using 32 Wistar rats during 14 days of treatment. The results showed that solubility, WHC, and viscosity porang glucomannan were 86.43 ± 1.32%; 34.50 ± 2.32 g water/g glucomannan; and 5400 ± 40.82 cps, respectively. Porang glucomannan was able to increase Lactobacillus acidophilus at 48 hours incubation and Bifidobacterium longum at 24 and 48 hours incubation. Diet supplemented with porang glucomannan had good impact on inhibiting the growth of E. coli but it had no good impact on stimulating the growth of bifidobacteria and lactobacilli. Diet with porang glucomannan could enhance the production of SCFA and decrease pH of cecal content in Wistar mice. The study indicated that glucomannan from porang maybe developed as functional food.

Kata Kunci : porang, Amorphophallus oncophyllus, prebiotik, glukomanan