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Norbert De Kimpe - One of the best experts on this subject based on the ideXlab platform.
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the interaction of metal ions with maillard reaction products in a lactose glycine model system
Food Research International, 2009Co-Authors: Danute Terese Ramonaityte, An Adams, Milda Kersiene, Kourosch Abbaspour Tehrani, Norbert De KimpeAbstract:Abstract The influence of Cu 2+ , Fe 2+ and Zn 2+ -ions on Maillard model reactions was studied by heat treatment of lactose/glycine model solutions. The presence of metals affected the intensity of browning. Fe 2+ -ions stimulated the accumulation of colored compounds at all concentrations (20–100 mg/L) tested, Cu 2+ and Zn 2+ only at the lowest concentrations applied (1 and 5 mg/L, respectively) but to a higher extent. Cu 2+ and Zn 2+ -ions at the highest concentrations applied (5 and 25 mg/L, respectively) suppressed browning of the model mixtures. The relative amounts of metal ions incorporated into the high molecular weight Melanoidin fraction increased initially with the reaction time, but near the end of the reaction time studied (5 h, reflux conditions) Cu 2+ and Fe 2+ -ions were released again from the Melanoidins. The amounts of metal ions incorporated into the lactose–glycine Melanoidins and their influence on Maillard browning of the different fractions depended on the time of interaction and the nature and concentration of the incorporated metals.
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thermal degradation studies of food Melanoidins
Journal of Agricultural and Food Chemistry, 2005Co-Authors: An Adams, Rosa Cinzia Borrelli, Vincenzo Fogliano, Norbert De KimpeAbstract:Food Melanoidins were isolated from bread crust, coffee, and tomato sauce and their composition was investigated by thermal degradation. Among the generated volatiles, important food flavor compounds were detected: in particular furans, carbonyl compounds, 1,3-dioxolanes, pyrroles, pyrazines, pyridines, thiophenes, and phenols. The results indicated that the isolated Melanoidin fractions mainly consisted of compounds formed from carbohydrates and their degradation products. Besides proteins, other food constituents were incorporated in the Melanoidin structure as well, such as lipid oxidation products in tomato Melanoidins and phenolic compounds in coffee Melanoidins. A comparison of the thermal generation of volatiles between these food-derived Melanoidins and model Melanoidins prepared from a single carbonyl compound and an amino acid showed that the degradation pattern of food Melanoidins is quite different from that obtained from a glucose−glycine model system. Keywords: Maillard reaction; food melan...
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genotoxicity of Melanoidin fractions derived from a standard glucose glycine model
Journal of Agricultural and Food Chemistry, 2004Co-Authors: Joslyn L S Taylor, Jan C R Demyttenaere, Kourosch Abbaspour Tehrani, Arribas C Olave, L Regniers, Luc Verschaeve, A Maes, E E Elgorashi, Johannes Van Staden, Norbert De KimpeAbstract:Genotoxic compounds can act at various levels in the cell (causing gene, chromosome, or genome mutations), necessitating the use of a range of genotoxicity assays designed to detect these different types of mutations. The production of Melanoidins during the processing and cooking of foods is associated with changes in their nutritional character, and the discovery of mutagenic substances in pyrolyzed protein and amino acids has raised concern about the safety of these foods. The aim of this work was to test Melanoidin fractions in three different in vitro assays (Ames test, Vitotox test, and micronucleus test). These Melanoidin fractions were produced from the condensation of glucose with glycine and their separation was conducted by dialysis. The crude reaction mixture (before dialysis) and both the LMW and HMW fractions obtained by dialysis showed no genotoxicity in these assays, despite being tested at concentrations much higher than those naturally found in food products. The LMW fraction, however, showed toxicity at these high concentrations. The volatile fraction produced in this reaction showed genotoxicity only in the Vitotox test, at high concentrations.
