Valorização da casca de ficus carica l. Como fonte de pigmentos naturais: estudos de extração, caracterização química e biológica e incorporação em alimentos

Abstract

Due to its coloration, the fig (ficus carica l.) peel, a by-product of fruit processing and/or consumption, is a potential source of anthocyanin compounds. In the present study, different extraction techniques (heat, ultrasound, and microwave), aiming to recover the anthocyanin pigments and optimize its extraction, were compared by response surface methodology using a circumscribed central composite design of three variables with five levels. The relevant tested and optimized variables were time, temperature, and solvent composition (ethanol/water ratio) for the heat and microwave extraction methods. For the ultrasound method, the variables were the ultrasonic power, time, and solvent composition. The anthocyanin composition of the extract was determined by hplc-dad-esi/ms, and the used criteria responses were the quantification of cyanidin 3-rutinoside (c) in the extracted residue (r; mg c/g r) and in the dried fig peel (p; mg c/g p dw), and the extraction yield of the obtained residue (g r/g p dw). Ultrasound extraction was the most effective method, yielding 17,0 ± 0,2 mg c/g r, 3,11 ± 0,05 mg c/g p dw e 0,19 ± 0,001 g r/g p dw at the optimal global extraction conditions (21 min and 310 w with 100% of ethanol and 180 g/l). Regarding its bioactive properties, the fig peel optimized extract showed antioxidant activity with ec50 of 2,447 mg/ml by the tbars method and ec80 in 60 min (ec80 (60 min)) and in 120 min (ec80 (120 min)) of 0,52 and 1,62 mg/ml, respectively by the oxhlia method. The extract revealed, for different gram-positive and gram-negative bacteria, antimicrobial activity, besides not presenting cytotoxic potential against non-tumor cells. However, the extract showed no anti-inflammatory or cytotoxic potential against human tumor cells. Its application in a food product was carried out aiming at the preparation of toppings for donuts. In conclusion, the obtained results highlight the potential application of f. Carica peels as source of anthocyanin compounds to be considered in different industries, such as food, pharmaceutical and cosmetic, adding the benefits derived from its antioxidant and antimicrobial activity to the colorant power.