20.500.12556/RUL-168814 Tvorba aflatoksina B1 in rast plesni vrste Aspergillus parasiticus v tekočem mesnem gojišču pri temperaturah nižjih od optimalne Aflatoxin B1 production and growth of Aspergillus parasiticus in liquid meat medium at temperatures lower than optimal Aflatoksin B1 (AFB1) je kancerogen, ki sodi v večjo skupino mikotoksinov. Mikotoksini so sekundarni metaboliti plesni, med katerimi plesni vrst Aspergillus parasiticus proizvajajo aflatoksine. Ti toksini se lahko pojavijo v različnih živilih, vključno s suhomesnatimi izdelki. Glavni cilj naloge je bil, da ugotovimo, kako temperature (12 ºC, 14 ºC, 16 ºC, 18 ºC), nižje od optimalne, čas inkubacije (3, 7, 10, 14, 17, 27, 34 dni) in substrat vplivajo na rast plesni vrste A. parasiticus ter tvorbo AFB1. Preskusne razmere smo poskušali približati tistim, ki so značilne za zorenje suhomesnatih izdelkov. Zato smo poleg standardnega tekočega gojišča YES (tekoče gojišče s kvasnim ekstraktom in saharozo) uporabili tekoče gojišče, pripravljeno kot mesni substrat (CMB, kuhano mesno gojišče z glukozo). V obe vrsti gojišč smo inokulirali plesni vrste A. parasiticus. V vzorcih smo po izbranih razmerah inkubacije ovrednotili rast plesni z določitvijo biomase. Vzporedno smo določili tudi koncentracijo AFB1 z ekstrakcijo s trdno fazo ter nadaljnjo analizo z metodo LC-MS/MS. Rezultati so pokazali, da substrat, čas inkubacije in temperatura vplivajo na rast plesni vrste A. parasiticus in tvorbo AFB1. Ključna ugotovitev je, da temperatura 18 ºC predstavlja kritično mejo, pri kateri se tvorba AFB1 izrazito poveča. Na podlagi teh rezultatov sklepamo, da znižanje temperature pod 18 ºC med zorenjem suhomesnatih izdelkov zmanjša tveganje za nastanek AFB1 in posledična zdravstvena tveganja za ljudi. Poleg tega smo ugotovili, da rast in tvorba AFB1 pri plesnih vrste A. parasiticus nista zanemarljivi niti pri temperaturah nižjih, od 18 ºC. Vpliv vrste gojišča na kinetiko tvorbe AFB1 je pomemben, kar zahteva nadaljnje raziskave na realnih vzorcih suhih salam. Dodatne poskuse bi bilo smiselno izvesti tudi z daljšim časom inkubacije, saj postopek pri izdelavi suhih salam traja od 30 do 90 dni, skladiščenje pa lahko doseže 120 dni. Aflatoxin B1 (AFB1) is carcinogen and belongs to a larger group of mycotoxins. Mycotoxins are secondary metabolites of moulds, among which Aspergillus parasiticus strains produce aflatoxins. These toxins can be found in various foods, including dry-cured meat products. The main objective of the study was to determine how lower (12 ºC, 14 ºC, 16 ºC, 18 ºC) than optimal temperature, incubation time (3, 7, 10, 14, 17, 27, 34 days), and substrate affect mould growth and AFB1 production. We aimed to simulate conditions characteristic for dry-cured meat maturation. Therefore, in addition to the standard YES broth (yeast extract with sucrose), we used a liquid culture medium prepared as a meat substrate (CMB, cooked meat broth with glucose). A. parasiticus was inoculated into both types of media. Mould growth was assessed by biomass determination after incubation under selected conditions. Simultaneously, AFB1 concentration was determined using solid-phase extraction followed by LC-MS/MS analysis. The results showed that the substrate, incubation time and temperature affect the growth of the A. parasiticus and the formation of AFB1. The key finding is that the temperature of 18 ºC represents a critical limit at which the formation of AFB1 increases significantly. Based on these results, we conclude that lowering the temperature below 18 ºC during the maturation of cured meat products reduces the risk of AFB1 formation and the resulting health risks for humans. In addition, we found that the growth and formation of AFB1 in A. parasiticus is not negligible even at temperatures lower than 18 ºC. The influence of the culture media type on the kinetics of AFB1 formation is important, which requires further research on real samples of cured meats. It would be reasonable to conduct additional experiments with a longer incubation time, as the process of making dry salami lasts from 30 to 90 days, and storage can reach 120 days plesni Aspergillus parasiticus aflatoksin B1 tekoče mesno gojišče rast plesni nizke temperature moulds Aspergillus parasiticus aflatoxin B1 liquid meat culture medium mould growth low temperature true false false [E. Homšak - Godler] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2025-04-26 07:15:21 2025-04-26 07:15:35 2025-04-28 07:31:37 0000-00-00 00:00:00 2025 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 579.67:615.9:637.52 257295 234378755 47839.pdf 47839.pdf 1 130D5D41F4E9716DC5D73A76FBC15D5E c6befae7623c4baeb53560cda14aeb3fcb851978830e4795ea96699ff3778b84 65480e61-225c-11f0-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=209780 Biotehniška fakulteta 0 0 0