Bernkopf


Die Bodenkultur - Journal for Land Management, Food and Environment

S. BERNKOPF:

Botanical-pomological and Physical-chemical Characterization and Evaluation of Apple and Pear Landraces From Upper Austria

Part II: Physical-chemical Investigations

 

Summary

During the period of this study, 1984 to 1986, 24 apple and 27 pear landraces from Upper Austria were characterized and evaluated in respect to their physical-chemical features.

They were mostly races traditionally used for the preparation of fruit juices, ciders, parries and other fruit products. The fruit was harvested from trees maintained in situ. Juice was pressed under reproducable conditions immediately after harvesting and ten days later.

Various physical-chemical parameters such as relative density, glucose, fructose, saccharose, D-sorbitol, malic acid, citric acid, titratable acids, pH-values, polyphenols, ash and the minerals sodium, potassium, calcium, magnesium and phospate were tested.

Thereby it was discovered that the pear landraces had much higher total sugar contents than the apple landraces. The landrace "Weiße Pelzbirne" had the highest average total sugar content (x =155.36 g/l, R =139.04 to 171.67 g/l). The highest total sugar values in one year was found in the landrace "Kleine Landlbirne" (230.71 g/l). The titratable acid values were higher in the apple landraces (x = 10.7 g/l, R = 6.3 to 20.4 g/l).

Also very high contents of polyphenols (up to 9.82 g/l) especially in some of the pear landraces were found. During a storage period of ten days the saccharose and titratable acid values declined and those of glucose and fructose increased. In many of the pear landraces a considerable reduction of the polyphenols could be observed.