The effect of post-harvest application of gamma-aminobutyric acid, calcium oxide and salicylic acid on the quality and storage of tomatoes

In 2021, an experiment was conducted to study the quality and storage of ‘Sena’ variety of tomato by application of calcium oxide, gamma-aminobutyric acid and salicylic acid in the postharvest laboratory of department of horticultural sciences and engineering in Vali-e-Asr university of Rafsanjan. The statistical design of the experiment was a factorial in the form of a completely random design. The first factor included control (distilled water), 0.5% calcium oxide (CaO), gammaaminobutyric acid with 10 mM concentration (GABA), salicylic acid with a concentration of 0.5 mM (SA) and combined treatment (CaO + GABA + SA), and the second factor included 3 storage times (7, 14 and 21 days). The results of the experiment showed that the effect of the combined treatment was significant in maintaining the quantitative and qualitative characteristics of tomatoes. The lowest content of soluble solids, the lowest activity percentage of pectin methyl esterase enzyme, the highest amount of phenol and the highest water activity were observed in gamma-aminobutyric acid treatment. Compared to the control sample, salicylic acid treatment prevented up to 32% of ion leakage, and 2.5% maintained the weight, and maintained titratable acidity on 7th day comparing the first day. According to the results, the highest level of firmness, general acceptance, water activity and vitamin C belonged to calcium oxide treatment. The lowest amount of malondialdehyde and lycopene, the lowest level of polygalacturonase enzyme activity (0.09% reduction in activity compared to the control), the lowest microbial contamination (0.63% colony reduction compared to the control), the lowest percentage of ion leakage and frostbite belonged to calcium oxide treatment. In general, among the treatments, 0.5% calcium oxide and 10 mM gamma-aminobutyric acid treatments best maintained the quantitative and qualitative traits of tomato fruit and are suggested for its storage.