The effects of different drying techniques on some nutritional values of black (M. nigra) and white (M. alba) mulberry fruits

Black mulberry (M. nigra) and white mulberry (M. alba) fruits were dried in three different ways. These methods are drying in the sun, drying in the oven (70, 90 and 110 Co) and microwave (450, 600 and 700 W drying). Fruit weight, moisture content, organic acid and phenolic composition changes depending on drying processes. Fruit weight is higher in microwave applications than other applications. In sun dried samples, white and black fruit weight were found as 1.07 and 1.59 g respectively. In the dormitory drying, the fruit weight was 0.57-0.88 g in the white mulberry, 1.57-1.87 g in the black mulberry, 0.62-1.22 g in the white mulberry in the microwave, and 0.76-1.41 g in the black mulberry. In the research, changes in the amount of organic acids were observed depended on drying methods. When looking the major organic acid distribution, white mulberry fruits; the highest oxalic acid content (2.88 g / 100 g) was determined in sun dried fruits, the highest citric acid content (14.15 g / 100 g) and the highest malic acid content (17.67) were determined in dried fruits in oven (110 Co). The highest vitamin C content was detected in fresh fruits (26.30 mg / 100g). When the organic acid contents of black mulberry fruits were examined; The highest oxalic acid (2.88 g / 100 g), malic acid content (18.39 g / 100 g) and citric acid contents (9.09 g / 100 g) were determined in sun dried fruits. In this study, the highest vitamin C content (31.66 mg / 100 g) was identified in fresh black mulberry fruits. When examined the changes in the content of major phenolic compounds according to the drying methods applied in white mulberry fruits; highest gallic acid (76.39 mg / 100g), chlorogenic acid (63.44 mg / 100 g) and caffeic acid contents were determined in the oven drying (110 Co). The highest routine content (16.79 mg / 100 g) was determined in microwave drying. The highest gallic acid (97.58 mg / 100 g), chlorogenic acid (51.75 mg / 100 g) and routine contents in (21.68 mg / 100 g) black mulberry fruits were obtained in microwaves (450 W) drying. In this study, High elagic acid content was also determined in the microwave at 700 W drying. As a result, it has been observed that there are significant changes in biochemical contents of white mulberry and black mulberry fruits depended on drying methods and fresh fruits are important in terms of vitamin C richness. KEYWORDS: Mulberry, drying, phenolic compound, organic acid