RESUMEN
This study was conducted to assess and correlate the sensory characteristics and volatile compounds of hot beverages from the calyces of four Mexican varieties of hibiscus (4Q4, Puebla Precoz, UAN 16-1, and Sudan). A panel of 10 judges, detected six flavour descriptors in all samples. Sensory studies revealed highly characteristic flavour profiles of these varieties. In order to obtain the extracts and further characterize the odour-active volatiles of the studied beverages, a simultaneous steam distillation and solvent extraction procedure followed by a GC-MS analysis was employed. A total of 104 volatile compounds were identified in all samples. By determining the odour activity values (OAVs) it was possible to identify compounds with high odor-activity in the beverages, such as: 2-furfural, 5-methyl-2-furfural, hexanal, (E)-2-hexenal, (Z)-3-hexen-1-ol, 1-octen-3-one, 1-octen-3-ol, 5-methyl-2(3H)-furanone, phenylacetaldehyde, nonanal, (E)-2-nonenal, geranylacetone, α-ionone and ß-ionone. Moreover, on the basis of their OAVs, the differences in odour profiles of beverages were predominately due to these odorants.
RESUMEN
The influence of lipoxygenase inactivation and extrusion cooking on the physical and nutritional properties of corn/cowpea (Vigna unguiculata) blends was studied. Corn was blended in an 80:15 proportion with cowpea flour treated to inactivate lipoxygenase (CI) or non-inactivated cowpea flour (CNI). Extrusion variables were temperature (150 degrees C, 165 degrees C and 180 degrees C) and moisture (15%, 17% and 19%). Based on their physical properties, the 165 degrees C/15% corn:CNI, and 165 degrees C/15% corn:CI, and 150 degrees C/15% corn:CI blends were chosen for nutritional quality analysis. Extrudate chemical composition indicated high crude protein levels compared with standard corn-based products. With the exception of lysine, essential amino acids content in the three treatments met FAO requirements. Extrusion and lipoxygenase inactivation are promising options for developing corn/cowpea extruded snack products with good physical properties and nutritional quality.