Manufacturing functional biscuits fortified with dill (Anethum graveolens L.) and assessing its physical and sensory properties and microbial activity

Abstract

Background: Natural substances derived from dill (Anethum graveolens) are characterized by broad antimicrobial activity against numerous human pathogens, attributable to their rich content of bioactive compounds and strong antioxidant and antimicrobial properties. Consequently, dill may be considered both a valuable nutritional supplement and a promising source of herbal medicinal agents. 

Objective: This research aimed to develop high-fiber biscuits through partial replacement of wheat flour with dill powder levels at 5% and 10%, and to evaluate the effects on chemical composition, antioxidant capacity, and antibacterial activity against selected pathogenic microorganisms.

Results: Chemical analysis of dill revealed carbohydrate, protein, fat, crude fiber, and ash contents of 9.02%, 3.26%, 2.10%, 3.12%, and 0.96%, respectively. The moisture content was 81.34%, indicting a high water-retention capacity that may positively influence both sensory and functional properties. Phytochemical analysis demonstrated a diverse profile of phenolic and aromatic compounds, as well as amino acids. Microbiological analysis confirmed that all biscuit samples were free of coliform bacteria. Additionally, the alcohol extract of dill exhibited strong inhibitory activity against the tested bacteria, including E. coli, Salmonella, and Staphylococcus. Sensory evaluation indicated that dill incorporation improved taste, aroma, texture, and overall acceptability of the biscuits compared with the control formulation.  

Novelty: This study is the first to systematically incorporate dill powder into high-fiber biscuits while simultaneously evaluating its nutritional enhancement, antioxidant capacity, and antimicrobial activity against foodborne pathogens. Unlike previous studies that have focused on dill extracts or on bakery product fortification in isolation, the present work demonstrates the dual functionality of dill as both a natural preservative and a functional food ingredient within a ready-to-eat bakery product. 

Conclusion: Dill exhibits valuable nutritional properties, including appreciable protein and lipid contents, in addition to serving as a rich natural source of phytonutrients. These findings highlight the multifaceted potential of dill as a source of bioactive compounds, supporting its application in the functional food industry as a natural antioxidant and preservative. Consequently, dill may serve as a safe and effective ingredient for enhancing both the nutritional value and sensory quality of food products. 

Keywords: Dill powder; Functional food; Natural preservative; Plant-based fortification; High-fiber biscuits; Antimicrobial activity; Antioxidant capacity