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Escola Superior Agrária

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Browsing Escola Superior Agrária by Subject "1-Kestose (GF2)"

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  • Screening of fungi with potential for producing fructooligosaccharides with enhanced bioactivity
    Publication . Lama, Aelina; Peres, António M.; Dias, Teresa
    Fructooligosaccharides (FOS) are present in plants and fruits at low concentrations and with varying individual relative proportions. So, for the industrial application, fructooligosaccharides extraction from natural sources may not be economically viable. Recently, several works have been published within the field of research usually aiming to establish the best experimental conditions to maximizing fructooligosaccharides yields/synthesis. However, although it is known that these compounds may have a great health impact, it is also reported that beneficial health effects may depend on the relative fructoligosaccharisdes composition, seeming that nystose-rich diet is preferable compared to a kestose-rich preparation, exhibiting a higher anti-hydroxyl radical activity. So, in this work, a screening study was firstly carried out aiming to evaluate the bioactive activity of the fermentation broths obtained using different fungi (A. aculeatus, A. japonicus, P. corylophilum, P. spinulosum and P. thomii) with reported potential for producing fructooligosaccharides. Based on the screening antioxidant results (DPPH free radical scavenging activity and iron chelating activity), A. aculeatus was selected as the fungi with the highest antioxidant potential. After, batch fermentations were carried out aiming to establish, based on an experimental design, the initial sucrose concentration (from 88 to 265 g/L) and fermentation temperature (from 22 to 32ºC), which enhance the broths bioactivities. Among the two evaluated experimental conditions, the initial sucrose concentration significantly influenced biomass growth (a maximum value of 16± 1.5 g was achieved) although it did not significantly affect the maximum FOS yield obtained, which varied between 51 to 59 g of FOS/g of initial sucrose. Finally, the preliminary results obtained did not allowed establishing straightforward correlation betwwen antioxidant activities of the fermentation broths and the individual or total FOS concentrations.
    2017Master thesis Open access Show more