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characterization of model Melanoidins by the thermal degradation profile
Journal of Agricultural and Food Chemistry, 2003Co-Authors: An Adams, Milda Kersiene, Rimantas Venskutonis, Kourosch Abbaspour Tehrani, Norbert De KimpeAbstract:Different types of model Melanoidins were thermally degraded, with subsequent identification of the volatiles produced, to obtain and compare the thermal degradation profile of various Melanoidins. At first, the volatiles produced from heated glucose/glycine standard Melanoidins were compared with glucose/glutamic acid and L-(+)-ascorbic acid/glycine standard Melanoidins. In the headspace of heated glucose/glycine Melanoidins, mainly furans, were detected, accompanied by carbonyl compounds, pyrroles, pyrazines, pyridines, and some oxazoles. Heating of L-(+)-ascorbic acid/glycine Melanoidins resulted in relatively more N-heterocycles, while from glucose/glutamic acid Melanoidins no N-heterocycles were formed. In a second part, a chemical treatment was applied to glucose/ glycine Melanoidins prior to the thermal degradation. Acid hydrolysis was performed to cleave glycosidically linked sugar moieties from the Melanoidin skeleton. Nonsoluble glucose/glycine Melanoidins were also subjected to an oxidation. The results indicate that the thermal degradation profile is a useful tool in the characterization of different types of Melanoidins.
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flavor release in the presence of Melanoidins prepared from l ascorbic acid and amino acids
Journal of Agricultural and Food Chemistry, 2002Co-Authors: Cvetan Obretenov, An Adams, Milda Kersiene, Jan C R Demyttenaere, Kourosch Abbaspour Tehrani, Norbert De KimpeAbstract:High-molecular-weight (HMW) water-soluble Melanoidins were prepared from model systems of l-(+)-ascorbic acid−glycine, l-(+)-ascorbic acid−lysine, l-(+)-ascorbic acid−glutamic acid, and glucose−glycine using a very recently approved standard protocol. The amount of HMW water-soluble Melanoidins prepared from l-(+)-ascorbic acid was over 5−15 times higher than the amount obtained from glucose. The study of the release of a model flavor compound, namely isoamyl acetate, from Melanoidins by solid-phase microextraction (SPME) showed that SPME is a suitable technique for the analysis of flavor release from Melanoidin-containing solutions. From the studies on the retention capacity of the Melanoidins toward isoamyl acetate, an increased release of the flavor compound was observed from the Melanoidins prepared from the l-(+)-ascorbic acid−glycine model system, whereas the opposite effect was observed from the Melanoidins prepared from the l-(+)-ascorbic acid−lysine/glutamic acid model systems. The Melanoidins pr...
Fernando M. Nunes - One of the best experts on this subject based on the ideXlab platform.
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Instant coffee as a source of antioxidant-rich and sugar-free coloured compounds for use in bakery: Application in biscuits
Food chemistry, 2017Co-Authors: Claudia P Passos, Fernando M. Nunes, Kristína Kukurová, Eva Basil, Pedro A.r. Fernandes, Andreia Neto, Michael Murkovic, Zuzana Ciesarová, Manuel A. CoimbraAbstract:Ammonia caramels are the most common antioxidant colour agent used in bakery formulations, although their high sugars content. An alternative could be coffee Melanoidins, which are brown coloured compounds with antioxidant properties, readily available from instant coffee. However, high caffeine content is limiting its direct application. To evaluate the possibility of obtaining coloured Melanoidin-rich, sugars- and caffeine-poor fractions from instant coffee, in this work, simple procedures based on their ethanol insolubility (fraction EtPp) or retention by ultrafiltration (fraction HWSn) were exploited. Melanoidins incorporation into biscuits formulation (amounts of 1, 5 and 10% w/w related to flour content) resulted in acceptable coloured products with higher antioxidant activity. The biscuits supplemented with 1% EtPp or HWSn had a low caffeine content. The caffeine of one espresso coffee was equivalent to 130 biscuits containing EtPp and 31 biscuits containing HWSn. Besides, both fractions did not promote extra formation of acrylamide or 5-hydroxymethylfurfural during baking.
