Assessment of Brown Color as an Indicator of Salty and Bitter Taste Perception: a Case of Reduced- and Low-sodium Barbecue Sauces

Jose Ramon Alonso — 2026-04-28

Color cue influences taste expectation. This study evaluated brown color as indices for salty and bitter tastes of reduced- and low-sodium barbecue sauces formulated with eight salt mixtures [10-60% NaCl: 30-60% KCl: 0-40% Glycine]. 240 consumers rated salty and bitter tastes based on brown color (expectation), then rated actual taste of the samples. The highest total color difference value was 2.12 (<2.3 for “just-noticeable-difference”), hence the color among treatments was presumed to be undifferentiated by the consumers. Six samples containing 20-50% NaCl; 30-60% KCl; 0-40% Glycine showed congruent saltiness expectation and actual salty taste perception [P>0.05, the Cochran-Mantel-Hansel test]; however, samples with 60%:40%:0% and/or 10%:60%:30% were incongruent in such association. Sample containing 10:60:30 was tasted less salty than expected (P=0.002). Congruent bitterness evoked by brown color (L*=47.6-48.3, a*=1.6-3.0, b*=2.6-3.6) and actual taste was observed for all samples. This study demonstrated that brown color may be used as an indicator for salty and bitter taste of barbecue sauces.

Structural and Biological Enhancement of Cu-Incorporated Biphasic Calcium Phosphate Synthesized via a Sol–Gel Combustion Method

Wutthigrai Sailuam — 2026-04-28

Biphasic Calcium Phosphate (BCP) is a critical bioceramic for bone regeneration due to its biocompatibility and osteoconductivity. This study investigates the enhancement of BCP through the incorporation of copper (Cu) ions using a sol–gel combustion method at concentrations of 0, 1, 3, and 5 mol%. XRD analysis revealed that while hydroxyapatite (HAp) remained the primary phase, Cu incorporation promoted the formation of secondary β-Tricalcium Phosphate (β-TCP) and Calcium Oxide (CaO) phases. XANES spectra confirmed that Cu exists in a +2 oxidation state and forms a separate CuO phase rather than substituting for Ca sites. Bioactivity assessments via 7-day immersion in Simulated Body Fluid (SBF) demonstrated that the 5Cu–BCP sample most effectively promoted the formation of a bone-like apatite layer with a Ca/P ratio of 1.63. Antibacterial tests showed that Cu-doped samples inhibited S. aureus growth, but only 5Cu–BCP was effective against the Gram-negative P. aeruginosa. Furthermore, while the 1Cu–BCP sample showed significant cytotoxicity, higher Cu concentrations (3Cu and 5Cu) exhibited better cell viability, likely due to more effective structural incorporation of CuO. These findings suggest that 5Cu–BCP is a promising material for biomedical applications, offering a superior balance of bioactivity, antibacterial performance, and biocompatibility.

Progress in Applied Science and Technology

Assessment of Brown Color as an Indicator of Salty and Bitter Taste Perception: a Case of Reduced- and Low-sodium Barbecue Sauces

Structural and Biological Enhancement of Cu-Incorporated Biphasic Calcium Phosphate Synthesized via a Sol–Gel Combustion Method