Response of Black (Morus nigra), White and White Shahtoot (Morus alba) Mulberry Fruits to Ascorbic Acid Treatment and Drying Methods

The drying process plays an important role in heat-sensitive product dehydration. This study was conducted to evaluate the response of three species of mulberry fruit (Morus nigra L. (Black mulberry), Morus alba L. (White mulberry), and Morus alba L. (White shahtoot) grown in Halabja, Kurdistan region, Iraq. Four levels of ascorbic acid treatment at 0%, 10%, 20% and 30% lthen, divided into two groups; the first dried under solar radiation the second dried by one of the very high-quality machines (oven) for drying all kinds of vegetables and fruits. The mulberry fruits were harvested at the ripening stage by hand in April 2021 from the trees 10 years old. The results appeared that black mulberry is significantly superior that has higher moisture and total sugars content while having the lowest ash content and polyphenol oxidase activity on the two other species. Additionally, the ascorbic acid treatment significantly decreased total sugars content and peroxidase activity, while significantly increasing moisture content and polyphenol oxidase activity in fruits as compared to untreated fruits. Furthermore, sun drying significantly increased the fruits content of moisture, ash, total sugars, and polyphenol oxidase activity as compared to oven drying.