Encapsulation of active components in pectin and chitosan for application in active packaging and biopesticides

[J. N. Jovanović ]

122 str.

Tehnološko inţenjerstvo - Biohemijsko inţenjerstvo i biotehnologija / Technological engineering - Biochemical engineering and biotechnology

Predmet istraţivanja ove doktorske teze je priprema biopolimernih emulzija i disperzija, kao i dobijanje tankih filmova i prevlaka od njih, koje se mogu koristiti u aktivnom pakovanju za zaštitu namirnica i kao biopesticid. Glavni koncept nauĉno-istraţivaĉkog rada zasniva se na ugradnji aktivnih komponenti (etarsko ulje limunove trave, Zn(CH3COO)2∙2H2O, nanoĉestice ZnO) u polimernu matricu pektina i hitozana, sa ciljem da se postigne njihovo sporo otpuštanje i produţena antimikrobna/insekticidna aktivnost. Emulzije i filmovi su ispitani razliĉitim metodama u cilju strukturne (Particle Analyzer, ATR-FTIR, TGA/DTG i DSC) i morfološke (AFM, SEM) karakterizacije. TakoĊe, odreĊena su mehaniĉka svojstava i rastvorljivost filmova. Antibakterijsko dejstvo emulzija i disperzija testirano je u in vitro uslovima na vrstama bakterija koje su ĉesti uzroĉnici kontaminacije i trovanja namirnicama (Escherichia coli, Bacillus subtilis i Staphylococcus aureus). Filmovi na bazi hitozana pokazali su bolja mehaniĉka svojstva i niţi stepen rastvorljivosti u poreĊenju sa filmovima na bazi pektina. Emulzije i disperzije na bazi hitozana su pokazale jaĉi antibakterijski efekat u in vitro uslovima, dok je kod emulzija na bazi pektina primećeno sinergistiĉko dejstvo izmeĊu aktivnih komponenti. Efikasnost prevlaka, koje bi se primenjivale u izradi aktivnog pakovanja, testirana je u in vivo uslovima na sveţim malinama (Rubus idaeus L.), pri ĉemu je ostvaren produţetak sveţine i roka trajanja maline sa ĉetiri na osam dana. Dejstvo emulzije na bazi pektina kao biopesticida ispitano je na krompirovom moljcu (Phthorimaea operculella L.), kada je efekat sporog otpuštanja doveo do produţenog dejstva bioaktivnih jedinjenja inkapsuliranog etarskog ulja u efikasnom suzbijanju krompirovog moljca.

The research subject of this doctoral thesis is the preparation of biopolymer emulsions and dispersions, as well as obtaining thin films and coatings from them, which can be used in active packaging for food protection and as a biopesticide. The main concept of the scientific research is based on the incorporation of active components (lemongrass essential oil, Zn(CH3COO)2∙2H2O, ZnO nanoparticles) into the polymer matrix of pectin and chitosan, to achieve their slow-release and prolonged antimicrobial/insecticidal activity. The emulsions and films were investigated by various methods for structural (Particle Analyzer, ATR-FTIR, TGA/DTG, and DSC) and morphological (AFM, SEM) characterization. Also, the mechanical properties and solubility of the films were determined. The antibacterial effect of emulsions and dispersions was tested in vitro on the bacteria that are frequent causes of contamination and food poisoning (Escherichia coli, Bacillus subtilis, and Staphylococcus aureus). The chitosan-based films showed better mechanical properties and a lower degree of solubility compared to the pectin-based films. The chitosan-based emulsions and dispersions showed a stronger antibacterial effect in vitro, while a synergistic effect between the active components was observed in the pectin-based emulsions. The effectiveness of the coatings, which would be applied in the production of active packaging, was tested in vivo on fresh raspberries (Rubus idaeus L.), whereby the freshness and shelf life of raspberries were extended from four to eight days. The effect of the pectin-based emulsion as a biopesticide was tested on the potato tuber moth (Phthorimaea operculella L.) when the slow release effect led to the prolonged activity of the bioactive compounds of the encapsulated essential oil in the effective control of the potato tuber moth.

biopolimeri, pektin, hitozan, aktivne komponente, inkapsulacija, aktivno pakovanje, biopesticidi.

biopolymers, pectin, chitosan, active components, encapsulation, active packing, biopesticides.

604:577.11(043.3)

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