Kemampuan Neurospora sp. oncom untuk menurunkan cemaran aflatoksin B1 pada media cair sintetik dan proses fermentasi oncom

SETYABUDI, Francis Maria Constance Sigit, Dr.Ir. Retno Indrati

2002 | Tesis | S2 Ilmu dan Teknologi Pangan

Aflatoksin BI (AFF1) adalah metabolit sekunder berpotensi toksik, karsinogen, teratogen, dan mutagen yang diproduksi Aspergillus flavus dan A. parmiticus. Cemaran AFBi terdapat pada komoditi kacang tanah dan produk olahannya, termasuk oncom, Omom adalah produk makanan tradisional khas Jawa Barat hasil fermentasi bungkil kacang tanah dan onggok oleh jamur Neurospora sitophila. Dalam penelitian ini diuji kemampuan Neurospora sp. hasil isolasi dari oncom untuk menurunkan cemaran AFBl tanpa keberadaan jamur penghasil AFB1. Penelitian ini bertujuan menguji kemampuan isolat Neurosporu sp. oncom untuk menurunkan cemaran AFBl pada media cair sintetik dan menerapkannya pada proses fermentasi oncom. Ada tiga tahap utama dalam penelitian ini, yaitu : (l).Enumerasi dan isolasi jamur yang tumbuh pada 8 sampel oncom yang diperoleh dari 4 pasar tradisional di Bandung; (2).Uji kemampuan isolat Neurospora sp. hasil isolasi dari oncom untuk menurunkan cemaran aflatoksin B1 dalam media sintetik; (3). Penerapan isolat Neurospora sp. terpilih untuk proses fermentasi oncom. “Crude aflafoxin” dihasilkan oleh A. flavus 0546 menggunakan media cair GAN. Diamati juga berat miselia kering isolat Neurospora sp. dan penurunan cemaran AFB1 selama pertumbuhannya dalam media sintetik. Metoda analisa AFBl dilakukan dengan Solid Phase Extraction dan ditera menggunakan TLC Scanner. Cemaran AFBl pada oncom berkisar 2 - 139 pg AFBl/kg oncom. Diperoleh 18 isolat jamur dari sampel, 13 diantaranya merupakan jkmur yang berkonidia kuning orange. Dari 13 isolat dipilih 8 isolat yang pertumbuhan miselianya paling lebat. Berdasarkan pada hasil pengamatan makroskopik dan mikroskopik 8 isolat tersebut termasuk genera neurospora sp. Isolat - isolat tersebut kemudian diuji potensinya menurunkan cemaran AFBl dan diperoleh hasil kemampuan menurunkan AFBl berkisar 0,300 - 2,287 µg AFBI/g miselia kering selama 4 hari. Selanjutnya dipilih 2 isolat paling berpotensi, yaitu PG.5 dan PA.3 untuk dilihat fenomena kemampuannya. Secara umum pertumbuhan miselia dari kedua isolat pada media yang dicemari ”crude afratoxin” lebih rendah dibanding tanpa dicemari ”crude uflatoxin”. Selama pertumbuhan isolat PG.5 dan PA.3 terjadi pemrunan konsentrasi AFB1 dalam media. Kemampuan terbesar isolat PG.5 menurunkan cemaran AFB1 terjadi di hari ke - 3 yaitu sebesar 8,394 pg AFB1/g miselia kering. Isolat PA.3 memiliki kemampuan menurunkan cemaran terbesar di hari ke - 1, yaitu 8,390 µg AFBl/g miselia kering. Isolat PG.5 berpotensi menurunkan cemaran AFBl dalam media cair dan fermentasi oncom serta menghasilkan oncom yang memiliki cemaran AFB1 rendah.

Aflatoxin BI (AFB1) is a secondary metabolite being a potent toxin, carcinogen, teratogen, and mutagen produced by Aspergillus flavus and A. paracificus. Peanut and their product, including onconz, are usually contaminated by AFB1. Oncom is a traditional fermented food of West Java made from peanut presscake and onggok fermented by Neurospora sitophila. This research was concerning on the ability of Neurospora sp. isolated from oncorn to reduce contaminant AFBl in lack of the AFBl producing fungi. The objectives of this research were to examine the ability of Neurospora sp. in reducing contaminant AFBl on a synthetic broth and during oncont fermentation. This research was carried out in 3 steps as followed. : (1) Enumeration and isolation of the micoflora grown in eight oncom samples that obtained from four traditional markets in West Java; (2) Examination on an ability of the isolated Neurospora sp. to reduce contaminant AFB1 in a synthetic broth; (3) Implementation of selected Neurospora sp. in oncom fermentatim process. Crude aflatoxin was prepared by growing the A. flavus 0546 on Glucose Ammonium Nitrate medium. Dry weight of each Neurospora sp. isolates was monitored and reduction of contaminant AFBl during their growth on a synthetic broth was calculated. The AFBI analysis method was conducted by Solid Phase Extraction (SPE) and measured by TLC Scanner 111. Contaminant AFBl in oncorn was calculated about 2 - 139 µg AFBl/kg oncom. Eighteen molds were isolates from the samples, of these 13 isolates were the molds having yellow-orange conidia. Eight isolates grown with a dense mycelium were selected from 13 isolates. According to the macroscopic and microscopic observation the 8 isolates belong to the genus Neurospora sp. Those isolates were examined their potential ability to reduce contaminant AFBl and the results obtained were at a range of 0,300 - 2,287 µg AFBl/g dry weight mycelia during 4 days incubation. Therefore it was selected 2 higher potential isolates than the others, PG.5 and PA.3, to study their phenomenal ability. Generally, the growth of two isolates in media infected by crude aflatoxin was lower than that with no infection of crude aflatoxin. The AFBl content was decreased during the growth of PG.5 and PA.3 on the synthetic broth. The highest to reduce AFBl content-in isolate of PG.5 was found after 3 days incubation was 8,394 µg/g dry weight mycelia. PA.3 isolate had the highest ability to reduce AFB1 at the first day of incubation, that was 8,390 µg AFBl/g dry weight mycelium. Neurospura sp. PG.5 was the potential isolate to reduce contaminant AFBl on synthetic broth as well as oncom fermentation process so that the oncom product possessed the lowest contaminant AFBl.

Kata Kunci : Fermentasi Oncom,Cemaran AFB1,Jamur Neurospora Spaflatoxin BI; fermentation; Neurospora sp.; oncom; reduction of AFB1