Extração de antocianinas de amora-preta (Rubus spp.) por método convencional e emergentes para desenvolvimento de corante bioativo e aplicação em balas de goma

Abstract

The use of artificial dyes has generated controversy because they are associated with allergic reactions. The replacement of artificial dyes by natural dyes is a reality in the food industry. Anthocyanins constitute an important group of natural pigments in plants and have biological properties. Blackberry (Rubus spp.) is a fruit rich in anthocyanins. There is no standard for anthocyanin extraction. Deep eutectic solvents and enzymatic extraction have been tested. Thus, this study was carried out with the aim of developing a natural red dye rich in anthocyanins from blackberry for subsequent application in gummy candies. Among the tested blackberry cultivars, the best anthocyanin extraction yield was from the BRS Cainguá cultivar. Conventional solvent extraction differed statistically from deep eutectic solvent and enzyme extractions. The ideal condition was using ethanol and water 1:1 (v/v), 2:3 g/mL at 20 ºC for 30 min. The values of total anthocyanins, phenolic compounds and antioxidant activity were 412.06 ± 6.22 mg of cyanidin-3-glycoside/100 g fresh sample, 552.17 ± 36.90 mg gallic acid/100 g fresh sample and 1086, 42 ± 65.05 µg trolox/g fresh sample, respectively. By chromatography (HPLC-DAD) the compound cyanidin 3-glycoside was identified in the extract. The anthocyanin extract obtained was tested as a natural bioactive dye in gum candy produced at pH 2.0. The luminosity (L*) of the anthocyanin extract at pH 8.0 differed from the others in the a* and b* values. The concentration of total anthocyanins, phenolic compounds and antioxidant activity in gummy candies were 0.98 ± 0.05 mg cyanidin-3-glucoside/100 g sample, 3.17 ± 2.32 mg gallic acid/100 g sample and 12 ± 2.92 µg trolox/g sample, respectively. Among the techniques tested, conventional solvent extraction was the most promising. Gummies were produced with the addition of blackberry extract as a natural bioactive dye. The results obtained showed the potential of anthocyanin extracts of blackberry as a natural bioactive dye for food. However, further studies are needed to evaluate the yield and stability of anthocyanin dyes in different food matrices.