Artículo De Fisiologia Vegetal

S cientiaHorticulturae, 36 (1988) 183-190

183

E lsevier Science Publishers B.V., Amsterdam - - Printed in The Netherlands

F lavour and Metabolic Changes in Asparagus
D uring Storage
G RAEME A. KING, KATE G. HENDERSON, ERIN M. O'DONOGHUE, WILHELMINA
M ARTIN and ROSS E. LILL

L evin Horticultural Research Centre, MAFTech, Private Bag, Levin (New Zealand)
(Accepted for publication 16March 1988)

A BSTRACT
K ing, G.A., Henderson, K.G., O'Donoghue, E.M., Martin, W. and Lill, R.E., 1988. Flavour and
m etabolic changes in asparagus during storage. S cientia Hortic., 36: 183-190.
F lavour acceptability of apical spear segments declined within 2 days of storage at 1 °C and
f urther declined after 7 days of storage. Decline in flavour acceptance was accompanied by offflavourdevelopment, a decrease in soluble carbohydrates and an increase in protein content of
s pear tip segments. Respiration rate of spears stored at 1 or 20°C declined after harvest before
r eaching an equilibrium. A significant loss of soluble carbohydrates and proteins from tip segm ents occurred during storage at 20 ° C. Storage at 1 ° C reduced the rate of substrate loss.
Keywords: asparagus;Asparagus officinalis; flavour; metabolism; protein; respiration; soluble carb ohydrate; storage.

I NTRODUCTION

S ea freight of fresh green asparagus from New Zealand to established mark ets in Japan and the U.S.A. would allow greater volumes at lower cost than
a ir freight. To achieve this, spears must remain in good condition for up to 4
w eeks and have at least 4 days shelf-life afterstorage.
R apid deterioration after storage has been the major problem preventing sea
f reight of asparagus from New Zealand (Lill, 1980; King et al., 1986), and a
b etter understanding of the processes of deterioration is needed before signifi cant p:cogress can be made in achieving good shelf-life after long-term storage.
T he :~lavour of asparagus changes rapidly during 7 days of cold storage(King
e t al., 1987 ). This change may signal the initial stages of deterioration limiting
t he post-harvest life of asparagus. In the present study, we monitored biochemi cal changes that accompany flavour deterioration.
T he asparagus spear obtains the sugars required for its growth from the
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c rown and storage roots(Robb, 1984). When the spear is harvested, this source
o f sugars is lost, even though the spear still requires metabolic substrate to
p rovide energy and structural components for maintaining tissue integrity.
R espiration rate and biochemical changes during storage of asparagus for up
t o 7 days are described and discussed in relation to factors limiting the storage
l ife of asparagus.
MATERIALS AND METHODS

H a r v e s t i n g a n d storage. - A sparagus spears (cultivar 'Limbras 10' ) were hand-

h arvested from production trials at Levin. Spears of 10-15 mm butt diameter
w ere trimmed to 180 mm length and graded so that only spears which were
s traight, undamaged, with closed bracts, and with no obvious signs of disease
w ere used in the experiments.
S pears to be storedat 1°C were hydro-cooled within 4 h of harvest by imm ersion for 10 min in a bath of chlorinated (200 mg available chlorine per
l itre) ice water agitated with compressed air to aid efficient heat exchange.
S pears were drained and stored at 1 ( + 0.5)°C with high humidity ( > 95%)
u ntil required for use.
S e n s o r y analysis of stored spears. - S pears were harvested at intervals over 7d ays, hydro-cooled and stored as above. Spears were removed from storage 7
d ays after the first harvest, giving treatments corresponding to 0 (freshly harv ested), 1, 2, 3, 5 and 7 days of storage.
S pears were trimmed to 120 mm and cooked upright in a covered pot in 20
m m of boiling water for 12 min. Spears were cut in half transversely and left
t o cool to room temperature. Each of 12...