Stabilization of a saffron extract through its encapsulation within electrospun/electrosprayed zein structures

In this work, electrospinning and electrospraying techniques were used to encapsulate the sensitive bioactive compounds of a saffron extract (i.e. picrocrocin, safranal, and crocin) using zein as protective matrix. Initially, a dried saffron extract (DSE) was obtained and characterized and was subsequently incorporated within zein solutions prepared at two concentrations (10% w/v for capsules and 20% for fiber development). The greatest encapsulation efficiency was observed for the fiber samples, with retention values for picrocrocin, safranal, and crocin of up to 97, 88, and 97%, respectively. The stability of the free and encapsulated extract when exposed to UV light, different pH (2, 7.4) and temperatures (25, 75 degrees C) was also studied. The photostability of crocin and safranal was significantly (p < 0.05) increased upon encapsulation. Similarly, while about 98% of the non encapsulated crocin degraded after 15 h of exposure to acetic acid at 75 degrees C, only 67.23% of the encapsulated compound was lost under the same conditions. The release profiles of crocin, safranal and picrocrocin from the encapsulation structures were fitted using the Peppas-Sahlin model (R-2 = 0.98), showing that the dominant release mechanism was diffusion. Finally, the encapsulation structures retained their integrity upon contact with water, highlighting their potential use as food packaging coatings.