Compositional Characteristics of Fruits of several Apple (Malus domestica Borkh.) Cultivars

Abstract

Fifteen apple cultivars grown in Valcea Research Station, Romania were evaluated in terms of fruit quality. Some selected compositional characteristics such as dry matter, total soluble solids, total sugar, titratable acidity, malic, citric and ascorbic acids and minerals content were investigated. Malic, citric and ascorbic acids were determined by a reversed-phase HPLC method. Sodium, calcium, magnesium, phosphorus, iron, manganese, copper, aluminium, chromium, zinc and strontium contents were determined by inductively coupled plasma-mass spectrometry following a microwave digestion while potassium content was determined by flame atomic absorption spectrometry. Large differences between cultivars were found for the contents of particular biochemical and mineral compounds. The dry matter content ranged between 12.49% (Prima) and 20.09% (Red Boskoop) while the total sugar content varied between 9.5% (Cadel) and 15.03% (Red Boskoop). The highest titratable acidity was found in Red Boskoop (0.771%), while in Starkrimson the titratable acidity was only 0.101%. The respective ranges of malic and citric acid contents of the tested samples were: 522.2-1993.7 mg/100 g and 3.5-49.1 mg/100 g. The ascorbic acid content was on average 6.18 mg/100 g. Potassium was the most accumulated nutrient in fruits. The potassium content was comprised between 82.25 mg/100 g (Mutzu) and 160.85 mg/100 g (Florina). Calcium follows, with variation limits between 1.70 mg/100 g (Starkrimson) and 8.74 mg/100g (Prima) while iron content varied between 0.19 mg/100 g (Ionagold) and 0.40 mg/100 g (Cadel and Early Red). The observed differences in composition are of such magnitude that they may affect both nutritional and sensory properties.