Solar drying of goji berries (Lycium barbarum)

Abstract

The goji (Lycium barbarum) is a shrubby tree, with delicious fruits in the shape of berries with red color. Goji berries are consumed fresh and are valued as a raw material for processing into high-quality products, especially as dried fruits, which allows their use throughout the year. The aim of the research is to determine the quality and nutritional composition of fresh and solar dried goji berries. The goji berries of the JB1 variety were dried. After preparing the berries, they were treated in several ways, with the aim of determining which is the best way to preserve the quality characteristics of the berries after drying. The following treatment methods were applied: berries without treatment (control); immersion of berries in boiling water, cooling and immersion in 1% ascorbic acid solution, 5 minutes; immersion of frozen berries in 1% ascorbic acid solution, 5 minutes. Solar drying was carried out in a solar dryer, registered as a Macedonian type, located in the vicinity of Veles. Goji berries (JB1) were harvested from an orchard near Skopje. In the samples of fresh and dried goji berries were determine the following parameters: the total dry matter, moisture, total acids, ash content, content of total sugars, vitamin C, cellulose, protein, fat and total polyphenols. For that purpose, the standard laboratory methods were used. Sensory analysis was also performed by scoring method (max. 20). According to this research, it has been determined that goji berries, variety JB1, have a good nutritional composition, rich in bioactive components, and they are also an excellent raw material suitable for drying. The application of the Macedonian solar dryer has shown good results, both from the economic and ecological point of view, as well as in terms of preserving of the components of the chemical composition.