KARAKTERISTIK SIFAT FISIK, KIMIA, DAN FISIKO-KIMIA TEPUNG SERAT BENGKUANG (Pachyrhizus erosus) SERTA POTENSINYA SEBAGAI PREBIOTIK

Ledy Purwandani, Dr. Ir. Eni Harmayani, M.Sc.

2011 | Tesis | S2 Ilmu dan Teknologi Pangan

Umbi bengkuang (Pachyrhizus erosus) umumnya dikonsumsi segar sebagai campuran salad dan rujak serta banyak digunakan pada industri kosmetik berupa pati, sedangkan ampasnya belum banyak dimanfaatkan. Ampas umbi bengkuang kaya akan serat pangan dan berpotensi sebagai sumber prebiotik, karena diduga masih mengandung inulin dan oligosakarida lainnya. Tujuan penelitian ini adalah untuk mengetahui potensi pemanfaatan tepung serat bengkuang sebagai prebiotik. Tahapan penelitian terdiri dari: 1) pembuatan tepung serat bengkuang dari ampas bengkuang; 2) pengujian sifat fisik, kimia, fisiko kimia tepung serat bengkuang; 3) uji aktivitas prebiotik menggunakan kultur Lactobacillus acidophilus dan Bifidobacterium longum in vitro; serta 4) uji potensi prebiotik dari tepung serat bengkuang in vivo menggunakan tikus Sprague Dawley. Analisis dilakukan terhadap rendemen tepung serat bengkuang, sifat fisik, kimia, fisiko kimia, serta aktivitas prebiotik. Hasil penelitian menunjukkan rendemen tepung serat bengkuang sebesar 12,1% terhadap ampas bengkuang. Tepung serat bengkuang mempunyai kandungan serat pangan larut 4,07%, serat tidak larut 51,21%, resistant starch 19,41%, inulin 172 ppm dan rafinosa 85,66 ppm. Swelling power, solubility, water binding capacity secara berurutan: 14,47 g/g, 18,92%, 649,84% dan warna yang mendekati putih dengan kecerahan (L) 83,95. Tepung serat bengkuang mempunyai aktivitas prebiotik yang positif terhadap B. longum setelah 48 jam. Konsumsi tepung serat bengkuang berpengaruh nyata menurunkan populasi Escherichia coli, meningkatkan kadar air, total short chain fatty acid (SCFA), proporsi molar butirat dan menurunkan pH digesta serta memberikan efek meruah pada feses. Konsumsi tepung serat bengkuang dapat meningkatkan kesehatan kolon dan berpotensi sebagai komponen makanan fungsional.

Yam bean tuber (Pachyrhizus erosus) is generally consumed fresh as salad and salad mixture while its starch is widely used in the cosmetics industry. Yam tuber fiber waste is rich in dietary fiber and potentially used as a source of prebiotic, since it is considered to contain inulin and other oligosaccharides. The aim of this study was to determine the potential application of yam bean fiber flour as prebiotic. Stages of the research consisted of: 1) production of flour from the fiber waste of yam bean tuber; 2) evaluation of physical, chemical, and physico chemical properties of yam bean fiber flour; 3) evaluation of the prebiotic activity using cultured probiotic Lactobacillus acidophilus and Bifidobacterium longum in vitro; and 4) evaluation of potential prebiotic of yam bean fiber flour in vivo using Sprague Dawley rats. The results showed that the yield of yam bean fiber flour was 12,1% based on yam bean waste. Yam bean fiber flour had 4,07% soluble dietary fiber, 51,21% insoluble fiber, 19,41% resistant starch, 172,81 ppm inulin and 85,66 ppm raffinose. The swelling power, solubility, water binding capacity of yam bean fiber flour were 14,47 g/g, 18,92%, 649,84% respectively and the color was nearly white with brightness (L) 83,95. Yam bean fiber flour had positive prebiotic activity to B. longum after 48 hours incubation. Yam bean fiber flour consumption significantly decreased Escherichia coli population, increased water content, total short chain fatty acid (SCFA), molar proportion of butyrate and reduced the pH of digesta. it also gave bulky effect in the stool. It can be concluded that yam bean fiber flour may be used as component of functional foods and consumption of yam bean fiber flour improve the health of the colon

Kata Kunci : tepung serat bengkuang, aktivitas prebiotik, mikrobiota kolon, dan SCFA.