Production process and characterization of the traditional Greek fruit distillate 'Koumaro' by aromatic and mineral composition.

摘要

Koumaria is the common name of the bushy shrub Arbutus unedo L., also known as the strawberry tree. Its fruits are round, fleshy and red colored at full maturity. They are mainly used for the production of an aromatic traditional distillate, named Koumaro. To gain a better understanding of this product, we gathered information regarding its traditional production process and we analyzed volatile substances by gas chromatography (GC) according to the official method of the Office International de la Vigne et du Vin (OIV), mineral compounds by atomic absorption spectrometry (AAS), sugar content of the fruit and pH level using standard methods. The fruit of Koumaria has a high mean sugar content of 24.6 degrees Brix, while its distillate has an alcoholic title with a mean value of 39.4% vol, but with great variations. Methanol content, generally, is lower than the limit of 1000 g/hL. Absolute alcohol (AA) and the higher alcohol values satisfy the qualitative demands of 140 g/hL AA. Isovaleric acid was found in high concentrations compared to other fruit distillates. Substances which can cause health hazards (e.g., estragol) or organoleptic faults (e.g., acetaldehyde, ethyl acetate, ethyl lactate, diethyl succinate) were lower than their respective limits or thresholds. Furthermore, the very low concentrations of Cu, Pb along with Ca and Fe indicate the good maintenance of the alembics and do not pose a threat to consumer safety. Since great variations in composition were observed, a better standardization process is required to achieve better control of the levels of the above compounds as well as the ethanol concentration, which was found to vary in many distillates. Areas where better quality control should be applied are the quality of the fruit, the fermentation and storage process, the distillation and the good condition of the equipment.