Characterization of Red, Orange, and Tomato Iraqi cultivars using FTIR and HPLC

This study aimed to compare three orange tomato cultivars and three red tomato cultivars in terms of their biochemical composition and sensory quality in order to support breeding programs and applications in the food and industrial sectors. The results clearly distinguished the two groups. The orange tomatoes had an ascorbic acid content of 12.8 to 22.6 mg/100 g, while the red tomatoes had higher values, ranging from 16.2 to 24.5 mg/100 g, indicating their superior potential as a vitamin C source. Orange tomatoes had higher total soluble solids (Brix) values (5.2–7.3° Brix) than red tomatoes (4.8–6.7° Brix), indicating greater sugar accumulation during ripening. The orange tomatoes' fructose and glucose levels, which ranged from 4.3 to 5.4 g/100 g and 4.3 to 5.5 g/100 g, respectively, also reflected these trends. These sugars were slightly lower in the red tomatoes, with fructose ranging from 3.8 to 5.1 g/100 g and glucose ranging from 3.9 to 5.3 g/100 g. Additionally, the orange cultivars had higher pH values (4.2–4.68 vs. 3.95–4.4) and a higher citric acid content (1.7–2.0 g/100 g) than the red cultivars (1.4–1.8 g/100 g), suggesting a profile with a more evenly distributed balance between sweetness and acidity. For a more comprehensive characterisation, Fourier-transform infrared (FTIR) spectroscopy was used to identify non-destructive biochemical differences between the samples. The higher absorbance of the red tomato juices at 1745 and 1620 cm1 suggests that they contain more lycopene and phenolic compounds. Orange tomatoes, on the other hand, had distinct absorption peaks at 2920 and 2850 cm1, indicating higher concentrations of lipid- and beta-carotene-associated compounds. Each cultivar's genetic focus on increasing beta-carotene in orange varieties and lycopene in red varieties is reflected in these spectral characteristics. The spectrum traits of each cultivar reflect its genetic emphasis on enhancing beta-carotene in orange variants and lycopene in red ones; also, this study was emphasised the need of integrating HPLC and FTIR approaches for accurate and speedy tomato freshness evaluation. FTIR, may help with breeding programs, the development of healthier meals, the identification of different types and their vegetable quality, and the calculation of fruit and vegetable nutritional content.