Spontaneously fermented traditional beverages as a source of bioactive compounds: an overview

Published online: 14 Jul 2020Fermented food has been present throughout history, since fermentation not only helps preserving food, but also provides specific organoleptic characteristics typically associated to these foods. Most of the traditional fermented foods and artisanal beverages are produced by spontaneous generation, meaning no control of the microbiota, or the substrate used. Nevertheless, even not being standardized, they are an important source of bioactive compounds, such as antioxidant compounds, bioactive beeps, short chain fatty acids, amino acids, vitamins, and minerals. This review compiles a list of relevant traditional fermented beverages around the world, aiming to detail the fermentation process itselfincluding source of microorganisms, substrates, produced metabolites and the operational conditions involved. As well as to list the bioactive compounds present in each fermented food, together with their impact in the human health. Traditional fermented beverages from Mexico will be highlighted. These compounds are of high interest for the food, pharmaceutical and cosmetics industry. To scale-up the home fermentation processes, it is necessary to fully understand the microbiology and biochemistry behind these traditional products. The use of good quality raw materials with standardized methodologies and defined microorganisms, may improve and increase the production of the desirable bioactive compounds and open a market for novel functional products.The authors acknowledge the National Council of Science and Technology (CONACYT, Mexico) for the financial support (CVU 559365). This study was also supported by the Portuguese Foundation for Science and Technology under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01- 0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte also, Project ColOsH 02/SAICT/2017 (POCI-01-0145- FEDER-030071).info:eu-repo/semantics/publishedVersio

Evaluation of Aloe vera juice as a substrate for Enterococcus faecium

Fermented plant material beverages stand out from fermented food in general, since their consumption presents no risk of intolerance and allergies associated with dairy food. Aloe vera has been used to varied medical purposes due to their bioactive compounds. Lactic acid bacteria, generally used in fermented beverages, are known also for their potential health and nutritional benefits. This study aimed to evaluate Aloe vera juice grown in Mexico as a substrate for Enterococus faecium isolated from breastmilk. To obtain the juice, Aloe vera gel was treated enzymatically with cellulase. The juice was inoculated with E. faecuim at 37ºC and initial pH 4.7 ± 0.2. Biomass growth and pH were evaluated along the fermentation. Fermentation was also run with Aloe vera juice supplemented with 20 g/L of glucose. Glucose consumption and organic acids produced were analyzed by HPLC, and Total phenols were determined by Folin- Ciocalteu colorimetric method. Results obtained with E. faecium were compared with fermentations run with a commercial Lactococus Lactis strain. Glucose from the Aloe vera juice was consumed in 24 h by the E. faecium, with a production of 2.25 g/L of lactic acid. In the juice supplemented with glucose, E. faecium did not consumed all the glucose up to 60 h fermentation, and produced 7.3 g/L of lactic acid. The pH droped to 3 units in both treatments. There was a significant difference between the total phenols determined for both fermentations. A total of 192.50±0.04 mg GAE/L was found for the fermentation run with the Aloe vera juice and 196.53±0.06 mg GAE/L for fermentation with addition of glucose to the juice. For fermentations run with the commercial strain of L. Lactis, a higher amount of total phenols was determined, 222.30±0.05mg GAE/L and 226.90±0.02 mg GAE/L for treatment without and with supplementation of glucose. The carbon source did not influence the production of total phenols, but it did influence the production of lactic acid. Other acids of interest were also produced by both bacteria such as succinate, format, acetate, propionate, and iso- butyrate. Aloe vera showed to be suitable for the growth of the probiotic E. faecium bacteria, boosting bioactive metabolites in the obtained juice, which after process optimization may result in a new functional beverage.info:eu-repo/semantics/publishedVersio