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 °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 °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 (R2 = 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.

A. Alehosseini received a scholarship by the Ministry of Science, Research and Technology (MSRT) of Iran. The authors would like to thank the Spanish MINECO project AGL2015-63855-C2-1 for financial support.

Peer reviewed