| dc.contributor.advisor | Karlovsky, Petr Prof. Dr. | |
| dc.contributor.author | Anggriawan, Riyan | |
| dc.date.accessioned | 2018-03-20T10:18:41Z | |
| dc.date.available | 2018-03-20T10:18:41Z | |
| dc.date.issued | 2018-03-20 | |
| dc.identifier.uri | http://hdl.handle.net/11858/00-1735-0000-002E-E395-C | |
| dc.identifier.uri | http://dx.doi.org/10.53846/goediss-6787 | |
| dc.language.iso | eng | de |
| dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/4.0/ | |
| dc.subject.ddc | 630 | de |
| dc.title | Microbiological and Food Safety Aspects of Tempeh Production in Indonesia | de |
| dc.type | doctoralThesis | de |
| dc.contributor.referee | Hadacek, Franz PD Dr. | |
| dc.date.examination | 2018-01-25 | |
| dc.description.abstracteng | Tempeh is traditional food from Indonesia made by fermenting soybeans with mold Rhizopus spp. It has solid form, distinctive aroma and white and slightly gray. Indonesia is known for the largest tempeh production in the world and has the largest soyfood market in Asia. Tempeh is produced mostly on a small scale home industry with poorly controlled fermentation that carried out without sufficient hygienic precautions. Various types of microorganisms can participate during the process of fermentation, natural contamination is always possible. Moreover, there is no standard on making tempeh and its starter. This causes many variations in the manufacture of tempeh in many areas and leads to inconsistencies in its quality and safety of tempeh product. Tempeh, as important food is massively produced and consumed by Indonesian people. It really needs standardized starter and controlled processing to fulfill safety aspects. The scope of this study was to address questions about microbiological and food safety in tempeh production in Indonesia.
Research was divided into three main topics. Topic 1 dealt with the exploration of mucoralean fungi involved during tempeh production as well as solid fermentation process. Zygomycetes strains were isolated from Indonesian tempeh and starter and screened toxicologically and clinically to evaluate possible health risks for human consumption. In this topic, the role of tempeh fungi on zearalenone (ZEN) biotransformation was also investigated. In Topic 2, we studied the toxigenic fungal contamination of usar (traditional tempeh inoculum). We characterized the contaminant strains and detect mycotoxins they produced. Mycotoxins contamination in traditional tempeh was also screened. In Topic 3, we characterized and investigated the diversity of lactic acid bacteria (LAB) and yeast by analyzing soak water samples collected from different tempeh manufactures in Java. Their potential as antifungal activity against Fusarium proliferatum was observed. Their role in ZEN biotransformation was also studied.
Result of Topic 1: Diverse fungal species found in Indonesian tempeh and inocula. RAPD typing was capable of producing discriminating DNA fingerprints of Rhizopus isolates and indicated there was genetic differences among them. Many distinct patterns were observed indicating that tempeh and inocula from different location in Indonesia composed of a quite wide number of strains. Combination of origin or geographical data with morphological and molecular characterization showed that isolates (identified as Rhizopus oryzae, R. delemar, and R. stolonifer) dominantly used by tempeh producer from outside Java, whereas isolates (Rhizopus microsporus complex isolates, identified as R. microsporus var. chinensis, R. microsporus var. microsporus and R. microsporus var. oligosporus) were mostly used by tempeh producer from Java. Tempeh fungi isolates are safe for human consumption since they are not mucormycosis or toxication agent. Fungal strains used in production of tempeh in Indonesia also could convert ZEN to conjugated ZEN and ZEL derivatives in vitro.
Result Topic 2: Six clusters (Banjarnegara, Banyumas, Gombong, Kebumen, Kudus, and Yogyakarta areas) showed a Fusarium contamination in usar. About 8.4% of total fungal isolates recognized belongs to Fusarium genera. Fifty-five pure isolates of Fusarium sp were collected, then observed via microscopy and molecular approach. We found two main species of Fusarium, identified as F. solani and F. proliferatum. Fusarium proliferatum extracts showed about 10-fold stronger activity as toxic agent toward F. solani extracts based on their value of LD50 (with brine shrimp test). About 214 traditional tempeh samples from the six clusters mentioned above were screened for F. proliferatum and F. solani contamination by real-time PCR. Contamination of traditional tempeh samples with F. proliferatum was found in 12% of the samples with amounts of 10-175 ng/mg fungal DNA. In these samples, the amount of FB1 and BEA ranged between 170-2682 µg/kg and 20-50 µg/kg, respectively. About 7 % of the traditional tempeh samples were contaminated with F. solani in amounts of 20-129 ng/mg fungal DNA. All samples had lower FB1 contents than legal limit in Indonesia (2000 µg/kg; SNI 7385:2009), except for one sample from Yogyakarta area which contained FB1 above the allowed limit.
Result of Topic 3: A certain variety of culturable LAB and yeast were found and investigated from soak water. The principal yeast found to be responsible for fermentation were Candida tropicalis, Kluyveromyces marxianus, and Saccharomyces cerevisiae, while the dominant LAB were Lactobacillus plantarum, L. paracasei and Pediococcus pentosaceous. We found LAB species were less diverse than yeast species. Cell free supernatants (CFS) of 20 LAB strains possessed antifungal properties against F. proliferatum B.J0905, while none of the yeast isolates showed the activity. It was found that phenyllactic acid (PLA) might has main role for the activity. The use of those selected LAB strains as part of starter culture has been proven to positively increase traditional tempeh safety. The results obtained from screening 20 isolates belonging to 10 different species revealed that nearly all the tested organisms were able to reduce ZEN in range 10 to 96.9%. In general, yeast and LAB isolates could only transform ZEN into two major biotransformation product α-ZEL and β-ZEL. In all cases no conjugation product detected. | de |
| dc.contributor.coReferee | Splivallo, Richard Prof. Dr. | |
| dc.subject.eng | Traditional tempeh, traditional inoculum (usar), soak water, Rhizopus, Fusarium, yeast, lactic acid bacteria, morphological and molecular characterization, mycotoxins contamination, antifungal activity, ZEN biotransformation | de |
| dc.identifier.urn | urn:nbn:de:gbv:7-11858/00-1735-0000-002E-E395-C-3 | |
| dc.affiliation.institute | Fakultät für Agrarwissenschaften | de |
| dc.subject.gokfull | Land- und Forstwirtschaft (PPN621302791) | de |
| dc.identifier.ppn | 1016200110 | |