3.2 Pasantías y ponencias

URI permanente para esta colección

https://hdl.handle.net/20.500.12390/361

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Examinando 3.2 Pasantías y ponencias por Tema "Amino acids"
  • Publicación
    Effect of Dry Heat Puffing on Nutritional Composition, Fatty Acid, Amino Acid and Phenolic Profiles of Pseudocereals Grains
    (Sciendo, 2018)
    Paucar-Menacho, Luz María
    ;
    Duenãs M.
    ;
    Penãs E.
    ;
    Frias J.
    ;
    Martínez-Villaluenga C.
    The impact of puffi ng on nutritional composition and phenolic profi les of kiwicha (Amaranthus caudatus L.) and quinoa (Chenopodium quinoa Willd.) was investigated. Popped kiwicha showed increased protein and lipid contents and lower contents of carbohydrates compared to the untreated grains. Higher lipid, ash and carbohydrates contents and a decreased protein content were observed after puffi ng of quinoa. Fatty acid profi le and ω-6/ω-3 ratio was not affected by puffi ng, although it was observed a healthier ratio in quinoa (7:1) compared to kiwicha (65:1). Thermal treatment reduced essential amino acid contents and protein quality of both grains, although amino acids content remained adequate according to FAO/WHO requirements for adults. Puffi ng decreased hydroxybenzoic and hydroxycinnamic acids content of both pseudocereals. Flavonoid levels were negatively affected by puffi ng in kiwicha while a noticeable increase was observed in popped quinoa. In summary, puffi ng of kiwicha and quinoa grains is an alternative processing method to obtain expanded products or precooked fl ours of adequate nutritional value.
  • Publicación
    Optimization of germination time and temperature to maximize the content of bioactive compounds and the antioxidant activity of purple corn (Zea mays L.) by response surface methodology
    (Academic Press, 2017)
    Paucar-Menacho, Luz María
    ;
    Martínez-Villaluenga C.
    ;
    Dueñas M.
    ;
    Frias J.
    ;
    Peñas E.
    The objective of this study was to optimize germination time and temperature for maximizing the content of γ-aminobutyric acid (GABA), total phenolic compounds (TPC), and antioxidant activity in purple corn sprouts by using Response Surface Methodology (RSM). The phenolic composition of purple corn sprouts obtained in the optimal conditions was analyzed by HPLC-DAD-ESI/MS. Temperature of 26 °C and time of 63 h were found to be the optimal germination conditions since they enhanced 3.5-fold GABA content compared with seeds. These conditions, however, reduced ∼30 and ∼15% TPC and antioxidant activity, respectively, in purple corn. The models developed showed high coefficients of determination, demonstrating their adequacy to explain the variations in experimental data. Sprouts obtained in the optimal conditions presented anthocyanins as the most abundant phenolic class, detected mainly as cyanidin, pelargonidin, and peonidin glycosides or their malonyl derivatives. Hydroxycinnamic acids derivatives and flavonols were detected as minor compounds. Thus, germination at 26 °C for 63 h can be considered as an innovative strategy for diversifying the utilization of purple corn, providing at the same time sprouts with high levels of phytochemicals. Purple corn sprouts may constitute promising health-promoting foods.
  • Publicación
    Response surface optimisation of germination conditions to improve the accumulation of bioactive compounds and the antioxidant activity in quinoa
    (Blackwell Publishing Ltd, 2018)
    Paucar-Menacho, Luz María
    ;
    Martínez-Villaluenga C.
    ;
    Dueñas M.
    ;
    Frias J.
    ;
    Peñas E.
    Germination has been proposed as an economic approach to improve the content of bioactive compounds in pseudocereals. In this work, response surface methodology (RSM) was employed to investigate the impact of germination conditions on the phytochemical content and antioxidant activity of quinoa. The use of desirability methodology showed that the optimum conditions to maximise the content of total phenolic content (TPC) and antioxidant activity in sprouted quinoa were 20 °C for 42 h. Sprouts produced under these conditions exhibited increases of 80% and 30% in TPC and antioxidant activity, respectively, compared to un-germinated seeds, and contained high c-aminobutyric acid (GABA) concentration. The nonsignificant lack-of-fit and high determination coefficients obtained confirmed the suitability of the predictive models developed for TPC and antioxidant activity, whilst the one obtained for GABA was not significant (R2 < 0.75) within the conditions studied. Sprouting under optimum conditions enhanced the content of both flavonoid and nonflavonoid compounds, being the increase in flavonoids more pronounced. Kaempferol-O-dirhamnosyl-galactopyranose and quercetin-O-glucuronide were the compounds that experienced the most noticeable increase in quinoa after germination. In conclusion, this study provides useful information on the optimum germination conditions to improve the levels of health-promoting compounds in quinoa.