Effects of Phosphate Fertilization Rates on Physicochemical Properties of Potato Starch

Abstract

AbstractThe objective of this study is to seek correlations between phosphate fertilization rates in potato cultivation and the chemical composition and physicochemical properties of the potato starch. Potato starches are prepared from the potato tubers cultivated in two different districts in Hokkaido, Japan, with different soil characteristics using varied phosphate fertilization rates. The chemical composition of the potato starches such as the amylose, phosphorus, and potassium contents and their physicochemical properties such as the swelling power, solubility, and pasting and thermal properties are evaluated. The results show that the phosphate fertilization rate has a moderate and positive correlation with the amylose content, while no correlations are found with any other chemical composition and physicochemical properties, including the phosphorus content. One plausible explanation for the lack of the correlation between the phosphate fertilization rate and the phosphorus content in the starch is that a sufficient amount of phosphorus has already been accumulated in the soils to phosphorylate the starch to the highest possible degree without further application of phosphate fertilizers. The present results imply that reducing the phosphate fertilization rate in potato cultivation in the studied fields has no negative impact on the chemical composition and physicochemical properties of potato starch.