|Tipo di tesi||Tesi di dottorato di ricerca|
|Autore||DE LEO, RICCARDO|
|Titolo||Implementazione tecnologica di film e coating antimicrobici per la conservazione di alimenti basati su pectina a basso metossile ammidata.|
|Titolo in inglese||Technological implementation of antimicrobial films and coatings for food preservation based on amidated low methoxyl pectin|
|Settore scientifico disciplinare||AGR/16 - MICROBIOLOGIA AGRARIA|
|Corso di studi||SCIENZE, TECNOLOGIE E BIOTECNOLOGIE AGRO-ALIMENTARI|
|Data inizio appello||2018-02-23|
|Disponibilità||Accessibile via web (tutti i file della tesi sono accessibili)|
La presente tesi dal il titolo “Technological implementation of antimicrobial films and coatings for food preservation based on amidated low methoxyl pectin” si basa sulle ricerche eseguite utilizzando la pectina ammidata e a basso metossile per la realizzazione di tecnologie applicabili all’industria del futuro. Grazie a collaborazioni nazionali ed internazionali è stato possibile sviluppare soluzioni innovative ed ecosostenibili per alcune matrici alimentari, in grado in futuro di incrementare la shelf-life la sicurezza degli alimenti. Il primo obbiettivo infatti della ricerca era quello di creare formulazioni di coating e film in grado di avere un effetto benefico sugli alimenti supportate da dati di livello scientifico che però siano anche di facile scalabilità industriale, questo per permettere alle ricerche di oggi di essere soluzioni e prodotti del domani.
This Ph.D. dissertation "Technological implementation of antimicrobial films and coatings for food preservation based on amidated low methoxyl pectin", is based on the development of technologies applicable to the future industry: to allow today research to be the solution and tomorrow products. Thanks to the external collaborations ( the Hebrew university of Jerusalem, ISRAEL and IFAPA, Spain), it was possible to develop innovative and eco-sustainable solutions for different food matrices, which in the future can increase both food shelf-life and safety. The main objective of the Ph.D. dissertation was to create coatings and film formulations with a double scope: a beneficial effects on foods on one side, on the other they show positive aptitude to the industrial scalability. The dissertation is divided into six chapters: the first one presents a general overview of pectin: the history of their discovery, structure and use in the food and pharmaceutical sectors. The second chapter focuses on improving pectin-based films using a wide range of plasticizers at different concentrations and studying the effect on the films barrier and mechanical properties. Glycerol, sorbitol, ribose, xylose and arabinose were tested to evaluate the effects on films: resistance to breakage, extensibility, oxygen permeability and transmittance. The results obtained were used elaborate a general evaluation of how plasticizers and their different concentrations can affects different coatings and films based on these polymers. The third chapter deal with how an antimicrobial pectin can extend the shelf-life of fresh meat in a normal stretch packaging. The analisys evaluated beef and chicken, sliced and minced. The meat was wrapped in the pods and then included in the stretch packaging: it showed significant increases in shelf-life and food safety, due to the fact that the pod is able to reduce the total mesophilic bacteria load, responsible for rapid decomposition and potential infections. The fourth chapter is focused on edible coatings, which extend post-harvest life of Tomato RAF. A pectin coating was developed with idro-alcholic extracts of Aloe barbadensis to slow the ripening and avoid the outbreak of molds during storage and logistic. The obtained results are very encouraging: from the chemical-physical prospective of the tomato there is a considerable delay in the ripening process; from a microbiological point of view, pectin-based coatings (with aloe extracts) could become a good substitute for nowadays technologies. The fifth chapter dealt exclusively with food safety: we covered egg-shells with pectin / alginate coatings with the aim of eradicate potential Salmonella spp. on the shell eliminating the phenomenon of cross-contamination. The results obtained show that this phenomenon has been eradicated and the coating did not adversely affect the shell structure. The sixth chapter, deal with the synthesis of random antimicrobial peptides: at each coupling step of the synthesis, we used a combination of protected α-amino acids. This approach leads to a product mixture in which the subunit sequence is random with the length more effectively controlled than a mixture of chains produced via a true polymerization process. Antimicrobial random peptides were included as a preservative in pectin-edible films to create active packaging. Preliminary results show great potential in the field of food preservation.