RESUMO
The radiolytic decomposition of glucose, fructose, sucrose, ascorbic acid (H2A) and dehydroascorbic acid (DHAA), induced by ionizing radiation, was investigated. Aqueous solutions of these compounds were gamma-irradiated at doses of 0.5, 0.7 and 1â¯kGy, with a dose rate of 0.04â¯kGy/min, in the presence of air, followed by HPLC, HPLC-MS, EPR, and UV-VIS spectroscopy analysis of the resulting mixtures. Carboxylic acids, 2-furaldehyde, 5-hydroxymethyl-2-furaldehyde, furfuryl alcohol, 2-furoic acid and 2(5H)-furanone were identified in solutions of sugars and vitamin C, by comparing with standards. EPR studies exhibited a higher amount of free radicals for fructose than the other sugars, and more for DHAA than H2A. Additionally, spectroscopic determinations showed a typical UV-VIS absorption for furans during the storage of irradiated solutions. Formation and decomposition routes for furanoids and aliphatic carboxylic acids, and mechanistic pathways for the radiolytic induced rupture of glucose, fructose, sucrose and vitamin C have been proposed.
Assuntos
Ácido Ascórbico/química , Raios gama , Açúcares/química , Ácidos Carboxílicos/química , Furanos/químicaRESUMO
In this chapter, a review is made on various aspects of chia seed in order to provide an overall, yet comprehensive view, about this important commodity with the aim of updating the current state of knowledge on its composition, possible nutraceutical properties, and potential benefits for human health. Based on this approach, the discussion includes some comments on the main historical aspects, morphology of the seed, its importance in the diet of humans and stresses the main results issued from investigations on its three main components; lipid, protein, and fiber. The chapter closes with a discussion on the potential benefits for human health, highlighting the contradictions that still exist in this area and the need for continued research in this direction and considerations on the role of chia seed as a functional food.
