Effect of the Structural Modification of Plant Proteins as Microencapsulating Agents of Bioactive Compounds from Annatto Seeds (Bixa orellana L.)

Julián Quintero Quiroz; Víctor Velazquez; Juan D Torres; Gelmy Ciro Gomez; Efren Delgado; John Rojas

doi:10.3390/foods13152345

Effect of the Structural Modification of Plant Proteins as Microencapsulating Agents of Bioactive Compounds from Annatto Seeds (Bixa orellana L.)

Foods. 2024 Jul 25;13(15):2345. doi: 10.3390/foods13152345.

Authors

Julián Quintero Quiroz^{1

2}, Víctor Velazquez³, Juan D Torres², Gelmy Ciro Gomez², Efren Delgado³, John Rojas²

Affiliations

¹ Faculty of Ciencias de la Nutrición y los Alimentos, CES University, Calle 10 # 22-04, Medellin 050018, Colombia.
² Department of Ciencias Farmacéuticas y Alimentarias, University of Antioquia, Calle 67 No. 53-108, University Campus, Medellín 050010, Colombia.
³ Department of Family and Consumer Sciences, College of Agriculture, Consumer and Environmental Sciences, New Mexico State University, NMSU Gerald Thomas Hall Room, 308 P.O. Box 30003 MSC 3470, Las Cruces, NM 88003, USA.

Abstract

This project studied the use of lentil protein (LP) and quinoa protein (QP) in their native and modified states as carrier material in the encapsulation process by the ionic gelation technique of annatto seed extract. Soy protein (SP) was used as a model of carrier material and encapsulated bioactive compounds, respectively. The plant proteins were modified by enzymatic hydrolysis, N acylation, and N-cationization to improve their encapsulating properties. Additionally, the secondary structure, differential scanning calorimetry (DSC), solubility as a function of pH, isoelectric point (pI), molecular weight (MW), the content of free thiol groups (SH), the absorption capacity of water (WHC) and fat (FAC), emulsifier activity (EAI), emulsifier stability (ESI), and gelation temperature (Tg) were assessed on proteins in native and modified states. The results obtained demonstrated that in a native state, LP (80.52% and 63.82%) showed higher encapsulation efficiency than QP (73.63% and 45.77%), both for the hydrophilic dye and for the annatto extract. Structural modifications on proteins improve some functional properties, such as solubility, WHC, FAC, EAI, and ESI. However, enzymatic hydrolysis on the proteins decreased the gels' formation, the annatto extract's encapsulated efficiency, and the hydrophilic dye by the ionic gelation method. On the other hand, the modifications of N-acylation and N-cationization increased but did not generate statistically significant differences (p-value > 0.05) in the encapsulation efficiency of both the annatto extract and the hydrophilic dye compared to those obtained with native proteins. This research contributes to understanding how plant proteins (LP and QP) can be modified to enhance their encapsulating and solubility properties. The better encapsulation of bioactive compounds (like annatto extract) can improve product self-life, potentially benefiting the development of functional ingredients for the food industry.

Keywords: antioxidant; modification proteins; plants proteins.

Grants and funding

This work was sponsored by COLCIENCIAS through grant 727 of 2015 for the formation of Colombian PhDs, by COLCIENCIAS through grant 715 for research and development projects in engineering-2015, and by the United States Department of Agriculture (USDA)-National Institute of Food and Agriculture, Hatch project (1010849).