Effects of phosphorus fertilizer application rates on physicochemical properties of potato starch

Authors: MORISHITA, AO - Obihiro University; KINOSHITA, RINTARO - Obihiro University; TANI, MASAYUKI - Obihiro University; SUGAWARA, MAYAYUKI - Obihiro University; Ikeda, Shinya

Submitted to: Starch
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary: Potato starch is widely used as a processing aid in food processing to control the quality and stability of various food products because it contains a significant quantity of esterified phosphorus and shows distinctively high viscosity and clarity. Phosphorus is one of the main limiting factor for plant growth, while, in order to increase the yield in potato production, reducing the rate of phosphorus fertilizer application may be recommended, depending on the history of fertilization practices. However, effects of reducing the phosphorus fertilizer application rate on the quality of potato starch have been hardly understood. The objective of this study was to seek correlations between phosphorus fertilizer application rates in potato production and the quality traits of the potato starch, including the phosphorus content and gelatinization characteristics. The results showed that the phosphorus fertilizer application rate had a positive correlation with the amylose content of the starch, while no correlations were found with any other quality traits, including the phosphorus content of the starch. One plausible explanation for the lack of the correlation between the phosphorus fertilizer application rate and the phosphorus content of the starch was that a sufficient amount of phosphorus had already been accumulated in the soils to phosphorylate the starch to the highest possible degree without further application of a phosphorus fertilizer. The present results imply that reducing the phosphorus fertilization rate in potato production has no negative impact on the quality of food products derived using the potato starch as a processing aid.

Technical Abstract: The objective of this study was to seek correlations between phosphorus fertilizer application rates in potato production and the chemical composition and physicochemical properties of potato starch. Potato starch samples were prepared from the potato tubers cultivated in two different districts in Hokkaido, Japan, with different soil characteristics using varied phosphorus fertilizer application 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 were evaluated. The results showed that the phosphorus fertilizer application rate had a weak and positive correlation with the amylose content, while no correlations were found with any other chemical composition and physicochemical properties, including the phosphorus content. One plausible explanation for the lack of the correlation between the phosphorus fertilizer application rate and the phosphorus content was that a sufficient amount of phosphorus had already been accumulated in the soils to phosphorylate the starch to the highest possible degree without further application of a phosphorus fertilizer. The present results imply that reducing the phosphorus fertilization rate in potato production has no negative impact on the chemical composition and physicochemical properties of potato starch.