Effect of ethephon and acetylene treatments on chlorophylls and carotenoids pigments in banana (Musa acuminata, AAB)

Abstract

The present study was conducted to analyze the effects of selected induce ripening agents on major pigments in peel and flesh of Ambul banana (Musa acuminata, AAB). Freshly harvested mature green banana obtained from Dankotuwa, Sri Lanka which are in same maturity stage were subjected to 1000 ppm ethephon and 1000 ppm acetylene and kept at 20 ℃, 80-85% RH for ripening. Chlorophyll a, chlorophyll b and β-carotene were analyzed in peel while β-carotene and lutein were analyzed in flesh at fully yellow stage (Stage 6) using spectrophotometric methods. Analytical standards of each pigment was used for quantification. Peel colour was measured using L*a*b* scale. According to the results obtained chlorophyll a in banana peel at stage 6 were 0.64±0.01, 0.64±0.00 and 0.86±0.03 μg/cm2 respectively in naturally ripened, acetylene and ethephon treated samples while Chlorophyll b levels were 1.09±0.02, 1.34±0.04 and 1.47±0.00 μg/cm2 respectively in those samples. Higher values of chlorophylls in ethephon treated samples at stage 6, corresponds with significantly lower value of a* (1.93 ± 0.03) of those samples. The highest β-carotene levels in both peel and flesh were recorded in naturally ripened samples where those values were 553.70±52.04 and 314.89±1.75 μg/100g respectively. β-carotene and lutein contents were significantly low (P<0.05) in flesh of ethephon treated banana where the recorded values were 146.74±0.72 and 189.87±2.27 μg/100g respectively. Lutein content was significantly (P<0.05) high in flesh of naturally ripened banana comparing to treated banana. Ethephon and acetylene treatments can significantly affect the pigment content in banana peel and flesh.