Maillard reaction
Please check back later for additional changes
The Maillard reaction, also called non-enzymatic browning, is a network of chemical reactions that begin with the addition of sugar molecule to proteins, peptides, amino acids or amines.[2][3] This yields a Schiff base, which undergoes a rapid rearrangement forming more stable Amadori compounds.[1][4] For our purposes, this process is also known as glycation.
High temperature treatments and high contents of reducing sugars (i.e. glucose) are favorable factors for the Maillard reaction to occur. Much of the protein in beer undergoes a Maillard reaction during malting, forming glycoproteins (especially LTP1 and Protein Z). During mashing and boiling processes, Maillard reactions may also occur to some extent.[3][5] See Protein and Glycoproteins for more information.
Maillard reactions are important for flavor stability because undesired flavor compounds such as the Strecker aldehydes and furfural can be formed.[6][7]
During brewing, kilning, mashing and wort boiling processes can produce melanoidins, ketones and other antioxidant substances through the Maillard reaction.[8] It is suggested that "browning" or the Maillard reaction is the main change that occurs during kilning.[9]
The reaction of an amine, amino acid, peptide, or protein with a reducing sugar and all possible reactions occurring thereafter are called “Maillard reactions” or “nonenzymatic browning reactions”. As these reactions commence at 50 °C in the pH range of 4−7,98 they are usually related to the application of heat and are responsible for an increase in color. the variety of Maillard products in beer is enormous and their chemical properties are very diverse. In general, the heterocyclic compounds furfural and 5-hydroxymethylfurfural (5-HMF) are quantitatively the most important Maillard products in beer. Their formation pathways are very similar (Figure 7). Both are important markers for the heat load placed on the mash, wort, and beer and for flavor staling in general.17,46,110−117 Throughout the aging process, their concentrations increase at a linear rate.110,112,113,117 According to several authors, furfural and 5-HMF concentrations do not exceed their respective flavor threshold values, and it is therefore said that they do not significantly affect beer flavor. This is however contradicted by more recent findings by De Clippeleer et al.,118 in which spiking of furfural to fresh pale lager beer resulted in a sharper, harsher, more lingering bitterness and increased astringency. The effect on taste and mouthfeel is often discarded in flavor threshold determinations, which are usually based on odor and aroma, or only odor.[10]
The carbonyl group of the sugar compound (in aldose form) reacts with an amine or with the amino group of an amino acid, peptide, or protein. This yields an imine (or Schiff base) and comprises the rate-limiting step of the early-stage mechanism.119 This imine stabilizes by undergoing a so-called Amadori rearrangement, forming an Amadori compound (1-amino-1-deoxyketose). Higher temperatures are favorable for the rearrangement.119 Due to instability at the beer pH, this Amadori compound can undergo 1,2-enolization. The subsequent release of an amine gives rise to 3-deoxyosone, an α-dicarbonyl (vicinal diketone). Cyclization yields the heterocyclic compound furfural, in the case of pentose, or 5-HMF, in the case of hexose.[10]
See also[edit]
To review:
- Rakete, S., Klaus, A., & Glomb, M. A. (2014). Investigations on the Maillard reaction of dextrins during aging of Pilsner type beer. Journal of Agricultural and Food Chemistry, 62, 9876–9884.
- Vanderhaegen, B., Neven, H., Verachtert, H., and Derdelinckx, G. The chemistry of beer aging—A critical review. Food Chem. 95:357-381, 2006.
- Maillard Reaction Products in Different Types of Brewing Malt
- https://sci-hubtw.hkvisa.net/10.1021/jf800094k Gallardo E, De Schutter DP, Zamora R, Derdelinckx G, Delvaux FR, Hidalgo FJ. Influence of lipids in the generation of phenylacetaldehyde in wort-related model systems. J Agric Food Chem. 2008;56(9):3155–3159.
- Čechovská, L.; Konečný, M.; Velíšek, J.; Cejpek, K. Effect of Maillard reaction on reducing power of malts and beers. Czech J. Food Sci. 2012, 30, 548–556.
References[edit]
- ↑ a b Bobálová J, Petry-Podgórska I, Laštovičková M, Chmelík J. Monitoring of malting process by characterization of glycation of barley protein Z. Eur Food Res Technol. 2010;230(4):665–673.
- ↑ Ferreira IM, Guido LF. Impact of wort amino acids on beer flavour: A review. Fermentation. 2018;4(23).
- ↑ a b Han Y, Wang J, Li Y, Hang Y, Yin X, Li Q. Circular dichroism and infrared spectroscopic characterization of secondary structure components of protein Z during mashing and boiling processes. Food Chem. 2015;188:201–209.
- ↑ Steiner E, Gastl M, Becker T. Protein changes during malting and brewing with focus on haze and foam formation: a review. Eur Food Res Technol. 2011;232:191–204.
- ↑ Gallardo E, De Schutter DP, Zamora R, Derdelinckx G, Delvaux FR, Hidalgo FJ. Influence of lipids in the generation of phenylacetaldehyde in wort-related model systems. J Agric Food Chem. 2008;56(9):3155–3159.
- ↑ Lund MN, Petersen MA, Andersen ML, Lunde C. Effect of protease treatment during mashing on protein-derived thiol content and flavor stability of beer during storage. J Am Soc Brew Chem. 2015;73(3):287–295.
- ↑ Narziss L. Technological factors of flavour stability. J Inst Brew. 1986;92:346–353.
- ↑ Yang D, Gao X. Research progress on the antioxidant biological activity of beer and strategy for applications. Trends Food Sci Technol. 2021;110:754-764.
- ↑ Jégou S, Douliez PJ, Mollé D, Boivin P, Marion D. Evidence of the glycation and denaturation of LTP1 malting and brewing process. J Agric Food Chem. 2001;49(10):4942–4949.
- ↑ a b Baert JJ, De Clippeleer J, Hughes PS, De Cooman L, Aerts G. On the origin of free and bound staling aldehydes in beer. J Agric Food Chem. 2012;60(46):11449–11472.