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Browsing by Author "Faria, Miguel A."

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  • Modeling of α-acids and xanthohumol extraction in dry-hopped beers
    Publication . Machado, Júlio C.; Faria, Miguel A.; Melo, Armindo; Martins, Zita E.; Ferreira, Isabel M.P.L.V.O.
    The practice of dry-hopping has been used by the brewing industry to obtain beers with increased contents of flavor and bitterness compounds. Notwithstanding this, other compounds such as α-acids (AA) and xhanthohumol (XN) are co-extracted influencing the final characteristics of the beer, particularly its beneficial bioactivity. In this context a model for the understanding of AA and XN extraction by dry-hopping is proposed. The varieties Chinook (CHI), East Kent Goldings (EKG) and Tettnanger (TET) were assayed and robust statistical approaches were applied for data interpretation. Concentration of AA in beers post-maturation reached values higher than 20 mg/L using 2.8 g/L of CHI hops and 10 days of maturation. For XN, a similar behavior was verified. The maximum efficiency of AA and XN extraction (transfer rate) were reached at 13.5 days with dose rates of 147 and 13.9 mg/L, respectively.
    2018-11-10Journal article Restricted access Show more
  • Nutritional quality of protein concentrates from Moringa Oleifera leaves and in vitro digestibility
    Publication . Benhammouche, Tassadit; Melo, Armindo; Martins, Zita; Faria, Miguel A.; Pinho, Susana C.M.; Ferreira, Isabel M.L.P.V.O.; Zaidi, Farid
    The nutritional value and digestibility of leaf proteins is still a major issue. Therefore, the goal of this work was to optimize the production of a protein concentrate (PC) from Moringa Oleifera defatted leaves (MODL) by enzymatic extraction using Viscozyme L and evaluate its nutritional quality and digestibility. Protein extraction conditions were screened using a factorial design. Enzyme/Substrate ratio and pH had no significant effect, whereas, the significant variables, temperature (°C), enzyme concentration and incubation time (h) were optimized by central composite design (CCD). PC contained 55.7% of proteins with a balanced amino acid profile when compared with MODL and higher content of essential amino acids (EAAs) (488.6-402.9 mg/g of protein respectively). Improvement on protein digestibility was observed for MODL compared to PC (64.75-99.86% respectively) and higher protein digestibility corrected amino acid score (PDCAAS) (62.10-91.41% respectively). PC meets FAO protein quality expectations.
    2020-12-24Journal article Restricted access Show more