Extraction of Jackfruit seed protein: Structural and functional analysis

Abstract

Jackfruit seeds, a by-product of the tropical fruit processing industry, are a rich protein source, with approximately 7% protein. The amino acids present in jackfruit seeds are histidine, threonine, valine, lysine, isoleucine, leucine, and phenylalanine. The study aimed to isolate the protein from jackfruit seeds and analyse its physicochemical, structural, and functional properties. In this study, the protein was isolated from jackfruit seed flour using acid-alkali precipitation and microwave-assisted extraction at 800 W. Protein solubility (81.48%) was improved for microwave-assisted extraction compared to the acid-alkali precipitation method (79.48%). The scanning electron microscope analysis showed compact, aggregated, irregular, and elongated flaky protein structure for microwave-assisted extraction compared to acid-alkali precipitation jackfruit seed protein isolate (JSPI). The differential scanning calorimetry study indicated a higher denaturation temperature for microwave-assisted extraction JSPI (106°C) than acid-alkali precipitation JSPI (95°C). FTIR spectra showed nine bands in the acid-alkali precipitation protein, indicating a more complex structure than the microwave-assisted extraction JSPI (6 bands). The XRD diffractogram showed that both isolated proteins were amorphous. Protein isolated by microwave-assisted extraction exhibited enhanced overall properties, making it better suited for a wide range of food applications.