Effects of Steam Distillation and Screw‐Pressing on Extraction, Composition and Functional Properties of Protein in Dehulled Coriander (Coriandrum sativum L.)

Abstract

AbstractCoriander (Coriandrum sativum L.) is a summer annual plant commonly used as fresh green herb, spice or for its essential oil. An integrated process combined steam distillation, dehulling, and screw pressing to recover the essential oil and edible oil from coriander fruit. The current work determined the impact of the dual oil extraction approach on coriander protein extractability, composition, and functional properties and compared the results with those of ground whole coriander. Coriander protein extracts were produced by the acid precipitation method. All the dehulled samples (steamed and non‐steamed) produced protein extracts with markedly higher protein content (84–90% dry basis, db) than did ground whole fruit (67% db). Coriander protein extracts showed similar amino acid compositions and had amino acid scores that were greater than those of their starting meals and soybean protein. Steam distillation had detrimental effects on the protein, based on major changes in SDS‐PAGE band patterns and reduced protein recovery [from 42 (control) to 26%]. However, solubilities of protein from steam‐distilled samples were enhanced from pH 7 to 10 (>90 versus 80% in non‐steam‐distilled coriander). Steam‐distillation did not negatively affect foaming, emulsification, and heat coagulability properties of the coriander proteins, as the values were equal to those of the non‐steamed samples.