Obtaining polyphenolic extracts from pomegranate peel (Punica granatum) to evaluate the bactericide and antioxidant activity.

Pomegranate (Punica granatum) contains secondary metabolites with antioxidant and bactericide activity; however, the study of the peel in the endemic varieties of Mexico has not been deepened. The polyphenols extraction of peel pomegranate endemic to the state of Michoacan, Mexico could be used in the formlulation of healthy food due contains antioxidant compounds or could be used like drugs due contains antibactericide compunds.In this work 3 varieties of pomegranate were analyzed; Wonderful, Apaseo and Tecozautla harvested in 2017 and 2018, carrying out a physicochemical characterization to establish the ripening, application of an experimental design of response surface for drying the peel and extracting polyphenols using two solvents (acetone and ethanol) by the Soxhlet method. As a result, the pomegranates were in the correct ripening, in the drying an optimal point of operation was found without affecting the metabolites (36 h at 55 °C) and in the extraction, the bactericide and antioxidant activity was evaluated observing that in the ketone extracts the best results were obtained in the Apaseo variety being; ABTS•+ technique of 150.78 ET mM/g, DPPH• 109.8 ET mM/g and 11.82 EAG mg/g in dry extract. For the bactericide activity measured by inhibition halos in S. aureus and E. coli it was had; 20.03 mm and 14.05 mm respectively for the Apaseo variety, which is why it is convenient to extract polyphenols under this method in peel of Mexican pomegranate varieties.

Antioxidant Activity and Kinetic Characterization of Chlorella vulgaris Growth under Flask-Level Photoheterotrophic Growth Conditions.

C. vulgaris is a unicellular microalgae, whose growth depends on the conditions in which it is found, synthesizing primary and secondary metabolites in different proportions. Therefore, we analyzed and established conditions in which it was possible to increase the yields of metabolites obtained at the flask level, which could then be scaled to the photobioreactor level. As a methodology, a screening design was applied, which evaluated three factors: type of substrate (sodium acetate or glycerol); substrate concentration; and exposure-time to red light (photoperiod: 16:8 and 8:16 light/darkness). The response variables were: cell division; biomass; substrate consumption; and antioxidant activity in intracellular metabolites (ABTS•+ and DPPH•). As a result, the sodium acetate condition of 0.001 g/L, in a photoperiod of 16 h of light, presented a doubling time (Td = 4.84 h) and a higher rate of division (σ = 0.20 h-1), having a final biomass concentration of 2.075 g/L. In addition, a higher concentration of metabolites with antioxidant activity was found in the sodium acetate (0.629 Trolox equivalents mg/L ABTS•+ and 0.630 Trolox equivalents mg/L DPPH•). For the glycerol, after the same photoperiod (16 h of light and 8 h of darkness), the doubling time (Td) was 4.63 h, with a maximum division rate of σ = 0.18 h-1 and with a biomass concentration at the end of the kinetics of 1.4 g/L. Sodium acetate under long photoperiods, therefore, is ideal for the growth of C. vulgaris, which can then be scaled to the photobioreactor level.