Alleviation of internal browning and fruit rot disease in ‘Pattavia’ pineapple using ethanolic shellac-modified coconut oil coating

Importance of the work: Internal browning (IB) and fruit rot disease are the main problems of harvested pineapple that limit its quality.

Objective: Investigate the effect of ethanolic shellac-modified coconut oil (ES-MCO) coating against IB and fruit rot disease in “Pattavia” pineapples.

Materials & Methods: Fruits were coated with ES-MCO (consisting of 8% shellac and 2% MCO) and stored at 13°C, 95% RH for 20 d. Uncoated fruits were the control. The IB, physiochemical qualities, and rot disease were determined.

Results: ES-MCO treatment maintains the quality through the reduction of respiration rate, resulting in slower weight loss and color changes (peel and pulp). Browning index and browning scores of coated fruits were lower than those of the control by 8.8% and 33.26%, respectively, while the TSS/TA ratio and ascorbic acid content were maintained. ES-MCO treatment significantly reduced polyphenol oxidase (PPO) and peroxidase (POD) activities (browning enzymes), by 1.56–5.52 and 1.16–2.14 times, respectively, relative to the control. These results correlated with the reduction of IB and the accumulation of total phenolic (TP) content. ES-MCO treatment slowed down the increase in the content of malondialdehyde (MDA) that is involved with the oxidative stress response, and it also suppressed rot disease in comparison with the control.

Main finding: Coating pineapple with ES-MCO can alleviate IB and rot disease and delay the changes in physiochemical qualities that are caused by the reduction of respiration rate.