Plant-Based (Hemp, Pea and Rice) Protein-Maltodextrin Combinations as Wall Material for Spray-Drying Microencapsulation of Hempseed (Cannabis sativa) Oil

Abstract

Conscious consumers have created a need for constant development of technologies and food ingredients. This study aimed to examine the properties of emulsions and spray-dried microcapsules prepared from hempseed oil by employing a combination of maltodextrin with hemp, pea, and rice protein as carrier materials. Oil content in the microcapsules was varied at two levels: 10 and 20%. Increasing oil load caused a decrease in viscosity of all samples. Consistency index of prepared emulsions was calculated according to Power Law model, with the lowest (9.2 ± 1.3 mPa·s) and highest values (68.3 ± 1.1 mPa·s) for hemp and rice protein, respectively, both at 10% oil loading. The emulsion stability ranged from 68.2 ± 0.7% to 88.1 ± 0.9%. Color characteristics of the microcapsules were defined by high L* values (from 74.65 ± 0.03 to 83.06 ± 0.03) and low a* values (-1.02 ± 0.015 to 0.12 ± 0.005), suggesting that the materials were able to coat the greenish color of the hemp seed oil acceptably. The highest encapsulation efficiency was observed in samples with rice protein, while the lowest was with hemp protein. Combination of maltodextrin and proteins had a preventive effect on the oxidative stability of hempseed oil. Oil release profile fitted well with the Higuchi model, with hempseed oil microencapsulated with pea protein-maltodextrin combination at 10% oil loading depicting lowest oil release rates and best oxidative stability.

Keywords: hempseed oil; maltodextrin; microencapsulation; plant-based protein; spray drying.

Figure 1

Protein–maltodextrin-coated hempseed oil microcapsules observed with SEM.

Figure 2

Oil release from hempseed oil microcapsules encapsulated with combination of proteins with maltodextrin.