Influence of Sunlight Exposure and Traditional Dehydration on Chemical and Nutritional Properties of Oxalis tuberosa (oca) Tubers.

Abstract

Oca (Oxalis tuberosa), a potato like crops, is cultivated extensively in the high altitude regions of the Andes. Traditionally, consumers have used sunlight to enhance the sweetness of oca and have used methods to produce a dehydrated product known as 'khaya' for its preservation. This research seeks to assess the chemical and nutritional changes that four oca cultivars undergo after exposure to sunlight and traditional dehydration techniques. The results of the study indicate that exposure of freshly harvested oca to sunlight contributes to antioxidant capacity, increased concentration of polyphenols, carotenoids and polyunsaturated fatty acids, and an overall improvement in nutritional properties characterized by a reduction in oxalate content and a significant increase in sugar concentration. On the other hand, dehydration byproducts are associated with a decrease in antioxidant capacity and polyphenols, a reduction in oxalate content and is accompanied by an increase in amylopectin. The changes in sugar content depend on the specific dehydration treatment used. Taken together, these results suggest that exposure of oca to sunlight not only improves its chemical and nutritional profile, but also contributes to an overall improvement in quality. On the other hand, dehydration of oca serves as a preservation technique, extending its shelf life while maintaining certain nutritional properties. This research provides valuable insights into optimizing the post-harvest handling of oca to improve quality and prolong shelf life.