Organic acids and sugar compositions of some loquat cultivars (Eriobotrya japonica L.) grown in Turkey

Abstract

Acidity and sugar contents of loquat fruits are one of the main quality properties for fresh consumption and for processing to juice, jam, marmalades etc. In this study, the main organic acid and sugar profiles of 15 loquat cultivars grown in Turkey were determined. The fruits were harvested at commercial maturity and analyzed without delay. The content of water soluble solids changed between 10.92 (Bassel Brown) and 14.58 °Bx (Champagne de Grasse). Titratable acidity expressed as malic acid ranged from 0.72% (Champagne de Grasse) to 1.25% (Dr.Trabut). The source of 72.31% of titratable acidity was organic acids. The malic acid was the major organic acid. The minimum and maximum levels of organic acids were between 14.96 (Ottowiani) and 26.57 mg kg-1 (Uzun Çukurgöbek) for oxalic acid, 40.88 (Kanro) and 89.54 mg kg-1 (Ottowiani) for tartaric acid, 368.56 (Champagne de Grasse) and 842.49 mg kg-1 (Taza) for malic acid, 6.24 (Gold Nugget) and 14.71 mg kg-1 (Sayda) for citric acid, and 10.39 (Madam Maria) and 28.68 mg kg-1 (Akko XIII) for succinic acid. Sugars were the main (94.53%) contributor to soluble solids. Glucose was the predominant sugar (6.62%) in fruits. Champagne de Grasse had the highest glucose (7.48%) and fructose (5.45%) content while Gold Nugget had the lowest glucose (5.92%) and Taza had the lowest fructose (3.88%) contents. The results could help to select the cultivar for growing, for fresh fruit consumption or for industrial processing.