Optimized formulation of a Physalis peruviana L. fruit nectar: physicochemical characterization, sensorial traits and antioxidant properties

The aim of this research was to develop and characterize an innovative nectar formulation of Physalis peruviana fruits from the Argentinean Northern Andean region with optimized proportions of pulp and sucrose that maximizes the antioxidant activity and with good sensorial acceptance, using the response surface methodology as optimization strategy. Physicochemical characteristics (total soluble solids, titratable acidity and pH), antioxidant activity (measured as the free radical scavenging activity against DPPH^·) and sensorial attributes (color, acidity, sweetness, texture, aroma and overall acceptance) were evaluated in a series of nectar formulations. A significant correlation between overall acceptance and antioxidant activity contributed to achieve the objective outlined. The mathematical modelling defined a nectar with 65% fruit juice and pulp and 8% sucrose; this nectar presented absence of indicator microorganisms (aerobic mesophilic microorganisms, molds and yeasts, Salmonella spp., total coliforms, and Staphylococcus aureus coagulase positive) despite having no added preservatives. β-carotene and vitamin C contents (1.13 ± 0.02 and 16.56 ± 0.52 mg/100 mL respectively) and antioxidant activity towards DPPH^· (EC₅₀: 2.43 ± 0.07 mg/mL), ABTS^·+ (3.48 ± 0.07 μmol Trolox/mL) and FRAP (10.16 ± 0.10 μmol Trolox/mL), make this nectar a functional food with potential for the food industry.

Keywords: Cape gooseberry; Functional food; Overall acceptance; Response surface methodology.