Sensory and Lipid Profile Optimization of Functional Brownies Through Cold-Pressed Nut Oil Substitution for Butter
Authors: Martínez Elena , Pardo José Emilio , Álvarez-Ortí Manuel , Martínez-Navarro M. Esther , Rabadán Adrián 
Published: January 2025

This study evaluated the effects of replacing butter, rich in saturated fats, partially (50%) and totally (100%) with nut oils (almond, pistachio, and walnut) on the physical, nutritional, and sensory properties of chocolate brownies. By replacing butter with nut oils, the brownies became softer and more elastic, particularly with walnut oil. This change could make the brownies more appealing to consumers who prefer a softer, chewier product. The increased cohesiveness in the brownies containing almond and walnut oils (50% substitution) suggests better structure and consistency, which could contribute to a more pleasant eating experience. The reduction in gumminess and chewiness, particularly in the 100% nut oil formulations, indicates a potentially improved texture, making the brownies easier to bite into and consume. Regarding color, the analysis showed that the luminosity of the brownies was quite similar across all samples, although small differences were noticed between the dough and the baked product. The colorimetric parameters a* and b* indicated that the baking process had an intensifying effect on the color, making the final product more uniform across all samples. In terms of nutritional composition, it was observed that the moisture content decreased as the proportion of nut oil increased. The fat content rose in all nut oil-replaced brownies, with the highest increase noted in the almond and pistachio oil formulations. As a result, the energy content also increased due to the higher fat content. The protein content showed only slight differences, with a slight decrease compared to the control (butter-based) brownies. When examining the fatty acid profile, the study found that the palmitic acid (saturated fatty acid) levels were significantly reduced in the brownies with 100% nut oil substitutions, especially in those made with almond and walnut oils. Oleic acid (monounsaturated fatty acid) increased significantly, particularly in almond and pistachio oil formulations. Linoleic acid (polyunsaturated fatty acid) also increased in all reformulated brownies, with the highest levels found in the walnut oil-based brownies. Additionally, the levels of Vitamin E were higher in the 100% nut oil substitutions, offering potential health benefits. The sensory evaluation of the brownies showed that consumers preferred the reformulated versions, with higher scores for flavor, texture, and overall acceptability compared to the traditional recipe. The brownies with nut oil replacements were favored for their softer, moister texture and improved flavor, which contributed positively to the overall consumer experience. These findings suggest that replacing butter with nut oils not only enhances the nutritional profile of the brownies, making them healthier, but also results in a product that is more appealing to consumers in terms of taste and texture. The study concluded that the substitution of butter with nut oils is a viable approach for improving both the nutritional content and sensory properties of baked goods.