3.3. Color and pH
All color parameters (L*, a* and b*) did not change significantly after
microwave heating treatments (pN0.05). There was no significant
difference of pHvalue between untreated and treated grape tomato. The
pH value of grape tomato without microwave heating was 4.22±0.03
while the pH values of treated tomatoes were around 4.20±0.03
(Table 1). Thus,microwave heating did not affect the color and pH value
of grape tomatoes (pN0.05).
3.4. Content of lycopene and ascorbic acid
The lycopene content of grape tomato without microwave heating
was 26.93±0.78 mg/kg FW. The lycopene contents of treated grape
tomatoes were ranged from 23.29±5.51 to 31.61±6.15 mg/kg FW
(Table 1). There were no statistically significant differences in lycopene
content between untreated and treated grape tomatoes (pN0.05). The
ascorbic acid content of tomatowithout heatingwas 14.32±0.20 mg AA /
100 g FW. Also, the ascorbic acid contents of heated grape tomatoeswere
around 14.00 mg AA/ 100 g FW. Different heating power and time used in
the test did not cause a significant change of the ascorbic acid in grape
tomatoes (pN0.05) (Table 2).