Bioactive Activities of the Phenolic Extract from Sterile Bracts of Araucaria angustifolia.

Sterile bracts can represent 80% of Araucaria angustifolia pinecone and are a rich source of phenolic compounds. This study aimed to optimize the extraction of the phenolic compounds from Araucaria angustifolia bracts using response surface methodology; the bioactivity properties were also investigated. The effects of the ethanol concentration, solute/solvent ratio, and temperature in relation to the phenolic composition and antioxidant activity were evaluated. The quantification and identification of the individual phenolic compounds (using high-performance liquid chromatography) and their bioactivity were evaluated. The optimized extraction conditions, which detected gallic acid, catechin, epicatechin, quercetin, and kaempferol, were obtained using 60% ethanol at a ratio of 1:38 (w/v) and a temperature of 80 °C. The extract showed high levels of phenolic classes and antioxidant activity. The extract also showed an inhibitory activity for pathogenic (approximately 80%, 10,000 µg/mL) and lactic acid (27.9%, 15,000 µg/mL) bacteria strains. The α-glucosidase inhibitory activity was approximately ten times greater than acarbose, demonstrating its high antiglycemic potential. No antioxidant and anti-inflammatory cellular activity were determined; however, a high cytotoxicity for non-tumor cells and the antiproliferative activity against the tumor cells were observed. Overall, the phenolic extract showed promising action in relation to the fight against the diseases related to oxidative stress and, hopefully, the application of the safe concentrations of the extract, based on bioavailability assays, can be verified.

Bioactive compounds recovered from apple pomace as ingredient in cider processing: monitoring of compounds during fermentation.

The apple pomace-industrial residue of apple beverages manufacture-presents 42-58% of the phenolic content of fresh fruit. As the phenolic composition influences the quality of ciders, it is very relevant to monitor the evolution of these compounds during the industrial process. Therefore, this research aim was to monitor the cider composition with the addition of phenolic extract from apple pomace during the fermentation. Two treatments, S1 (without extract) and S2 (with added extract), were evaluated during 15 days of fermentation. After 15 fermentation days, the sample S2 presented an increase of 23% in total phenolic compounds and 40% in flavonoids without harm to the fermentation kinetics. Concerning the evolution of monomeric phenolic compounds, the phenolic acids in S1 and S2 presented a similar trend during the fermentation period. Enzymatic hydrolysis reactions resulted in the chlorogenic acid content decreasing, in line with increased levels of caffeic acid. Phloridzin and quercetin glycosides content showed the greatest increase in S2. The final product S2 presented higher antioxidant activity and some sensorial characteristics (astringency, bitterness and colour) were accentuated. This work shows that phenolic compounds added were maintained during the process and it did not prejudice the fermentation reactions. Therefore, this is a good alternative to valorize apple pomace and improve the functional and sensorial quality of the cider.