Formulation and Characterisation of a Hibiscus rosa-sinensis L. Natural Preservative

Abstract

Aims: This study aimed to develop and characterise a maltodextrin-enriched aqueous extract of Hibiscus rosa-sinensis L. flowers and to evaluate its suitability as a natural preservative coating for selected fruits and vegetables. Study Design: Experimental laboratory study. Place and Duration of Study: Department of Food Science and Nutrition, Tamil Nadu, India, between December 2025 and April 2026. Methodology: Fresh Hibiscus rosa-sinensis L. petals were extracted with sterile distilled water and formulated with maltodextrin at 0% (control), 5%, 10%, 15% and 20%. The formulations were assessed                 for pH, titratable acidity, total soluble solids, total phenolic content, tannin content, flavonoid content,             DPPH radical-scavenging activity, microbial load, colour attributes and browning index. The formulations were also applied as coatings to selected fruits and vegetables, and weight loss was monitored during            storage. Results: The pH decreased from 4.30±0.00 in the control to 3.78±0.03 in the 20% maltodextrin formulation, while total soluble solids increased from 0.03±0.06 to 17.67±0.29 °Brix. Total phenolic content increased from 15.72±0.06 to 17.75±0.11 mg GAE/g, tannin content from 9.12±0.05 to 21.60±0.05 mg TAE/g and flavonoid content from 10.42±0.52 to 49.21±0.52 mg/g. DPPH activity varied among formulations, with IC50 values ranging from <0.20 to 0.88 mg/mL. Colour difference increased up to 2.08, and browning was lower at higher maltodextrin concentrations. Coated samples generally showed lower weight loss than controls; brinjal treated with 10% maltodextrin showed 20.38% weight loss compared with 93.16% in the control. Conclusion: Maltodextrin-enriched Hibiscus rosa-sinensis L. extract showed potential as an edible coating component; however, microbial results indicate that further preservation studies are required.