Formulation and Characterisation of a Hibiscus rosa-sinensis L. Natural Preservative
Vijayalakshmi Karthi
Department of Food Science and Nutrition, Periyar University, Salem, Tamil Nadu, India.
Kaviyarasu Munikrishnan
Department of Food Science and Nutrition, Periyar University, Salem, Tamil Nadu, India.
Karthika Periyasami
*
Department of Food Science and Nutrition, Periyar University, Salem, Tamil Nadu, India.
*Author to whom correspondence should be addressed.
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.
Keywords: Hibiscus rosa-sinensis L., maltodextrin, natural preservative, edible coating, aqueous extract, phenolic compounds, flavonoids, antioxidant activity, microbial load, postharvest weight loss, browning index