Arabic coffee infusion based kombucha: Characterization and biological activity during fermentation, and in vivo toxicity.

In this study, arabic coffee infusion was used to produce a fermented beverage known as kombucha. The physicochemical, antioxidant and antimicrobial activities, as well as in vivo toxicity were evaluate throughout 21 days of fermentation. Reduction in pH and sugar levels were observed throughout the fermentation period. There was no significant difference in the content of total phenolic compounds between the unfermented and fermented beverage, nor between the fermentation times, as well as in the antioxidant activity. The 5-caffeoylquinic acid was identified at all fermentation times evaluated, and no significant difference was observed regarding its concentration. It showed antibacterial and antifungal activity against all strains tested. No toxic effect of the beverages was observed in the in vivo model (Galleria mellonella) studied. These results demonstrated that coffee infusion is a possible alternative for kombucha production since the physicochemical changes prove the metabolic activity of Symbiotic Culture of Bacteria and Yeast.

Evolution of the metabolic profile of virgin olive oil during deep-frying: Assessing the transfer of bioactive compounds to the fried food.

Deep-frying in virgin olive oil (VOO) is favorable due to its desirable composition and high content of bioactive compounds that can be transferred to fried food. The main goal of this work was to investigate the evolution of VOO metabolic profile during consecutive deep-frying cycles and assess the transfer of metabolites to French fries. The evolution of 56 compounds was monitored by two complementary liquid chromatography methods, using mass spectrometry, diode array, and fluorescence detectors. Sterols and lignans were remarkably stable (greater than 70 % retention in frying oil). Seven out of the ten compounds' classes identified in the oil were transferred to the fried food. Potatoes fried in Arbequina oil from Brazil incorporated the highest amounts of VOO minor components, among the analyzed samples, and sterols presented the highest transfer rate. French fries were enriched by VOO bioactive compounds during deep-frying, especially on the first two days, improving their nutritional value.