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carbohydrate content dietary fibre and Melanoidins composition of espresso from single dose coffee capsules
Food Research International, 2016Co-Authors: Guido R Lopes, Andreia S Ferreira, Mariana Pinto, Claudia P Passos, Elisabete Coelho, Carla Rodrigues, Claudia Figueira, Sílvia M. Rocha, Fernando M. Nunes, Marco Antonio Afonso CoimbraAbstract:Abstract Single-dose coffee capsule system is a technology used to prepare espresso coffee which offers consumers the possibility to choose among several blends. However, the characterization of espresso coffees extracted with these systems, namely regarding polysaccharides structures and Melanoidin content, is scarce. In order to define a carbohydrate and Melanoidin composition pattern for single-dose espresso coffee base blends, a range of 6 commercial espresso coffee blends was studied. In addition, a decaffeinated blend and a blend supplemented with plant natural extracts were also included. The base blends showed galactomannans as the predominant polysaccharides over arabinogalactans, on the contrary of the decaffeinated blend. The blend supplemented with natural plant extracts showed glucose-rich polysaccharides. The labelled intensity of coffee single-dose seems to be related with the unknown brown compounds of Melanoidins, present in the high molecular weight material of the brews. A pattern could be obtained for single-dose espresso coffee base blends, presenting an average per cup of 1.21 g of total solids and 242 mg of soluble dietary fibre, constituted by 62 mg of galactomannans and 48 mg of arabinogalactans, and 123 mg of Melanoidins. On average, 46% of espresso coffee low molecular weight compounds are adsorbed to the high molecular weight material, evidencing the importance of the adsorption/desorption phenomena for the properties of coffee dietary fibre.
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chlorogenic acid arabinose hybrid domains in coffee Melanoidins evidences from a model system
Food Chemistry, 2015Co-Authors: Ana S P Moreira, Claudia P Passos, Fernando M. Nunes, Manuel A. Coimbra, Sonia A O Santos, Armando J D Silvestre, Andre M N Silva, Maria Rangel, Rosario M M DominguesAbstract:Arabinose from arabinogalactan side chains was hypothesized as a possible binding site for chlorogenic acids in coffee Melanoidins. To investigate this hypothesis, a mixture of 5-O-caffeoylquinic acid (5-CQA), the most abundant chlorogenic acid in green coffee beans, and (a1 ? 5)-L-arabinotriose, structurally related to arabinogalactan side chains, was submitted to dry thermal treatments. The compounds formed during thermal processing were identified by electrospray ionization mass spectrometry (ESI-MS) and characterized by tandem MS (ESI-MS n ). Compounds composed by one or two CQAs covalently linked with pentose (Pent) residues (1–12) were identified, along with compounds bearing a sugar moiety but composed exclusively by the quinic or caffeic acid moiety of CQAs. The presence of isomers was demonstrated by liquid chromatography online coupled to ESI-MS and ESI-MS n . Pent1–2CQA were identified in coffee samples. These results give evidence for a diversity of chlorogenic acid–arabinose hybrids formed during roasting, opening new perspectives for their identification in Melanoidin structures. 2015 Published by Elsevier Ltd.
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nature of phenolic compounds in coffee Melanoidins
Journal of Agricultural and Food Chemistry, 2014Co-Authors: Carina Coelho, Miguel Ribeiro, Ana C S Cruz, Rosario M M Domingues, Marco Antonio Afonso Coimbra, Mirko Bunzel, Fernando M. NunesAbstract:Phenolic compounds are incorporated into coffee Melanoidins during roasting mainly in condensed form (42–62 mmol/100 g) and also in ester-linked form (1.1–1.6 mmol/100 g), with incorporation levels depending on the green coffee chlorogenic acid content. The phenolic compounds are incorporated in different coffee Melanoidin populations, but mainly in those soluble in 75% ethanol (82%), a significant correlation between the amount of phenolic compounds and the amount of protein and color characteristics of the different Melanoidin populations being observed. The incorporation of phenolic compounds into coffee Melanoidins is a significant pathway of chlorogenic acid degradation during roasting, representing 23% of the chlorogenic acids lost. These account for the nearly 26% of the material not accounted for by polysaccharides and proteins present in coffee melanodins. The cleavage mechanism and the efficiency of alkaline fusion used to release condensed phenolics from coffee Melanoidins suggest that the phen...
