Preservation of bioactive compounds in mulberry species (Morus spp.) under different drying conditions

This study aimed to investigate the changes in the free amino acid profile, mineral content, phenolic compounds, and antioxidant activity of three mulberry species white (Morus alba), red (Morus rubra), and black (Morus nigra) following different drying methods (shade drying, and controlled drying at 55 and 65 °C). The results indicated that drying temperature significantly affected the retention of bioactive compounds. In the amino acid analyses, the highest proline content was recorded in white mulberry dried under shade conditions, reaching 834.80 mg/100 g. The GABA content was found to be 336.17 mg/100 g in red mulberry. In the mineral analyses, calcium content was determined as 4474 mg/kg in white mulberry and 10,660 mg/kg in red mulberry. Regarding phenolic content, shade-dried red mulberry showed the highest level at 10.34 mg GAE/g, followed by black mulberry at 9.69 mg GAE/g and white mulberry at 2.86 mg GAE/g. The highest antioxidant activity was observed in red mulberry, with a value of 47.68%. Overall, the findings suggest that low-temperature drying, particularly shade drying, is the most effective method for preserving the bioactive components of mulberry fruits.