Profiling antioxidant, vitamins and other phytochemicals in Portuguese Tomato Landraces
Artigo de Conferência
Visão geral
Visão geral
resumo
Tomato (Solanum lycopersicum L.) is a key element of the Mediterranean diet and a source of
nourishment for the world's population [1]. During the evolution and domestication of this plant,
genetic modifications and severe inbreeding of limited genotypes occurred [2]. As a result, a wide
range of fruits with different morphological and sensorial attributes gave rise to a number of landraces
that have been cultivated for centuries. These landraces represent a reservoir of genetic diversity that
can be used in fruit breeding programs. However, since information about the chemical variation
present among tomato landrace populations is still limited, this study aimed to profile the bioactive
compounds of Portuguese landraces. Seeds from tive accessions of tomato landraces ("coração de
boi", "maçã", "tomate", "redondo" and "vermelho") from the "Santarém" region, conserved ex-situ at
the Portuguese Bank of Plant Germplasm, in Braga, were grown in order to regenerate and
characterize these plant materiais. The ripe fruits were hand harvested and analyzed for lycopene (by
a spectrophotometric method), ascorbic acid (by HPLC coupled to a photodiode array detector) and
tocopherols (by HPLC coupled to a fluorescence detector) [3]. The antioxidant activity of
hydroalcoholic extracts was evaluated using the in vitro assays of DPPH' scavenging activity,
reducing power and p-carotene bleaching inhibition capacity. Total phenolics and flavonoids were
estimated by colorimetric methods [3]. Different leveis of vitamins and other phytochemicals were
detected in the studied samples, as well as different antioxidant activities. In general, the highest
leveis of lycopene and tocopherols (important lipophilic antioxidants) were found in the "coração de
boi" and "vermelho" landraces. a-Tocopherol was the most abundant isoform in ali samples, followed
by Y-tocopherol. Ascorbic acid was particularly abundant in the "redondo" and "coração de boi"
varieties. The "vermelho" tomato also revealed an interesting levei of total phenolics and a high
reducing capacity. High leveis of total flavonoids and a high DPPH' scavenging activity were attributed
to the "maçã" landrace. This study highlights Portuguese tomato landraces as health-promoting
superfoods (or functional foods) with high leveis of powerful antioxidants involved in protection against
free radical-induced diseases.
