Abstract:
Tomato (Solanum lycopersicum L.) is major dietary source of antioxidant such as lycopene, total
carotene and ascorbic acid. Lycopene is a bright red carotenoid pigment and most potent
antioxidant among dietary carotenoids. This study was to (a) investigate the change of
phytochemical content in tomato fruit during ripening, and (b) find the relationship of colour
changes and lycopene content in tomato fruit. Physicochemical properties investigation carried
out on, pH, total soluble solid (TSS), ascorbic acid, lycopene and total carotene content, Total
Phenolic (TPC) and Total Flavonoid content (TFC). Fruit colour which is important physical
characteristic to assess ripening of tomato fruit were assess using chroma meter as L*a*b*
values. The a* value was considerably increase with fruit colour development of tomato. The
significantly highest pH was recorded in dark red stage (4.96 ± 0.0829) and followed by the
lowest pH was recorded in green stage (3.81 ± 0.0505). The significantly highest TSS was
recorded in dark red stage (5 ± 0.1333%) and the lowest pH was recorded in green stage (3.9 ±
0.4243%). The significantly highest lycopene content revealed in dark red stage (205.469 ±
10.84mg/kg) and followed by the lowest resulted in green stage (6.379 ± 0.4268 mg/kg). The
highest total carotene content resulted in dark red stage (0.4165 ± 0.0278 mg/kg) and the
lowest resulted in green stage (0.0291 ± 0.00225 mg/kg). The highest ascorbic acid revealed in
dark red stage (14.432 ± 1.797%) and the lowest revealed in green stage (0.76763 ± 0.4320%).
The Folin Ciocalteau method was resulted significantly highest TPC in dark red stage
(0.5569±0.041mg Gallic acid equivalent/g) while lowest resulted in green stage (0.0969 ± 0.051
GAE/g). The significantly highest TFC was resulted in dark red stage (0.5569±0.0020 Quercetin
equivalent/g) while lowest resulted in green stage (0.0969 ± 0.0067 Quercetin equivalent/g) of
fruit. There was a better fit linear correlation between lycopene and (a*/b*) value and same as
total carotene and (a*/b*) value. (R2=0.8572 and R2=0.7337 respectively). The result shows the
phytochemical content of tomato fruit increase with fruit color development. The a* value is the
best physical parameter to measure the colour of the tomato fruit to detect the colour
development during ripening. There is a positive correlation between colour development and
lycopene content of tomato fruit and also with the total carotene.
