BIOMETRICS AND CHEMICAL COMPOSITION OF USSURIAN PEAR FRUIT

Abstract

Biometrics and chemical parameters of Ussurian pear fruits cultivated under conditions of the West Siberian forest steppe were investigated. The fruits were harvested at the optimum stage of maturity, evenly from the upper, medium and bottom branches of the trees, from all sides of the crown with respect to cardinal directions. The rounded and oval shapes of fruits prevailed. Color of fruits varied from bright yellow to yellow with reddish patches and dirty-green with yellowish tint. The fruits have an expressed smell, firm skin and rough pulp. The taste is tart, sough-sweet. The average length and diameter of the fruit were 3.4 ± 0.1 cm and 3.7 ± 0.1 cm, respectively. The weight of the fruit varied from very small (22.3 g) to medium (53.5 g), with the average weight of 33.2 ± 1.3 g. The weight of thousand seeds obtained by the method of water flotation is 33.8 g; the average number of seeds in the fruit is 7.6 ± 0.3. The length of the seed is 0.4–0.6 cm; the width is 0.2–0.3 cm. The amount of soluble dry substances in the fruit pulp is 26.6 ± 0.3%. The sum of total sugars is 11.5 ± 0.3%. The mass fraction of arbutin on conversion in initial matter made up 0.59 ± 0.04; the average C vitamin content was 7.6 ± 0.4 mg/100 g; carotene content 2.5 ± 0.1 mg/100 g; the average nitrate content in the Ussurian pear fruits was 8.1 ± 0.2 mg/kg as compared with a maximum allowable value of 60 mg/kg. Titratable acidity (total acidity) was equal to 1.1 ± 0.1%. The Ussurian pear plants introduced to the forest-steppe areas near the Ob are able to form fruits possessing qualities similar to those, which the fruits of this species formed in a natural area have.