The aim of the research was to determine the impact of fermentation with Pleurotus ostreatus on kidney beans, black beans, and oats. The results indicate that the fungus has a positive effect on the substrates when compared to the controls. The antioxidant activity (39.5% on kidney beans and 225% on oats in relation to the controls) and content of total polyphenols (kidney beans three times higher regarding the controls) increased significantly by the presence of the fungus mycelium, even after simulated digestion. There was a significant increase in protein digestibility (from 39.99 to 48.13% in black beans, 44.06 to 69.01% in kidney beans, and 63.25 to 70.01% in oats) and a decrease of antinutrient tannins (from 65.21 to 22.07 mg in black beans, 35.54 to 23.37 in kidney beans, and 55.67 to 28.11 in oats) as well as an increase in the contents of some essential amino acids. Overall, this fermentation treatment with Pleurotus ostreatus improved the nutritional quality of cereals and legumes, making them potential ingredients for the elaboration and/or fortification of foods for human nutrition.
26 September 2019 in IEEE Transactions on Nanobioscience
In developing countries, the incidence of postharvest losses reduces the quantity and quality of food for human consumption and causes an economical damage along the food chain, especially, for primary producers. In this study, a multisystem coating (NC-EOt-C) based on pullulan and polymeric nanocapsules containing EO of Thymus vulgaris L. (EOt) was applied to increase the shelf life of table grapes (Vitis vinifera L.). The major components of EOt, chemically characterized by GC-MS, were o-cymene (32.68%), thymol (31.90%), and γ -terpinene (15.69%). The NC-EOt were prepared by nanoprecipitation and showed a particle mean size of 153.9 nm, a polydispersity index of 0.186, a zeta potential of -4.11 mV, and an encapsulation efficiency of 52.81%. The antioxidant capacity (DPPH and ABTS + methods) of EOt was maintained, or even improved, after its incorporation into NC. The shelf life study showed that grapes having the NC-EOt-C multisystem maintained their characteristics of color, firmness, TA, and SSC for longer time than those without the multisystem. NC-EOt-C multisystem acted as a barrier which reduced the metabolism of fruits. In addition, the compounds of EOt with antimicrobial activity avoided microorganism growth, while those with antioxidant activity reduced the oxidative stress induced during postharvest of grapes. Additionally, the polymeric structure of NC prevented the rapid evaporation of volatile compounds of EOt, increasing then their residence time on the fruit. Our study demonstrated that NCEOt-C multisystem can be a viable alternative to preserve horticultural products for longer storage periods.
Oregano (Poliomintha longiflora) essential oil (Ooil) is a product of high commercial value and many applications, including chemotherapy. Aiming to achieve the best use of this resource, the present study focuses on the characterization of separated fractions of Ooil by fractional vacuum distillation at low pressure. Four fractions (F1–F4) and undistilled oil (Unoil) were separated from Ooil and analyzed for their chemical composition and biological activities, such as antioxidant and antimicrobial activities. Gas chromatography–mass spectrometry shows differences in the composition among the fractions and Ooil. The amount of monoterpenes oxygenated (MO), sesquiterpenes hydrocarbon (SeH) and monoterpenes hydrocarbon (MH) varied between the fractions in ranges of 1.51–68.08, 3.31–25.12 and 1.91–97.75%, respectively. The major concentrations of MO and SeH were observed in F4 and Unoil. On the other hand, the highest concentrations of MH were found in F1 and F2, while the lowest were in F4 and Unoil. These results were correlated with the biological activity. Free-radical scavenging activity varied among fractions, with F4 and Unoil showing the highest activity. The antimicrobial test showed that F4 and Unoil had the highest activity in almost all cases. The correlation between the variables studied in the different fractions allows the definition of the particular properties for each one of them.