Changes in anthocyanin concentration in Lychee (Litchi chinensis Sonn.) pericarp during maturation

Lychee has an edible aril surrounded by an anthocyanin-rich pericarp. Chemical and physical changes during lychee ripening were studied focusing on anthocyanins (Acy). Length increased up to the 17th week after anthesis (waa), and width and weight increased continuously. Pericarp % decreased until the 17th waa while aril % increased until the 19th waa. The fruit became darker during ripening and changed from light green to yellow-green (12–15th waa), and from yellow-red to dark red (16–20th waa). pH decreased from 3.18 to 2.68 (12–15th waa), finally increasing to 4.49. Highest titratable acidity occurred in the 14th waa (4.44% malic acid) decreasing to a final 0.16%. Soluble solids were highest at ripeness (18 °Bx). Increases in monomeric (mAcy) and total Acy levels were observed up to the the 17th waa. Green fruits contained only malvinidin-3-acetylglucoside and polymeric pigment while the ripe fruit contained cyanidin-3-rutinoside (>75%), cyanidin-3-glucoside (<17%) and malvinidin-3-acetylglucoside (<9%).