Maturity criteria for litchis (lychees)

Five varieties of litchi (lychee) were harvested from five different locations over a period of two years. The fruit varied from immature to almost fully mature. It was subjected to taste testing and analysed for total soluble solids (TSS) and titratable acidity (A). TSS (°Brix) was not suitable as a maturity indicator whereas titratable acidity and the TSS/A ratio were both good predictors of taste. A titratable acidity of 4.4 cmol H⁺ kg^?1 juice or a TSS/A ratio of 4.3 Brix.kg juice cmol^?1 H⁺ would be suitable maturity indexes.