Effect of Postharvest Application of Chitosan, Vanillin and Acetic Acid on Quality and Storage Life of Tomato

Tomato is the second most important vegetable in the world after potato, which is rich in minerals and vitamins and has a special place among vegetables, agricultural and commercial economy, although one of the postharvest problems of this product is its high wastes. In 2021, an experiment was conducted to study the quality and storage life of ‘Sena’ cultivar of tomato by application of chitosan, vanillin and acetic acid treatments 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 randomized design. The first factor included the control (distilled water), chitosan 1% (Chit), acetic acid 1% (AA), vanillin 1% (Van), and a combined treatment (AA1%+Van1%+ Chit1%), while the second factor comprised the storage time during 3 storage periods (7, 14 and 21 days) at a temperature of 4±1°C and relative humidity of 85±5%. The results of the experiment showed that acetic acid prevented ionic leakage, microbial contamination, weight loss and maintained firmness. Vanillin treatment kept the fruit firmness during storage up to two times and prevented weight loss (3%) and ion leakage (14%), compared to the control. The lowest content of malondialdehyde, pectin methyl esterase activity, and microbial activity were observed in vanillin. In general, among the investigated treatments, vanillin, due to its antioxidant properties, performed more impressively in the preservation of tomato products than other treatments, and in the last period of storage samples treated with vanillin had the highest score. The vanillin treatment best preserved the evaluated characteristics of tomato fruit and is recommended for the tomato storage process. The treatment of acetic acid as a chitosan solvent was evaluated separately and this application led to the prevention of ionic leakage, microbial contamination, weight loss and maintaining firmness. With regard to results obtained from this research, chitosan and combined treatment had destructive effects on tomatoes, therefore the use of chitosan with low molecular weight is not recommended for the storage of tomato products.