Vpliv sestave hitozanskega premaza na rast plesni Penicillium expansum in tvorbo toksina - patulina : magistrsko delo

Jeler, Ana Marija (author), Bavcon Kralj, Mojca (mentor), Godič Torkar, Karmen (comentor), Trebše, Polonca (reviewer)

Uvod: Zagotavljanje varnih in kakovostnih živil s čim manjšim vplivom na okolje in zdravje predstavlja vedno večji izziv v naši družbi. Živila pakiramo v embalažo, da jim podaljšamo obstojnost, rok uporabe in ohranjamo organoleptične lastnosti. Večinoma uporabljamo embalažo iz materialov, ki niso razgradljivi. V magistrski nalogi smo raziskovali lastnosti hitozanskega premaza, ki bi ga lahko uporabili za zaščito jabolk. Namen: Namen magistrskega dela je raziskati, ali hitozanski premaz zavira rast plesni Penicillium expansum ter posledično zmanjšuje vsebnost toksina patulina, ki ga ta tvori. Cilj je proučiti, katera koncentracija citronske in ocetne kisline v hitozanskem premazu vpliva na zaviranje rasti plesni. Metode dela: Za preverjanje hipotez smo izvedli poskuse v treh delih. V prvem poskusu smo preverili ali hitozanski premaz zavira rast plesni na jabolkih in če na rast plesni vpliva poleg hitozanskega premaza tudi barva jabolk. V nadaljevanju smo želeli ugotoviti, ali rast plesni zavira hitozan ali ocetna oziroma citronska kislina, ki je dodana hitozanski raztopini. V zadnjem poskusu smo tudi določili koncentracijo toksina patulina, ki ga tvoji plesen Penicillium expansum. Rezultati: V prvem poskusu smo ugotovili, da hitozanski premaz zavira rast plesni in da barva jabolk ne vpliva na njeno rast. Ocetna kislina v 1-% in 0,5-% koncentraciji popolnoma zavre rast plesni v 1-% hitozanskemu premazu, medtem ko je citronska kislina manj učinkovita. Z večanjem premera plesni pri vzorcih 1-% raztopine hitozana z ocetno in citronsko kislino, se je koncentracija toksina patulina večala. Razprava in zaključek: Ocetna kislina se uporablja v živilski industriji, z našimi ugotovitvami pa sklepamo, da ima hitozanski premaz v ocetni kislini dober potencial za nadaljnji razvoj. Prav tako bi bilo zanimivo izvesti poskuse z drugimi kislinami in preveriti njihov protimikroben učinek.

• Language: Slovenian
• Keywords: magistrska dela, sanitarno inženirstvo, jabolka, hitozan, Penicillium expansum, patulin, ocetna kislina, citronska kislina
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: ZF - Faculty of Health Sciences
• Place of publishing: Ljubljana
• Publisher: [A. M. Jeler]
• Year: 2022
• Number of pages: 55 str.
• PID: 20.500.12556/RUL-141204
• UDC: 614
• COBISS.SI-ID: 123002115
• Publication date in RUL: 25.09.2022

Secondary language

• Language: English
• Title: The influence of chitosan coating composition on the growth of mold Penicillium expansum and its production of the toxin - patulin : master thesis

Abstract

Introduction: Ensuring safe and quality food with the least possible impact on the environment and health is an increasing challenge in our society. Foods are packed in packaging to extend their shelf lifemand and to maintain organoleptic properties. Packaging made of non-degradable materials is mostly used. Purpose: The purpose of the master's thesis is to investigate whether chitosan coating inhibits the growth of mold Penicillium expansum and consequently reduces the content of patulin toxin produced by it. The aim is to investigate which organic acid in the chitosan coating affects the inhibition of mold growth mostly. Methods: To test the hypotheses, experiments were performed in three parts. The first part was devoted to check whether the chitosan coating reality inhibits the growth of the mold. In the second experiment, the color of apples and consequently its impact on mold growth after application of the chitosan coating was studied. Whereas in the last experiment, the organic acids, which inhibited the most growth of mold was defined. Two acids, acetic and citric, were used for this part of the experiment. In the last experiment, we also determined the concentration of the toxin patulin, which is produced by the mold Penicillium expansum. Results: In the first experiment, we obtained promising results suggesting that chitosan coating inhibited mold growth. In the second experiment, we found that apple color did not affect the inhibition of mold growth. In the third experiment, we came to the conclusion that acetic acid has the greatest antimicrobial effect in chitosan coating. As the mold diameter increased in the samples of 1 % chitosan solution with acetic and citric acid, the concentration of patulin increased. Discussion and conclusion: Acetic acid is used in the food industry, and with our findings we could conclude that chitosan coating in acetic acid has good potential for further development. As part of the master's thesis, we were limited by finances, so we could only conduct the research up to this point (only in a single experiment, without additional repetitions). For more repetable and accurate results the experiment should be done in more replicates.

• Keywords: master's theses, sanitary engineering, apples, chitosan, Penicillium expansum, patulin, acetic acid, citric acid