Application of natural extracts from pineapple juice on inhibiting browning symptom of fresh-cut 'Nam dok mai' mango

As a preliminary experiment, the effects of pineapple juice extracted from core and pulp on the browning process occurring in fresh-cut 'Nam Dok Mai' mango was investigated. We found that pineapple juice extracted from core effectively reduced surface browning of fresh-cut mango. So, efficiency of 50% pineapple core juice on physical and physiological changes of fresh cut mango was determined. Fresh-cut mangos were dipped into 50% pineapple juice extracted from core, then exposed to air drying and packing in a clamshell plastic box and stored at 4°C. The results showed that mango treated with pineapple juice had lower browning value than untreated mango. The brightness expressed as L* values of treated fruit was higher than the control. The L* value significantly decreased with time in the control sample held in air, but not in those treated with pineapple juice. The change in the L* value was due to slight browning on the surface of the fresh-cut mango. Browning intensity value of treated fresh-cut mango was lower than the untreated sample during storage. Polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL) activity of the control sample was significantly higher than in the pineapple juice-treated mango. Furthermore, fresh cut mango treated with pineapple juice dipping also exhibited significantly higher levels of total phenolic content than untreated fresh-cut mango. Firmness of pineapple juice-treated mango was higher than the untreated sample while the control sample revealed a high amount of malondialdehyde (MDA) compared to pineapple juice-treated fresh-cut mango. Sensory evaluation proved the efficacy of pineapple juice dipping by maintaining the overall quality of fresh-cut mango during the storage period for 6 days.