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coffee Melanoidins structures mechanisms of formation and potential health impacts
Food & Function, 2012Co-Authors: Ana S P Moreira, Rosario M M Domingues, Fernando M. Nunes, Marco Antonio Afonso CoimbraAbstract:During the roasting process, coffee bean components undergo structural changes leading to the formation of Melanoidins, which are defined as high molecular weight nitrogenous and brown-colored compounds. As coffee brew is one of the main sources of Melanoidins in the human diet, their health implications are of great interest. In fact, several biological activities, such as antioxidant, antimicrobial, anticariogenic, anti-inflammatory, antihypertensive, and antiglycative activities, have been attributed to coffee Melanoidins. To understand the potential of coffee Melanoidin health benefits, it is essential to know their chemical structures. The studies undertaken to date dealing with the structural characterization of coffee Melanoidins have shown that polysaccharides, proteins, and chlorogenic acids are involved in coffee Melanoidin formation. However, exact structures of coffee Melanoidins and mechanisms involved in their formation are far to be elucidated. This paper systematizes the available information and provides a critical overview of the knowledge obtained so far about the structure of coffee Melanoidins, mechanisms of their formation, and their potential health implications.
Jose Angel Rufianhenares - One of the best experts on this subject based on the ideXlab platform.
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microtiter plate based assay for screening antimicrobial activity of Melanoidins against e coli and s aureus
Food Chemistry, 2008Co-Authors: Jose Angel RufianhenaresAbstract:Abstract A rapid plate reader based method examining the antimicrobial activity of both model and food Melanoidins (coffee, beer, sweet wine) is described. Antimicrobial activity against Escherichia coli and Staphylococcus aureus is evaluated as area under the growth curve compared to a control. Method was settled for an aqueous Melanoidin concentration of 2 mg/ml inoculated to 10 6 cfu/ml culture. All tested model and food Melanoidins exerted antimicrobial activity in some extent, but inhibition was significantly higher over S. aureus (Gram-positive) than E. coli (Gram-negative). Antimicrobial activity can be further quantified by expressing it as OTEV (oxytetracyclin equivalent value, μg/l) which could serve to compare the results obtained within different laboratories, methodologies and/or compounds. Results indicate that both strains have different sensitivity against the presence of Melanoidins and probably different mechanism of inhibition. Procedure can be used for a rapid screening of the potential antimicrobial properties of Melanoidins, and subsequently to Maillard reaction products as well, against pathogenic strains in order to isolated substances with biological activity.
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effect of in vitro enzymatic digestion on antioxidant activity of coffee Melanoidins and fractions
Journal of Agricultural and Food Chemistry, 2007Co-Authors: Jose Angel RufianhenaresAbstract:Traditionally antioxidant activity of Melanoidins has only been evaluated in food for implication in shelf life but gastrointestinal digestion is necessary to study their potential bioactivity. In addition, the biological fate of Melanoidins has been stressed during the past decade since they did not behave as inert substances. In the present paper a soluble coffee Melanoidin isolated from brewed coffee after ultrafiltration with a 10 kDa cutoff membrane was treated ionically and enzymatically collecting the respective high and low molecular weight fractions. Antioxidant activity of these fractions was evaluated with five well-described assays (DPPH, ABTS, ORAC, HOSC, and FRAP) that were previously setup in a plate reader based automatized analysis. Low molecular weight compounds released from Melanoidin after gastrointestinal digestion exerted the highest antioxidant activity, even higher than compounds bound ionically to Melanoidins. Gastrointestinal digestion is able to modify coffee Melanoidins to som...
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functional properties of Melanoidins in vitro antioxidant antimicrobial and antihypertensive activities
Food Research International, 2007Co-Authors: Jose Angel RufianhenaresAbstract:Abstract Melanoidins formed at the last stage of the Maillard reaction have been pointed out to possess certain functional properties such as antioxidant, antimicrobial and antihypertensive activities. In order to gain more insights on these functional properties different soluble Melanoidins and Melanoidin fractions isolated from several amino acid–glucose model systems has been analysed In the case of antioxidant and antimicrobial properties, low molecular weight compounds bounded to Melanoidins (BMC fraction) exerts antioxidant and antimicrobial activities usually higher than those of the pure Melanoidins to whom they are linked. Contrary, in the case of antihypertensive activity it has been found that the main activity is related to the Melanoidin core, not to BMC fraction. In addition it has been found no correlation, except for ABTS assay, among colour and antioxidant, antimicrobial or antihypertensive activity, supporting the idea that Melanoidin chromophores are not responsible for these actions.
