The recognition of high molecular weight melanoidins as the main components responsible for radical-scavenging capacity of unheated and heat-treated Canadian honeys

Melanoidins produced by the Maillard reaction: Structure and biological activity

“…In real foods, most of the melanoidins have been shown to be HMW compounds. For example, the browning intensity of the ethanol extracts of bread crust , manuka, and dandelion honey (Brudzynski & Miotto, 2011a) increased with increasing molecular weight upon heating, demonstrating that the browning is due in large part to HMW melanoidins. In coffee, 59% of the melanoidins are HMW (>12-14 kDa).…”

“…In conclusion, though brown MRPs containing melanoidins may show modest genotoxic and cytotoxic effects in high doses and after long incubation times (Bartling et al, 2005;Glosl et al, 2004;Jing & Kitts, 2000), the low concentrations found in foods do not pose a health risk. Morales & Jiménez-Pérez, 2004), bread crust Michalska, Amigo-Benavent, Zielinski, & del Castillo, 2008;Somoza et al, 2005), beer (Morales & Jiménez-Pérez, 2004), biscuit (Martin et al, 2009), roasted barley (Papetti et al, 2006), roasted cocoa (Summa et al, 2008), vinegar Xu, Tao, & Ao, 2007), honey (Brudzynski & Miotto, 2011a) and meat flavouring (Wang, YU, & Qian, in press;Wang, YU, QIAN, & YAO, 2010). These studies demonstrated that brown chromophoric MRPs, independent of the reaction conditions, displayed in vitro antioxidant protective effects on lipids (Borrelli et al, 2002;Wang et al, 2010), rat microsomes (Daglia et al, 2008;Papetti et al, 2006), hepatocytes Valls-Bellés et al, 2004), HepG2 cells (Martin et al, 2009) and human lymphocytes (Wang et al, 2010) against oxidation challenge.…”

Polyphenol-Protein Complexes and Their Consequences for the Redox Activity, Structure and Function of Honey. A Current View and New Hypothesis – a Review

“…In honey, the incorporation of polyphenol-protein complexes into melanoidin was responsible for both gain and loss of melanoidins' antioxidant activity [Brudzynski & Miotto, 2011a]. In unheated honeys, the radical scavenging activity of melanoidins depended on the initial content and antioxidant activity of polyphenols.…”

Changes of antioxidant activity in honey after heat treatment

“…The antioxidant activity of natural honey is mainly caused by phenolic antioxidants originating from the pollen of flowering plants and trees, and especially the dark-coloured honeydew honey types contain them in high amounts (Lachman et al 2010a,b). However, high-molecular-mass melanoidins have also been identified as the main components responsible for radical scavenging capacity of unheated and heat-treated honey (Brudzynski & Miotto 2011a). Principal component analysis revealed the highest correlation between ORAC (oxygen radical absorbance capacity) and Maillard reaction-like products and, in addition, the extremely significant correlations among the antioxidant activity, Maillard reaction-like products, phenolic content and honey colour may suggest that these compounds represent the same chemical entity and exert their antioxidant activity while being part of a higher molecular mass structure (Brudzynski & Miotto 2011b).…”