Quality evaluation of tomato fruits by specific gravity and color

The specific gravity, soluble solid content (Brix value), sugar and organic acid contents of harvested tomato fruits were measured. The firmness and surface color of tomato fruits were also determined. The Brix value of tomato fruits was strongly correlated to specific gravity with high coefficient of correlation (r=0.829). The strongly positive correlations were also found between malic acid content and firmness (r=0.800), malic acid content and L* value (r=0.813), whereas malic acid content correlated negatively to a* value (r =-0.807). It was suggested that the soluble solid content of tomato fruits could be determined by specific gravity nondestructively. But the results also showed that there was significant effect of the cavity inside fruit on the specific gravity of tomato fruit. The organic acid expressed high Brix value resulted in remarkable effect on measuring the value of soluble solid content.