Low Glycemic Index Biscuits Enriched with Beetroot Powder as a Source of Betaine and Mineral Nutrients

This study aimed to evaluate the potential of beetroot powder (BP) as a functional ingredient in biscuits by investigating its effects on nutritional composition, sensory properties, and glycemic response. The primary goal was to determine whether BP could serve as a natural alternative to synthetic additives while maintaining product stability and consumer acceptability. Biscuits were formulated by replacing spelt flour with 15, 20, and 25% BP. The functional impact of the BP was assessed based on betaine content, macro- and microelements, glycemic index (GI), and acrylamide concentration. Thermal analysis (DSC and TGA) and water activity measurements confirmed the BP's stability during six months of storage. Increased BP content led to higher betaine levels and mineral enrichment, particularly with potassium and phosphorus among the macroelements and zinc among the microelements. Sensory analysis identified biscuits with 20% BP as the most preferred, maintaining acceptable ratings even after six months. Hardness initially increased with BP incorporation but decreased over time (p < 0.05). The acrylamide content in the BP-enriched biscuits was significantly lower than in control samples and well below the reference safety threshold. Notably, consuming beetroot biscuits did not trigger a sharp postprandial glucose spike, with the GI of the most acceptable sample (20% BP) measured at 49 ± 11. These findings confirm that BP improves the nutritional and sensory characteristics of biscuits while ensuring product safety and stability, supporting its application as a natural functional ingredient in confectionery products.