abstracts - INCDCSZ Brasov

PHYSICAL, PRODUCT AND SENSORY PROPERTIES OF POTATO TUBERS
(SOLANUM TUBEROSUM L.) AS AFFECTED BY CULTIVATION SITE AND
GENOTYPE
Lombardo S. 1 , Mauromicale G. 1 , Tedone L. 2 , Marzi V. 2 , Palchetti E. 3 , Manzelli M. 3
1
D.A.C.P.A. – Scienze Agronomiche, Università di Catania, via Valdisavoia 5, 95123 Catania, Italy;
2
Dipartimento di Scienze delle Produzioni Vegetali, Università di Bari, via Amendola 165/a,
70126 Bari, Italy;
2 Dipartimento di Scienze Agronomiche e Gestione del territorio Agro-Forestale, Università di
Firenze, Piazzale delle Cascine 18, 50144 Firenze
Introduction
Specific pedo-climatic conditions of Italy allow potato cultivation in very different periods of
the year. It is possible to distinguish an ordinary crop, carried out mainly in spring-summer cycle in
the lowland (potato for consumption) and mountain ("seed" tuber) areas of central-northern Italy, and
the off-seasonal crops, implemented in coastal areas of southern Italy and islands. The latter can be
accomplished in two cycles: autumn-winter-spring and summer-autumn. The first allows the typical
and well known early production (early potato) from March to June, while the second cycle allows
obtaining winter production (from December to February) (Mauromicale and Ierna, 1999a; 1999b).
The very marked environmental diversities, particularly regarding temperature, light and soil type,
may affect the organographic features, physiological and productive plant process, as well as the tuber
qualitative characteristics (Mauromicale et al., 2003).
Potato tubers from the autumn-winter-spring cycle, both for the particular environmental
conditions in which the plants grow and above all since they are harvested and marked before their full
“ripening” at a more or less advanced growth stage, have particular external and nutrient
characteristics. These differ from tubers from ordinary cycle, which are harvested at complete
“ripeness”.
In this view, the aim of the present study was to evaluate the effects of cultivation site, which
allows different crop cycles, and genotype on the physical, product and sensory characteristics of
potato tubers.
Materials & methods
Plant material and experimental design
The field-experiments were conducted over two years (2006 and 2007) in Cetica (Tuscany),
Ugento (Apulia) and Cassibile (Sicily), typical areas for potato cultivation in Italy. Three potato
genotypes: “Rossa di Cetica”, “Sieglinde” and “Arinda”, typically cultivated in Tuscany, Apulia and
Sicily, respectively, were selected.
In each year, planting was done manually in January (Apulia and Sicily) and in May
(Tuscany), using whole disease-free seed-tubers and adopting a completely randomized block design
with 4 replications. Each plot was 3.5 by 5.0 m with a planting density of 6.0 plant m -2 . Phosphorus
(120 Kg ha -1 ), potassium (120 Kg ha -1 ) and nitrogen (50 Kg ha -1 ) were applied in pre-sowing. 80 Kg
ha -1 of nitrogen was supplied at tuber induction stage. Irrigation and pest management were in
agreement with usual practice and uniform in the three locations.
Tubers were harvested at the end of the cycle (about 125 days after planting) when 70% of
leaves were dry. A representative sample of marketable tubers (diameter 35-65 mm), belonging to the
3 genotypes and from the 3 localities under study, was selected and evaluated for the following
analyses as fresh tubers or subjected to cooking procedures (boiling and frying).
Preparation of cooked samples
40 tubers for replication were peeled manually using a kitchen vegetable peeler, washed and
drained.
30 tubers were boiled in a pressure cooker until soft (~ 15 min), cooled immediately in
running cold water and kept at room temperature (20°C). For frying, a sample of ten pre-peeled tubers
for replication was pushed through a vegetable slicer to obtain from the core region two sticks of
uniform size (section 8 x 8 mm) trimmed to a length of 10 cm. After draining excess water, these
sticks were fried in peanut oil at constant temperature of 180 °C for 5 min.
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