Riyadh Abdulmalek Hassan, Lee Yook Heng, Sharina Abu Hanifah, Fawaz Al-Badaii, Alizar Ulianas, Gameel Qasim Esmail
Carrageenan’s, widely utilized as food thickeners, can pose health risks at high concentrations, making precise detection crucial for quality control. This study introduces a novel reflectance spectrophotometer sensor for carrageenan analysis using a methylene blue (MB)-immobilized methylcellulose/poly n-butyl acrylate (Mc/PnBA) film. By combining the hydrophilic properties of Mc with the hydrophobicity of PnBA, we created a stable membrane for MB immobilization at room temperature. Upon interacting with carrageenan, the sensor changes color from blue to purple, indicating their presence and concentration. The reflectance intensity of MB shows a linear relationship with kappa, iota, and lambda carrageenan concentrations in the 100-1000 mg L⁻¹ range, with detection limits of 80, 67, and 60 mg L⁻¹, respectively, and correlation coefficients (R²) of 0.992, 0.972, and 0.955. Recovery experiments with spiked apple juice showed 96% and 106% results, underscoring the sensor's practical applicability. Starch, alginate, and Arabic gum were used to test the reflectance sensor, and no interference was observed from these hydrocolloids. It provides a fast, uncomplicated, and efficient alternative to intricate analytical procedures, effectively addressing significant problems regarding food safety and quality control. © 2025, Malaysian Society of Analytical Sciences. All rights reserved.
Department of Chemical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), Selangor, Bangi, 43600, Malaysia; Department of Chemistry, Faculty of Science, Ibb University, PO Box 70270, Ibb, Yemen; Department of Biology, Faculty of Applied Science, Thamar University, Yemen; Department of Chemistry, Faculty of Mathematics and Natural Science, Universitas Negeri Padang, Sumatera Barat, Padang, 25131, Indonesia
