Physico-chemical changes in litchi cultivar Rose Scented during fruit development and maturation

Physico-chemical changes during fruit development of litchi (Litchi chinensis Sonn.) cultivar Rose Scented were studied. The initial fruit growth phase up to 40 days after full bloom (DAFB) is mainly contributed by peel and seed growth and the later growth phase until maturity is characterized by a rapid pulp growth. Fruit size, fruit weight, peel weight and specific gravity showed increasing trend while peel thickness showed declining trend with the advancement of age in litchi fruits. Pulp growth was not noticed until 40 DAFB and after appearance showed increasing trend. Incidence of cracking occurs after appearance of pulp during later growth period. Seed size and seed weight showed increase until appearance of pulp, then showed a declining trend. Fruit growth follows a simple sigmoid growth curve for majority of physical characters. Simultaneous occurrence of chlorophyll degradation and anthocyanin synthesis led to the development of red colour at maturity. Pulp pH, total soluble solids, total soluble solids to acid ratio and ascorbic acid increased, while titratable acidity decreased with advancement of maturity. Mineral contents like potassium, calcium and boron were also determined during fruit development period and the relative order of concentration at different growth stages was K > Ca > B. Harvesting at optimum maturity can be done during 66 to 70 DAFB.