Influence of vacuum drying temperature on: Physico-chemical composition and antioxidant properties of murta berries

Murta (Ugni molinae T.) berries were vacuum dried at a constant pressure of 15 kPa. The effects of processing temperatures (50, 60, 70, 80 and 90 °C) on the physico-chemical characteristics, the phenolic and flavonoid compounds, the antioxidant activity and the sugar and β-carotene contents of the fruit were evaluated. The dried samples had lower protein contents than the fresh sample. Also, drying temperatures significantly affected the phenolic compounds. The antioxidant activity decreased in value after vacuum drying at each temperature. Fructose was the predominant sugar, followed by sucrose and glucose. Overall, sugar contents were affected by drying temperatures, especially at 50 °C with a noticeable sucrose content decrease. However, β-carotene contents showed significant increases in value with an increase in temperature. These results indicated that vacuum drying might be a good alternative for dried murta production. Dried murta could be an important source of bioactive compounds. Practical applications: Murta berries are rich in phenolic compounds having antioxidant activity and beneficial potential effects on human health. Drying is widely used in the fruit processing industry. This process has proven to be a good alternative for preservation of many fruits and vegetables. The obtained results provide the necessary vacuum drying conditions to stand out the nutritional value of murta berries. Thus, we believe that our findings can contribute to obtain the best process that retains the nutritional quality of murta berries.