Priprava kapsulacijskega sistema za stabilizacijo rastlinskih dodatkov v mlečnih izdelkih

Trlep, Blaž (author), Osojnik Črnivec, Ilja Gasan (mentor), Poklar Ulrih, Nataša (comentor)

Cilj naloge je bil pripraviti kapsulacijski sistem za zaščito bioaktivnih spojin vodnega ekstrakta žafrana v mlečnih izdelkih. Ekstrakt žafrana smo kapsulirali v proste kazeinske micele in kazeinske micele z vezanim polisaharidom alginata oziroma pektina pri različnih razmerjih ekstrakta glede na ogrodni material (5 %, 10 %, 15 %, 20 %) ter posušili, z liofilizacijo ali z razprševanjem. Tako pripravljenim vzorcem (kot tudi praznim kazeinskim micelam in ekstraktu žafrana) smo določali kapsulacijsko učinkovitost ter velikost delcev in zeta potencial s tehnikami dinamičnega sipanja svetlobe. Interakcije med molekulami ekstrakta in nosilnim materialom smo določali s FTIR spektrofotometrijo, antioksidativno učinkovitost z ABTS metodo, stabilnost glavnih bioaktivnih spojin žafrana (krocina, pikrokrocina in safranala) med hranjenjem pri različnih pogojih pa smo analizirali z UV/VIS spektrometrijo. Najboljšo stabilnost (med hranjenjem v hladilniku) so imeli vzorci, ki so bili hranjeni v suhi obliki in niso bili suspendirani v jogurtu ali vodi milliQ s pH vrednostjo jogurta ali mleka. V vseh primerih so bile bioaktivne spojine v vzorcih kapsuliranega ekstrakta žafrana bolj stabilne kot v vzorcih prostega ekstrakta. Ugotovili smo tudi, da na stabilnost bioaktivnih spojin vpliva (i) temperatura hranjenja, saj smo dosegli daljšo časovno obstojnost vzorcev pri hranjenju le teh v hladilniku v primerjavi s sobno temperaturo; (ii) metoda sušenja vzorcev, večjo stabilnost smo dosegli z liofilizacijo kot s sušenjem z razprševanjem.

• Language: Slovenian
• Keywords: žafran, kazeinske micele, kapsulacija, pektin, alginat, stabilizacija, liofilizacija, sušenje z razprševanjem
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [B. Trlep]
• Year: 2024
• PID: 20.500.12556/RUL-155901
• UDC: 664.022:615.014.4/.6:577
• COBISS.SI-ID: 193737731
• Publication date in RUL: 24.04.2024

Secondary language

• Language: English
• Title: Formulation of an encapsulation system for stabilization of plant additives in dairy products

Abstract

The aim of the work was to formulate an encapsulation system for protection of bioactive compounds of aqueous saffron extract in dairy products. We encapsulated the saffron extract into free casein micelles and casein micelles with binded polysaccharide alginate and pectin respectively at different ratios of extract compared to wall material (5 %, 10 %, 15 %, 20 %) and dried it with freeze or spray drying. Encapsulation efficiency, particle diameter and zeta potential were analyzed for described samples (and also free casein micelles and free saffron extract). Interactions between molecules of extract and wall material were determined with FTIR spectrophotometry, antioxidant capacity of prepared samples with ABTS method, stability of three major saffron bioactive compounds (crocin, picrocrocin and safranal) during storage at different conditions was analyzed using UV/VIS spectrometry. The optimal stability (during cold storage) was determined for samples that were stored in dry form and were not suspended in dairy yoghurt or milliQ water with pH value of dairy yoghurt or bovine milk. In all studied cases were the analyzed bioactive compounds in samples of encapsulated saffron extract more stable compared to samples of free saffron extract. We also determined that the stability of studied bioactive compounds is affected by (i) the storage temperature, as stability was longer for cold stored samples in comparison with storage at room temperature; (ii) drying method, as longer stability was achieved with freeze drying compared to spray drying.

• Keywords: saffron, casein micelles, encapsulation, pectin, alginate, stabilization, lyophilization, spray drying