RELATION OF HARVEST DATE AND SKIN COLOR T O FRUIT-QUALITY OF LOQUAT MOGI DURING MATURATION

Maturing loquat (Eriobotrya japonica Lindl. cv. Mogi) fruit were harve sted on 11, 18, and 25 May 1992 and grouped into four to nine classes based on the skin color measured as the Hunter ''a'' value. The relati onship between the skin color and fruit quality, such as sugar content s, organic acid contents, and flesh firmness was investigated. 1. The soluble solids content increased and the titratable acidity (TA) decre ased with maturation. TA in the fruit whose ''a'' value was more than 4, decreased concurrent with a delay in harvest. 2. Glucose and fructo se contents in the flesh increased as the color intensity deepened wit h each harvest date. Sucrose content of the fruit harvested on 11 May increased with maturation, whereas, it decreased in fruit harvested on 25 May. 3. Malic acid content in the flesh decreased as the ''a'' val ue increased on every harvest date. Citric acid content was higher in immature fruit than it was in mature fruit, whereas, succinic and fuma ric acid contents rose with maturation. 4. The flesh firmness graduall y decreased until the ''a'' value reached 6-8, it then increased sligh tly. The flesh of the over-ripe fruit was more elastic than that of ea ting-ripe ones.