Chemical Composition and Biological Activities of Strawberry Pulp Stored under Refrigeration

Introduction: Fruits have a very important role in our diet, as they are natural sources of nutrients, vitamins and other important compounds for preventing various diseases. Strawberries are rich in Vitamin C and phenolic compounds, bioactive compounds known for their ability to scavenge free radicals.

 Purpose: Evaluate the chemical composition and biological activities of ethanolic extracts of raw strawberry pulp, during the times 0, 7, 14 and 21 d of storage under refrigeration.

Methods: After obtaining the pulp, at each time, this was subjected to extraction with 100% ethanolic at 70°C for 30 min. The quantification of phenolic compounds was made by the method of Folin Ciocalteu. The antioxidant activity was evaluated by DPPH method (IC₅₀), and the antimicrobial activity, by the Minimum Inhibitory Concentration (MIC₅₀) against yeasts and bacteria.

Results: The phenolic content showed the highest value at the time 21 d, of 38.84 ± 2.2 mg GAE/g. Time 0 showed the highest antioxidant activity, with IC₅₀ = 138.38 µg/ml, in the time 21 the IC₅₀ was 287.15 µg/ml. For antimicrobial activity at time 0, there was activity, with MIC₅₀ of 15.63 µg/ml for C. krusei yeast and for the bacteria B. cereus. Both S. aureus and E. coli, at 0 and 7 days, showed MIC₅₀ of 500 µg/ml. In the 7 and 14 days, the best results were to MIC₅₀ of 15.63 and 31.25 µg/ml, respectively, against B. cereus. At time 21 days, the MIC₅₀ decreased to 125 µg/ml against B. cereus.

Significance: Storage time interferes with the chemical composition and biological activities of strawberry pulp, increasing the concentration of phenolic compounds, and the antioxidant and antimicrobial activities were reduced. It is important to the rapid consumption of strawberry pulp stored under refrigeration so you can take advantage of its functional properties.