Evaluation of Color, Texture, Sensory and Antioxidant Properties of Gels Composed of Freeze-Dried Maqui Berries and Agave Sugar

Abstract

The study aimed to determine the textural, sensory, and antioxidant properties of gels composed of maqui (Aristotelia chilensis) berries. These freeze-dried berries were tested in a powdered form as an additive (0–5%) to agave sugar (20%) gels. Freeze-dried maqui powdered berries were dark purple to almost black in color and were characterized by an L* value of 16.3, an a* value of 8.3, and a b* value of −9.6. The b* values decreased from 11.8 to 2.3 with the increase in the amount of berry powder. There were no significant changes in the color of gels composed of berries at 4% and 5% concentration. Gels lost (almost twice) their hardness as the amount of maqui increased. The lowest values of hardness and the highest values of elasticity, springiness, gumminess, and chewiness were observed at 4% concentration of dried berries. The type of sugar did not affect the lightness of the gels (L* parameter) and the a* value. The assessors evaluated the gels composed of agave sugar (20%) and 4% maqui and 0.5% citric acid to be the best. Phenolic content and antioxidant activity were significantly higher in these gels compared to the control gels. After obtaining this low sugar gels, consumers could enrich their diets with healthier products.