Proximate Composition of Chia Seeds, Functional, and Antioxidant Properties of Their Mucilage.

Abstract

This study aims to evaluate the nutritional composition of chia seeds (Salvia hispanica), along with the antioxidant and functional properties of their extracted mucilage, with a focus on its potential as a multifunctional ingredient for the food and related industries. To assess the nutritional profile, the association of official analytical chemists methods were used. Antioxidant activity was measured using DPPH radical scavenging, reducing power, and iron chelation capacity at various mucilage concentrations. Functional properties such as water holding capacity, oil binding capacity, swelling index, solubility, emulsifying capacity, and foam behavior were determined using gravimetric and volumetric methods. Preliminary chemical analyses showed that chia seeds possess a balanced nutritional profile, with moisture content at 10.09 ± 0.11%, ash at 4.25 ± 0.06%, protein at 20.95%, fat at 24.70 ± 5.96%, total fiber at 22.79 ± 2.31%, and carbohydrates at 17.23%. The extracted mucilage exhibited a neutral pH (7.56 ± 0.04) and moderate electrical conductivity (1.298 ± 0.11 mS/cm). Functionally, the mucilage demonstrated a high-water holding capacity (97.62 ± 3.40 g H₂O/g), a notable oil binding capacity (9.56 ± 0.72 g oil/g), and a significant swelling index (19.94 ± 5.88 g H₂O/g), indicating its suitability for moisture retention and texture enhancement in food systems. Solubility improved with temperature, increasing from 78.83% at 30°C to 90.00% at 80°C. Chia seed mucilage also showed an excellent emulsifying capacity (97.5 ± 3.54%), though emulsion stability was moderate (38.42 ± 2.23%). Its foaming capacity was relatively low (3.67 ± 1.53% at 1% concentration), but highly stable over time (95.83 ± 8.84%), making it useful in select formulations. Antioxidant testing revealed strong activity, with DPPH radical scavenging increasing from 58.56% to 79.59% between 0.375 and 3 mg/mL, and iron chelation capacity rising from 53.70% to 98.05%. Overall, these findings highlight the potential of chia seed mucilage as a natural hydrocolloid with valuable functional and antioxidant properties, supporting its use in food, pharmaceutical, and cosmetic applications.