Food Chemistry

362 5 Aroma Compounds

Table 5.18.Furanones in food

Structure Substituent/trivial name or Aroma Occurrence
trade name (odor threshold quality
in μg/kg, water)

A.3(2H)-Furanones

4-Hydroxy-5-methyl

Norfuraneol(nasal:

23 ,000)

Roasted

chicory-like,

caramel

Meat broth

4-Hydroxy-2,5-dimethyl

Furaneol

(nasal: 60;

retronasal: 25)

Heat-treated

strawberry,

pineapple-like,

caramel

cf. Table 5.20

2-(5)-Ethyl-4-hydroxy-

5-(2)-methyla

Ethylfuraneol

(nasal: 7.5)

Sweet,

pastry,

caramel

Soya sauce

Emmental

cheese

4-Methoxy-2,5-dimethyl

Mesifuran(nasal: 3400)

Sherry-like Strawberry,

raspberryb

B.2(5H)-Furanones

3-Hydroxyl-4,5-dimethyl

Sotolon

(nasal, R-form 90,

recemate, retronasal: 3)

Caramel,

protein

hydrolysate

S-form 7

Coffee, sherry,

seasonings,

fenugreek

seeds

5-Ethyl-3-hydroxy-

Abhexon

hydrolysate

(nasal: 30, retronsal: 3)

Caramel,

4-methyl

protein

Coffee,

seasonings

aOf the two tautomeric forms, only the 5-ethyl-4-hydroxy-2-methyl isomer is aroma active.
bArctic bramble (Rubus arcticus).

an aroma quality similar to that of sotolon and
is formed by aldol condensation of 2,3-pentane-
dione and glycol aldehyde, which can be obtained
from theMaillardreaction, or by aldol conden-
sation of 2 molecules of α-oxobutyric acid,
a degradation product of threonine (Fig. 5.16).

Quantitative analysis of furanones is not very

easy because due to their good solubility in wa-

ter, they are extracted from aqueous foods with

poor yields and easily decompose, e. g., sotolon

(cf. Formula 5.6). Correct values are obtained

by IDA.