Sugars and Organic Acid Contents in Different Parts of Juice Sacs in 'Shiranuhi' Mandarin Fruit at Harvest

摘要

Sugar and organic acid contents in different parts of juice sacs in 'Shiranuhi' mandarin ([Citrus unshiu x C. sinensis] x C. reticulata} fruit were determined at harvest. Total sugar and sucrose contents increased from the center parts outwards of juice sacs, while reducing sugar (fructose and glucose) contents increased inwards from the outer to central parts. Sucrose/hexose ratios ranged from 1.31 to 1.59 in different parts of juice sacs, with the central parts showing the lowest ratios. Citric acid content was the highest whereas malic and oxalic acid contents were the lowest in the central parts of juice sacs. These results suggest that sugar accumulation in the central parts of juice sacs in 'Shiranuhi' mandarin fruit continues in the radial direction up to the latest stages of maturation.