Description
Tomato (Lycopersicon esculentum L.) is one of the most widely consumed vegetables,
being the second most important vegetable crop worldwide. lt is a key component in the
so-called "Mediterranean diet", which is strongly associated with a reduced risk of chronic
degenerative diseases. Local populations from Trás-os-Montes (Portugal) still prefer to
consume traditional vegetables (e.g. different farmer' varieties of tomato) which they find
very tasty and healthy, as they are grown using extensive farming techniques. These
farmer' varieties of tomato are thus being cultivated, but their nutritional composition has
remained unreported until now. The main purpose of this study was to analyse
biomolecules with nutritional and antioxidant properties in four non-analyzed tomato
farmer 'varieties from Trás-os-Montes, widely cultivated in homegardens. The analysed
components included macronutrients, individual profiles of sugars and fatty acids by
chromatographic techniques, hydrophilic antioxidants such as vitamin C, phenolics,
flavonols and anthocyanins, and lipophilic antioxidants such as tocopherols, I)-carotene
and lycopene. Furthermore, the antioxidant activity was evaluated through DPPH
scavenging activity, reducing power, ~-carotene bleaching inhibition and TBARS formation
inhibition. One of the four varieties, which is locally known as round tomato or potato
tomato, proved to be the most powerful in antioxidant activity (EC50 values :5 1.63 mg/ml)
and phenolic compounds (phenolics 31.23 mg CIAE/g extract, flavonols 6.36 mg QE/g
extract and anthocyanins 3.45 mg ME/g extract) and carotenoids (I)-carotene 0.51 mg/100
g and lycopene 9.49 mg/100 g), while the so-called yellow tomato variety revealed
interesting nutritional composition, including higher fructose (3.42 g/100 g), glucose (3.18
g/100 g), a-linolenic acid (15.53%) and total tocopherols (1.44 mg/100 g) levels. Overall,
these farmer' varieties of garden tomato cultivated in the northeastern Portuguese region
could contribute as sources of important antioxidants related to the prevention of chronic
diseases associated to oxidative stress, such as cancer and coronary artery disease. The
results validate and confirm the importance of local uses.