Hydroalcoholic extraction of antioxidant compounds in Japanese grape pseudofruits

The pseudofruit of Japanese grape is rich in sugar and phenolic compounds but little explored for extracting antioxi- dant compounds. The objective of the study was to extract and evaluate the antioxidant capacity of these pseudofruits harvested at two maturation stages: the development phase (DP) and the mature phase (MP). The pseudofruits were evaluated regarding the centesimal composition and physicochemical characteristics and submitted to extraction with 100% water, 50% ethanol, and 100% ethanol. For the extracts, we determined the phenolic compound content and the antioxidant activity using radical capture methods ABTS and DPPH. Pseudofruits may be considered a good source of dietary fiber, regardless of the maturation stage, proving to be a promising raw material for use in foods. Moreover, pseudofruits in the MP presented an increase in the contents of soluble solids, reducing and non-reducing sugars, and titratable acidity, attributed to the formation of the galacturonic acid during the maturation process. Among the solvent used, extraction with 50% ethanol resulted in a larger phenolic compound content and better antioxidant activity, especially for the pseudofruits in the DP, characterizing them as a vegetable matrix of excellent antioxidant capacity and with potential for application in foods and drugs.