Dados do Trabalho

Título

EFFECT OF THE FERMENTATION PROCESS ON THE BIOACTIVE COMPOUNDS OF A KOMBUCHA-LIKE BEVERAGE USING FEIJOA PEELS (Acca sellowiana) AND GREEN TEA (Camellia sinensis)

Introdução

The integral use of feijoa (Acca sellowiana) is highly promising since all its fractions (peel, pulp, and seeds) are rich in compounds that perform biologically important functions. In this sense, using its peel as a raw material for preparing infusions could enrich the sensory and bioactive properties of kombucha-like beverages, as well as contribute to the concept of circular economy and the valorization of Brazilian raw materials. Therefore, this study aimed to evaluate the effect of the fermentation process on feijoa peel infusions with green tea (Camellia sinensis) through the parameters of total phenolic compounds (TPC) and in vitro antioxidant activity.

Material e Métodos

The feijoa peels were dried in an oven with forced air circulation (55ºC for ≈24h) and then processed in a knife mill with a particle size of 400 mesh. The infusion was prepared in boiling water in a 1:1 (w/w) ratio of feijoa peel and green tea for 15 minutes. Afterward, 5% (w/v) of sucrose and 10% (v/v) of the inoculum were added. Fermentation was carried out at 25ºC for 7 days until pH 3.67 ± 0.01. TPC was determined using the Folin-Ciocalteu method, and antioxidant activity was assessed using the ABTS+• radical inhibition assay and the FRAP (ferric reducing antioxidant power) assay.

Resultados e Discussão

An increase (p<0.05) of ≈31% was observed in the TPC content after fermentation of the infusion, with results ranging from 108.97 ± 2.55 to 143.14 ± 7.28 mg of gallic acid equivalent (GAE)/100mL in the pre-fermentation and post-fermentation stages, respectively. For antioxidant activity using the ABTS+• method, no significant difference was observed between the pre-fermentation stage (65.78 ± 4.21 μM Trolox/mL) and the post-fermentation stage (71.90 ± 3.71 μM Trolox/mL). On the other hand, the FRAP method showed an increase (p<0.05) of ≈23%, ranging from 3.08 ± 0.04 in the pre-fermentation stage to 3.79 ± 0.05 μM Trolox/mL in the post-fermentation stage.

Conclusão

In this context, it was observed that using feijoa peel to prepare infusions could be an alternative for using this by-product, and it proved to be a potential raw material for producing kombucha-like beverages.