Effect of coating material on microencapsulated phenolic compounds extracted from agroindustrial ciriguela peel...

Extract of ciriguela residue was microencapsulated by spray-drying and freeze-drying using maltodextrin (M), gum arabic (GA) and their mixture (50% M; 50% GA on dry basis) as encapsulating agents. Total phenolic compounds (TPC), antioxidant activity, physicochemical properties, profile of phenolic compounds by HPLC with diode-array detection and storage stability were evaluated.

TPC content of powders ranged from 306.9 to 451.2 mg gallic acid equivalent g^-1 dry powder. The spray-dried powder prepared using GA as encapsulating agent had higher TPC content and antioxidant activity, whereas the freeze-dried powder had lower moisture and water activity. Spray-dried microcapsules had spherical shape, whereas freeze-dried products had irregular structures. The profile of phenolic compounds identified in samples was similar, with rutin (342.59 and 72.92 μg g^-1 ) and quercetin (181.02 and 43.24 μg g^-1 ) being the major compounds in liquid and freeze-dried extracts, respectively, whereas myricetin (97.41 μg g^-1 ) was predominant in spray-dried ones. Storage stability tests carried out for 45 days at 7 or 25 °C revealed no statistically significant difference in TPC.

Ciriguela residue can be considered a source of TPC and used as ingredient with good antioxidant activity in the food industry. © 2023 Society of Chemical Industry.