Blackberries ( Rubus ulmifolius Schott) from Calabria (Italy): a comprehensive characterisation

摘要

The establishment of the corresponding standards of quality to promote the commercialization of Rubus ulmifolius Schott (Rosaceae) blackberries from Calabria (Italy) has been aimed in this study. Data on the volatile composition gathered by Solid-Phase Microextraction (SPME) followed by GC-MS have been complemented with the study for the first time of physicochemical parameters and antioxidant capacity of wild and cultivated blackberries collected in seven different locations of Calabria. Wild fruits showed significantly higher dry matter content (16.34-22.14%) and pH (3.92-5.12) and lower total acidity (0.23-0.74 as % of citric acid) compared to the cultivated sample (dry matter: 15.31%; pH: 3.30 and total acidity: 1% citric acid), whereas colour and total soluble solids were similar. Antioxidant capacity (DPPH assay) of wild blackberries, correlated (r = 0.71) with results from ABTS assay, was significantly higher (SE50 = 1.6-3.4 mg DW), in agreement with its higher content of total anthocyanins and total phenolics. Ethanol (11.8-32.4%), trans-2-hexenal (2.7-21.3%), methylbutanal (5.7-17.4%), and ethyl acetate (4.6-11.9%) were the major compounds in both wild and cultivated blackberries. Although the presence or relative concentration of several volatiles (e.g. p-cymen-8-ol, decanal, 3-hydroxy esters, etc.) seemed to be characteristic of the harvest location/blackberry type, further research on a higher number of samples should be carried out to confirm these results. The comprehensive characterisation addressed for the first time in this paper is a valuable preliminary contribution to satisfy the demand by consumers and farmers of objective data to support the premium quality of Calabrian blackberries.