Anais do Simpósio Latino Americano de Ciências de Alimentos
Actas del 14 SLACA - Simposio Latinoamericano de Ciencia de los Alimentos

Jambolan is a good source of polyphenols, which play an essential role in its physical, sensory, and functional properties. Conventional methods for polyphenols extraction require extended extraction times and/or high temperature, which can lead to partial degradation of the bioactive compounds. Ultrasound-assisted extraction (UAE) is a technique known to reduce extraction time, solvent usage and increase yield. This study aimed to compare three polyphenols extraction techniques: heated bath extraction (HBE) at 70°C/2 h; exhaustive centrifugation (EC) at 2540xg at 25°C/20 min each run until the residue became colorless; and UAE at 40 KHz, 135W at approximately 30°C/ 20 min. Acidified ethanol 70% was used as solvent at the proportion of 1:25 (g of dried fruit-DF/mL of solvent). A comparison of these methods was performed using the spectrophotometric assays Folin-Ciocalteu to determine the total phenolic compounds content and the pH differential method to measure the total monomeric anthocyanin content. No statistical difference (p<0.05) was found between the three methods regarding the total phenolic compounds content (HBE: 21.971 mg/g DF; EC: 18.031 mg/g DF; UAE: 21.442 mg/g DF). However, by evaluating the anthocyanin content (HBE: 5.468 mg/g DF; EC: 8.762 mg/g DF; UAE: 8.699 mg/g DF), it can be implied that the temperature of the heated bath favors the extraction of certain types of polyphenols whereas considerably increases degradation of anthocyanins, which also suggests that the extracts obtained by different methods might also present differentiated phenolic profiles. Although there was no statistical difference (p<0.05) between the anthocyanin content of the EC and UAE methods, UAE reached the same anthocyanin content in 1/3 of the EC extraction time. These results show that the UAE was the fastest and more efficient extraction method for obtaining jambolan extracts rich in anthocyanins and other polyphenols.