Effect of Chitosan Coating on Physiological Responses and Nutritional Qualities of Tomato Fruits during Postharvest Storage

Abstract

This experiment was conducted to evaluate the effect of chitosan coating on physiological responses and nutritional qualities of tomato fruits at postharvest storage. There were four treatments of chitosan viz. T0 (control), T1 (0.10%), T2 (0.20%) and T3 (0.30%), and two storage conditions viz. in refrigerator (4°C) and room temperature (≈23-25°C). The matured light yellow tomato fruit samples were collected at 10, 20, 30 and 50 days after postharvest storage to assess physiological parameters viz. shelf life and weight loss as well as to determine lycopene and mineral constituents viz. Ca, Mg, P, S, Na and K. The mean weight loss of tomato fruits were 0.64, 1.28, 1.59 and 2.28% at 4°C, while it was 0.88, 1.84, 2.60 and 4.80% at room temperature at 10, 20, 30 and 50 days after postharvest storage, respectively. The shelf life of tomato fruits ranged between 58.3-100.0, 50.0-100.0, 33.3-75.0 and 16.7-66.8% at 4°C, while the ranges were 66.8-100.0, 50.0-100.0, 33.3-75.0 and 0.0-41.8% at room temperature at 10, 20, 30 and 50 days after postharvest storage, respectively. As regards to weight loss and shelf life, the study results inferred that chitosan coating with 0.2% solution is useful at postharvest storage of fruits. The study results revealed that storage temperatures (4°C and ≈23-25°C) had no effect on the total contents of different mineral element of tomato fruits but lycopene content reduced almost twice at refrigerated condition. On the other hand, the effect of chitosan coating on Ca, Mg, P, S, Na and K contents of tomato fruits at different days after postharvest storage were highly significant at both conditions. Finally, the study results concluded that 0.2% chitosan based coatings in tomato fruits proved to extend the shelf life by decreasing the decay incidence and weight loss, and refrigerated condition is better than that of room temperature.