Formation of Furan and Methylfuran by Maillard-Type Reactions in Model Systems and Food

Abstract

The formation of furan and 2-methylfuran was studied in model systems based on sugars and selected amino acids. Both compounds were preferably formed under roasting conditions in closed systems yielding up to 330 micromol of furan and 260 micromol of 2-methylfuran per mol of precursor. The amounts obtained under pressure cooking conditions were much lower, usually below 20 micromol/mol, except for 2-furaldehyde, which yielded 70-100 micromol/mol of furan. Labeling studies indicated two major formation pathways for both furans: (i) from the intact sugar skeleton and (ii) by recombination of reactive C(2) and/or C(3) fragments. Under roasting conditions in the absence of amino acids, furan was mainly formed from the intact sugar skeleton. Formic and acetic acid were identified as byproducts of sugar degradation, indicating the split off of C(1) and/or C(2) units from hexoses. The presence of alanine, threonine, or serine promoted furan formation by the recombination of C(2) fragments, such as acetaldehyde and glycolaldehyde, which may originate from both sugars and amino acids. In aqueous solution, about half of furan was generated by the recombination of sugar fragments. 2-Methylfuran was preferably formed in the presence of amino acids by aldol-type reactions of C(2) and C(3) fragments with lactaldehyde as a key intermediate, the Strecker aldehyde of threonine. The total furan levels in cooked vegetables were increased by spiking with hexoses. However, in pumpkin puree, only about 20% of furan was formed from sugars, preferably from the intact carbon skeleton.

Basic Chemistry and Process Conditions for Reaction Flavours with Particular Focus on Maillard‐Type Reactions

“…This work can be considered as another milestone in the history of research on Maillard chemistry. The CAMOLA technique has recently also been applied for studying the formation of furan in both model systems and foodstuffs (Limacher et al, 2008).…”

Furan in food - a review

“…The presence of alanine, threonine, or serine promoted the furan formation by recombination of C 2 fragments, such as acetaldehyde and glycolaldehyde, which might originate from both sugars and amino acids. In the aqueous solution, about a half of furan was generated by the recombination of the sugar fragments (Limacher et al 2008).…”

Furan and alkylated furans in heat processed food, including home cooked products

“…The diversity of foods which contain furan suggests that multiple pathways are likely to be involved in the formation of furan in foods (Morehouse et al 2007;Owczarek-Fendor et al 2011;. Studies performed in model systems have shown that furan and methylfuran can be generated from heating ascorbic acid, polyunsaturated fatty acids, unsaturated aldehydes, sugars, and amino acids (Perez & Yalayan 2004;Becalski & Slaman 2005;Limacher et al 2007;Limacher 2008;Roberts et al 2008;Vranová & Ciesarová 2009;Owczarek-Fendor et al 2010a,b, 2012Adams et al 2011;Duan & Barringer 2012;Anese & Suman 2013).…”