The yacon tuber has gained interest due to its health-promoting components, such as high amounts of fructooligosaccharides (FOS) and phenolic compounds with strong antioxidant properties. However, the high water content and the soft, delicate internal tissues render it highly perishable, leading to significant losses during postharvest handling. The packaging and storage temperatures, two important factors in maintaining quality when storing fresh yacon tubers, were studied. The results showed that modified atmosphere packaging (MAP) combined with low temperature (10°C) had positive effects on the visual quality of yacon. Weight loss and shriveling were reduced in MAP compared to the unpacked yacon under room and 10°C storage temperatures. The use of MAP under room temperature for an extended storage period was limited by the development of disease and the occurrence of root sprouts and surface cracks in yacon, which reduced its visual quality. FOS hydrolysis by fructan exohydrolase occurred during storage, leading to higher amounts of fructose, glucose, and sucrose. The use of MAP regardless of storage temperature delayed the onset of rapid FOS decline. The total phenolic contents in the range of 4.84-5.98 mg Gallic acid equivalent per gram dry sample and antioxidant activity of yacon did not decrease relative to its initial content. Yacon could be stored at 10°C in conjunction with MAP to maintain quality and extend the shelf life of fresh yacon tubers.

Browning is the major problem associated with yacon [Smallanthus sonchifolius (Poepp.) H. Rob.] processing as it takes place rapidly and intensely after tissue damage. This study investigated the effects of different blanching conditions on the browning parameters and some chemical components of yacon. Whole yacon tubers were blanched in hot water under different temperature and time conditions and immediately cooled in ice water. Increasing blanching temperature and time significantly reduced the polyphenol oxidase (PPO) activity but resulted in an undesirable change in firmness; lightness (L*) decreased approaching to a black color flesh of yacon, and the a* and b* values decreased representing a tendency to a green and blue colors, respectively. Blanching the whole yacon at 60⁰C for 20 mins was found to be the most effective and can be used as preprocessing treatment to reduce browning of the product. At this condition, PPO activity was reduced to 70%, firmness was retained, and further browning was decelerated when the cut surface of yacon was allowed to stand at room temperature. Moreover, the total phenolic content (TPC), antioxidant activity, glucose, sucrose and fructose were not significantly different from unblanched yacon but fructooligosaccharide (FOS) content was reduced from 51.36 to 36.29% on dry weight basis