Biodiversity of Prokaryotic Microorganisms in Whey Tofu from Lembang, Sumedang and Garut West Java

• Main Author: JUNITASARI (NIM: 20514036), ASSYIFA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/19937
• Institution: Institut Teknologi Bandung

Tofu is one of the products processed from soybeans that contain nutrients for the body. Tofu from Lembang, Tofu from Sumedang and Tofu from Garut are three types tofu that are produced in different places, but still close (in the provinces of West Java). Although made from the same raw material that is soy, every tofu will produce a different tofu, both in terms of taste, aroma, texture and suppleness. This difference could be due to differences in treatment during the manufacturing of tofu. Differences in the type of coagulant used can also be a factor causing divergence of any tofu product. Whey, which is known as a by product of tofu, it can be function as a coagulant in the tofu making process. Types of microorganisms found in whey can influence the flavor of tofu. This research was conducted to find out the type of microorganisms contained in whey Tofu from Lembang, Sumedang and Garut through metagenom approach. Through this approach, the microbial species in an environment can be known, even without the need to cultivate the microorganism. Whey samples filtered by cellulose acetate membrane of 0.2 µm. Total DNA was isolated by the Klijn method, and used as a template to obtain a fragment of 16S rRNA with ± 400 bp long using touchdown PCR. Amplicons obtained then separated again by DGGE analysis. Optimization of DGGE was made with 8% gel and a denaturant range of 30%-80%. Bacterial diversity information was obtained by comparing the DNA sequences of 16S rRNA gene samples with GenBank database and phylogenetic analysis. DGGE separation results show 5 bands in electrophoregram for Lembang samples, 14 bands for Sumedang sample and 11 bands for Garut sample with different intensities. The results of the homology analysis based on nucleotides sequence on each band showed that the microorganisms contained in Tofu from Lembang, Sumedang and Garut were different. The microorganisms contained in whey Tofu from Lembang have closer homology to the Bacterium EM, microorganisms contained in Tofu from Sumedang were closer with Acinobacter sp. and Uncultured Bacterium, while microorganisms contained in Tofu from Garut were closer to Uncultured bacterium. The results of the analysis also indicate the presence of microorganisms on separate branch on the phylogenetic tree. This suggests that these microorganisms may be a new strain. Result of phylogenetic homology analysis also showed that the three whey tofu contains different types of microorganisms that affect the characteristics of the resulting tofu product. The characteristic of the tofu were determined by identifying the flavour compouds GC-MS, as well as organoleptic tests. To determine differences in compound-producing falvour in the tofu. The results extraction method was carried out on tofu samples using n-pentane as solvent then analyzed using GCMS (Shimadzu Qp-5000), with beginning temperature of 40oC for 5 minutes and a final temperature of 225oC for 5 minutes, at a rate of temperature increase of 40oC/min. Flavour compounds of all three types of tofu included into the ester group, alkenes and aldehydes. Organoleptic tests show that the panelists prefered. Tofu from Sumedang for test of colour appearance (82%), for the test texture panelists like Tofu from Garut (83%), for test of elasticity panelists prefered Tofu from Garut Lembang (75%), for taste test panelists prefered Tofu from Lembang (88%), panelists prefered Tofu from Lembang for flavour test (82%).