Chlorophyll, ascorbic acid and total phenolic contents of sweet potato leaves affected by minimum postharvest handling treatment

Abstract

There is a wide variety of native vegetables utilized by rural people in developing countries. However, information about their chemical content primarily that have functional properties and their degradation during handling is scarce and not well quantified. One example of those native leafy dark-green vegetables is sweet potato tips. Sweet potato leaves or tips are biomass waste after the sweet potato tubers are harvested. In addition, this leaves, as other leafy vegetables, are very susceptible to degradation leading to deterioration. Therefore, the objective of this research was to investigate the effect of minimum handling on some qualities of sweet potato tips. The three factors experiment was arranged in a completely randomized design with 4 replications. The first factor was dipping solution: Water or solution containing sucrose and citric acid. The second was solution changing or no changing. The third factor was basal stem cutting or no cutting. All the leaves were hold for 5 days at 30 ± 5°C, and then analyzed for their chlorophyll, ascorbic acids, and phenolic contents. The results showed holding solution of 1.5% sucrose containing 300 ppm citric acid helped to reduced chlorophyll degradation of sweet potato tips. However, this treatment induced a higher degradation of ascorbic acid. Daily changing pulsing and daily basal stem cutting did not affect chlorophyll, but it helped to maintain ascorbic acid and induced higher phenolic content of the tips.