20.500.12556/DKUM-78584 Spremembe nitritov pri skladiščenju toplotno obdelane zelenjave Changes in pre-cooked vegetable nitrite content during storage V sklopu magistrskega dela smo izvedli poskus, pri katerem smo preučili spremembe nitritov pri toplotno obdelani zelenjavi med skladiščenjem pri različnih pogojih. Spremembe vsebnosti nitritov smo spremljali pri kuhanem brokoliju, cvetači in krompirjevem pireju. Skladiščenje je potekalo pri 4 °C in 25 °C, pri sterilnih in nesterilnih pogojih. Vsebnost nitritov smo določali po 0 h, 24 h in 48 h. Vzorce zelenjave smo spremljali tudi na mikrobiološko onesnaženost. Koncentracije nitritov smo določili spektrofotometrično. Rezultati so pokazali, da ima temperatura shranjevanja velik vpliv na rast mikroorganizmov v testirani zelenjavi in posledično na spremembe v nitritih. Pri vzorcih zelenjave, razen pri pireju iz krompirja, ki so pri sobni temperaturi ostali sterilni/negativni na mikrobiološko onesnaženost, se vsebnost nitritov ni povišala. V nesterilnih pogojih se je pri cvetači in brokoliju vsebnost nitritov predvidoma spreminjala le zaradi mikrobiološke onesnaženosti. Pri krompirjevem pireju smo sicer nitrite zaznali tudi pri mikrobiološko negativnih vzorcih, vendar ostaja delovanje endogenih rastlinskih encimov vprašljivo zaradi možne prisotnosti sporogenih bakterij po kuhanju. Changes in the nitrite content of pre-cooked vegetables during storage under different conditions were studied. Changes were monitored in broccoli, cauliflower and mashed potatoes. Storage took place at 4 °C and 25 °C at sterile and non-sterile conditions. The nitrite content was determined at 0 h, 24 h and 48 h. Vegetable samples were monitored for microbiological contamination as well. Nitrite ion concentration was determined spectrophotometrically. The results have shown that storage temperature has a profound influence on the growth of microorganisms in cooked vegetables and consequently on the changes in nitrites. Nitrite content did not increase in vegetable samples that remained sterile/negative for microbiological contamination, with the exception of mashed potatoes. In non-sterile conditions, nitrite changes in cauliflower and broccoli were presumably a consequence of microbial contamination. In mashed potatoes, nitrites were also detected in microbiologically negative samples, but the activity of endogenous plant enzymes remains questionable due to the potential presence of sporogenic bacteria after cooking. nitriti skladiščenje brokoli cvetača krompir nitrites storage brocolli cauliflower potato true true false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2021-01-21 14:42:23 2021-02-04 13:44:41 2022-08-09 19:15:14 2021-02-05 03:35:36 2021 0 Maribor 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 URN:SI:UM:DK:KOZAQE9X MAG_Pernek_Jana_2021.pdf MAG_Pernek_Jana_2021.pdf 1 5E45C5E247AF2615799B2174EE0E85E2 9ac003bcde70e6a17f20bb94da4318801feafa6e8b0b41ab59c4b3658d04e277 17f8bd47-7c12-11eb-bb7a-00155d0001ca 20.500.12556/dkum/1ee9fcd4-eddb-4902-a2d3-bb89f136a180 https://dk.um.si/Dokument.php?lang=slv&id=148599 Fakulteta za kmetijstvo in biosistemske vede 0 0 0