Distribution of Soluble Components and Quality Factors in the Edible Portion of Citrus Fruits1

There was a definite trend of increasing titratable acidity and decreasing soluble solids from the periphery of the segments toward the core in ‘Pineapple’ and ‘Valencia’ oranges and in ‘Marsh’ and ‘Duncan’ grapefruit. Soluble solids generally increased along the axis of the fruit from the stem regions toward the stylar end. Titratable acidity was higher at the central regions than at either end. Ratios of soluble solids to acid varied from 9.6 to 20.5 at different positions in ‘Valencia’ orange and from 5.5 to 12.5 in ‘Marsh’ grapefruit. Reducing sugars were lower and non-reducing sugars higher at the stem and stylar ends than at the central regions of both oranges and grapefruit. Ratios of nonreducing to reducing sugars decreased from both ends and from the periphery towards the central core. Total nitrogen and vitamin C were slightly higher in the stem halves than in the stylar halves and higher at the core than at the periphery.