frutilla

1248

J. Agric. Food Chem. 2004, 52, 1248−1254

Changes in Physicochemical Characteristics and Volatile
Constituents of Strawberry (Cv. Cigaline) during Maturation
ISABELLE MEÄ NAGER, MICHEL JOST,

AND

CHRISTOPHE AUBERT*

Downloaded by PEDECIBA QUIMICA URUGUAY on October 29, 2009 | http://pubs.acs.org
Publication Date (Web): February 6, 2004 | doi: 10.1021/jf0350919

CentreTechnique Interprofessionnel des Fruits et Le´gumes, route de Molle´ge`s,
13210 Saint-Re´my-de-Provence, France

Changes in the volatile composition of strawberries (cv. Cigaline) at six stages of maturity, from 28
to 44 days after anthesis, were investigated over two harvesting seasons. Volatiles were isolated by
direct solvent extraction and analyzed by means of GC-FID and GC-MS, with specialattention to the
quantification of furanones. Firmness, skin color, soluble solids (SS), titratable acidity (TA), SS/TA
ratio, organic acids, and sugars were also determined. With increasing maturity, soluble solids, SS/
TA ratio, Minolta a* value, and levels of sucrose, glucose, fructose, and malic acid increased, whereas
Minolta L value, hue angle (Θ), titratable acidity, and levels of citricacid decreased. Furanones and
esters were generally not detected before half-red fruits, whereas C6 compounds were the main
compounds in immature fruits. During maturation, levels of these so-called green components
decreased drastically, whereas levels of key flavor compounds increased significantly and were closely
correlated with skin color development. Maximum volatile production wasobserved in fully red fruits.
KEYWORDS: Strawberry; furanones; flavor; aroma; volatile compounds; maturation

INTRODUCTION

Strawberry plants, wild and cultivated, belong to the Rosacea
family and Fragaria genus. The wild European strawberry is
mainly from F. Vesca L., whereas the cultivated varieties (F.
ananassa) are hybrids from F. chilosensis and F. Virginiana.
The strawberry (F. ananassa)is cultivated worldwide and plays
an important economic role. Strawberries are consumed as fresh
fruits but are also frequently found in processed products such
as liquor, syrup, jam, juice, ice cream, and concentrated flavor
preparations.
Because of its typical aroma, the volatile components of
strawberry have been extensively studied, and >360 volatiles
have been reported (1-3). Differentstudies have shown that
esters largely contribute to the strawberry aroma. Among them,
ethyl 2-methylbutanoate, methyl and ethyl butanoates, methyl
and ethyl hexanoates, and hexyl and (E)-hex-2-enyl acetates
are considered to be important flavor-active components providing green and sweet fruity notes (4-7). Sulfur compounds
(methanethiol, dimethyl sulfide, dimethyl disulfide, methylthiolacetate, and butanoate) are also considered to be important
constituents, particularly in some “older” cultivars (cv. Souvenir
de Charles Machiroux) (8). Due to their very low odor thresholds
(respectively, 0.04 and 0.03 µg/kg), and their large amounts
present in several cultivars, Furaneol [2,5-dimethyl-4-hydroxy3(2H)-furanone] (DHF) and mesifurane [2,5-dimethyl-4-methoxy-3(2H)-furanone] (DMF)are considered to be the two major
flavor contributors to strawberry aroma (4, 5, 9-11). Neverthe* Corresponding author (telephone
+33 490.92.48.87; e-mail aubert@ctifl.fr).

+33

490.92.05.82;

fax

less, due to its water-soluble nature and its thermal instability
(5, 12, 13), Furaneol is rarely quantified. According to Ulrich
et al. (14), methyl anthranilate (MA), which ischaracterized
by an intensive spicy-aromatic and flowery note, is responsible
for the typical character of the wild strawberry aroma. Douillard
and Guichard (5) reported that lactones, particularly γ-decalactone, which are found in high concentrations in some
cultivars, are among the key flavor compounds. Alcohols, even
if numerous, are not thought to contribute significantly to
strawberry flavor,...