Application of RTU Media for Biosafety of Mie Lethek, Indonesian Bendo-Cassava Noodles, Based on Chromogenic Agar
Nurhayati Nurhayati (a*), Maria Belgis (a), Enny Suswati (b), Ummi Purwandari (c)
a)Department of Agricultural Product Technology – Faculty of Agricultural Technology – University of Jember, East-Java, Indonesia
Jl. Kalimantan No. 37 FTP UNEJ Jember 68121
*) nurhayati.ftp[at]unej.ac.id
b)Faculty of Medicine - University of Jember, East-Java, Indonesia
Jl. Kalimantan No. 37 FTP UNEJ Jember 68121
c)Department of Agricultural Industry Technology, Faculty of Agricultural – University of Trunojoyo, Madura, Indonesia
Jl. Raya Telang, Kecamatan Kamal, Bangkalan, Madura 69162 Indonesia
Abstract
Detection of microbial contamination by plating methods, especially coliform bacteria and other pathogens, many still use conventional methods and take about 7 days to find out the results. RTU media is one of the selective media to determine microbes more quickly based on the color of the colonies on the agar media. This study applied the use of RTU media (ready to use) for determination of biosafety of cassava product i.e Mi Lethek. Mi Letheg or Mi Lethek, is one of the culinary noodles originating from Bendo, Srandakan, Bantul, Yogyakarta, made from cassava starch and cassava flour. Production of Lethek noodles is still using the traditional machinery and equipments. The noodle is a murky brown color and less attractive (not white or bright like general noodles), without using chemical dyes or preservatives, but dry Lethek noodles can be preserved until more durable three months. Biosafety analysis was performed on dried Lethek noodles. The presence of enteric bacteria is known by the presence of blue colonies for Eschericia coli and purple/magenta for Salmonella. 10 g of dried Lethek noodles was dissolved into a physiological solution and continued with dilution up to 106, and 1 ml of sample was placed in a sterile petri dish then plated with RTU media (35oC) and incubated at 37oC for 24 hours. The results showed that microbial contamination in dried Lethek noodles was less than 105 cfu/g. Contamination of enteric bacteria was less than 102 cfu/10g. Indonesian standart (SNI) of dried noodles was 106 cfu/g for total of microbial and 10 cfu/g for enteric bacteria (E. coli). Although Lethek quality is still in SNI quality standards, but need efforts to improve the process like advanced technology of the machinery processing.
Keywords: chromogenic agar; enteric bacteria; Eschericia coli; RTU; Salmonella
Topic: Food Safety