Sujitra Ratanamarno, Jamnong Uthaibutra, and Kobkiat Saengnil

pp. 711 - 717

Abstract

The purpose of this research is to investigate the effect of bagging and storage temperature on
anthocyanin content and phenylalanine ammonia-lyase (PAL) activity of mangosteen fruit pericarp. Six
maturity stages (stage 1 to stage 6, defined by the extension of red or purple colouration on the pericarp) of
attached mangosteen fruits with bagged and unbagging were compared. It was found that sunlight had no
significant effect on both anthocyanin content and PAL activity. The effect of storage temperature on
anthocyanin content and PAL activity were also studied. Fruits at stage 1 (indicated by scattered of pink spot
on pericarp) were harvested and allowed to develop red colour to stage 6 at different storage temperatures: 15º, 25º, 30º (room temperature) and 35ºC. It was found that temperature had no effect on anthocyanin
content in any stage of fruit development. At all temperature levels, the anthocyanin content was increased
accordingly and had the highest level at stage 6. Temperature affected on PAL activity at different stages.
Levels of PAL activity decreased at the early stages and increased at the final stage of maturity except for
fruits held at 25ºC, PAL activity remained at a low level through stage 6, while fruit at 35ºC had the highest
level of PAL at stage 5.