Developing microencapsulated powders containing polyphenols and pectin extracted from Georgia-grown pomegranate peels

Abstract

This study aimed to determine the feasibility of producing polyphenol (PPP) and pectin powders (PPE) from Georgia-grown pomegranate peels and to develop microencapsulated PPP (MPPP) powders. PPP and PPE were solvents extracted and characterized. Suspensions containing deionized water, 3 g/100 mL of PPP, and 15 g/100 mL of a blend of maltodextrin (MD):PPE of weight ratios (0:1, 3:1, 4:1, 5:1, and 1:0 g:g) were prepared and spray-dried at 140 °C inlet air temperature to produce MPPP powders. PPE had a degree of methyl esterification of 53.67%. The total polyphenol (mg GAE/mL), α-punicalagin (mg/g, dry basis, d.b.), β-punicalagin (mg/g d.b.), ellagic acid (mg/g, d.b.) content of PPP was 522.82, 108.3, 101.0, and 73.8, respectively. MPPP powders produced with higher amounts of PPE had significantly (p < 0.05) higher moisture and particle agglomeration than the rest of the powders. While MPPP powders prepared with a blend of MD:PPE had significantly (p < 0.05) higher encapsulation efficiencies (EE) (>89.90%), water solubilities (>88.09%), and antioxidant activities than the powders microencapsulated with only MD or PPE. MPPP powders produced with MD:PPE (ratio 4:1) showed the highest antioxidant activity, EE, and the particle sizes. MPPP powders with larger particles were positively correlated with higher antioxidant activities. MPPP powders may be used as novel food ingredients.