Isolation of an in Vitro and ex Vivo Antiradical Melanoidin from Roasted Barley

Abstract

The antiradical properties of water-soluble components of both natural and roasted barley were determined in vitro, by means of DPPH* assay and the linoleic acid-beta-carotene system, and ex vivo, in rat liver hepatocyte microsomes against lipid peroxidation induced by CCl4. The results show the occurrence in natural barley of weak antioxidant components. These are able to react against low reactive peroxyl radicals, but offer little protection against stable DPPH radicals deriving from peroxidation in microsomal lipids. Conversely, roasted barley yielded strong antioxidant components that are able to efficiently scavenge free radicals in any system used. The results show that the barley grain roasting process induces the formation of soluble Maillard reaction products with powerful antiradical activity. From roasted barley solution (barley coffee) was isolated a brown high molecular mass melanoidinic component, resistant to acidic hydrolysis, that is responsible for most of the barley coffee antioxidant activity in the biosystem.

Assessing the Influence of Roasting Process Parameters on Mepiquat and Chlormequat Formation in Dark Barley Malts

“…Melanoidins were also reported to be formed by Maillard-like reaction, leading to the color change (Bekedam et al 2008;Moreira et al 2012;Papetti et al 2006). L* color parameter of roasted products has already been correlated with the quantity of acrylamide and MPQ and results have already been reported, where these products were proposed to be formed via Maillard reaction (Bessaire et al 2016;Mizukami et al 2016Mizukami et al , 2014.…”

“…In addition to MPQ, melanoidins have also been reported to be formed by Maillard-like reactions during the roasting process of Barley and coffee (Bekedam et al 2008;Moreira et al 2012;Papetti et al 2006). These melanoidins are also responsible for color changes during the roasting process (Papetti et al 2006). Therefore, a close connection between product color changes and MPQ formation can be assumed.…”

“…Maillard reaction drove the MPQ formation through to the degradation of lysine (amino acid) in the presence of trigonelline (alkaloid), conjugated with a temperature of typical roasting conditions (Hammel et al 2014). In addition to MPQ, melanoidins have also been reported to be formed by Maillard-like reactions during the roasting process of Barley and coffee (Bekedam et al 2008;Moreira et al 2012;Papetti et al 2006). These melanoidins are also responsible for color changes during the roasting process (Papetti et al 2006).…”

Comparative studies on antioxidant activities of extracts and fractions from the leaves and stem of Epimedium koreanum Nakai

“…Icariin (C 33 H 40 O 15 ; molecular weight: 676.67, ICA) was one of the main flavonoids of Epimedium koreanum Nakai and it was always used as the standard for the quality control of Epimedium related remedies. Icariin was reported to have multiple activities including vasodilatory effect on the coronary vessels by its inhibition on Ca 2+ channels (Middleton 1998), cardioprotective effects during ischemia and reoxygenation (Behera et al 2008) , improving the spatial learning and memory abilities in aluminum-intoxicated rats and decreasing the level of Aβ 1-40 in the hippocampus of aluminum-intoxicated rats (Papetti et al 2006).…”

Chemical composition, antioxidant and antibacterial activities and evaluation of cytotoxicity of the fractions obtained fromSelaginella convoluta(Arn.) Spring (Selaginellaceae)

“…It is associated with many chronic diseases such as cancer, neurodegenerative, cardiovascular disease and diabetes [1]. Consumption of fruits, vegetables and other derived plant products, because of the presence of bioactive molecules, such as phenolic compounds, flavonoids and tannins, has been associated with a lower incidence of diseases related to oxidative stress [2][3][4]. These substances are secondary metabolites, biosynthesized by plants to prevent pathogen attack, ultraviolet stress or to attract pollinator insects [5].…”