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Synthesis of materials rich in pyrazines employing no sugar
Author(s) -
Coleman W M,
Lawson S N
Publication year - 2000
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/1097-0010(200006)80:8<1262::aid-jsfa634>3.0.co;2-t
Subject(s) - chemistry , alkyl , organic chemistry , aldehyde , side chain , reagent , sugar , yield (engineering) , catalysis , materials science , metallurgy , polymer
The characteristics of the headspace volatiles above materials rich in pyrazines prepared with no added sugars have been determined. Formulations void of sugar and rich in branched alkyl side chain pyrazines can be prepared in a microwave oven from formulations containing hydroxyketones, selected low‐molecular‐weight aldehydes, selected amino acids and an additional nitrogen compound such as ammonium hydroxide. A relatively low temperature of 105 °C coupled with short reaction times, 60 min, affords formulations with rich aromas and relatively high concentrations of alkyl pyrazines with straight and branched alkyl side chains. The amount and type of branched chain‐containing pyrazines are a function of the amount and type of hydroxyketone, aldehyde and amino acid employed. Stepwise substitution of the hydroxyketones for high‐fructose corn syrup (HFCS) produces stepwise increases in total pyrazines. Stepwise increase in the amount of added aldehyde produces stepwise increases in the amount of pyrazines containing branched alkyl side chains. Use of 3‐hydroxy‐2‐propanone produces materials containing a set of pyrazines characterised by the presence of cis ‐ and/or trans ‐propenyl side chains. The semi‐quantitative yield of pyrazines, ∼3500 µg mL −1 , and per cent branched alkyl side chain pyrazines, ∼35%, from these formulations were determined through the use of an internal standard in the headspace measurements. Previously postulated reaction mechanisms for the formation of pyrazines are confirmed through the use of selected reagents. © 2000 Society of Chemical Industry