Incorporation of natural antioxidants in biscuits using aqueousPelargonium ×hortorum red flower orAloysia citrodora leaf extracts

Abstract

Aim: This study aimed to evaluate the effect of incorporating aqueous extracts fromAloysia citrodora (lemon verbena) leaves andPelargonium ×hortorum (geranium) red flowers into semi-sweet biscuits in order to enhance antioxidant capacity and support the development of functional bakery products. Methods: Aqueous extracts were incorporated into a standard biscuit formulation at two inclusion levels (10% and 30%). Dough and baked biscuits were analyzed for texture, colour, total phenolic content, and antioxidant capacity. The influence of extract type, concentration, and baking temperature (130°C and 160°C) on technological properties and bioactivity was assessed. Results: The low pH of the geranium extract (pH<4) resulted in significantly softer dough textures (P<0.05). Biscuit fracture stress did not differ among formulations (P > 0.05), indicating no adverse effects on structural integrity. Baking at 160°C produced crisper biscuits, particularly in control samples and those containing 30% lemon verbena, as indicated by higher Young’s modulus and lower fracture strain values. Antioxidant capacity was strongly dependent on extract type and concentration. Biscuits and doughs containing 30% geranium extract exhibited the highest antioxidant values (P<0.05), while samples with 10% lemon verbena extract did not differ significantly from controls. Conclusions: Pelargonium ×hortorum red flower extract demonstrated strong potential as a natural antioxidant ingredient in bakery products, enabling the production of functional biscuits without compromising technological quality and supporting strategies aimed at reducing oxidative stress.

Keywords

FRAP / TPC / antioxidants / biscuits / flowers / leaves

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