Effects of cold storage on quality traits of Sardinian Myrtle (Mytrus communis L.) berries and their alcoholic extracts

Myrtus communis L. is a spontaneous aromatic plant typical of the Mediterranean area. Myrtle berries hydrodistilled products and ethanolic extracts are mainly used as flavouring agents and food supplements. This study evaluated the effect of long-term storage on the quality-related properties of myrtle berries. Storage at 2 °C for three months effectively preserved myrtle berries quality, both in the chemical composition and external appearance. No symptoms of chilling injury and decay occurred during the first two months of storage, at the end of storage only the 1.3% of rotting was detected. Total anthocyanic content and anthocyanin glycosides diminished whereas the antioxidant capacity increased in all samples till the end of storage. The antioxidant properties of myrtle berries were not correlated with the anthocyanic fraction. The pH of myrtle berries decreased, while gluconic acid levels increased. The results reported in this paper showed that the storage at 2 °C for three months appears to be an effective way to preserve myrtle berries quality. The changes in the chemical composition of the fruits subjected to storage had revealed the importance of gluconic acid and pH for myrtle quality assessment. These two parameters can be used as quality markers since a strong relationship has been found between myrtle decay and the changes in these parameters.