Functional food formulation by incorporating the encapsulated extract of Phlogacanthus thyrsiflorus flower

Abstract

Phlogacanthus thyrsiflorus flower (locally known as Nongmangkha), an underutilized medicinal flower, is a rich source of polyphenols with reported antioxidant, hypoglycemic, and hepatoprotective activities. However, its direct incorporation into food systems is constrained by sensory interference, thermal degradation of polyphenols, and limited bioavailability. This study presents a technological approach for delivering phenolics from this flower through encapsulation and their incorporation into watermelon gummies (containing 0.5–2% encapsulated flower extract) and ash gourd ready-to-serve (RTS) beverages (containing 1% encapsulated flower extract), with appropriate controls. The flower extract was obtained via ultrasound–microwave-assisted extraction (250 W, 15 min and 700 W, 5 min) and encapsulated through ionic gelation (3% sodium alginate and 5% CaCl₂). The total phenolic content in the gummies increased (0.078 to 1.35 mg GAE per g), accompanied by an improved flavonoid content and antioxidant activity, without altering certain parameters such as moisture, titratable acidity (0.05–0.06%), pH (4.2–4.6), and total soluble solids (∼72 °Brix) in the gummies. Texture analysis revealed formulation-dependent changes in hardness and chewiness, while 1.5% incorporation of the encapsulated flower extract achieved optimal sensory acceptability. RTS beverages also demonstrated a significantly elevated phenolic content and antioxidant radical-scavenging capacity. The cell viability study of the flower extract exhibited minimal cytotoxicity in the HEK-293 cell line at a concentration of 12.5 µg mL⁻¹. This study demonstrates a scalable approach for integrating encapsulated edible flower bioactives into functional food formulations. However, their in vivo bioavailability and storage stability warrant further investigation.