Povećanje stabilnosti i antioksidacijske aktivnosti antocijana iz ploda duda aciliranjem s jantarnom kiselinom

Research background. Anthocyanins possess valuable health-promoting activities with significant health benefits for humans. However, their instability is a limiting factor for their usage in functional foods and beverages. Experimental approach. In this work, a new method to enhance the stability of anthocyanins from mulberry fruit through acylation by using succinic acid as a selected acyl donor was explored. The Box-Behnken design of response surface methodology was applied to determine the optimized conditions for the acylation process. Results and conclusions. The highest acylation conversion rate was 79.04% at anthocyanins to succinic acid mass ratio 1:8.96, acylation duration 3 h and temperature 50 °C. Structural analysis of acylated anthocyanins revealed that succinic acid introduces a C-O-C bond and a hydroxyl group. The thermostability and light stability of mulberry anthocyanins were significantly improved after acylation, and the antioxidant activity expressed as total reducing power and Fe2+-chelating capacity of the acylated anthocyanins was also enhanced. Novelty and scientific contribution. Succinic acid acylation provides a novel method for stabilizing mulberry anthocyanins, as evidenced by the increased stability and antioxidant ability of anthocyanins, and thus facilitates its use in the food and nutraceutical industries.Pozadina istraživanja. Antocijani imaju pozitivni učinak na ljudsko zdravlje, no njihova im nestabilnost ograničava uporabu u proizvodnji funkcionalne hrane i pića. Eksperimentalni pristup. U ovom je radu ispitana nova metoda povećanja stabilnosti antocijana iz ploda duda aciliranjem s jantarnom kiselinom kao donorom acilne skupine. Optimalni uvjeti reakcije određeni su pomoću Box-Behnkenovog statističkog plana i metodom odzivnih površina. Rezultati i zaključci. Najveći postotak konverzije od 79,04 % postignut je pri masenom omjeru antocijana i jantarne kiseline od 1:8,96; trajanju acilacije od 3 h i temperaturi od 50 °C. Analizom strukture aciliranih antocijana utvrđeno je da sadržavaju C-O-C vezu i hidroksilnu skupinu iz jantarne kiseline. Aciliranje je bitno povećalo stabilnost antocijana pri izlaganju povišenim temperaturama i svjetlosti, te njihovu antioksidacijsku aktivnost, izraženu kroz ukupnu reducirajuću snagu i sposobnost keliranja Fe2+ iona. Novina i znanstveni doprinos. Aciliranje jantarnom kiselinom predstavlja novu metodu stabilizacije antocijana iz duda, što potvrđuje njihova povećana stabilnost i antioksidacijska sposobnost, čime je olakšana njihova primjena u proizvodnji hrane i nutraceutika