1Universidad de Chile, Santiago, Chile, 2Universidad Finis Terrae, Santiago, Chile, 3Pontificia Universidad Católica de Chile, Santiago, Chile.
Introduction: Pomegranate peel is an attractive agroindustrial residue for reuse as it is high in total polyphenols (TP). The pomegranate peel extract (PPE) has shown favorable effects on obesity, energy expenditure (EE) being a key target. Nevertheless, once extracted, the stability of these compounds can be affected. Microencapsulation could improve the stability of PPE. However, studies on the biological effects of PPE microparticles (MPPE) in obesity are lacking. Objective: To study the effect of MPPE on energy expenditure in a mice obesity model. Methods: PPE was microencapsulated by spray drying using inulin (IN). Male C57BL/6J mice (n = 40) were divided into five groups: control diet, high-fat diet (HFD), HFD+IN, HFD+PPE and HFD+MPPE (50 mg/kg/day TP), for 14 weeks. MPPE were characterized. EE (indirect calorimetry), adipose tissue morphology (histology) and UCP1 expression (qRT-PCR) were determined. Results: MPPE exhibited high encapsulation efficiency (~76%) and a Sauter mean of 3.53 μm. MPPE administration favored adipose tissue browning, higher UCP1 expression in brown adipose tissue (p<0.05), and increased EE (p<0.05) versus HFD. Conclusions: MPPE supplementation favored EE in animals fed HFD. MPPE presented adequate technological characteristics. MPPE could be a potential functional ingredient.
Keywords: agroindustrial by-products, pomegranate peel, ellagitannins, energy expenditure, high-fat diet, microencapsulation.