Utilization of Yacon Damaged Roots as a Source of FOS-Enriched Sweet-Tasting Syrup

Featured Application This work can be used for the development of sweet-tasting syrups rich in fructooligosaccharides by taking advantage of yacon agri-food by-products.Abstract Damaged yacon roots, often discarded, are a rich source of sweet carbohydrates. In this context, yacon roots from the Hualqui and Crespo varieties were characterized and processed into low-calorie and low-glycemic syrups for sugar reduction in foods. Syrups were obtained using, as technological adjuvants, lemon juice and its most relevant components: citric acid and ascorbic acid. The Hualqui variety was found to be mostly composed of fructose (210 g/kg), while the Crespo variety was rich in inulin (352 g/kg). The use of lemon juice during syrup production promoted the hydrolysis of inulin to fructooligosaccharides and fructose, yielding syrups with competitive relative sweetness (0.52-0.91), glycemic index (0.21-0.40), and caloric values (186-263 kcal/100 g) to commercial syrups. The increase in citric acid concentrations promoted inulin hydrolysis, yielding, at the highest concentration, syrups with higher fructose (333-445 g/kg) and kesto-type fructooligosaccharides (11-85 g/kg) content and lower surface stickiness and stringiness. The addition of ascorbic acid, as an antioxidant agent, decreased by 10% the free sugar content, negatively impacting the sweetness level. These results evidence that fructooligosaccharides-rich syrup can be obtained from yacon-damaged roots with tailored sweetness and low glycemic and caloric properties.