Effects of Chitosan or Calcium Chloride on External Postharvest Qualities and Shelf-Life of ‘Holland’ Papaya Fruit

Papaya (Carica papaya L.) is an important fruit widely cultivated commercially throughout Thailand. Its all year around fruit bearing capability makes papaya a popular fruit with Thai people. Unfortunately, papaya has a very limited shelf-life, as such; the objective of this research was to delay the external postharvest qualities by using chitosan and calcium chloride on the ‘Holland’ variety of papaya fruit. The experiment was arranged in a Factorial Completely Randomized Design, composed of two factors- coating with chitosan at four concentrations (1.0, 1.5, 2.0 or 2.5%) or dipping in calcium chloride solution at four levels (1.0, 1.5, 2.0, or 2.5%), compared with control fruits. After treating, all treatments were stored under ambient temperature (27 °C, 80% R.H.). The results showed that fruit treated with chitosan, irrespective of any concentrations, had the least similar fruit weight loss after six days of storage; however, fruit-treated with 2.5% chitosan showed the maximum fruit firmness and a delayed red color appearance on the fruit skin. In addition, the best treatment for extending shelf-life proved to be from a treatment of 2.5% chitosan.