Physicochemical and Rheological Characterization and Antioxidant Activity of the Juice of “Puro Puro” (<i>Passiflora pinnatistipula</i>)

Abstract

The genus Passiflora spp. stands out as an important source of bioactive compounds and health promoters; however, not all its species have been studied in depth, as in the case of Passiflora pinntistipula, or “puro puro”. In this sense, the main objective of this research is to study the antioxidant capacity, physicochemical properties and rheological behavior of “puro puro” juice from the Pamuri Community, Tayacaja Province, Huancavelica. The physicochemical characterization was carried out according to the official methods of international analysis (AOAC). The parameters evaluated were the percentage of humidity (66%), ashes (3%), fat (1.5%), proteins (4.5%), carbohydrates (25%), total energy (100%), pH (4.5), total acidity (1.3%), and soluble solids (18.5%). The color was determined on the CieLab scale and was L* (34.5), a* (1.2), b (4.4), C* (4.5) and h* (74.3). The antioxidant capacity was evaluated with the 2,2′-azino-bis (3-ethylbenziozoline-6)-sulfonic acid (ABTS) method, and the value obtained was 5.2 µmol-Equi. Trolox/g. The rheological parameters of the pure cigar juice were evaluated using a rotary viscometer at temperatures of 15, 20, 25, and 30 °C; and in concentrations of 18.5, 20, 25, 30, and 35 °Brix. The power law model fitted the experimental results and showed non-Newtonian flow behavior. The value of the flow behavior index (n) was less than unity at all temperatures and concentrations, indicating the pseudoplastic nature of the juice. The Arrhenius model was able to relate apparent viscosity to temperature. The consistency index (k) varied in the range between 0.42 and 1.38 Pa sn, and flow behavior index (n) was in the range between 0.26 and 0.55.

Keywords

• <i>Passiflora pinnatistipula</i>
• antioxidant capacity
• rheological behavior
• pseudoplastic fluid