Lycopene andβ-carotene content during growth of ‘Manee-Esan’ pummelo (Citrus grandis(L.) Osbeck) fruit

Abstract

'Manee-Esan' is a new promising pummelo cultivar of the northeast of Thailand. This cultivar was locally found in the orchard at Baan Bung 14 Tambon Nonthong, Amphoe Kasetsomboon, Chaiyaphum province in the northeast of Thailand. The flesh of this cultivar has an attractive deep red color. It is believed that it is rich in antioxidants, especially lycopene and β-carotene. The taste of the fruit is sweet with a slight acidity. However, there was no scientific information supporting its quality, especially its harvest maturity. The research that was conducted was given the name: “Production System of Quality Pummelo for Identifying Creation of Chaiyaphum Pummelo” and was supported by the Thailand Research Fund and Khon Kaen University during 2015-2017. It was conducted to determine the content of lycopene and β-carotene, as well as the total soluble solid and total titratable acidity during fruit growth. The results showed that during fruit growth between 150-300 d after full bloom (DAFB), the content of lycopene, β-carotene, and the total soluble solid gradually increased (2.75-8.65 mg 100 g-1 FW, 0.90-2.55 mg 100 g-1 FW and 9.89-10.34%, respectively) while the Hue angle, titratable acidity and pulp firmness gradually decreased (42.67-20.64, 1.32-0.66% and 54.13-17.77 N cm-2, respectively). Lycopene and β-carotene reached the maximum content on the 270th DAFB (8.65 and 2.55 mg 100 g-1 FW, respectively) and no significantly decrease on the 300th DAFB (7.13 and 2.31 mg 100 g-1 FW, respectively). The total soluble solid content reached the maximum (10.34%) on the 240th DAFB, there was nog no significant decrease on the days that followed (10.26 and 10.17%). The top most ratio of TSS/TA (15.54) was also found on the 270th DAFB followed by the second most ratio on the 240th DAFB (14.98). However, the granulation of the pulp was found on the 270th DAFB. It should be concluded that to have a good taste and high content of lycopene, β-carotene and total soluble solids, 'Manee-Esan' pummelo should be harvested at 240th DAFB.