Impact of cooking method on phenolic composition and antioxidant potential of four varieties of Phaseolus vulgaris L. and Glycine max L.

The present study aimed to investigate the effects of different cooking conditions - atmospheric (100°C) and pressure cooking (115°C) - on the phenolic composition and antioxidant activity of methanolic extracts of four Phaseolus vulgaris varieties and soy (Glycine max). Contrary to soy, in P. vulgaris varieties both cooking methods increased drastically the total phenolic, flavonoid, and ortho-diphenol content, as well as antioxidant capacity. These results were corroborated by HPLC analysis, where an overall increase of phenolic acids and flavonoids was detected in processed samples. However, draining the cooking water significantly decreased phenolic acids, flavonoids and antioxidant activity in all P. vulgaris varieties and as well as soy. The hypothesis that cooking increases the compound accessibility and nutritional value through increased release of phytochemicals was verified in the present study for P. vulgaris varieties. Keeping the cooking water is crucial to the increased nutritional value of all Phaseolus varieties. Overall, compared with the tested varieties of Phaseolus, soy, to which many health benefits are attributed, is not the best legume source of antioxidants.The author Catarina I. Teixeira-Guedes acknowledges the financial support provided FCT-Portuguese Foundation for Science and Technology (SFRH/BD/52544/2014), under the Doctoral Program “Agricultural Production Chains – from fork to farm” (PD/00122/ 2012). This work was supported by the European Investment Funds FEDER/COMPETE/POCI– Operational Competitiveness and Internationalization Programme [POCI-01-0145-FEDER-006958] and Portuguese Foundation for Science and Technology (FCT) [UID/AGR/ 04033/2019]; Project I&D Interact - Integrative Research in Environment, Agro-Chain and Technology [NORTE-01-0145-FEDER000017], co-financed by European Regional Development Fund (FEDER) through NORTE 2020 (Programa Operacional Regional do Norte 2014/2020).info:eu-repo/semantics/publishedVersio

Application of photo-selective films to manipulate wavelength of transmitted radiation and photosynthate composition in red beet (Beta vulgaris var. conditiva Alef.)

BACKGROUNDInterest is increasing around both the use of plants as functional foods and the agronomic techniques which can increase nutrients and phytochemicals. Nevertheless, little research has focused on the effects of light on accumulation of active compounds in root storage organs. Red beet was treated with RED (red/far red ratio: 1.29; transmitted photosynthetically active radiation: 66.9%) and GREEN (red/far red ratio: 0.43; transmitted photosynthetically active radiation: 25.8%) photo-selective films and changes in nutrients and biomass accumulation were measured.RESULTSPlants subjected to GREEN treatment had less dry weight accumulation both in storage roots (68%) and leaves (42%); moreover, soluble and structural carbohydrate concentration in roots was increased, as were the K, Mg and Zn concentrations (40.08, 2.95 and 0.023 mg g−1 fresh weight, respectively). Conversely, GREEN lowered total phenolic concentration (0.33 vs. 0.47 mg g−1 fresh weight) and antioxidant activity (0.65 vs. 0.94 µm Trolox equivalents g−1 fresh weight) compared to CONTROL. Total pigment concentration was reduced by 20% and 48% with RED and GREEN treatments, respectively.CONCLUSIONRed beet showed a strong plasticity in its adaptation to light availability. Some macronutrients (fiber, sugars, minerals) can be concentrated in roots by modifying the amount and quality of the light, principally with GREEN photo-selective films.[...