Metabolic alternation in the accumulation of free amino acids and γ-aminobutyric acid in postharvest mature green tomatoes following irradiation with blue light

Tomatoes (Solanum lycopersicum L.) are known as a super food because they contain many compounds beneficial to human health. To elucidate the role of specific wavelength of light on the accumulation of free amino acids and -aminobutyric acid (GABA) in postharvest tomato fruits, mature green tomato fruits were treated with darkness, or blue or red light by using light emitting diode (LED) for seven days. All free amino acids, except glutamic and aspartic acids, increased more in fruits treated with blue light than in those treated with either darkness or red light. The GABA, a non-protein amino acid and having health beneficial effects, increased in the blue light treatment with the maximum content being observed on the third day. Taken together, these findings indicate that irradiation with blue light has an effect in increasing the GABA contents in postharvest tomato fruits.