Microencapsulated olive leaf extract enhances physicochemical stability of biscuits
Maria Paciulli, Maria Grazia Grimaldi, Massimiliano Rinaldi, Antonella Cavazza, Federica Flamminii, Carla Di Mattia, Mattia Gennari, Emma Chiavaro
Abstract
Free and microencapsulated olive leaves extracts (OLE) have been proposed as natural antioxidant to prolong the stability of biscuits, under two accelerated storage conditions, with and without UV light. The equivalent of 500 µg gallic acid/ g of dough has been selected as sensory acceptable OLE concentration. Higher total phenol content and antioxidant activity were observed in biscuits enriched with both free (B-OLE) and microencapsulated (B-MCR) OLE, in comparison to the controls (B-C), being B-MCR less affected than B-OLE during storage. Higher oxidative stability was detected for B-MCR than B-OLE and B-C, when measured by both peroxide value and Oxitest. A general hardness decrease was observed for all the formulations during storage, being however B-MCR always harder than B-OLE and B-C, probably because of the interactions of the microsphere polymers (alginate and pectin) with water. Darker colours were measured for the enriched biscuits in comparison to the control, being slightly affected during storage by water migration and lipid oxidation phenomena.