First results of agronomic and chemical evaluation of yacon (Smallanthus sonchifolius) in Mediterranean environment

Yacon is a perennial herbaceous plant, native to South America, where it is consumed as food. The plant grows in warm and low frost areas and does not require pesticides for protection from fungi and insects. This is a crop relatively new to the global market and the interest is growing due to the nutraceutical effect of the final products, mainly leaves, and tubers. Traditionally used in folk medicine for diabetes, constipation, and other diseases, in recent years, syrup and powder of tubers and infusion of leaves have steadily emerged with scientific evidence to validate their applications. Yacon has sweet-tasting tuberous roots with a tan-coloured thin skin, and they are characterized by over 20% sugars, mainly fructooligosaccharides (FOS) and inulin. Leaves are a rich source of antioxidants, mainly chlorogenic, caffeic, and ferulic acids. In this work, one new line of yacon was grown in Sicily to evaluate its potential as a new crop in the Mediterranean climate to obtain new products with nutraceutical effects. The trial was conducted at Acireale (southern Sicily, Italy) during the 2020- 2021 seasons in a typic volcanic soil. The accession was grown by single-tuber in pots (20 cm diameter) in November 2019 and transplanted in open field in April 2020, using 1 plant m-2. During the crop cycle, the main phenological parameters were determined. Leaves, stalks, and tubers were harvested in February 2021. The number of tubers plant-1 (total and marketable), the fresh biomass weight and its partitioning, and the height of the plants were determined. In the laboratory, tubers were characterized for the dry matter content, inulin, and water-soluble carbohydrates. Results showed about 1,000 g plant-1 of marketable tubers, with a good inulin content. Due to the high residual biomass yield (stalks, leaves, and not marketable tubers) other utilization (recovery of biocompounds or energy production) could be achieved.