Inhibition of chlorophyll degradation in stay-green langra mango (Mangifera indica L.) fruits.
Janave M. T., Arun Sharma
Author Affiliation: Bhabha Atomic Research Centre, Food Technology Division, FIPLY, Trombay, Mumbai 400 085, India.
Indian Journal of Plant Physiology 9 : 112-117
Abstract : Langra mangoes (Mangifera indica) ripened at tropical temperature (25-30°C) appear green due to incomplete degradation of chlorophyll even though the fruits are table ripe. About 30% of total chlorophyll was retained and a two-fold increase in total carotenoids was observed during ripening. Ripening at lower temperature resulted in more loss of chlorophyll and reduced levels of carotenoids. RP-HPLC of the pigments extracted from various stages of ripening indicated the accumulation of an unknown Chl derivative (retention time 7.32 min) and pheophytin a (retention time 20.4 min). Soluble protein fraction from peel catalysed faster degradation of Chl a as compared to Chl b. Screening of the intermediates of enzymatic Chl a degradation by RP-HPLC indicated the activity of chlorophyllase pathway. Accumulation of the unknown intermediate was observed when Chl b was used as a substrate with respect to incubation time up to 60 min. However, other polar intermediates were formed and disappeared after 30 min. The results indicated that upon ripening, a derivative of Chl b and pheophytin a possibly accumulated, giving the fruit a 'stay-green' character.