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The aim of this work was to evaluate different concentrations of ethanol on antioxidant (phenolic and flavonoid) compounds extraction of Mentha x Piperita aiming at applying the extract in whey-based dairy beverages. The extracts were obtained by cold maceration using water and ethanol as solvents. The extract using water and 70% ethanol had a 13.83 (w w-1) yield, 61.72 mg GAE g-1 phenolic compounds extract, 37.27 mg QE g-1 flavonoid content extract and 0.056 mg mL-1 antioxidant activities. The dairy beverage formulations followed a 22 factorial design in order to evaluate the effect of whey/milk and starch addition on the physical-chemical (pH, acidity, moisture, ash, fat, protein, viscosity, and color) and sensorial characteristics (acceptability) of the product. Analysis of variance (ANOVA) allowed for the development and validation of mathematical models for ash content, lipids, viscosity, and luminosity of the dairy beverage. The effects of whey/milk and starch variables on such characteristics were analyzed by the elaboration of contour curves. The product presented a lower color intensity at the highest whey concentration (75%). The product had a good sensory acceptance, and the 50 whey and 50% milk formulation presented a 7.16 points average and 79.51% acceptance index, suggesting that 50% of whey could be added up to the product’s formulation.

Eucalyptus leaves are a secondary product of wood production. The pressurized liquid extraction (PLE) technique is an attractive process due to its advantages. The objective of this work was to obtain extracts of Eucalyptus saligna leaves using the PLE technique, and to characterize different extraction time fractions in relation to bioactive compounds and antioxidant and antimicrobial activities. The extraction of E. saligna leaves was carried out in a jacketed extractor at 40 °C, pressure of 10.4 MPa, with a solvent flow of 2.5 mL.min-1 , using 95% ethanol. The system remained pressurized for 30 minutes in static extraction, followed by 180 minutes in dynamic extraction. The levels of total phenols, flavonoids, antioxidant activity and antimicrobial potential against Staphylococcus aureus and Escherichia coli were evaluated. The extraction showed an overall yield of 12.3% after 180 minutes. The total concentrations of phenols and flavonoids were 618.57 mgGAE.g-1 and 160.28 mgQE.g-1 respectively. The extracts showed good antioxidant and antimicrobial potential, with IC50 between 0.016 and 0.043 mg.mL-1 , and MIC against S. aureus and E. coli between 0.313 and 1.25 mg.mL-1. PLE demonstrated efficiency in obtaining extracts of E. saligna leaves with bioactive properties.

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