Author/Authors :
Loiudice، نويسنده , , R. and Impembo، نويسنده , , M. and Laratta، نويسنده , , B. and Villari، نويسنده , , G. and Lo Voi، نويسنده , , A. R. Siviero، نويسنده , , P. and Castaldo، نويسنده , , D.، نويسنده ,
Abstract :
Compositional characteristics of 11 lines of San Marzano tomatoes have been determined. The results come from a 3 year study (1989–1991), during which the following parameters were evaluated: total solids, soluble solids, organic acids (citric, malic, succinic and ascorbic), sugars (glucose, fructose and sucrose), cations (Na, K, Mg and Ca), anions (sulfate, phosphate and chloride), amino acids and formol value. The mean pH value of the San Marzano lines was 4.6, a value somewhat higher than that of the hybrid varieties usually employed in the food industry. Instead, the contents of Na+, K+, Ca2+ and Mg2+ ions were close to those of hybrid varieties. Three amino acids, i.e. glutamic acid, γ-aminobutyric acid and glutamine, represent about 65% of the total free amino acid content. Although, in the case of glutamic acid, the mean value was close to that of the hybrid varieties (240 mg/100 g), the variability of the content in the lines was high (between 110 and 360 mg/100 g). The elevated heterogeneity of the San Marzano populations strongly influenced the difference in parameters studied. From a compositional viewpoint it is very difficult to differentiate pure San Marzano lines from hybrids without a careful morphological examination of the product.
