Fabrication of citric acid-modified starch nanoparticles to improve their thermal stability and hydrophobicity

Sumaira Miskeen; Jung Sun Hong; Hee-Don Choi; Jong-Yea Kim

doi:10.1016/j.carbpol.2020.117242

Fabrication of citric acid-modified starch nanoparticles to improve their thermal stability and hydrophobicity

Carbohydr Polym. 2021 Feb 1:253:117242. doi: 10.1016/j.carbpol.2020.117242. Epub 2020 Oct 18.

Authors

Sumaira Miskeen¹, Jung Sun Hong², Hee-Don Choi², Jong-Yea Kim³

Affiliations

¹ Department of Food Science and Biotechnology, Kangwon National University, Chuncheon 24341, Republic of Korea.
² Research Group of Food Processing, Research Division of Strategic Food Technology, Korea Food Research Institute, Iseo-myeon, Wanju-gun, Jeollabuk-do 55365, Republic of Korea.
³ Department of Food Science and Biotechnology, Kangwon National University, Chuncheon 24341, Republic of Korea. Electronic address: jongkim@kangwon.ac.kr.

PMID: 33278998
DOI: 10.1016/j.carbpol.2020.117242

Abstract

Starch nanoparticles (SNPs) were reacted at 130 °C for 1.5 h in the presence of citric acid (30 %) to enhance their thermal stability and hydrophobicity. Citric acid content in SNP was controlled by washing with different concentrations of ethanol (95 %, 70 % and 60 %) for 2, 5 and 10 min and then subjected to heat treatment at 130 °C. After the modification, the peak at 1732 cm^-1 representing ester bond was observed via FT-IR, and the intensity of the peak was decreased with a lower ethanol content in washing medium. For the 60 % ethanol condition, the granular structure was promptly fragmented into particles less than 50 nm in the aqueous solution. The modification enhanced the thermal stability and hydrophobicity of the SNPs. The modified SNPs was used as a nano-vehicle wall material for encapsulating beta-carotene as a model hydrophobic material. Approximately 80 % beta-carotene was encapsulated in the modified SNPs.

Keywords: Citric acid; Cross-linking; Hydrophobicity; Starch nanoparticles; Thermal stability.