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antimicrobial activity of Melanoidins
Journal of Food Quality, 2007Co-Authors: Jose Angel RufianhenaresAbstract:Melanoidins are high molecular weight compounds formed during the final stage of the Maillard reaction. Melanoidins have been studied in recent years because of their nutritional, biological and health implications, apart from their role on the stability during processing and shelf life of foods. A fast and robust microtiter plate-based assay for a quantitative screening of the antimicrobial activity of Melanoidins was applied. Oxytetracyclin was used as reference for assessing the antimicrobial activity of different Melanoidins isolated from model systems. The minimum inhibitory concentration was calculated, and activity was related to the antimicrobial activity of an oxytetracyclin solution (100 µg/L). Glucose–lysine Melanoidin exerted the highest antimicrobial activity, being at a concentration of 1 mg/mL, equivalent to an oxytetracyclin solution of 170 µg/L.
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angiotensin i converting enzyme inhibitory activity of coffee Melanoidins
Journal of Agricultural and Food Chemistry, 2007Co-Authors: Jose Angel RufianhenaresAbstract:Melanoidins formed at the last stage of the Maillard reaction have been pointed out to possess certain functional properties. Potential antihypertensive activity of food Melanoidins (coffee, beer, and sweet-wine) has been evaluated according to in-vitro ACE-inhibitory activity. Precision of the assay (3.2% of coefficient of variation, n = 10) for Melanoidins is similar to those reported of well-known antihypertensive peptides. Assay was applied on food Melanoidins obtained from coffee (three roasting degrees), beer, and sweet-wine. All samples showed in-vitro ACE-inhibitory activity. The activity in coffee Melanoidins was significantly higher at more severe heating conditions. These experiments demonstrate that food Melanoidins could inhibit ACE activity. In-vitro ACE-inhibitory activity of coffee Melanoidins is likely located within the Melanoidin structure. But ACE-inhibitory activity is also partly due to the low-molecular-weight compound nonchemically bound to the Melanoidin structure, then Melanoidin...
Yongqiang Cheng - One of the best experts on this subject based on the ideXlab platform.
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effect of laboratory scale decoction on the antioxidative activity of zhenjiang aromatic vinegar the contribution of Melanoidins
Journal of Functional Foods, 2016Co-Authors: Yongjian Yu, Yongqiang ChengAbstract:Abstract Decoction, the characteristic heat-treatment procedure in Zhenjiang Aromatic Vinegar (ZAV) processing, was performed in laboratory to investigate its effect on the antioxidative activity (AA) of ZAV. Owing to the laboratory-scale decoction, DPPH radical scavenging activity, ORAC value and cellular antioxidant activity (CAA) of ZAV increased by 63, 24 and 54% of that of undecocted vinegar, respectively. Enzymatic assay and HPLC determination proved that phenolic content decreased after the decoction, while Melanoidins, also with antioxidative activity and recently found in ZAV, were generated. Regardless of the fluctuation in AA of Melanoidins during decoction, increased Melanoidin content was responsible for the increase in AA of ZAV. At the end of the decoction, Melanoidins accounted for 57.1 and 44.1% of the total AA of ZAV, according to DPPH and ORAC assays, respectively. Incorporation of phenolic compounds into Melanoidins and degradation of Melanoidins might both occur during decoction.
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effect of laboratory scale decoction on the antioxidative activity of zhenjiang aromatic vinegar the contribution of Melanoidins
Journal of Functional Foods, 2016Co-Authors: Yongjian Yu, Yongqiang ChengAbstract:Abstract Decoction, the characteristic heat-treatment procedure in Zhenjiang Aromatic Vinegar (ZAV) processing, was performed in laboratory to investigate its effect on the antioxidative activity (AA) of ZAV. Owing to the laboratory-scale decoction, DPPH radical scavenging activity, ORAC value and cellular antioxidant activity (CAA) of ZAV increased by 63, 24 and 54% of that of undecocted vinegar, respectively. Enzymatic assay and HPLC determination proved that phenolic content decreased after the decoction, while Melanoidins, also with antioxidative activity and recently found in ZAV, were generated. Regardless of the fluctuation in AA of Melanoidins during decoction, increased Melanoidin content was responsible for the increase in AA of ZAV. At the end of the decoction, Melanoidins accounted for 57.1 and 44.1% of the total AA of ZAV, according to DPPH and ORAC assays, respectively. Incorporation of phenolic compounds into Melanoidins and degradation of Melanoidins might both occur during decoction.
