Evaluation of edible chitosan, agar and thyme films to maintain the quality ofHass'avocado fruits during storage

In this work, edible films (PCs) based on chitosan (Q), agar (A) and thyme oil (T) were prepared in four different formulations (Q, A, QA and QAT), and their mechanical properties (tension and elongation at break) and water vapor permeability were evaluated. Infrared spectroscopy (FTIR), thermogravimetric analysis ( TGA) and scanning electron microscopy (SEM) were also performed. The QA and QAT PCs stood out for their tensile strength, transparency, water vapor transmission rate and permeance, as well as the highest antioxidant activity. The effect of the application of the edible coatings (RCs) of QA and QAT on the quality of 'Hass' avocado fruit was evaluated during 13 d of storage at 25 degrees C. The following variables were evaluated periodically: weight loss, respiration rate, ethylene production, visual appearance, and rotting. The application of RCs to the fruit reduced their weight loss and extended their shelf life. The RCs gave the fruit a barrier to water vapor, reducing weight loss by 40 with respect to the control. In addition, the incidence of fruit rots was reduced.