IMPROVEMENT OF SOME NUTRITIONAL VALUES OF TOMATOES VIA SALINITY

Abstract

The antioxidant activity status is important to determine the nutritional value of fruits and vegetables. Increased antioxidant levels not only have high benefits in preventing widespread human diseases, including cancer and cardiovascular pathogens but also it enhances shelf life as well. This study was carried out to test the effects of 100 mM NaCl on some antioxidants (vitamins C and E) and some monosaccharides (glucose and fructose) of TYLCV virus-free tomato plants (Solanum lycopersicon) cultivar Castle Rock. The plants were treated at 30 days old with 100 mM NaCl for the next 45 days. At 75 days old, mature leaves were harvested and tested for TYLCV infection, as this virus affects the amount of antioxidants in tomato plants. Plants were kept in cages to avoid infection with TYLCV. The plants gave negative results, confirming that they are virus-free. Levels of vitamin C and vitamin E were determined by a reverse-phase HPLC technique while levels of glucose and fructose were determined using UPLC-MS in 75 days treated tomato leaves. Plants showed an increase in vitamin C, α-tochopherol, glucose and a slight increase in fructose contents versus the control plants. These results are of great importance from the nutritional and health points of view where salt stress improved the plant quality by increasing the concentrations of important antioxidants (vitamin C and vitamin E). In conclusion, the use of controlled salinity level can be an effective method to produce tomatoes of good nutritional quality and with higher market price.