COMPARING THE QUALITY PROPERTIES OF FRESH AND DRIED APPLE FRUIT - VARIETIES PINOVA AND RED DELICIOUS

Апстракт

The quality and the nutritional composition of fresh and dried apple fruits of the varieties pinova and red delicious were tested. The apples were grown in the region of Bitola in the Republic of Macedonia. The fruits were harvested manually after the visual assessment on terrain and after determination of harvesting time. After analyzing the mechanical and chemical properties of the fresh fruit, the fruit was prepared for drying. The treatment of the raw material was done with 0.1 % solution of citric acid and 0.5 % solution of K2S2O5, with time of immersion of five minutes. In order to compare the impact of applied treatments on the tested chemical properties, we also applied a variant of untreated fruit (control). Drying was performed in a chamber dryer from the type S-100, at a temperature between 65 °C to 70 °C for 6 to 8 hours. From the chemical composition of fresh and dried apple fruit, we examined: the total dry matter, total sugars, total acids, vitamin C, pectin, flavonoids, tannins and mineral matter. The fresh fruits from the pinova variety were characterized by better mechanical properties (weight 137.35 g, height 62.56 mm, width 68.78 mm) compared to the fruits of the red delicious variety. In fruits from this variety there were higher values 14.16 % for: total sugars, 0.34 % total acids, flavonoids 2.66 µg/g, tannins 1.39 µg/g and mineral matters 0.25 %. After the analysis of dried apple fruits, the varieties of pinova and red delicious, the higher content of vitamin C was found in fruits treated with 0.5 % solution of K2S2O5. The process of drying in a chamber drier enabled preservation of the chemical properties and getting a quality final product.