Optimisation of Biscuits Fortified with Underutilised Iron-Rich Plant Sources

The present study aimed to develop an optimised (via Response Surface Methodology) fortified biscuit using underutilised, iron-rich plant sources - Amaranth grain flour (AGF), Moringa oleifera leaf powder (MOLP), and garden cress seed powder (GCSP) to address the widespread iron deficiency anaemia and poor snacking habits that worsen micronutrient deficiencies. The final optimised product underwent nutritional profiling and assessment of quality parameters. The R 2 values of the models for the response variables ranged from 0.60 to 0.83, indicating well-fitted models. Additionally, models were validated with predicted values closely matching the experimental results. The optimised biscuit formulation was particularly achieved with 12% MOLP and 7.50% GCSP, resulting in a high desirability score of 0.852. The fortifiers (MOLP and GCSP) increased the iron content of the biscuit by 26.03%. Although some sensory attributes, such as body and texture and colour and appearance, correlated negatively with MOLP, they showed positive correlation with GCSP. Overall acceptability and iron content both demonstrated positive correlations with MOLP and GCSP. The optimised biscuit contained 467 ± 0.5 Kcal energy, 10.6 ± 0.1 g protein, 63.4 ± 0.1 g carbohydrate, 0.5 ± 0.01 g fibre, 2.7 ± 0.1 g ash, and 18.7 ± 0.1 g fat. Post-baking, the spread ratio and weight of the biscuits decreased by 11.3% and 22.1%, respectively, while their diameter and thickness increased by 2.3% and 12.9%. Scanning electron microscopy revealed a fused yet disrupted surface and an ideal crumbly texture, indicating starch–protein interactions. The mean particle area at the highest (1500x) and lowest (50x) magnifications was 171.2 μm 2 and 148.94 μm 2 , respectively. Consequently, this study presents a pathway to develop an optimised, fortified iron-rich snack leveraging traditional, sustainable, and underutilised plants, supporting healthy snacking, dietary diversification, and local farming. • Sustainable fortification was achieved using Moringa oleifera leaves and garden cress seeds. • RSM-based optimisation yielded a high model reliability (R 2 = 0.95) • Optimised fortified-biscuits exhibited superior nutritional and sensory performance