Changes in fruit maturity indices along the harvest season in ‘Algerie’ loquat

Loquat is a subtropical fruit tree that presents an annual cycle reverse to that of the well-known temperate fruit crops. Loquat rests during summer, blooms in autumn, develops its fruit through winter and ripens them in early spring. Its unusual phenology allows growers to obtain high prices for its fruits, especially for early harvests. Although loquat is harvested based on skin colour, a minimum soluble solid content (TSS) of 10° Brix is often required for commercialization. However, we have noticed that the relationship between skin colour and eating quality seems to change along the season leading costumers to complain for the high acidity of the earliest fruits. In order to establish a reliable maturity index, we have evaluated the changes in different fruit maturation parameters along the harvest period in four consecutive seasons for ‘Algerie’ loquat. The results show that in samples collected with similar skin colour, TSS and, especially, fruit titratable acidity (TA) tend to decline as harvest season progresses. This makes fruit skin colour on its own not suitable as a harvest index to assure an adequate fruit quality under all circumstances. We propose instead to monitor continuously TSS and TSS/TA ratio along the season in order to fulfill consumer's expectations.