Produce Degradation Pathways and Prevention

164 Produce Degradation: Reaction Pathways and their Prevention

6.3.1.5.1 Strawberry

Among the various small fruit, strawberry (Fragaria ananassa) flavor has by far

received the greatest attention. More than 360 volatile compounds have been iden-

tified in strawberries [32,56]. Determination of the relative importance of various

volatile compounds to the aroma of fresh strawberries has been the subject of

numerous investigations [27,101–111]. Aldehydes, esters, ketones, alcohols, acids,

terpenes, and lactones have long been recognized as important contributors to straw-

berry aroma. Recent studies that employed GCO and sensory studies of model aroma

systems have been able to more exactly define the important strawberry aroma

components (Table 6.1). As mentioned previously, DMHF is a key aroma component,

and fruity esters and green-smelling aldehydes such as (Z)-3-hexenal are necessary

for typical strawberry flavor.

6.3.1.6 Citrus

Much of what is known about citrus flavors is the result of studies performed on

peel essential oils, essence oils, aqueous essences, and juices, with considerably less

TABLE 6.1
Key Aroma Components of Strawberries on the Basis
of Gas Chromatography-Olfactometry and Sensory Studies

Schieberle [106]a

Schieberle and

Hofmann [27]a Ulrich et al. [107]b Ulrich et al. [108]c

DMHFd DMHFd Acetone Methyl butanoate
(Z)-3-hexenal (Z)-3-hexenal Methyl butanoate Ethyl butanoate
Methyl butanoate Methyl butanoate Ethyl butanoate Methyl hexanoate
Ethyl butanoate Ethyl butanoate Butyl acetate Ethyl hexanoate
Ethyl 2-methylbutanoate Ethyl 2-methylpropanoate 2-Heptanone Linalool
Ethyl 3-methylbutanoate 2,3-Butanedione Methyl hexanoate Mesifuran
Methyl 2-methylbutanoate Methyl 2-methylbutanoate (E)-2-hexenal Butanoic acid
Methyl 3-Methylbutanoate Methyl 3-Methylbutanoate Ethyl hexanoate 2-Methylbutanoic acid
Acetic acid (Z)-3-hexen-1-ol Hexanoic acid
2,3-Butanedione Linalool 2-Phenyl ethanol
Butanoic acid Mesifuran DMHF
3-Methylbutanoic acid Butanoic acid γ-Decalactone
2-Methylbutanoic acid 2-Methylbutanoic acid
Ethyl 2-methylpropanoate hexanoic acid
Mesifuran 2-Phenyl ethanol
DMHF
γ-Decalactone

Note:Components are^ not necessarily listed in order of importance.

aFresh strawberry juice.
bThirteen strawberry varieties.
cCultivated and wild strawberries.
d2,5-Dimethyl-4-hydroxy-3(2H)-furanone.