WOS: 000442606600002, The growing consumer demand for produces without chemical residues has focused efforts on the assessment of innovative natural antimicrobials. In this context, chitosan, derived from abundantly available chitin sources such as crab, shrimp and insects, has been reported to possess an excellent film-forming ability and inherent antimicrobial properties suitable for development of edible antimicrobial films. Thus, the present study was established to study the effect of chitosan coating on extending postharvest quality of fresh tomatoes (Lycopersicon esculentum Mill. cv. 'Diamentino') maintained at two different storage temperatures (5 degrees C with 90% relative humidity and 21 degrees C with 65% relative humidity). Coating the tomatoes with chitosan solutions reduced the weight loss, with greater effect at 1% than 0.5 or 2% concentrations. Chitosan-coated tomatoes were firmer, higher in titratable acidity, and exhibited less biochemical changes than the control fruit at the end of storage. The loss in visual quality was significantly reduced by coating the fruits with chitosan solutions of 0.5, 1.0 and 2.0% as compared to the control. Among the applied concentrations, chitosan at 1% can be recommended as it was pioneering for most of the parameters analyzed during cold storage at both 5 degrees C for 20 d and at 21 degrees C for 10 d. Due to its lower cost and convenience to human health, chitosan may be one of the attractive and effective biopolymers for achieving adequate conservation of fresh tomatoes., Selcuk University Scientific Research Project Coordination Unit (BAP) [17201097], This paper has been generated from Master Science Thesis of Hayriye Fatma Kibar. Authors would like to thank Selcuk University Scientific Research Project Coordination Unit (BAP) for supporting the study (Project No: 17201097).