Physico-chemical and sensory evaluation of biscuits fortified with spirulina powder

Abstract:

Spirulina (Arthrospira platensis) is among the richest microalgal sources of protein, iron, and beta-carotene, yet its incorporation into baked goods has received limited attention in South Asian food research. This research evaluated biscuits prepared by replacing refined wheat flour with spirulina powder at 0, 2, 4, and 6% (w/w) for physico-chemical properties, colour, texture, and sensory acceptability. Protein content rose from 7.3% in the control to 14.1% at the 6% level, and iron increased from 2.8 to 9.7 mg/100 g. Hardness decreased progressively from 42.6 N (control) to 31.4 N at 6% substitution. Sensory evaluation by a 25-member semi-trained panel showed that the 2% spirulina biscuit scored highest for overall acceptability (7.8/9), while the 6% variant was penalised for a strong algal aftertaste and dark green colour. Moisture uptake during 35-day ambient storage was higher in spirulina-containing samples. Results indicate that 2-4% spirulina fortification offers a practical route to improving the nutritional profile of wheat biscuits without major sensory compromise.