Evaluation of fruit quality in peach and apricot

The fruits of nine white-fleshed and three yellow-fleshed peaches, one white-fleshed nectarine and five apricot cultivars were compared as to chemical composition and sensory evaluation. Three acids (succinic, malic and citric) and eight sugars (xylitol, fructose, glucose, mannose, sorbitol, inositol, sucrose and maltose) were identified. The total amount (mg/100g FW) of acids ranged from 300 to 1,500 in peach and from 2,900 to 4,600 in apricot. The total amount of sugars ranged from 6,700 to 12,500 and from 7,400 to 10,800 for peach and apricot respectively. Total phenolics were very varia- ble, ranging from an average of 30 mg/100g FW in the yellow-fleshed peaches to values two-seven fold higher in the white ones and from 27 to 91 in apricots. According to the sensory and chemical evaluations conducted in this study, acceptable or good flavor should match the following composition (mg/100g FW). Peach: 1,000-1,600 organic acids, 8,500-13,000 alcohol- soluble sugars, 7.8-8.5 acid-sugar ratio; less than 80-90 phenolics. Apricot: 3,500-4,500 organic acids, 10-12,000 sugars, 2-3.5 sugar/acid ratio, less than 60 phenolics. The present study also suggests that sugar and acid patterns of fruit flesh may be useful in cultivar characterization.