Composition and antioxidant properties of fresh and frozen stored blackthorn fruits (Prunus spinosa L.)

Aim. Blackthorn (Prunus spinosa L.) is quite widespread bush occurring in Poland. Its fruits are easily available food products. The aim of this study was to investigate the basal chemical composition, especially antioxidant compounds in fresh and frozen stored blackthorn fruits. Material and methods. Research material consisted of blackthorn fruits collected from the wild grown bushes, near Łącko. In the wash-out, dried and stone-loss fruits, the content of dry matter, protein, simple sugars, dietary fi bre and ash was determined. The amount of antioxidant compounds was also tested: β-carotene, vitamin C, polyphenols, in this anthocyannins, as well as antioxidant activity expressed as an ability to quench free radical ABTS. Analyses were repeated in fruits stored in frozen state for three months. Results. On the basis of the obtained results, it was observed that concerning basal chemical composition, the blackthorn fruits do not single out among other fruits from Rosaceae family. It was also reported that blackthorn fruits are rich in polyphenolic compounds, as well as in vitamin C, and those compounds, most probably contribute to their high antioxidant activity, being at the level of 43.6 μmol Trolox/g f.m. Storage in the freezing state reduced the contents of water, fat, dietary fi ber and ash, but did not have signifi cant impact on the other compounds. Conclusions. Blackthorn fruits may constitute valuable source for preparations (tincture, wines, and teas), as well as an additive to other fruit processing, as a product of great pro-healthy properties. Freezing process and storage in that state did not signifi cantly infl uence on nutritive and antioxidant compounds of blackthorn fruits. It may be therefore observed that several months of frozen storage is a good way to make them available for fruit processing and for the consumers, also the off-season.