Enhancing Naturally Phosphorylated Starch: Effects of Phosphate Fertilization on Sweet Potato Cultivars

ABSTRACT

Food manufacturers can increase the value of their products by using unmodified phosphate starch when industries choose a naturally phosphorylated starch ingredient. In addition to technological advantages arising from changes in physicochemical properties, this choice offers benefits. This study evaluated the effects of phosphate fertilization (0–400 kg P ₂ O ₅ ha ^{− 1} ) on the agronomic yields, root phosphorus content, and the physicochemical characteristics of the starches of two sweet potato cultivars, Canadense and Uruguaiana. The results showed that the Uruguaiana cultivar had higher phosphorus content in its roots regardless of the fertilizer dose. The Canadense cultivar was more responsive to fertilization, exhibiting higher increases in both root and starch yields. All starches showed an A‐type diffraction pattern. Phosphate fertilization increased starch phosphorylation by 20% in both cultivars, altering their morphological and physicochemical properties, which differed between the cultivars. Starches obtained under phosphate fertilization exhibited larger granule size, higher resistant starch content, greater swelling power, and lower breakdown. This characteristic is of interest to the food industry due to enhanced stability during industrial processing. These results suggest that phosphate fertilization is a viable option for natural phosphorylation of starch with desirable functional properties, while simultaneously increasing its added value.