Extrato de erva-mate (Ilex paraguariensis) como antioxidante e antimicrobiano natural em produto cárneo cru curado

Abstract

Yerba mate (Ilex paraguariensis) is recognized for its high content of bioactive compounds, and consequent antioxidant activity, presenting a positive impact on consumer health. Due to their susceptibility to oxidation, meat products require the application of antioxidants, and studies are suggested to evaluate the obtainment and application of natural antioxidants, replacing synthetic ones. Thus, the aim of this study was to evaluate the feasibility of ultrasound-assisted extraction of the constituent antioxidant compounds of yerba mate, for subsequent application of this extract in total replacement of synthetic antioxidants in Tuscan sausage. The parameters applied in the extraction were a temperature of 70 ºC, frequency of 37 kHz, power of 80% of 580 W, and a time of 60 min, using different extractor solvents (30% hydroethanolic solution, acidified hydroethanolic solution with 1% phosphoric acid and 1% phosphoric acid solution). The responses evaluated in the extracts were chlorogenic acid content, caffeine, total phenolic compounds content, flavonoids, antioxidant activity by ABTS, DPPH, and FRAP methods, as well as antimicrobial activity, minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC), for Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae. The values for chlorogenic acid and caffeine varied, respectively, from 3.76 to 7.04 g 100 g-1 and from 1.94 to 3.43 g 100 g-1 . Regarding antioxidant activity, the results for the characterization of total phenolic compounds ranged between 9.76 and 12.89 g EAG 100 g-1 , for ABTS ranged from 58.60 to 75.97 g ET 100 g-1 , for DPPH from 24.94 to 30.22 g ET 100 g-1 , for FRAP from 67.49 to 85.53 g E Fe(II) 100 g-1 and finally, the levels for flavonoid analysis varied from 236.21 to 646.28 mg EQ 100 g-1 . For antimicrobial activity, MIC values ranged from 3.13 to 12.50 mg mL-1 for the microorganisms tested, and MBC ranging from 12.5 to 25 mg mL-1 . Based on the results found, it was defined that the extract to be used in the formulation of Tuscan sausage was obtained with hydroethanolic solution (30%) without acidification, from the sample of Cascavel/PR. The yerba mate extract was spray-dried and applied as a natural antioxidant in Tuscan sausages produced with concentrations of 0.5% m/m (F1) and 2% m/m (F2) of extract, compared to a formulation control (FC) with 0.5% sodium erythorbate. The sausages produced were characterized in terms of chemical composition, physicochemical and oxidative parameters, and fatty acid profile. The samples did not differ in terms of proximate composition and are in accordance with the standards recommended by current legislation. The instrumental color measurement confirmed that the addition of yerba mate extract resulted in samples with a darker and greener hue, through the reduction of the L* and a* parameters and a higher value of the b* parameter. The TBARS analysis showed that the application of yerba mate extract maintained the oxidative stability in the sausages, when compared to the standard one, not differing significantly over the 30 days of storage under refrigeration. In the fatty acid profile, differences in the content of unsaturated fatty acids could be observed after 30 days of storage, being higher in the F2 sample compared to the others, which suggests that this extract concentration may have contributed to the reduction of oxidation of these fatty acids.