Search

Uporaba fungicidov za zatiranje plesni, ki povzročajo kvar sadja in zelenjave, je vse bolj omejena. Vzroki so v dolgoletni preobsežni uporabi fitofarmacevtskih sredstev (FFS), razvoju novih sevov plesni, ki so prilagojeni ali celo odporni proti fungicidom ter v potencialno škodljivih vplivih ostankov pesticidov na zdravje ljudi. Zato so pomembne alternativne metode in ena od njih je uporaba modre LED-svetlobe, katere osnovni mehanizem temelji na fotodinamični inaktivaciji (PDI). Namen diplomskega dela je pojasniti fotodinamični vpliv modre LED-svetlobe in možnosti uporabe v praksi za zaviranje kvara sadja in zelenjave, ki ga povzročajo plesni. Pregled strokovne literature o uporabi modre LED-svetlobe na plodovih sadja in zelenjave med skladiščenjem je pokazal spodbudne rezultate. Pri obsevanju plesni na/v živilu z modro LED-svetlobo se tvorijo reaktivni kisikovi radikali (ROS), ki povzročijo poškodbe različnih celičnih sestavin kot so lipidi, proteini in nukleinske kisline, ki lahko vodijo do inhibicije rasti ali celo celične smrti in propada plesni. Modra LED-svetloba lahko vpliva tudi na samo kakovost živil, npr. sprememba barve plodov, povečanje vsebnosti nekaterih antioksidantov, kot so fenolne spojine, antocianini, upočasni se gnitje in staranje pridelkov ter poveča odpornost plodov proti boleznim, povzročenim s strani plesni. Uporaba modre LED-svetlobe predstavlja okolju prijaznejšo metodo v primerjavi z uporabo fungicidov in bi jo lahko komplementarno povezovali z drugimi metodami za zaščito in podaljšanje trajnosti sadja in zelenjave. Ker na učinkovitost modre LED- svetlobe vpliva veliko dejavnikov, bo za njeno uporabo v praksi potrebnih še veliko raziskav. The use of fungicides to control molds that cause spoilage of fruits and vegetables is increasingly limited. Mainly due to their excessive use in past, the development of new resistant mould strains and because of potentially harmful effects of pesticide residues to human health. Alternative methods are therefore increasingly important. One of them is irradiation of fruits and vegetables with blue LED light or photodynamic inactivation (PDI) with blue LED light. Researchers have demonstrated the antimicrobial effect of blue LED light mainly as antibacterial treatment and less frequently as antifungal treatment. The purpose of this work is to explain photodynamic effect of blue LED light irradiation and possibilities of its practical application as antifungal method used to prevent fruit and vegetable spoilage. The results have showed potential of blue LED light irradiation as it can inactivate mould by producing reactive oxygen species (ROS) that cause damage to different cellular components such as lipids, proteins and nucleic acids. These effects can lead to growth inhibition or even moulds destruction. Blue LED light might also affect quality of fruit and vegetables such as colour, increasing content of certain antioxidants, such as phenolic compounds, anthocyanins, slows rot and aging of fruits and vegetables and increase their resistance to mold-borne diseases. The use of blue LED light is a more environmentally friendly method compared to the use of fungicides and could be use as complementary strategies to protect fruit and vegetables from mould spoilage. As the efficiency of blue LED light is influenced by many factors, its application still requires many scientific research.