Dados do Trabalho

Título

EFFECT OF FERMENTATION TEMPERATURES ON CHEMICAL AND AROMATIC PROFILES OF PITAYA AND PASSION FRUIT MEAD

Introdução

Producing fruit mead (melomel) offers a viable alternative for utilising and adding value to fruits and honey produced in Brazil. Nevertheless, there is no standardised ideal fermentation temperature. This study aimed to evaluate the influence of fermentation temperatures on fruit mead production and its chemical and aromatic profiles.

Material e Métodos

The must (1.5L) comprised honey diluted to 20.0 °Brix and pH 3.8. Additionally, it contained 1g/L of bee pollen, 0.38g/L of freeze-dried Saccharomyces cerevisiae yeast, and 10% (w/v) of pitaya and passion fruit pulps. Fermentation was conducted for 192 hours at two test temperatures: 25°C and 30°C. Subsequently, the beverages were clarified under refrigeration (10°C) for 60 days, then filled into glass bottles and pasteurised in a water bath at 65°C for 30 minutes. The fruit meads were analysed (in triplicate) for alcohol content, total acidity, fixed and volatile acidity, total reducing sugars (TRS), total phenolic content and antioxidant activity (AA) using DPPH, ABTS and FRAP methods. The volatile compounds (VOCs) were evaluated using HSSE/GC-MS technique and the odour activity values (OAV) were obtained by dividing the concentration by the odour thresholds. Treatment comparisons were made using Student's t-test, with R software.

Resultados e Discussão

The beverages had an alcohol content of 11.26% (v/v), with no significant difference between the treatments (p>0.05). The same was observed for pH, volatile acidity and TRS. However, fermentation at 30°C showed significantly higher values (p≤0.05) for total phenolics, DPPH, FRAP and ABTS. A total of 34 VOCs were identified in both treatments, with a higher concentration (p≤0.05) of higher alcohols (48.08; 73.52 mg/L), aldehydes (1.64; 3.53 mg/L) and acetals (6.50; 8.94 mg/L) in the mead fermented at 30°C compared to that fermented at 25°C. Among these volatiles, 22 showed OAV ≥ 1 in mead fermented at 25°C, whereas 25 compounds were observed in mead produced at 30°C, contributing to floral, fruity, honey-like and citrus aromatic notes in the meads.

Conclusão

It is concluded that the fermentation temperature influenced the chemical and aromatic composition of the meads, indicating that the higher temperature provided a greater availability of compounds with antioxidant and aromatic activity.