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@article{198030,
        author = {J Divya and M Dhanalakshmi and P Thiruvasuki and V Manivasagan},
        title = {Development of pH-Responsive Smart Colorimetric Biobeads from Gomphrena Globosa Flower for Food Quality Monitoring},
        journal = {International Journal of Innovative Research in Technology},
        year = {2026},
        volume = {12},
        number = {11},
        pages = {8535-8540},
        issn = {2349-6002},
        url = {https://ijirt.org/article?manuscript=198030},
        abstract = {The replacement of synthetic dyes with natural pigments in food packaging has gained significant attention due to environmental and safety concerns. In this study, pH-responsive colorimetric biobeads were fabricated using betalain pigments extracted from Gomphrena globosa (Globe Amaranth) flowers and encapsulated within a sodium alginate–calcium chloride hydrogel matrix. Betalains were extracted through Soxhlet extraction using 75% ethanol, concentrated, and characterized by UV–Visible spectroscopy, showing a major absorption peak at 538 nm, confirming the presence of betacyanin. The extract demonstrated pH-dependent color transitions from deep pink in acidic media to yellow in alkaline environments, confirming its suitability as a natural pH indicator. The pigment was successfully entrapped in calcium-crosslinked alginate beads, producing uniform, magenta- colored spheres of 2.5–3.2 mm diameter. Phytochemical screening confirmed the presence of betalains, phenols, and alkaloids. The biobeads exhibited high stability under dark, cool storage conditions and biodegraded naturally within 15 days when buried in soil. When tested with milk, fish, and meat samples, the beads displayed visible color changes corresponding to spoilage stages, shifting from pink (fresh) to yellow (spoiled). These results demonstrate that G. globosa-based pH-responsive biobeads provide a biodegradable, eco-friendly, and low-cost solution for real-time food freshness monitoring and intelligent packaging applications.},
        keywords = {Gomphrena globosa, betalains, sodium alginate, colorimetric indicator, pH- responsive biobeads, food freshness.},
        month = {April},
        }