Effects of beetroot (Beta vulgaris) preparations on the Maillard reaction products in milk and meat-protein model systems

The effects of beetroots (Beta vulgaris) on the formation of Maillard reaction (MR) products possessing health, nutritional and sensory implications were studied. The effect of dried beetroot juice on the formation of N-epsilon-(carboxymethyl)lysine (CML) and N-epsilon-(2-furoylmethyl)-L-lysine (furosine) was determined in a milk model system. Beetroot juice reduced furosine formation more than CML, inferring that betalain compounds present in the juice are more effective in reducing the formation of MR products in the early stage than in the advanced stage of MR. Beetroot water extract was fractionated on Sephadex LH20 and obtained three beetroot fractions were used to assess their effect on the formation of heterocyclic amines in a meat-protein model system. Beetroot fraction possessing the highest antioxidant capacity and containing the highest betalain content reduced the amounts of 2-amino-1-methyl-6-phenylimidazo-[4,5-b]-pyridine (PhIP), 2-amino-3,8-dimethyl-imidazo[4,5-f]-quinoxaline (MeIQx), and 2-amino-3-methylimidazo-[4,5-f]-quinoline (IQ) by approximately 60, 77 and 87%, respectively. Beetroot preparations were characterized by ultra performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-Q-TOF-MS/MS). The antioxidant activities of beetroot preparations were also evaluated by 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS') scavenging capacity, oxygen radical absorbance capacity (ORAC) and total phenolic compound assays. Our findings could be useful for creating novel source of functional ingredients exerting anti-carcenogenic and antiglycation activities. (C) 2015 Elsevier Ltd. All rights reserved.