Influence of drying method on the functional and microstructural properties of starch from Oxalis tuberosa

Due to the versatile uses of starch, worldwide demand for it is constantly growing, compelling the exploration of new potential sources for its extraction and industrialization. In this study, the functional and microstructural properties of the starch from Oxalis tuberosa dried by oven drying (ODS), freeze-drying (FDS), and spray drying (SDS), were evaluated. Regarding the particle analysis, average sizes of 33.61 μm for ODS, 35.7 μm for SDS, and 39.16 μm for FDS were found, while the convexity of the granules was higher for SDS (0.86) and FDS (0.87) compared to ODS (0.92). The crystallinity obtained by XRD was higher in ODS (37.31%) and SDS (36.23%) compared to FDS (24.55%). The clarity of the paste was highest in FDS (80.93 ± 0.66%) followed by SDS (76.33 ± 0.3%). The swelling power was higher in SDS (16.07 ± 0.7), followed by FDS (13.16 ± 1.23) and ODS (8.59 ± 0.69). Regarding the water solubility index, FDS showed the highest solubility followed by SDS and ODS. An improvement in powder flow was noticed for SDS, followed by FDS and ODS, respectively. The results showed that the properties of O . tuberosa starch varied according to the drying method.