Engineering starch-based matrices: comparative impacts of conventional hydrocolloids versus novel algal biomass on potato purée.

Hydrocolloids are traditionally used to structure starch-based foods, yet demand is rising for sustainable, nutrient-dense matrices with enhanced bioactivity. To the best of our knowledge, this study is among the first to characterize algal fortification effect on potato purée, providing a novel route to develop starch-based foods with enhanced nutritional and functional properties. Light microscopy, colorimetry, texturometry and rheology were performed. Chlorella vulgaris at 3% exhibited the strongest water immobilization (aw = 0.27 ± 0.01), suggesting a possible mechanism of physical cellular packing. Moreover, Arthrospira platensis at 3% caused severe network disruption, reducing firmness and viscosity to 41.29 Pa.s. In contrast, Ulva ohnoi at 3% reinforced the starch matrix, maintaining high viscosity (309.13 Pa.s), and largest thixotropic area (35.42*104 Pa.s-1), which may be attributed to interactions involving its structural polysaccharides like ulvan. Arthrospira platensis produced the strongest hue shift (145-157°), while Chlorella vulgaris and Scenedesmus sp. generated the most saturated colors. These results demonstrate broad rheological variations-spanning structural destabilization to mechanical reinforcement alternatives-dictated by the specific biochemical composition of biological additives.