Effect of exogenous methyl jasmonate on the internal browning of pineapple Fruit (Ananas comosus L.) cv. Pattavia

Abstract

Internal browning in pineapples (Ananas comosus L.) cv. Pattavia was studied in non-treated (control) fruit and fruit treated with 0.01, 0.1 and 1 mM methyl jasmonate (MeJA) after being stored at 10 ํC and 85% relative humidity (RH). The parameters, such as browning index, phenolic content, polyphenol oxidase (PPO) and peroxidase (POD) activity, were assessed. The browning symptom was initially mild, but rapidly increased at 21 days of storage which could be observed with the naked eye. Non-treated (control) pineapple had a browning index that was above 50% of the surface area while those treated with MeJA showed delayed browning of pulp in pineapple and had less damage. The phenolic content, PPO and POD activity were initially low, but steadily increased until 28 days of storage. The pineapple fruit treated with 0.1mM MeJA had the lowest PPO and POD activity as compared with non-treated fruit and those treated with 0.01 and 1 mM MeJA. The result showed significantly that MeJA treatments were able to delay internal browning. The accumulation of phenolic content, PPO and POD activity corresponded to changes in the colour of the pulp in pineapples. Therefore, MeJA can play a role in the reduction of internal browning in pineapples.