Yacon (Smallanthus sonchifolius) flour obtention: Effect of process conditions on quality attributes and its incorporation in gluten-free muffins

Abstract

Yacon is a little-known, non-starchy Andean root crop recognized as a rich source of β-(2-1) fructooligosaccharides. The aim of this research is to study different drying conditions to obtain yacon flour with high color and bioactive conservation to be used as a functional ingredient. Three different types of pre-drying processing were tested: pulped, cut as cubes and sliced with addition of bisulfite, and drying for 16 h at 65 °C. Dried sliced-yacon remained light-yellow with the lowest anti-browning index. The flour obtained from this sample also showed high reducing sugar content, and good fructans conservation (around 60% compared to freeze-dried) and the highest total polyphenol content (≈450 mg GAE/100 g) and antioxidant activity. Starch-based gluten-free muffins were made with 5% and 10% of substitution of corn starch by flour obtained from dried sliced-yacon with minimal effect on crust and crumb color. Addition of yacon flour made muffins less firm and more cohesive with a decrease in chewiness as compared to control. Its addition also generated a larger number of smaller pores in the muffin's microstructure. The results highlight that yacon flour may be produced by different methods and this powder represents an ingredient with considerable potential for food enrichment.