Rosario M M Domingues - One of the best experts on this subject based on the ideXlab platform.
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chlorogenic acid arabinose hybrid domains in coffee Melanoidins evidences from a model system
Food Chemistry, 2015Co-Authors: Ana S P Moreira, Claudia P Passos, Fernando M. Nunes, Manuel A. Coimbra, Sonia A O Santos, Armando J D Silvestre, Andre M N Silva, Maria Rangel, Rosario M M DominguesAbstract:Arabinose from arabinogalactan side chains was hypothesized as a possible binding site for chlorogenic acids in coffee Melanoidins. To investigate this hypothesis, a mixture of 5-O-caffeoylquinic acid (5-CQA), the most abundant chlorogenic acid in green coffee beans, and (a1 ? 5)-L-arabinotriose, structurally related to arabinogalactan side chains, was submitted to dry thermal treatments. The compounds formed during thermal processing were identified by electrospray ionization mass spectrometry (ESI-MS) and characterized by tandem MS (ESI-MS n ). Compounds composed by one or two CQAs covalently linked with pentose (Pent) residues (1–12) were identified, along with compounds bearing a sugar moiety but composed exclusively by the quinic or caffeic acid moiety of CQAs. The presence of isomers was demonstrated by liquid chromatography online coupled to ESI-MS and ESI-MS n . Pent1–2CQA were identified in coffee samples. These results give evidence for a diversity of chlorogenic acid–arabinose hybrids formed during roasting, opening new perspectives for their identification in Melanoidin structures. 2015 Published by Elsevier Ltd.
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nature of phenolic compounds in coffee Melanoidins
Journal of Agricultural and Food Chemistry, 2014Co-Authors: Carina Coelho, Miguel Ribeiro, Ana C S Cruz, Rosario M M Domingues, Marco Antonio Afonso Coimbra, Mirko Bunzel, Fernando M. NunesAbstract:Phenolic compounds are incorporated into coffee Melanoidins during roasting mainly in condensed form (42–62 mmol/100 g) and also in ester-linked form (1.1–1.6 mmol/100 g), with incorporation levels depending on the green coffee chlorogenic acid content. The phenolic compounds are incorporated in different coffee Melanoidin populations, but mainly in those soluble in 75% ethanol (82%), a significant correlation between the amount of phenolic compounds and the amount of protein and color characteristics of the different Melanoidin populations being observed. The incorporation of phenolic compounds into coffee Melanoidins is a significant pathway of chlorogenic acid degradation during roasting, representing 23% of the chlorogenic acids lost. These account for the nearly 26% of the material not accounted for by polysaccharides and proteins present in coffee melanodins. The cleavage mechanism and the efficiency of alkaline fusion used to release condensed phenolics from coffee Melanoidins suggest that the phen...
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coffee Melanoidins structures mechanisms of formation and potential health impacts
Food & Function, 2012Co-Authors: Ana S P Moreira, Rosario M M Domingues, Fernando M. Nunes, Marco Antonio Afonso CoimbraAbstract:During the roasting process, coffee bean components undergo structural changes leading to the formation of Melanoidins, which are defined as high molecular weight nitrogenous and brown-colored compounds. As coffee brew is one of the main sources of Melanoidins in the human diet, their health implications are of great interest. In fact, several biological activities, such as antioxidant, antimicrobial, anticariogenic, anti-inflammatory, antihypertensive, and antiglycative activities, have been attributed to coffee Melanoidins. To understand the potential of coffee Melanoidin health benefits, it is essential to know their chemical structures. The studies undertaken to date dealing with the structural characterization of coffee Melanoidins have shown that polysaccharides, proteins, and chlorogenic acids are involved in coffee Melanoidin formation. However, exact structures of coffee Melanoidins and mechanisms involved in their formation are far to be elucidated. This paper systematizes the available information and provides a critical overview of the knowledge obtained so far about the structure of coffee Melanoidins, mechanisms of their formation, and their potential health implications.