Differentiation of roselle calyx preparation by hexane-extractable volatile/semi-volatile profiles and sensory aroma characteristics

This study characterized the volatile/semi-volatile profiles of roselle calyx preparations using GC-MS analysis of n-hexane extractable compounds obtained by maceration, and aroma characteristics by quantitative descriptive analysis. Independent PCA mapping of volatile/semi-volatile and sensory datasets, together with OPLS-DA, differentiated dried and powder samples to fresh roselle calyx. Fresh calyx and dried calyces (dehydrator- and sun-dried) formed distinct clusters to foamed calyx powders (TBM and SP). Thus, sun-dried and dehydrator-dried calyces showed more similar characteristics to fresh calyx under the evaluated conditions. Fresh calyx was characterized by linoleate, palmitate, phytosterols, and alpha-tocopherol. Both dried calyces were characterized by lupeol, hexahydrofarnesyl acetone, hexadecanoic acid methyl ester, beta-sitosterol, and 2,4-bis(1,1-dimethylethyl)phenol. Foamed calyx powders were characterized by stearic acid and (Z)-9-octadecenamide. Although PCA mapping showed consistent clustering across GC-MS and sensory datasets, the hexane-extractable volatile/semi-volatile profiles did not fully account for the observed sensory aroma characteristics.