Produção de fermentado alcoólico de maçã adicionado do cogumelo Cordyceps militaris: cinética de fermentação, composição química, potencial antioxidante e toxicidade

Abstract

Cider, an alcoholic beverage fermented from apples, has its sensory profile defined primarily by varieties and processing. In Brazil, its mild and low-complexity character results from the predominant use of table apples (such as Gala and Fuji). This study proposes incorporating the medicinal fungus Cordyceps militaris—which contains bioactive compounds with functional properties—to enhance sensory and functional attributes of national cider. The methodology comprised two stages. First, the mushroom was characterized (moisture, ash, proteins, lipids) and bioactive extraction was optimized via Box-Behnken design (15 experiments), evaluating total phenols, antioxidant activity (FRAP, DPPH, ABTS), cordycepin, and adenosine. Optimal extraction employed a 15% hydroalcoholic solution, 80% ultrasonic amplitude, and 30:1 solute:solvent ratio, with toxicity tested on Artemia salina. Subsequently, fermentations were conducted in 250 mL flasks (200 mL working volume, 20°C ± 2, 15 days) with four groups: control (C), dried mushroom (COG), optimized extract (EXT), and fungal liquid medium (ML). Daily monitoring included cell viability (Neubauer chamber/methylene blue), pH, color, and CO2 loss. Late additions (after day 12: COGAFT, EXTAFT) were also evaluated, with post-fermentation analyses of phenols, organic acids, volatiles, and sugars. Results revealed the optimized extraction model was valid for total phenols (r = 0.98), FRAP (r = 0.94), and ABTS (r = 0.97), increasing these parameters by 147%, 182%, and 89% respectively. The extract proved non-toxic (DL50 = 1379 ± 504 μL/mL). In fermentations, the COG group increased CO2 production, total phenols, chlorogenic acid, and organic acids but reduced aromas and exhibited slight toxicity. EXT was non-toxic, with higher ethanol and lower CO2. Late additions prolonged fermentation while maintaining non-toxicity and elevating malic acid and residual sugar (~1%); COGAFT increased phenols, organic acids, and ethanol, while EXTAFT surpassed the control in phenolic content. Electron microscopy confirmed the comminuted mushroom acted as a support for Saccharomyces cerevisiae. It is concluded that C. militaris adds functionality to ciders, though elevated organic acid levels require sensory adjustments.